ContentProvider应用间数据共享案例

描述： contentProvider主要用在不用应用之间的数据共享

注意：在第二个用用获取第一个应用的数据时，必须保证第一个应用是在运行着的。

效果展示

第一个应用	第二个应用

完整的实例代码

应用1

MainActivity

package com.example.www.app2;

import android.content.ContentValues;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    private MySQLiteDataBase mMySQLiteDataBase;
    private SQLiteDatabase mDb;
    private EditText mName;
    private EditText mAge;
    private TextView mContent;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mMySQLiteDataBase = new MySQLiteDataBase(this);
        mDb = mMySQLiteDataBase.getWritableDatabase();

        mName = (EditText) findViewById(R.id.editText);
        mAge = (EditText) findViewById(R.id.editText2);
        mContent = (TextView) findViewById(R.id.textView);

    }


    public void insert(View view) {
         String name = mName.getText().toString();
        String age = mAge.getText().toString();
        if(name.isEmpty() || age.isEmpty()) {
            Toast.makeText(this, "年龄或姓名不能为空", Toast.LENGTH_SHORT).show();
            return;
        }
        ContentValues cv = new ContentValues();
        cv.put("name", name);
        cv.put("age", Integer.parseInt(age));
        long result = mDb.insert("user", null, cv);
        if(result != -1) {
            Toast.makeText(this, "插入成功", Toast.LENGTH_SHORT).show();
        } else {
            Toast.makeText(this, "插入失败", Toast.LENGTH_SHORT).show();
        }

    }

    public void query(View view) {
        Cursor cursor = mDb.query("user", null, null, null, null, null, null, null);
        StringBuffer sb = new StringBuffer();
        if(cursor.moveToFirst()) {
            do {
                sb.append("姓名: ").append(cursor.getString(cursor.getColumnIndex("name"))).append("年龄：").append(cursor.getInt(cursor.getColumnIndex("age")));

                sb.append("\n");
            } while (cursor.moveToNext());

            cursor.close();
        }

        mContent.setText(sb.toString());
    }
}

MyContentProvider

package com.example.www.app2;

import android.content.ContentProvider;
import android.content.ContentValues;
import android.content.UriMatcher;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.net.Uri;

public class MyContentProvider extends ContentProvider {

    // 1. 定义一个 urimathcher 定义路径匹配规则
    private static final UriMatcher sURIMather = new UriMatcher(UriMatcher.NO_MATCH);
    private static final int QUERYSUCCESS = 1;
    private static final int INSERTUCCESS = 2;
    private static final int UPDATESUCCESS = 3;
    private static final int DELETESUCCESS = 4;

    // 2. 定义静态代码块 添加匹配规则
    static {
        // authority 和清单文件定义的要一样
        sURIMather.addURI("com.wl.lhw", "query", QUERYSUCCESS);
        sURIMather.addURI("com.wl.lhw", "insert", INSERTUCCESS);
        sURIMather.addURI("com.wl.lhw", "update", UPDATESUCCESS);
        sURIMather.addURI("com.wl.lhw", "delete", DELETESUCCESS);
    }

    private MySQLiteDataBase mOpenHelper;


    @Override
    public boolean onCreate() {
        mOpenHelper = new MySQLiteDataBase(getContext());

        return false;
    }


    @Override
    public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
        int code = sURIMather.match(uri);
        if (code == QUERYSUCCESS) {
            SQLiteDatabase db = mOpenHelper.getWritableDatabase();
            Cursor cursor = db.query("user", projection, selection, selectionArgs, null, null, null);
            return cursor;
        } else {
            throw new IllegalArgumentException("您的路径不匹配");
        }
    }

    @Override
    public String getType(Uri uri) {
        return null;
    }


    @Override
    public Uri insert(Uri uri, ContentValues values) {
        int code = sURIMather.match(uri);
        if (code == INSERTUCCESS) {
            SQLiteDatabase db = mOpenHelper.getWritableDatabase();
            long user = db.insert("user", null, values);
            Uri uri2 = Uri.parse("content://com.wl.insert/" + user);
            return uri2;
        } else {
            throw new IllegalArgumentException("您的路径不匹配");
        }
    }

    @Override
    public int delete(Uri uri, String selection, String[] selectionArgs) {
        int code = sURIMather.match(uri);
        if (code == DELETESUCCESS) {
            SQLiteDatabase db = mOpenHelper.getWritableDatabase();
            int user = db.delete("user", selection, selectionArgs);

            return user;
        } else {
            throw new IllegalArgumentException("您的路径不匹配");
        }

    }

    @Override
    public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
        int code = sURIMather.match(uri);
        if (code == INSERTUCCESS) {
            SQLiteDatabase db = mOpenHelper.getWritableDatabase();
            int user = db.update("user", values, selection, selectionArgs);
            return user;
        } else {
            throw new IllegalArgumentException("您的路径不匹配");
        }
    }
}

MySQLiteDataBase

package com.example.www.app2;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class MySQLiteDataBase extends SQLiteOpenHelper {
    public MySQLiteDataBase(Context context) {
        super(context, "test.db", null, 1);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        String sql = "create table user(id INTEGER PRIMARY KEY AUTOINCREMENT, name varchar(20), age int)";
        db.execSQL(sql);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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="match_parent"
    tools:context=".MainActivity">

    <EditText
        android:id="@+id/editText"
        android:layout_width="180dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:ems="10"
        android:hint="姓名"
        android:inputType="textPersonName"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <android.support.constraint.Guideline
        android:id="@+id/guideline"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="vertical" />

    <EditText
        android:id="@+id/editText2"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        android:layout_marginEnd="8dp"
        android:ems="10"
        android:hint="年龄"
        android:inputType="number"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toEndOf="@+id/editText"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/button"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:layout_marginEnd="8dp"
        android:text="插入"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/editText"
        android:onClick="insert"/>

    <Button
        android:id="@+id/button2"
        android:layout_width="362dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="164dp"
        android:layout_marginTop="24dp"
        android:layout_marginEnd="8dp"
        android:text="查询"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="1.0"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/button"
        android:onClick="query"/>

    <TextView
        android:id="@+id/textView"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginBottom="8dp"
        android:textColor="@android:color/black"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/button2" />
</android.support.constraint.ConstraintLayout>

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.www.app2">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <provider
            android:name=".MyContentProvider"
            android:exported="true"
            android:authorities="com.wl.lhw">
        </provider>
    </application>

</manifest>

第二个应用

MainActivity

package com.example.www.providerdemo;

import android.content.ContentValues;
import android.database.Cursor;
import android.net.Uri;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;

import java.net.URI;
import java.net.URL;

public class MainActivity extends AppCompatActivity {

    private TextView mTv_content;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mTv_content = (TextView) findViewById(R.id.textView);
    }

    public void query(View view) {
        Uri uri = Uri.parse("content://com.wl.lhw/query"); // 路径和 定义的路径一样（在contentProvider中定义的）
        Cursor cursor = getContentResolver().query(uri, null, null, null, null);
        StringBuffer sb = new StringBuffer();
        if (cursor.moveToFirst()) {
            do {

                String name = cursor.getString(cursor.getColumnIndex("name"));
                int age = cursor.getInt(cursor.getColumnIndex("age"));
                sb.append("姓名: ").append(name).append("----").append("年龄: ").append(age);

                sb.append("\n");

            } while (cursor.moveToNext());

            mTv_content.setText(sb.toString());
        }
    }

    public void insert(View view) {
        Uri uri = Uri.parse("content://com.wl.lhw/insert"); // 路径和 定义的路径一样（在contentProvider中定义的）
        ContentValues cv = new ContentValues();
        cv.put("name", "lhw" + Math.random());
        cv.put("age", 20);
        Uri insert = getContentResolver().insert(uri, cv);
        System.out.println("insert: " + insert);
    }

    public void update(View view) {
        Toast.makeText(this, "暂时没做更新数据", Toast.LENGTH_SHORT).show();
    }

    public void delete(View view) {
        Toast.makeText(this, "暂时没做删除数据", Toast.LENGTH_SHORT).show();
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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="match_parent"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/button"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:layout_marginEnd="8dp"
        android:onClick="query"
        android:text="查询"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/button2" />

    <TextView
        android:id="@+id/textView"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginBottom="8dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/button" />

    <Button
        android:id="@+id/button2"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:layout_marginEnd="8dp"
        android:text="插入"
        app:layout_constraintEnd_toStartOf="@+id/button3"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        android:onClick="insert"/>

    <Button
        android:id="@+id/button3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        android:layout_marginEnd="8dp"
        android:text="修改"
        app:layout_constraintEnd_toStartOf="@+id/button4"
        app:layout_constraintTop_toTopOf="parent"
        android:onClick="update"/>

    <Button
        android:id="@+id/button4"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        android:layout_marginEnd="8dp"
        android:text="删除"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        android:onClick="delete"/>
</android.support.constraint.ConstraintLayout>

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.www.providerdemo">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

    </application>

</manifest>

ContentProvider应用间数据共享案例

完整的实例代码

应用1

第二个应用

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