<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android">
    <data>
        <variable
            name="vm"
            type="com.ktl.mvvm_calculadoraimc.CalculadoraIMCViewModel" />
    </data>
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:padding="16dp">
        <EditText
            android:id="@+id/editTextPeso"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:autofillHints=""
            android:hint="@string/digite_seu_peso"
            android:inputType="numberDecimal" />
        <EditText
            android:id="@+id/editTextAltura"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:autofillHints=""
            android:hint="@string/digite_sua_altura"
            android:inputType="numberDecimal" />
        <Button
            android:id="@+id/buttonCalcular"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/calcular" />
        <TextView
            android:id="@+id/textViewResultado"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@{vm.tipo}" />
        <TextView
            android:id="@+id/textViewResultadoNumero"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@{vm.resultado}" />
    </LinearLayout>
</layout>

public class CalculadoraIMC {
    public static double calcular(double peso, double altura) {
        return peso / (altura * altura);
    }
    public static String getTipo(double imc) {
        if (imc < 18.5) {
            return "Abaixo do peso";
        } else if (imc <= 24.9) {
            return "Peso normal";
        } else if (imc <= 29.9) {
            return "Sobrepeso";
        } else if (imc <= 34.9) {
            return "Obesidade Grau I";
        } else if (imc <= 39.9) {
            return "Obesidade Grau II";
        } else {
            return "Obesidade Grau III (mórbida)";
        }
    }
}

import androidx.lifecycle.MutableLiveData;
import androidx.lifecycle.ViewModel;
public class CalculadoraIMCViewModel extends ViewModel {
    private final MutableLiveData<String> resultado;
    private final MutableLiveData<String> tipo;
    public CalculadoraIMCViewModel() {
        this.tipo = new MutableLiveData<>();
        resultado = new MutableLiveData<>();
    }
    public MutableLiveData<String> getResultado() {
        return resultado;
    }
    public MutableLiveData<String> getTipo() {
        return tipo;
    }
    public void calcular(double peso, double altura) {
        double imc = CalculadoraIMC.calcular(peso, altura);
        resultado.setValue(String.valueOf(imc));
        tipo.setValue(CalculadoraIMC.getTipo(imc));
    }
}

import android.os.Bundle;
import androidx.activity.EdgeToEdge;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.graphics.Insets;
import androidx.core.view.ViewCompat;
import androidx.core.view.WindowInsetsCompat;
import androidx.databinding.DataBindingUtil;
import androidx.lifecycle.ViewModelProvider;
import com.ktl.mvvm_calculadoraimc.databinding.ActivityMainBinding;
public class MainActivity extends AppCompatActivity {
    private CalculadoraIMCViewModel vm;
    private ActivityMainBinding binding;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        binding = DataBindingUtil.setContentView(this, R.layout.activity_main);
        vm = new ViewModelProvider(this).get(CalculadoraIMCViewModel.class);
        binding.setVm(vm);
        binding.setLifecycleOwner(this);
        binding.buttonCalcular.setOnClickListener(v -> {
            double peso = Double.parseDouble(binding.editTextPeso.getText().toString());
            double altura = Double.parseDouble(binding.editTextAltura.getText().toString());
            vm.calcular(peso, altura);
        });
    }
}

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools">
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:padding="10dp"
        tools:context=".view.MainActivity">
        <Button
            android:id="@+id/btObterDados"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="20dp"
            android:gravity="center"
            android:text="@string/obter_dados" />
        <ListView
            android:id="@+id/listViewDados"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:divider="@android:color/darker_gray"
            android:dividerHeight="1dp" />
    </LinearLayout>
</layout>

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android">
    <data>
        <variable
            name="contato"
            type="com.example.appgsonhttp_01.model.InformacoesContato" />
    </data>
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        android:padding="16dp">
        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@{contato.nome}"
            android:textColor="@android:color/black"
            android:textSize="18sp"
            android:textStyle="bold" />
        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@{contato.telefone}"
            android:textSize="14sp" />
        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@{contato.email}"
            android:textSize="14sp" />
    </LinearLayout>
</layout>

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android">
    <data>
        <variable
            name="viewModel"
            type="com.example.appgsonhttp_01.viewmodel.RelatorioViewModel" />
    </data>
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:layout_marginTop="30dp"
        android:padding="16dp">
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text='@{"Nome: " + viewModel.nome_professor}'
            android:textSize="20sp"
            android:textStyle="bold" />
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text='@{"Email: " + viewModel.email_professor}'
            android:textSize="18sp" />
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text='@{"Telefone: " + viewModel.telefone_professor}'
            android:textSize="18sp"
            android:layout_marginBottom="12dp" />
    </LinearLayout>
</layout>

import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
public class Conexao {
    public InputStream obterRespostaHTTP(String endURL) {
        HttpURLConnection conexao = null;
        try {
            URL url = new URL(endURL);
            conexao = (HttpURLConnection) url.openConnection();
            conexao.setConnectTimeout(50000);
            conexao.setReadTimeout(50000);
            conexao.setRequestMethod("GET");
            conexao.connect();
            return new BufferedInputStream(conexao.getInputStream());/// n esqueça
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }//
}

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
public class Conversao {
    public String converter(InputStream inputStream) {
        if(inputStream == null){
            return null;
        }
        InputStreamReader inputStreamReader = new InputStreamReader(inputStream);
        BufferedReader br = new BufferedReader(inputStreamReader);
        StringBuilder stringBuilder = new StringBuilder();
        String conteudo;
        try{
            while((conteudo = br.readLine())!= null){
                stringBuilder.append(conteudo).append("\n");
            }
        }catch (IOException e){
            e.printStackTrace();
        }
        return stringBuilder.toString();
    }
}

import javax.annotation.processing.Generated;
import com.google.gson.annotations.Expose;
import com.google.gson.annotations.SerializedName;
@Generated("jsonschema2pojo")
public class Adicionais {
    @SerializedName("id")
    @Expose
    private Integer id;
    @SerializedName("email")
    @Expose
    private String email;
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
}

import javax.annotation.processing.Generated;
import com.google.gson.annotations.Expose;
import com.google.gson.annotations.SerializedName;
@Generated("jsonschema2pojo")
public class Agenda {
    @SerializedName("id")
    @Expose
    private Integer id;
    @SerializedName("nome")
    @Expose
    private String nome;
    @SerializedName("telefone")
    @Expose
    private String telefone;
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getNome() {
        return nome;
    }
    public void setNome(String nome) {
        this.nome = nome;
    }
    public String getTelefone() {
        return telefone;
    }
    public void setTelefone(String telefone) {
        this.telefone = telefone;
    }
}

import java.io.Serializable;
public class InformacoesContato implements Serializable {
    private int id;
    private String nome, telefone, email;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getNome() {
        return nome;
    }
    public void setNome(String nome) {
        this.nome = nome;
    }
   public String getTelefone() {
        return telefone;
    }
    public void setTelefone(String telefone) {
        this.telefone = telefone;
    }
    public String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
}

import java.util.List;
import javax.annotation.processing.Generated;
import com.google.gson.annotations.Expose;
import com.google.gson.annotations.SerializedName;
@Generated("jsonschema2pojo")
public class Professores {
    @SerializedName("agenda")
    @Expose
    private List<Agenda> agenda;
    @SerializedName("adicionais")
    @Expose
    private List<Adicionais> adicionais;
    public List<Agenda> getAgenda() {
        return agenda;
    }
    public void setAgenda(List<Agenda> agenda) {
        this.agenda = agenda;
    }
    public List<Adicionais> getAdicionais() {
        return adicionais;
    }
    public void setAdicionais(List<Adicionais> adicionais) {
        this.adicionais = adicionais;
    }
}

mport android.os.Handler;
import android.os.Looper;
import com.example.appgsonhttp_01.util.Conexao;
import com.example.appgsonhttp_01.util.Conversao;
import com.google.gson.Gson;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
public class Repositorio {
    private static final String URL = "digite a URL";
    private ExecutorService executor;
    private Handler mainHandler;
    public Repositorio() {
        this.executor = Executors.newSingleThreadExecutor();
        this.mainHandler = new Handler(Looper.getMainLooper());
    }
    public interface Callback {
        void sucesso(List<InformacoesContato> lista);
        void erro(String mensagem);
    }
    private void sucesso(Callback c, List<InformacoesContato> lista) {
        mainHandler.post(new Runnable() {
            @Override
            public void run() {
                c.sucesso(lista);
            }
        });
    }
    private void erro(Callback c, String mensagem) {
        mainHandler.post(new Runnable() {
            @Override
            public void run() {
                c.erro(mensagem);
            }
        });
    }
    public void obterDados(Callback c) {
        executor.execute(new Runnable() {
            @Override
            public void run() {
                //tarefa da thread
                try {
                    Conexao conexao = new Conexao();
                    InputStream inputStream = conexao.obterRespostaHTTP(URL);
                    Conversao conversao = new Conversao();
                    String jsonString = conversao.converter(inputStream);
                    if (jsonString == null || jsonString.isEmpty()) {
                        erro(c, "Erro - Não existe informações disponíveis");
                        return;
                    }
                    Gson gson = new Gson();
                    Professores professores = gson.fromJson(jsonString, Professores.class);
                    List<InformacoesContato> listaContatos = new ArrayList<>();
                    if (professores != null && professores.getAgenda() != null) {
                        for (Agenda ag : professores.getAgenda()) {
                            InformacoesContato contato = new InformacoesContato();
                            contato.setId(ag.getId());
                            contato.setNome(ag.getNome());
                            contato.setTelefone(ag.getTelefone());
                            if (professores.getAdicionais() != null) {
                                for (Adicionais ad : professores.getAdicionais()) {
                                    if (ad.getId().equals(ag.getId())) {
                                        contato.setEmail(ad.getEmail());
                                        break;
                                    }
                                }
                            }
                            listaContatos.add(contato);
                        }
                    }
                    sucesso(c, listaContatos);
                } catch (Exception e) {
                    e.printStackTrace();
                    erro(c, "Erro - Não foi possível realizar o download" + e.getMessage());
                }
            }
        });
    }//
}//class

import androidx.lifecycle.LiveData;
import androidx.lifecycle.MutableLiveData;
import androidx.lifecycle.ViewModel;
import com.example.appgsonhttp_01.model.InformacoesContato;
import com.example.appgsonhttp_01.model.Repositorio;
import java.util.List;
public class MainViewModel extends ViewModel {
    private final MutableLiveData<List<InformacoesContato>> listaContatos = new MutableLiveData<>();
    private final MutableLiveData<String> mensagemErro = new MutableLiveData<>();
    private final Repositorio repositorio = new Repositorio();
    public LiveData<List<InformacoesContato>> getListaContatos() {
        return listaContatos;
    }
    public LiveData<String> getMensagemErro() {
        return mensagemErro;
    }
    public void carregarDadosDoRepositorio() {
        repositorio.obterDados(new Repositorio.Callback() {
            @Override
            public void sucesso(List<InformacoesContato> lista) {
                listaContatos.setValue(lista);
            }
            @Override
            public void erro(String mensagem) {
                mensagemErro.setValue(mensagem);
            }
        });
    }
}

import androidx.lifecycle.MutableLiveData;
import androidx.lifecycle.ViewModel;
public class RelatorioViewModel extends ViewModel {
    private final MutableLiveData<String> nome_professor = new MutableLiveData<>();
    private final MutableLiveData<String> email_professor = new MutableLiveData<>();
    private final MutableLiveData<String> telefone_professor = new MutableLiveData<>();
    public MutableLiveData<String> getNome_professor() {
        return nome_professor;
    }
    public MutableLiveData<String> getEmail_professor() {
        return email_professor;
    }
    public MutableLiveData<String> getTelefone_professor() {
        return telefone_professor;
    }
    public void pegarInformacoes(String nome_p, String email_p, String telefone_p) {
        this.nome_professor.setValue(nome_p);
        this.email_professor.setValue(email_p);
        this.telefone_professor.setValue(telefone_p);
    }
}

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import androidx.databinding.DataBindingUtil;
import com.example.appgsonhttp_01.R;
import com.example.appgsonhttp_01.databinding.ItemContatoBinding;
import com.example.appgsonhttp_01.model.InformacoesContato;
import java.util.List;
public class ContatoAdapter extends ArrayAdapter<InformacoesContato> {
    public ContatoAdapter(Context context, List<InformacoesContato> contatos) {
        super(context, 0, contatos);
    }
    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ItemContatoBinding binding;
        if (convertView == null) {
            binding = DataBindingUtil.inflate(LayoutInflater.from(getContext()),
                    R.layout.item_contato, parent, false);
            convertView = binding.getRoot();
            convertView.setTag(binding);
        } else {
            binding = (ItemContatoBinding) convertView.getTag();
        }
        InformacoesContato contato = getItem(position);
        if (contato != null) {
            binding.setContato(contato);
            binding.executePendingBindings();
        }
        return convertView;
    }
}

import android.os.Bundle;
import androidx.activity.EdgeToEdge;
import androidx.appcompat.app.AppCompatActivity;
import com.example.appgsonhttp_01.R;
import com.example.appgsonhttp_01.viewmodel.RelatorioViewModel;
import com.example.appgsonhttp_01.databinding.ActivityRelatorioBinding;
import androidx.databinding.DataBindingUtil;
import androidx.lifecycle.ViewModelProvider;
public class RelatorioActivity extends AppCompatActivity {
    private ActivityRelatorioBinding binding;
    private RelatorioViewModel viewModel;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        EdgeToEdge.enable(this);
        setContentView(R.layout.activity_relatorio);
        binding = DataBindingUtil.setContentView(this, R.layout.activity_relatorio);
        binding.setLifecycleOwner(this);
        viewModel = new ViewModelProvider(this).get(RelatorioViewModel.class);
        binding.setViewModel(viewModel);
        String professor_nome = getIntent().getStringExtra("nome");
        String professor_email = getIntent().getStringExtra("email");
        String professor_telefone = getIntent().getStringExtra("telefone");
        viewModel.pegarInformacoes(professor_nome,professor_email,professor_telefone);
    }
}

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import androidx.appcompat.app.AppCompatActivity;
import androidx.databinding.DataBindingUtil;
import androidx.lifecycle.Observer;
import androidx.lifecycle.ViewModelProvider;
import com.example.appgsonhttp_01.viewmodel.MainViewModel;
import com.example.appgsonhttp_01.R;
import com.example.appgsonhttp_01.databinding.ActivityMainBinding;
import com.example.appgsonhttp_01.model.InformacoesContato;
import java.util.ArrayList;
import java.util.List
public class MainActivity extends AppCompatActivity {
    private ActivityMainBinding binding;
    private ContatoAdapter adapter;
    private List<InformacoesContato> lista;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        MainViewModel viewModel = new ViewModelProvider(this).get(MainViewModel.class);
        binding = DataBindingUtil.setContentView(this, R.layout.activity_main);
        lista = new ArrayList<>();
        adapter = new ContatoAdapter(this, lista);
        binding.listViewDados.setAdapter(adapter);
        binding.listViewDados.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                InformacoesContato contatoSelecionado = lista.get(position);
                Intent intent = new Intent(MainActivity.this, RelatorioActivity.class);
                intent.putExtra("nome", contatoSelecionado.getNome());
                intent.putExtra("email", contatoSelecionado.getEmail());
                intent.putExtra("telefone", contatoSelecionado.getTelefone());
                startActivity(intent);
            }
        });
        binding.btObterDados.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                viewModel.carregarDadosDoRepositorio();
            }
        });
        viewModel.getListaContatos().observe(this, new Observer<List<InformacoesContato>>() {
            @Override
            public void onChanged(List<InformacoesContato> contatos) {
                lista.clear();
                lista.addAll(contatos);
                adapter.notifyDataSetChanged();
            }
        });
    }
}

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".activity.MainActivity">
    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/consolidacao"
        app:layout_constraintBottom_toTopOf="@+id/student_list"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/student_list"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="63dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="@+id/guideline" />
    <androidx.constraintlayout.widget.Guideline
        android:id="@+id/guideline"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        app:layout_constraintGuide_begin="227dp" />
</androidx.constraintlayout.widget.ConstraintLayout>

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/status_activity"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".activity.StatusActivity">
    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/voltar"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.498"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.120000005" />
    <TextView
        android:id="@+id/class_average"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toTopOf="@+id/guideline2"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/button" />
    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/student_status_list"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_marginBottom="63dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="@+id/guideline2" />
    <androidx.constraintlayout.widget.Guideline
        android:id="@+id/guideline2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        app:layout_constraintGuide_begin="227dp" />
</androidx.constraintlayout.widget.ConstraintLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/student_status_list_item"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="vertical">
    <TextView
        android:id="@+id/student_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
    <TextView
        android:id="@+id/student_age"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
    <TextView
        android:id="@+id/student_attendance"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
    <TextView
        android:id="@+id/student_grades"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:id="@+id/student_list_item">
    <TextView
        android:id="@+id/student_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.0"
        tools:layout_editor_absoluteX="102dp" />
    <TextView
        android:id="@+id/student_age"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="24dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/student_name"
        app:layout_constraintVertical_bias="0.0"
        tools:layout_editor_absoluteX="0dp" />
    <TextView
        android:id="@+id/student_grades"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="24dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/student_age"
        app:layout_constraintVertical_bias="0.0"
        tools:layout_editor_absoluteX="16dp" />
    <TextView
        android:id="@+id/student_attendance"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="24dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/student_grades"
        app:layout_constraintVertical_bias="0.0"
        tools:layout_editor_absoluteX="-27dp" />
</androidx.constraintlayout.widget.ConstraintLayout>

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import androidx.appcompat.app.AppCompatActivity;
import androidx.lifecycle.Observer;
import androidx.lifecycle.ViewModelProvider;
import androidx.recyclerview.widget.LinearLayoutManager;
import com.example.atividade3.adapter.StudentListAdapter;
import com.example.atividade3.data.model.Student;
import com.example.atividade3.databinding.ActivityMainBinding;
import com.example.atividade3.viewmodel.MainViewModel;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
    private ActivityMainBinding binding;
    private MainViewModel viewmodel;
    private StudentListAdapter adapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        binding = ActivityMainBinding.inflate(getLayoutInflater());
        setContentView(binding.getRoot());
        viewmodel = new ViewModelProvider(this).get(MainViewModel.class);
        adapter = new StudentListAdapter(new ArrayList<>());
        binding.studentList.setLayoutManager(new LinearLayoutManager(this));
        binding.studentList.setAdapter(adapter);
        binding.button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this, StatusActivity.class);
                startActivity(intent);
            }
        });
        viewmodel.getStudents().observe(this, new Observer<List<Student>>() {
            @Override
            public void onChanged(List<Student> students) {
                if (students != null) {
                    adapter.setStudents(students);
                    adapter.notifyDataSetChanged();
                }
            }
        });
        viewmodel.loadData();
    }
}

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import androidx.appcompat.app.AppCompatActivity;
import androidx.lifecycle.Observer;
import androidx.lifecycle.ViewModelProvider;
import androidx.recyclerview.widget.LinearLayoutManager;
import com.example.atividade3.adapter.StudentStatusListAdapter;
import com.example.atividade3.data.model.Student;
import com.example.atividade3.databinding.ActivityStatusBinding;
import com.example.atividade3.viewmodel.StatusViewModel;
import java.util.ArrayList;
import java.util.List;
public class StatusActivity extends AppCompatActivity {
    private ActivityStatusBinding binding;
    private StatusViewModel viewmodel;
    private StudentStatusListAdapter adapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        binding = ActivityStatusBinding.inflate(getLayoutInflater());
        setContentView(binding.getRoot());
        viewmodel = new ViewModelProvider(this).get(StatusViewModel.class);
        adapter = new StudentStatusListAdapter(new ArrayList<>());
        binding.studentStatusList.setLayoutManager(new LinearLayoutManager(this));
        binding.studentStatusList.setAdapter(adapter);
        binding.button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(StatusActivity.this, MainActivity.class);
                startActivity(intent);
            }
        });
        viewmodel.getStudents().observe(this, new Observer<List<Student>>() {
            @Override
            public void onChanged(List<Student> students) {
                if (students != null) {
                    adapter.setStudents(students);
                    adapter.notifyDataSetChanged();
                }
            }
        });
        viewmodel.getClassAverage().observe(this, new Observer<String>() {
            @Override
            public void onChanged(String s) {
                if (s != null) {
                    binding.classAverage.setText("Média da turma: " + s);
                }
            }
        });
        viewmodel.loadData();
    }
}

import android.view.LayoutInflater;
import android.view.ViewGroup;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import com.example.atividade3.data.model.Student;
import com.example.atividade3.databinding.StudentsListItemBinding;
import java.util.List;
public class StudentListAdapter extends RecyclerView.Adapter<StudentListAdapter.StudentViewHolder> {
    private List<Student> students;
    public StudentListAdapter(List<Student> students) {
        this.students = students;
    }
    public List<Student> getStudents() {
        return students;
    }
    public void setStudents(List<Student> students) {
        this.students = students;
    }
    @NonNull
    @Override
    public StudentViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        StudentsListItemBinding binding = StudentsListItemBinding.inflate(LayoutInflater.from(parent.getContext()), parent, false);
        return new StudentViewHolder(binding);
    }
    @Override
    public void onBindViewHolder(@NonNull StudentViewHolder holder, int position) {
        holder.binding.studentName.setText("Nome: " + students.get(position).getName());
        holder.binding.studentAge.setText("Idade: " + students.get(position).getAge().toString());
        holder.binding.studentAttendance.setText("Notas: " + students.get(position).getAttendance().toString());
        holder.binding.studentGrades.setText("Presenças: " + students.get(position).getGrades().toString());
    }
    @Override
    public int getItemCount() {
        return students.size();
    }
    public static class StudentViewHolder extends RecyclerView.ViewHolder {
        StudentsListItemBinding binding;
        public StudentViewHolder(StudentsListItemBinding binding) {
            super(binding.getRoot());
            this.binding = binding;
        }
    }
}

import android.view.LayoutInflater;
import android.view.ViewGroup;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import com.example.atividade3.data.model.Student;
import com.example.atividade3.databinding.StudentStatusListItemBinding;
import java.util.List;
public class StudentStatusListAdapter extends RecyclerView.Adapter<StudentStatusListAdapter.StudentStatusViewHolder> {
    private List<Student> students;
    public StudentStatusListAdapter(List<Student> students) {
        this.students = students;
    }
    public List<Student> getStudents() {
        return students;
    }
    public void setStudents(List<Student> students) {
        this.students = students;
    }
    @NonNull
    @Override
    public StudentStatusListAdapter.StudentStatusViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        StudentStatusListItemBinding binding = StudentStatusListItemBinding.inflate(LayoutInflater.from(parent.getContext()), parent, false);
        return new StudentStatusListAdapter.StudentStatusViewHolder(binding);

import java.util.ArrayList;
import java.util.List;
public class Student {
    private String name;
    private Integer age;
    private List<Double> grades;
    private List<Boolean> attendance;
    public Student(String name, int age) {
        this.name = name;
        this.age = age;
        this.grades = new ArrayList<>();
        this.attendance = new ArrayList<>();
    }
    public Integer getAge() {
        return age;
    }
    public String getName() {
        return name;
    }
    public List<Double> getGrades() {
        return grades;
    }
    public List<Boolean> getAttendance() {
        return attendance;
    }
    public double calculateAverageGrade() {
        double sum = 0.0;
        for (double grade : grades) {
            sum += grade;
        }
        return sum / grades.size();
    }
    public double calculateAttendancePercentage() {
        int presentCount = 0;
        for (boolean present : attendance) {
            if (present) {
                presentCount++;
            }
        }
        return ((double) presentCount) / attendance.size() * 100;
    }
    public void addGrades(List<Double> grades) {
        this.grades.addAll(grades);
    }
    public void addAttendance(List<Boolean> attendance) {
        this.attendance.addAll(attendance);
    }
    public String isApproved() {
        boolean isApproved = calculateAverageGrade() >= 6.0 && calculateAttendancePercentage() >= 75.0;
        if (isApproved){
            return "Aprovado";
        }else{
            return "Reprovado";
        }
    }
}

import android.util.Log;
import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
public class Connection {
    public InputStream sendRequest(String endURL) {
        HttpURLConnection connection = null;
        try {
            URL url = new URL(endURL);
            connection = (HttpURLConnection) url.openConnection();
            connection.setConnectTimeout(50000);
            connection.setReadTimeout(50000);
            connection.setRequestMethod("GET");
            connection.connect();
            return new BufferedInputStream(connection.getInputStream());
        } catch (IOException e) {
            Log.e("Connection error", "Error while connecting to the url");
        }
        return null;
    }
}

import com.google.gson.annotations.SerializedName;
import java.util.List;
public class ResponseDto {
    @SerializedName("students")
    public List<StudentDto> students;
}

import com.google.gson.annotations.SerializedName;
import java.util.List;
public class StudentDto {
    @SerializedName("nome")
    public String name;
    @SerializedName("idade")
    public int age;
    @SerializedName("notas")
    public List<Double> notes;
    @SerializedName("presenca")
    public List<Boolean> attendance;
}

import android.os.Handler;
import android.os.Looper;
import com.example.atividade3.data.model.Student;
import com.example.atividade3.repository.connection.Connection;
import com.example.atividade3.repository.dto.ResponseDto;
import com.example.atividade3.repository.dto.StudentDto;
import com.google.gson.Gson;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
public class StudentRepository {
    private static StudentRepository instance;
    private List<Student> students;
    private final String API_URL = "digite a URL";
    private ExecutorService executor;
    private Handler mainHandler;
    public StudentRepository() {
        this.executor = Executors.newSingleThreadExecutor();
        this.mainHandler = new Handler(Looper.getMainLooper());
    }
    public static StudentRepository getInstance() {
        if (instance == null) {
            instance = new StudentRepository();
        }
        return instance;
    }
    public interface Callback {
        void onSuccess(List<Student> items);
        void onError(String msg);
    }
    private void success(Callback c, List<Student> students) {
        mainHandler.post(new Runnable() {
            @Override
            public void run() {
                c.onSuccess(students);
            }
        });
    }
    private void error(Callback c, String msg) {
        mainHandler.post(new Runnable() {
            @Override
            public void run() {
                c.onError(msg);
            }
        });
    }
    public void fetchStudents(Callback callback) {
        executor.execute(new Runnable() {
            @Override
            public void run() {
                try {
                    Connection connection = new Connection();
                    InputStreamReader reader = new InputStreamReader(connection.sendRequest(API_URL));
                    ResponseDto studentsResponse = new Gson().fromJson(reader, ResponseDto.class);
                    List<Student> students = new ArrayList<>();
                    for (StudentDto studentDto : studentsResponse.students) {
                        Student student = new Student(studentDto.name, studentDto.age);
                        student.addGrades(studentDto.notes);
                        student.addAttendance(studentDto.attendance);
                        students.add(student);
                    }
                    success(callback, students);
                } catch (Exception e) {
                    error(callback, "Error while fetching students");

import android.util.Log;
import androidx.lifecycle.MutableLiveData;
import androidx.lifecycle.ViewModel;
import com.example.atividade3.data.model.Student;
import com.example.atividade3.repository.StudentRepository;
import java.util.List;
public class MainViewModel extends ViewModel {
    private MutableLiveData<List<Student>> students;
    private final StudentRepository repository;
    public MainViewModel() {
        this.students = new MutableLiveData<>();
        this.repository = StudentRepository.getInstance();
    }
    public MutableLiveData<List<Student>> getStudents() {
        return students;
    }
    public void loadData() {
        repository.fetchStudents(new StudentRepository.Callback() {
            @Override
            public void onSuccess(List<Student> items) {
                students.setValue(items);
            }
            @Override
            public void onError(String msg) {
                Log.e("Error", msg);
            }
        });
    }
}

import android.util.Log;
import androidx.lifecycle.MutableLiveData;
import androidx.lifecycle.ViewModel;
import com.example.atividade3.data.model.Student;
import com.example.atividade3.repository.StudentRepository;
import java.util.List;
public class StatusViewModel extends ViewModel {
    private MutableLiveData<List<Student>> students;
    private MutableLiveData<String> classAverage;
    private final StudentRepository repository;
    public StatusViewModel() {
        this.repository = StudentRepository.getInstance();
        this.students = new MutableLiveData<>();
        this.classAverage = new MutableLiveData<>();
    }
    public MutableLiveData<List<Student>> getStudents() {
        return students;
    }
    public MutableLiveData<String> getClassAverage() {
        return classAverage;
    }
    private double calculateAverageGrade() {
        double sum = 0.0;
        for (Student s : students.getValue()) {
            sum += s.calculateAverageGrade();
        }
        return sum / students.getValue().size();
    }
    public void loadData() {
        repository.fetchStudents(new StudentRepository.Callback() {
            @Override
            public void onSuccess(List<Student> items) {
                students.setValue(items);
                classAverage.setValue(String.format("%.2f", calculateAverageGrade()));
            }
            @Override
            public void onError(String msg) {
                Log.e("Error", msg);
            }
        });
    }
}

import java.util.List;
import com.google.gson.annotations.Expose;
import com.google.gson.annotations.SerializedName;
public class Student{
    @SerializedName("nome")
    @Expose
    private String nome;
    @SerializedName("idade")
    @Expose
    private Integer idade;
    @SerializedName("notas")
    @Expose
    private List<Double> notas;
    @SerializedName("presenca")
    @Expose
    private List<Boolean> presenca;
    public Student(String nome, Integer idade, List<Double> notas, List<Boolean> presenca) {
        this.nome = nome;
        this.idade = idade;
        this.notas = notas;
        this.presenca = presenca;
    }
    public String getNome() {
        return nome;
    }
    public void setNome(String nome) {
        this.nome = nome;
    }
    public Integer getIdade() {
        return idade;
    }
    public void setIdade(Integer idade) {
        this.idade = idade;
    }
    public List<Double> getNotas() {
        return notas;
    }
    public void setNotas(List<Double> notas) {
        this.notas = notas;
    }
    public List<Boolean> getPresenca() {
        return presenca;
    }
    public void setPresenca(List<Boolean> presenca) {
        this.presenca = presenca;
    }
    public String obterStatus() {
        double media = calcularMedia();
        if (media >= 6 && calcularPresenca() >= 75) {
            return "Aprovado";
        } else {
            return "Reprovado";
        }
    }
    public double calcularMedia() {
        double soma = 0;
        for (int i = 0; i < notas.size(); i++) {
            soma += notas.get(i);
        }
        return soma / notas.size();
    }
    public double calcularPresenca() {
        double soma = 0;
        for (int i = 0; i < presenca.size(); i++) {
            if (presenca.get(i)) {
                soma++;
            }
        }
        return (soma / presenca.size()) * 100;
    }
    public String getNotasFormatadas() {
        if (notas == null || notas.isEmpty()) {
            return "Sem notas";
        }
        StringBuilder sb = new StringBuilder();
        int tamanho = notas.size();
        for (int i = 0; i < tamanho; i++) {
            sb.append(notas.get(i));
            if (i < tamanho - 1) {
                sb.append(", ");
            }
        }
        return sb.toString();
    }
    public String getPresencaFormatada() {
        if (presenca == null || presenca.isEmpty()) {
            return "Sem registro";
        }
        StringBuilder sb = new StringBuilder();
        int tamanho = presenca.size();
        for (int i = 0; i < tamanho; i++) {
            if (presenca.get(i)) {
                sb.append("presente");
            } else {
                sb.append("faltou");
            }
            if (i < tamanho - 1) {
                sb.append(", ");
            }
        }
        return sb.toString();
    }
}

import java.util.List;
import com.google.gson.annotations.Expose;
import com.google.gson.annotations.SerializedName;
public class Turma {
    @SerializedName("students")
    @Expose
    private List<Student> students;
    public List<Student> getStudents() {
        return students;
    }
    public void setStudents(List<Student> students) {
        this.students = students;
    }
}

import android.util.Log;
import com.example.tarefa4estudantesnavviewdrawer.pojo.Student;
import com.example.tarefa4estudantesnavviewdrawer.pojo.Turma;
import com.example.tarefa4estudantesnavviewdrawer.util.Conexao;
import com.example.tarefa4estudantesnavviewdrawer.util.Conversao;
import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;
import java.io.InputStream;
import java.lang.reflect.Type;
import java.util.List;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
public class Repository {
    private static final String URL = "digite a URL";
    private ExecutorService executorService;
    public Repository() {
        this.executorService = Executors.newSingleThreadExecutor();
    }
    public interface Callback{
        void sucesso (List<Student> estudantes);
        void erro (String mensagem);
    }
    public void obterDados(Callback c){
        executorService.execute(() -> {
            try {
                Conexao conexao = new Conexao();
                InputStream inputStream = conexao.obterRespostaHTTP(URL);
                Conversao conversao = new Conversao();
                String jsonString = conversao.converter(inputStream);
                if (jsonString == null || jsonString.isEmpty()) {
                    c.erro("Resposta vazia");
                    return;
                }
                Log.i("JSON", "Recebido " + jsonString);
                Gson gson = new Gson();
                Type type = new TypeToken<Turma>(){}.getType();
                Turma dados = gson.fromJson(jsonString, type);
                c.sucesso(dados.getStudents());
            } catch (Exception e) {
                c.erro("Erro ao baixar dados: " + e.getMessage());
            }
        });
    }
    public void shutdown() {
        executorService.shutdown();
    }
}

import android.content.Intent;
import android.os.Bundle;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import androidx.lifecycle.ViewModelProvider;
import androidx.recyclerview.widget.LinearLayoutManager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Toast;
import com.example.tarefa4estudantesnavviewdrawer.SharedViewModel;
import com.example.tarefa4estudantesnavviewdrawer.StudentAdapter;
import com.example.tarefa4estudantesnavviewdrawer.databinding.FragmentMainBinding;
public class MainFragment extends Fragment {
    private FragmentMainBinding binding;
    private SharedViewModel viewModel;
    private StudentAdapter adapter;
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        binding = FragmentMainBinding.inflate(inflater, container, false);
        return binding.getRoot();
    }
    @Override
    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        adapter = new StudentAdapter();
        binding.listView.setLayoutManager(new LinearLayoutManager(requireContext()));
        binding.listView.setAdapter(adapter);
        viewModel = new ViewModelProvider(requireActivity()).get(SharedViewModel.class);
        viewModel.getEstudantesLiveData().observe(getViewLifecycleOwner(), estudantes -> {
            if (estudantes != null && !estudantes.isEmpty()) {
                adapter.substituirLista(estudantes);
            }
        });
        viewModel.getMensagem().observe(getViewLifecycleOwner(), mensagem -> {
            Toast.makeText(requireContext(), mensagem, Toast.LENGTH_SHORT).show();
        });
    }
}

import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import androidx.lifecycle.ViewModelProvider;
import com.example.tarefa4estudantesnavviewdrawer.SharedViewModel;
import com.example.tarefa4estudantesnavviewdrawer.databinding.FragmentMediaBinding;
public class MediaFragment extends Fragment {
    private FragmentMediaBinding binding;
    private SharedViewModel viewModel;
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        binding = FragmentMediaBinding.inflate(inflater, container, false);
        return binding.getRoot();
    }
    @Override
    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        viewModel = new ViewModelProvider(requireActivity()).get(SharedViewModel.class);
        viewModel.getMediaTurmaLiveData().observe(getViewLifecycleOwner(), media -> {
            if (media != null) {
                binding.txtViewMediaTurma.setText(String.format("Média Geral: %.1f", media));
            }
        });
    }
}

import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import androidx.lifecycle.ViewModelProvider;
import androidx.recyclerview.widget.LinearLayoutManager;
import com.example.tarefa4estudantesnavviewdrawer.SharedViewModel;
import com.example.tarefa4estudantesnavviewdrawer.StudentStatusAdapter;
import com.example.tarefa4estudantesnavviewdrawer.databinding.FragmentResultadoBinding;
public class ResultadoFragment extends Fragment {
    private FragmentResultadoBinding binding;
    private SharedViewModel viewModel;
    private StudentStatusAdapter adapter;
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        binding = FragmentResultadoBinding.inflate(inflater, container, false);
        return binding.getRoot();
    }
    @Override
    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        adapter = new StudentStatusAdapter();
        binding.listView.setLayoutManager(new LinearLayoutManager(requireContext()));
        binding.listView.setAdapter(adapter);
        viewModel = new ViewModelProvider(requireActivity()).get(SharedViewModel.class);
        viewModel.getEstudantesLiveData().observe(getViewLifecycleOwner(), estudantes -> {
            if (estudantes != null && !estudantes.isEmpty()) {
                adapter.substituirLista(estudantes);
            }
        });
    }
}

import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
public class Conexao {
    public InputStream obterRespostaHTTP(String end) {
        HttpURLConnection conexao = null;
        try {
            URL url = new URL(end);
            conexao = (HttpURLConnection) url.openConnection();
            conexao.setConnectTimeout(50000);
            conexao.setReadTimeout(50000);
            conexao.setRequestMethod("GET");
            conexao.connect();
            return new BufferedInputStream(conexao.getInputStream());
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }
}

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
public class Conversao {
    public String converter(InputStream inputStream) {
        if (inputStream == null) return null;
        InputStreamReader inputStreamReader = new InputStreamReader(inputStream);
        BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
        StringBuilder stringBuilder = new StringBuilder();
        String conteudo;
        try {
            while ((conteudo = bufferedReader.readLine()) != null) {
                stringBuilder.append(conteudo).append("\n");
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return stringBuilder.toString();
    }
}

import android.os.Bundle;
import android.view.View;
import android.view.Menu;
import com.google.android.material.snackbar.Snackbar;
import com.google.android.material.navigation.NavigationView;
import androidx.navigation.NavController;
import androidx.navigation.Navigation;
import androidx.navigation.ui.AppBarConfiguration;
import androidx.navigation.ui.NavigationUI;
import androidx.drawerlayout.widget.DrawerLayout;
import androidx.appcompat.app.AppCompatActivity;
import com.example.tarefa4estudantesnavviewdrawer.databinding.ActivityMainBinding;
public class MainActivity extends AppCompatActivity {
    private AppBarConfiguration mAppBarConfiguration;
    private ActivityMainBinding binding;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        binding = ActivityMainBinding.inflate(getLayoutInflater());
        setContentView(binding.getRoot());
        setSupportActionBar(binding.appBarMain.toolbar);
        DrawerLayout drawer = binding.drawerLayout;
        NavigationView navigationView = binding.navView;
        // Passing each menu ID as a set of Ids because each
        // menu should be considered as top level destinations.
        mAppBarConfiguration = new AppBarConfiguration.Builder(
                R.id.nav_main, R.id.nav_resultado, R.id.nav_media)
                .setOpenableLayout(drawer)
                .build();
        NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment_content_main);
        NavigationUI.setupActionBarWithNavController(this, navController, mAppBarConfiguration);
        NavigationUI.setupWithNavController(navigationView, navController);
    }
    @Override
    public boolean onSupportNavigateUp() {
        NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment_content_main);
        return NavigationUI.navigateUp(navController, mAppBarConfiguration)
                || super.onSupportNavigateUp();
    }
}

import androidx.lifecycle.LiveData;
import androidx.lifecycle.MutableLiveData;
import androidx.lifecycle.ViewModel;
import com.example.tarefa4estudantesnavviewdrawer.pojo.Student;
import com.example.tarefa4estudantesnavviewdrawer.repository.Repository;
import java.util.List;
public class SharedViewModel extends ViewModel {
    private Repository repository;
    private MutableLiveData<List<Student>> estudantesLiveData;
    private MutableLiveData<String> mensagemLiveData;
    private MutableLiveData<Double> mediaTurmaLiveData;
    public SharedViewModel() {
        this.repository = new Repository();
        this.estudantesLiveData = new MutableLiveData<>();
        this.mensagemLiveData = new MutableLiveData<>();
        this.mediaTurmaLiveData = new MutableLiveData<>();
        carregarDados();
    }
    public LiveData<List<Student>> getEstudantesLiveData() {
        return estudantesLiveData;
    }
    public LiveData<String> getMensagem() {
        return mensagemLiveData;
    }
    public LiveData<Double> getMediaTurmaLiveData() {
        return mediaTurmaLiveData;
    }
    public void carregarDados() {
        if (estudantesLiveData.getValue() != null) {
            return;
        }
        repository.obterDados(new Repository.Callback() {
            @Override
            public void sucesso(List<Student> estudantes) {
                estudantesLiveData.postValue(estudantes);
                calcularMediaGeral(estudantes);
            }
            @Override
            public void erro(String mensagem) {
                mensagemLiveData.postValue(mensagem);
            }
        });
    }
    private void calcularMediaGeral(List<Student> estudantes) {
        if (estudantes == null || estudantes.isEmpty()) {
            mediaTurmaLiveData.postValue(0.0);
            return;
        }
        double somaTodasAsMedias = 0;
        for (Student aluno : estudantes) {
            somaTodasAsMedias += aluno.calcularMedia();
        }
        double mediaFinal = somaTodasAsMedias / estudantes.size();
        mediaTurmaLiveData.postValue(mediaFinal);
    }
    @Override
    protected void onCleared() {
        super.onCleared();
        repository.shutdown();
    }
}

import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import com.example.tarefa4estudantesnavviewdrawer.pojo.Student;
import java.util.ArrayList;
import java.util.List;
public class StudentAdapter extends RecyclerView.Adapter<StudentAdapter.ViewHolder>{
    private final List<Student> estudantes = new ArrayList<>();
    @NonNull
    @Override
    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_lista_completa, parent, false);
        return new ViewHolder(view);
    }
    @Override
    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
        Student estudante = estudantes.get(position);
        holder.nome.setText(estudante.getNome());
        holder.idade.setText(String.valueOf(estudante.getIdade()));
        holder.notas.setText("Notas: " + estudante.getNotasFormatadas());
        holder.presenca.setText("Presença: " + estudante.getPresencaFormatada());
    }
    @Override
    public int getItemCount() {
        return estudantes.size();
    }
    public void substituirLista(List<Student> estudantesNovo) {
        estudantes.clear();
        if(estudantes!=null){
            estudantes.addAll(estudantesNovo);
        }
        notifyDataSetChanged();
    }
    static class ViewHolder extends RecyclerView.ViewHolder{
        TextView nome;
        TextView idade;
        TextView notas;
        TextView presenca;
        public ViewHolder(@NonNull View itemView) {
            super(itemView);
            nome = itemView.findViewById(R.id.txtViewNome);
            idade = itemView.findViewById(R.id.txtViewIdade);
            notas = itemView.findViewById(R.id.txtViewNotas);
            presenca = itemView.findViewById(R.id.txtViewPresenca);
        }
    }
}

import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import com.example.tarefa4estudantesnavviewdrawer.pojo.Student;
import java.util.ArrayList;
import java.util.List;
public class StudentStatusAdapter extends RecyclerView.Adapter<StudentStatusAdapter.ViewHolder> {
    private final List<Student> estudantes = new ArrayList<>();
    @NonNull
    @Override
    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_lista_status, parent, false);
        return new ViewHolder(view);
    }
    @Override
    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
        Student estudante = estudantes.get(position);
        holder.nome.setText(estudante.getNome());
        holder.status.setText(estudante.obterStatus());
    }
    @Override
    public int getItemCount() {
        return estudantes.size();
    }
    public void substituirLista(List<Student> estudantesNovo) {
        estudantes.clear();
        if(estudantes!=null){
            estudantes.addAll(estudantesNovo);
        }
        notifyDataSetChanged();
    }
    static class ViewHolder extends RecyclerView.ViewHolder{
        TextView nome;
        TextView status;
        public ViewHolder(@NonNull View itemView) {
            super(itemView);
            nome = itemView.findViewById(R.id.txtViewNomeStatus);
            status = itemView.findViewById(R.id.txtViewStatus);
        }
    }
}