Armzenamento Interno e Externo

Para mais detalhes sobre as formas de armazenar dados no Android acesse:

GOOGLE DEVELOPERS. Visão geral do armazenamento de dados e arquivos. Disponível em: https://developer.android.com/training/data-storage?hl=pt-br. Acesso em: 16 ago. 2025.

Exemplos práticos (Armazenamento interno):

ManipulaArquivo.java

import android.content.Context;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
public class ManipulaArquivo {
    private final Context context;
    public ManipulaArquivo(Context context) {
        this.context = context;
    }
    public void salvarArquivo(String nome, String conteudo, boolean append) throws IOException {
        File arquivo = new File(context.getFilesDir(), nome);
        try (FileOutputStream fos = new FileOutputStream(arquivo, append)) {
            fos.write(conteudo.getBytes());
        }
    }
    public String lerArquivo(String nome) throws IOException {
        StringBuilder sb = new StringBuilder();
        try (FileInputStream fis = context.openFileInput(nome)) {
            int letra;
            while ((letra = fis.read()) != -1) {
                sb.append((char) letra);
            }
        }
        return sb.toString();
    }
    public void deletarArquivo(String nome) {
        context.deleteFile(nome);
    }
}//class

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="16dp">
    <EditText
        android:id="@+id/editTextTexto"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Digite algo"
        android:inputType="text" />
    <Button
        android:id="@+id/buttonSalvar"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Salvar" />
    <Button
        android:id="@+id/buttonExcluir"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Excluir" />
</LinearLayout>

MainActivity.java

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import androidx.appcompat.app.AppCompatActivity;
import java.io.IOException;
public class MainActivity extends AppCompatActivity {
    private EditText editTextTexto;
    private Button buttonSalvar, buttonExcluir;
    private ManipulaArquivo arquivo;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        editTextTexto = findViewById(R.id.editTextTexto);
        buttonSalvar = findViewById(R.id.buttonSalvar);
        buttonExcluir = findViewById(R.id.buttonExcluir);
        arquivo = new ManipulaArquivo(this);
        Intent intent = getIntent();
        if (intent != null && intent.hasExtra("texto")) {
            String texto = intent.getStringExtra("texto");
            editTextTexto.setText(texto);
        }
        buttonSalvar.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                salvarTexto();
            }
        });
        buttonExcluir.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                excluirArquivo();
            }
        });
    }
    private void salvarTexto() {
        String conteudo = editTextTexto.getText().toString();
        try {
            arquivo.salvarArquivo("meuArq.txt", conteudo,true);
            Toast.makeText(this, "Texto salvo com sucesso", Toast.LENGTH_SHORT).show();
            editTextTexto.setText("");
            Intent intent = new Intent(MainActivity.this, SegundaActivity.class);
            startActivity(intent);
        } catch (IOException e) {
            e.printStackTrace();
            Toast.makeText(this, "Erro ao salvar o arquivo", Toast.LENGTH_SHORT).show();
        }
    }
    private void excluirArquivo() {
        try {
            arquivo.deletarArquivo("meuArq.txt");
            editTextTexto.setText("");
            Toast.makeText(this, "Arquivo excluído", Toast.LENGTH_SHORT).show();
        } catch (Exception e) {
            e.printStackTrace();
            Toast.makeText(this, "Erro ao excluir o arquivo", Toast.LENGTH_SHORT).show();
        }
    }
}//class

activity_segunda.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="16dp">
    <TextView
        android:id="@+id/textViewTexto"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Texto da primeira tela"
        android:textSize="18sp" />
    <Button
        android:id="@+id/buttonVoltar"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Voltar" />
</LinearLayout>

SegundaActivity.java

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import androidx.appcompat.app.AppCompatActivity;
import java.io.IOException;
public class SegundaActivity extends AppCompatActivity {
    private TextView textViewTexto;
    private Button buttonVoltar;
    private ManipulaArquivo arquivo;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_segunda);
        textViewTexto = findViewById(R.id.textViewTexto);
        buttonVoltar = findViewById(R.id.buttonVoltar);
        arquivo = new ManipulaArquivo(this);
        try {
            String texto = arquivo.lerArquivo("meuArq.txt");
            textViewTexto.setText(texto);
        } catch (IOException e) {
            e.printStackTrace();
            textViewTexto.setText("Erro ao carregar conteúdo");
            Toast.makeText(this, "Erro ao ler o arquivo", Toast.LENGTH_SHORT).show();
        }
        buttonVoltar.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                voltarTela();
            }
        });
    }
    private void voltarTela() {
        Intent intent = new Intent(SegundaActivity.this, MainActivity.class);
        intent.putExtra("texto", textViewTexto.getText().toString());
        startActivity(intent);
        finish();
    }
}//class

Exemplos práticos (Armazenamento no External Storage):

ManipulaArquivo.java

import android.content.Context;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
public class ManipulaArquivo {
    private final Context context;
    public ManipulaArquivo(Context context) {
        this.context = context;
    }
    private File getArquivo(String nome) {
        File dir = context.getExternalFilesDir(null);
        return new File(dir, nome);
    }
    public void salvarArquivo(String nome, String conteudo) throws IOException {
        File arquivo = getArquivo(nome);
        try (FileOutputStream fos = new FileOutputStream(arquivo,true)) {
            fos.write(conteudo.getBytes());
        }
    }
    public String lerArquivo(String nome) throws IOException {
        File arquivo = getArquivo(nome);
        StringBuilder sb = new StringBuilder();
        try (FileInputStream fis = new FileInputStream(arquivo)) {
            int letra;
            while ((letra = fis.read()) != -1) {
                sb.append((char) letra);
            }
        }
        return sb.toString();
    }
    public void deletarArquivo(String nome) {
        File arquivo = getArquivo(nome);
        if (arquivo.exists()) {
            arquivo.delete();
        }
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="16dp">
    <EditText
        android:id="@+id/editTextNome"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Digite algo para salvar"
        android:inputType="text"/>
    <Button
        android:id="@+id/buttonS"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="clicar"
        android:text="Salvar" />
    <Button
        android:id="@+id/buttonE"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="clicar"
        android:text="Excluir" />
</LinearLayout>

MainActivity.java

import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import java.io.IOException;
public class MainActivity extends AppCompatActivity {
    private EditText editTextTexto;
    private Button buttonSalvar, buttonExcluir;
    private ManipulaArquivo arquivo;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        editTextTexto = findViewById(R.id.editTextTexto);
        buttonSalvar = findViewById(R.id.buttonSalvar);
        buttonExcluir = findViewById(R.id.buttonExcluir);
        arquivo = new ManipulaArquivo(this);
        Intent intent = getIntent();
        if (intent != null && intent.hasExtra("texto")) {
            String texto = intent.getStringExtra("texto");
            editTextTexto.setText(texto);
        }
        buttonSalvar.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                salvarTexto();
            }
        });
        buttonExcluir.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                excluirArquivo();
            }
        });
    }
    private void salvarTexto() {
        String conteudo = editTextTexto.getText().toString();
        try {
            arquivo.salvarArquivo("meuArq.txt", conteudo);
            Toast.makeText(this, "Texto salvo com sucesso", Toast.LENGTH_SHORT).show();
            editTextTexto.setText("");
            Intent intent = new Intent(MainActivity.this, SegundaActivity.class);
            startActivity(intent);
        } catch (IOException e) {
            e.printStackTrace();
            Toast.makeText(this, "Erro ao salvar o arquivo", Toast.LENGTH_SHORT).show();
        }
    }
    private void excluirArquivo() {
        try {
            arquivo.deletarArquivo("meuArq.txt");
            editTextTexto.setText("");
            Toast.makeText(this, "Arquivo excluído", Toast.LENGTH_SHORT).show();
        } catch (Exception e) {
            e.printStackTrace();
            Toast.makeText(this, "Erro ao excluir o arquivo", Toast.LENGTH_SHORT).show();
        }
    }
}

activity_segunda.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="16dp">
    <TextView
        android:id="@+id/textViewTexto"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Texto da primeira tela"
        android:textSize="18sp" />
    <Button
        android:id="@+id/buttonVoltar"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Voltar" />
</LinearLayout>

SegundaActivity.java

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import androidx.appcompat.app.AppCompatActivity;
import java.io.IOException;
public class SegundaActivity extends AppCompatActivity {
    private TextView textViewTexto;
    private Button buttonVoltar;
    private ManipulaArquivo arquivo;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_segunda);
        textViewTexto = findViewById(R.id.textViewTexto);
        buttonVoltar = findViewById(R.id.buttonVoltar);
        arquivo = new ManipulaArquivo(this);
        try {
            String texto = arquivo.lerArquivo("meuArq.txt");
            textViewTexto.setText(texto);
        } catch (IOException e) {
            e.printStackTrace();
            textViewTexto.setText("Erro ao carregar conteúdo");
            Toast.makeText(this, "Erro ao ler o arquivo", Toast.LENGTH_SHORT).show();
        }
        buttonVoltar.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                voltarTela();
            }
        });
    }
    private void voltarTela() {
        Intent intent = new Intent(SegundaActivity.this, MainActivity.class);
        intent.putExtra("texto", textViewTexto.getText().toString());
        startActivity(intent);
        finish();
    }
}

Exemplos práticos (Armazenamento externo no Diretório Downloads):

ManipulaArquivo.java

import android.content.ContentUris;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.os.Environment;
import android.provider.MediaStore;
import android.util.Log;
import java.io.InputStream;
import java.io.OutputStream;
public class ManipulaArquivo {
    public static boolean salvarDados(Context context, String data) {
        try {
            ContentValues valores = new ContentValues();
            valores.put(MediaStore.MediaColumns.DISPLAY_NAME, "meuArq.txt");  // Nome do arquivo
            valores.put(MediaStore.MediaColumns.MIME_TYPE, "text/plain");  // Tipo MIME
            valores.put(MediaStore.MediaColumns.RELATIVE_PATH, Environment.DIRECTORY_DOWNLOADS);
            Uri uri = context.getContentResolver().insert(MediaStore.Files.getContentUri("external"), valores);
            if (uri != null) {
                try (OutputStream outputStream = context.getContentResolver().openOutputStream(uri)) {
                    if (outputStream != null) {
                        outputStream.write(data.getBytes());
                        return true;
                    }
                }
            }
        } catch (Exception e) {
            Log.e("FileManager", "Erro ao salvar o arquivo no diretório Downloads", e);
        }
        return false;
    }
    public static String lerDados(Context context) {
        StringBuilder dados = new StringBuilder();
        Uri uri = MediaStore.Files.getContentUri("external");
        String selecao = MediaStore.MediaColumns.DISPLAY_NAME + " = ?";
        String[] argumentos = new String[]{"meuArq.txt"};
        try (Cursor cursor = context.getContentResolver().query(uri, null, selecao, argumentos, null)) {
            if (cursor != null && cursor.moveToFirst()) {
                int idColuna = cursor.getColumnIndex(MediaStore.MediaColumns._ID);
                if (idColuna != -1) {
                    long idArquivo = cursor.getLong(idColuna);
                    Uri uriArquivo = ContentUris.withAppendedId(MediaStore.Files.getContentUri("external"), idArquivo);
                    try (InputStream inputStream = context.getContentResolver().openInputStream(uriArquivo)) {
                        if (inputStream != null) {
                            int letra;
                            while ((letra = inputStream.read()) != -1) {
                                dados.append((char) letra);
                            }
                        }
                    }
                }
            }
        } catch (Exception e) {
            Log.e("FileManager", "Erro ao ler o arquivo", e);
        }
        return dados.toString();
    }
    public static boolean deletarDados(Context context) {
        Uri uri = MediaStore.Files.getContentUri("external");
        String selecao = MediaStore.MediaColumns.DISPLAY_NAME + " = ?";
        String[] argumentos = new String[]{"meuArq.txt"};
        try {
            int linhasDeletadas = context.getContentResolver().delete(uri,
                    selecao,
                    argumentos);
            return linhasDeletadas > 0;
        } catch (Exception e) {
            Log.e("FileManager", "Erro ao excluir o arquivo", e);
        }
        return false;
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="16dp">
    <EditText
        android:id="@+id/editTextNome"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Digite algo para salvar"
        android:inputType="text"/>
    <Button
        android:id="@+id/buttonS"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="clicar"
        android:text="Salvar" />
    <Button
        android:id="@+id/buttonE"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="clicar"
        android:text="Excluir" />
</LinearLayout>

MainActivity.java

import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
    private EditText editTextNome;
    private Button buttonS, buttonE;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        editTextNome = findViewById(R.id.editTextNome);
        buttonS = findViewById(R.id.buttonS);
        buttonE = findViewById(R.id.buttonE);
        Intent i = getIntent();
        editTextNome.setText(i.getStringExtra("msg"));
    }
    public void clicar(View view) {
        if (view.getId() == R.id.buttonS) {
            String dado = editTextNome.getText().toString();
            if (ManipulaArquivo.salvarDados(getApplicationContext(), dado)) {
                Toast.makeText(getApplicationContext(), "Salvo com sucesso", Toast.LENGTH_SHORT).show();
                startActivity(new Intent(getApplicationContext(), SegundaActivity.class));
            } else {
                Toast.makeText(getApplicationContext(), "Erro ao salvar", Toast.LENGTH_SHORT).show();
            }
        }
        if (view.getId() == R.id.buttonE) {
            // Exclui o arquivo do diretório Downloads
            if (ManipulaArquivo.deletarDados(getApplicationContext())) {
                Toast.makeText(getApplicationContext(), "Arquivo excluído", Toast.LENGTH_SHORT).show();
                editTextNome.setText("");
            } else {
                Toast.makeText(getApplicationContext(), "Erro ao excluir", Toast.LENGTH_SHORT).show();
            }
        }
    }
}

activity_segunda.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="16dp">
    <TextView
        android:id="@+id/textView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Texto lido do arquivo"
        android:textSize="18sp"/>
</LinearLayout>

SegundaActivity.java

import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
import android.widget.TextView;
public class SegundaActivity extends AppCompatActivity {
    private TextView textView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_segunda);
        textView = findViewById(R.id.textView);
        String data = ManipulaArquivo.lerDados(getApplicationContext());
        textView.setText(data);
    }
}