Content Provider

Recurso que possibilita compartilhar dados privados entre aplicativos.

Para mais detalhes: GOOGLE DEVELOPERS. Fundamentos do provedor de conteúdo. Disponível em: https://developer.android.com/guide/topics/providers/content-provider-basics?hl=pt-br. Acesso em: 01 set. 2025.

Content Provider

Exemplo 01: (Adaptado de: Stack overflow. Android: não estou obtendo nenhum contato da lista de contatos. 2018. Disponível em: https://stackoverflow.com/questions/53956496/android-not-getting-any-contacts-from-contact-list. Pergunta feita pelo usuário https://stackoverflow.com/users/4951663/mohit-suthar e respondida pelo https://stackoverflow.com/users/4390987/%e0%a5%90-rakesh-kumar.):

No arquivo AndroidManifest.xml, deve-se acrescentar a tag <uses-permission android:name="android.permission.READ_CONTACTS" />

Contato.java

public class Contato {
   private int id;
   private String nome, fone;
   public Contato(int id, String nome, String fone) {
       this.id = id;
       this.nome = nome;
       this.fone = fone;
   }
   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 getFone() {
       return fone;
   }
   public void setFone(String fone) {
       this.fone = fone;
   }
   @Override
   public String toString() {
       return "Contato{" +
               "id=" + id +
               ", nome='" + nome + '\'' +
               ", fone='" + fone + '\'' +
               '}';
   }
}

activity_main.xml

<?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:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:layout_margin="10dp"
    tools:context=".MainActivity">
    <ListView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/lista"/>
</LinearLayout>

MainActivity.java

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import android.Manifest;
import android.content.ContentResolver;
import android.content.pm.PackageManager;
import android.database.Cursor;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.provider.ContactsContract;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
import java.util.ArrayList;
public class MainActivity extends AppCompatActivity
        implements AdapterView.OnItemClickListener {
    private ListView lista;
    private ArrayAdapter<Contato> dadosAdapter;
    private static final int PERMISSIONS_REQUEST_READ_CONTACTS = 100;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        lista = findViewById(R.id.lista);
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M &&
                checkSelfPermission(Manifest.permission.READ_CONTACTS)
                        != PackageManager.PERMISSION_GRANTED) {
            requestPermissions(new String[]{Manifest.permission.READ_CONTACTS},
                    PERMISSIONS_REQUEST_READ_CONTACTS);
        } else {
            carregarContatos();
        }
    }
    private void carregarContatos() {
        ArrayList<Contato> contatos = obterDados();
        dadosAdapter = new ArrayAdapter<>(MainActivity.this,
                android.R.layout.simple_list_item_1, contatos);
        lista.setAdapter(dadosAdapter);
        lista.setOnItemClickListener(this);
    }
    public ArrayList<Contato> obterDados() {
        ArrayList<Contato> dados = new ArrayList<>();
        Uri uri = ContactsContract.CommonDataKinds.Phone.CONTENT_URI;
        String[] projection = {
                ContactsContract.CommonDataKinds.Phone.CONTACT_ID,
                ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME,
                ContactsContract.CommonDataKinds.Phone.NUMBER
        };
        ContentResolver resolver = getContentResolver();
        Cursor cursor = resolver.query(uri, projection, null, null,
                ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME + " ASC");
        if (cursor != null) {
            int idIndex = cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.CONTACT_ID);
            int nameIndex = cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME);
            int phoneIndex = cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER);
            while (cursor.moveToNext()) {
                int id = cursor.getInt(idIndex);
                String nome = cursor.getString(nameIndex);
                String fone = cursor.getString(phoneIndex);
                dados.add(new Contato(id, nome, fone));
            }
            cursor.close();
        }
        return dados;
    }
    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
        Contato item = (Contato) parent.getItemAtPosition(position);
        Toast.makeText(MainActivity.this, item.toString(), Toast.LENGTH_SHORT).show();
    }
    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions,
                                           @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if (requestCode == PERMISSIONS_REQUEST_READ_CONTACTS) {
            if (grantResults.length > 0 &&
                    grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                carregarContatos();
            } else {
                Toast.makeText(this, "Permissão negada!!!!", Toast.LENGTH_SHORT).show();
            }
        }
    }
}

Exemplo 02: (criar dois apps, um para prover o conteúdo e outro para consumir)

App provedor

No arquivo AndroidManifest.xml acrescentar <provider android:name=".DadosProvider" android:authorities="nomeDaAutoridade" android:exported="true" android:grantUriPermissions="true"/>

DadosProvider.java

import android.content.ContentProvider;
import android.content.ContentUris;
import android.content.ContentValues;
import android.content.Context;
import android.content.UriMatcher;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.database.sqlite.SQLiteQueryBuilder;
import android.net.Uri;
import android.util.Log;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
public class DadosProvider extends ContentProvider {
    private static final int BANCO_VERSAO = 1;
    private static final String BANCO_NOME = "meu_banco.db";
    private static final String BANCO_TABELA = "contato";
    public static final String ID = "_id";
    public static final String NOME = "nome";
    public static final String TELEFONE = "telefone";
    private static final String CRIA_TABELA =
            "CREATE TABLE " + BANCO_TABELA + " (" +
                    ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
                    NOME + " TEXT, " +
                    TELEFONE + " TEXT)";
    private static final String DELETA_TABELA =
            "DROP TABLE IF EXISTS " + BANCO_TABELA;
    private SQLiteDatabase banco;
    private static final String TAG = DadosProvider.class.getSimpleName();
    public static final String AUTHORITY = "nomeDaAutoridade";
    public static final String PATH = "dados";
    public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/" + PATH);
    private static final int CODIGO_URI_TODOS = 1;
    private static final UriMatcher URI_MATCHER;
    static {
        URI_MATCHER = new UriMatcher(UriMatcher.NO_MATCH);
        URI_MATCHER.addURI(AUTHORITY, PATH, CODIGO_URI_TODOS);
    }
    @Override
    public boolean onCreate() {
        Context context = getContext();
        BancoHelper helper = new BancoHelper(context);
        banco = helper.getWritableDatabase();
        if (banco != null) {
            Log.i(TAG, "Provedor criado");
            return true;
        }
        return false;
    }
    @Nullable
    @Override
    public Cursor query(@NonNull Uri uri, @Nullable String[] projection,
                        @Nullable String selection, @Nullable String[] selectionArgs,
                        @Nullable String sortOrder) {
        SQLiteQueryBuilder sqb = new SQLiteQueryBuilder();
        sqb.setTables(BANCO_TABELA);
        Cursor cursor = sqb.query(banco, projection, selection, selectionArgs,
                null, null, sortOrder);
        if (cursor != null) {
            cursor.setNotificationUri(getContext().getContentResolver(), uri);
        }
        Log.i(TAG, "Query executada");
        return cursor;
    }
    @Nullable
    @Override
    public String getType(@NonNull Uri uri) {
        switch (URI_MATCHER.match(uri)) {
            case CODIGO_URI_TODOS:
                return "vnd.android.cursor.dir/vnd." + AUTHORITY + "." + PATH;
            default:
                throw new IllegalArgumentException("URI inválida: " + uri);
        }
    }
    @Nullable
    @Override
    public Uri insert(@NonNull Uri uri, @Nullable ContentValues values) {
        long id = banco.insert(BANCO_TABELA, null, values);
        if (id > 0) {
            Uri uriID = ContentUris.withAppendedId(CONTENT_URI, id);
            getContext().getContentResolver().notifyChange(uriID, null);
            Log.i(TAG, "Dados inseridos: ID = " + id);
            return uriID;
        }
        throw new SQLException("Erro ao inserir registro em " + uri);
    }
    @Override
    public int delete(@NonNull Uri uri, @Nullable String selection,
                      @Nullable String[] selectionArgs) {
        int count;
        switch (URI_MATCHER.match(uri)) {
            case CODIGO_URI_TODOS:
                count = banco.delete(BANCO_TABELA, selection, selectionArgs);
                Log.i(TAG, "Registros deletados: " + count);
                break;
            default:
                throw new IllegalArgumentException("URI inválida para delete: " + uri);
        }
        getContext().getContentResolver().notifyChange(uri, null);
        return count;
    }
    @Override
    public int update(@NonNull Uri uri, @Nullable ContentValues values,
                      @Nullable String selection, @Nullable String[] selectionArgs) {
        int count;
        switch (URI_MATCHER.match(uri)) {
            case CODIGO_URI_TODOS:
                count = banco.update(BANCO_TABELA, values, selection, selectionArgs);
                Log.i(TAG, "Registros alterados: " + count);
                break;
            default:
                throw new IllegalArgumentException("URI inválida para update: " + uri);
        }
        getContext().getContentResolver().notifyChange(uri, null);
        return count;
    }
    private static class BancoHelper extends SQLiteOpenHelper {
        BancoHelper(Context context) {
            super(context, BANCO_NOME, null, BANCO_VERSAO);
        }
        @Override
        public void onCreate(SQLiteDatabase db) {
            db.execSQL(CRIA_TABELA);
        }
        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            db.execSQL(DELETA_TABELA);
            onCreate(db);
        }
    }
}

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">
    <Button
        android:id="@+id/btnAdicionar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Adicionar Contato" />
    <Button
        android:id="@+id/btnMostrar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="12dp"
        android:text="Mostrar Contatos" />
    <ListView
        android:id="@+id/lista"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginTop="12dp"
        android:divider="@android:color/darker_gray"
        android:dividerHeight="1dp"/>
</LinearLayout>

MainActivity.java

import androidx.appcompat.app.AppCompatActivity;
import android.content.ContentValues;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
import java.util.Random;
public class MainActivity extends AppCompatActivity {
    private static final String TAG = "MainActivity";
    private ListView lista;
    private SimpleCursorAdapter adapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button btnAdicionar = findViewById(R.id.btnAdicionar);
        Button btnMostrar = findViewById(R.id.btnMostrar);
        lista = findViewById(R.id.lista);
        String[] colunas = new String[]{DadosProvider.NOME, DadosProvider.TELEFONE};
        int[] views = new int[]{android.R.id.text1, android.R.id.text2};
        adapter = new SimpleCursorAdapter(
                this,
                android.R.layout.simple_list_item_2,
                null,
                colunas,
                views,
                0
        );
        lista.setAdapter(adapter);
        btnAdicionar.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                ContentValues values = new ContentValues();
                values.put(DadosProvider.NOME, "Contato " + new Random().nextInt(100));
                values.put(DadosProvider.TELEFONE, "9999-" + new Random().nextInt(9999));
                Uri uri = getContentResolver().insert(DadosProvider.CONTENT_URI, values);
                Log.i(TAG, "Inserido em: " + uri);
            }
        });
        btnMostrar.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                atualizarLista();
            }
        });
    }
    private void atualizarLista() {
        Cursor cursor = getContentResolver().query(
                DadosProvider.CONTENT_URI,
                null,
                null,
                null,
                null
        );
        adapter.changeCursor(cursor);
    }
    @Override
    protected void onDestroy() {
        super.onDestroy();
        if (adapter != null && adapter.getCursor() != null) {
            adapter.getCursor().close();
        }
    }
}

AppCliente

No AndroidManifest.xml acrescente a tag <queries> <provider android:authorities="nomeDaAutoridade" /> </queries>

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">
    <Button
        android:id="@+id/btnMostrar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Mostrar Contatos" />
    <ListView
        android:id="@+id/lista"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginTop="12dp"
        android:divider="@android:color/darker_gray"
        android:dividerHeight="1dp"/>
</LinearLayout>

MainActivity.java

import androidx.appcompat.app.AppCompatActivity;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
public class MainActivity extends AppCompatActivity {
    private ListView lista;
    private SimpleCursorAdapter adapter;
    private static final String AUTHORITY = "nomeDaAutoridade";
    private static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/contatos");
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button btnMostrar = findViewById(R.id.btnMostrar);
        lista = findViewById(R.id.lista);
        String[] colunas = new String[]{"nome", "telefone"};
        int[] views = new int[]{android.R.id.text1, android.R.id.text2};
        adapter = new SimpleCursorAdapter(
                this,
                android.R.layout.simple_list_item_2,
                null,
                colunas,
                views,
                0
        );
        lista.setAdapter(adapter);
        btnMostrar.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                atualizarLista();
            }
        });
    }
    private void atualizarLista() {
        Cursor cursor = getContentResolver().query(
                CONTENT_URI,
                null,
                null,
                null,
                null
        );
        adapter.changeCursor(cursor);
    }
    @Override
    protected void onDestroy() {
        super.onDestroy();
        if (adapter != null && adapter.getCursor() != null) {
            adapter.getCursor().close();
        }
    }
}