android content provider内容提供者
content provider内容提供者：让其他app可以访问私有数据库（文件）
1.AndroidManifest.xml
配置provider
<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.dbtest" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="8" android:targetSdkVersion="21" /> <application android:allowBackup="true" android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" >
<!--android:name="com.example.dbtest.PersonContentProvider" 必须为内容提供者类的路径 不然会报notfoundclass--> <provider android:name="com.example.dbtest.PersonContentProvider" android:authorities="com.example.dbtest.provider.personprovider" android:exported="true"></provider> <activity android:name=".MainActivity" android:label="@string/app_name" > <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application> </manifest>
2.PersonContentProvider
package com.example.dbtest; import com.example.dbtest.dbHelper.DbOpenHelper; 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 PersonContentProvider extends ContentProvider { private DbOpenHelper helper; //定义一个uri的匹配器用于匹配uri 如果路径不满足条件 返回-1 private static UriMatcher matcher = new UriMatcher(UriMatcher.NO_MATCH); private static final int INSERT = 1; private static final int DELETE = 2; private static final int UPDATE = 3; private static final int QUERY = 4; static{ matcher.addURI("com.example.dbtest.provider.personprovider", "insert", INSERT); matcher.addURI("com.example.dbtest.provider.personprovider", "delete", DELETE); matcher.addURI("com.example.dbtest.provider.personprovider", "update", UPDATE); matcher.addURI("com.example.dbtest.provider.personprovider", "query", QUERY); } //content://com.itheima.db.personprovider/insert 添加操作 //content://com.itheima.db.personprovider/delete 删除操作 //content://com.itheima.db.personprovider/update 更新操作 //content://com.itheima.db.personprovider/query 查询操作 @Override public boolean onCreate() { helper = new DbOpenHelper(getContext()); return true; } @Override public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) { if(matcher.match(uri)==QUERY) { SQLiteDatabase db = helper.getWritableDatabase(); Cursor cursor = db.query("person", projection, selection, selectionArgs, null, null, sortOrder); //注意 使用contentprovider时 不要将数据关闭掉 不然拿不到数据 //db.close(); 不要关闭 return cursor; } else { throw new IllegalArgumentException("路径不配对，不能执行查询操作"); } } @Override public String getType(Uri uri) { return null; } @Override public Uri insert(Uri uri, ContentValues values) { if(matcher.match(uri)==INSERT) { SQLiteDatabase db = helper.getWritableDatabase(); db.insert("person",null,values); } else { throw new IllegalArgumentException("路径不配对，不能执行插入操作"); } return null; } @Override public int delete(Uri uri, String selection, String[] selectionArgs) { if(matcher.match(uri)==DELETE) { SQLiteDatabase db = helper.getWritableDatabase(); db.delete("person", selection, selectionArgs); } else { throw new IllegalArgumentException("路径不配对，不能执行删除操作"); } return 0; } @Override public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) { if(matcher.match(uri)==UPDATE) { SQLiteDatabase db = helper.getWritableDatabase(); db.update("person", values, selection, selectionArgs); } else { throw new IllegalArgumentException("路径不配对，不能执行修改操作"); } return 0; } }
3.其他app调用内容提供者
package com.example.getcontentprovider; import android.content.ContentResolver; import android.content.ContentValues; import android.database.Cursor; import android.net.Uri; import android.os.Bundle; import android.support.v7.app.ActionBarActivity; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.widget.Toast; public class MainActivity extends ActionBarActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); } public void query(View view) { System.out.println("start query..............."); ContentResolver resolver = getContentResolver(); Uri uri = Uri.parse("content://com.example.dbtest.provider.personprovider/query"); Cursor cursor = resolver.query(uri, null, null, null, null); StringBuffer sb = new StringBuffer(); while(cursor.moveToNext()) { System.out.println("name:"+cursor.getString(cursor.getColumnIndex("name"))); sb.append("name:"+cursor.getString(cursor.getColumnIndex("name"))+"\n"); } System.out.println("end query.............."); Toast.makeText(this, sb.toString(),0).show(); } public void delete(View view) { ContentResolver resolver = getContentResolver(); Uri uri = Uri.parse("content://com.example.dbtest.provider.personprovider/delete"); resolver.delete(uri, "id=?", new String[]{"1"}); Toast.makeText(this, "删除成功",0).show(); } public void update(View view) { ContentResolver resolver = getContentResolver(); Uri uri = Uri.parse("content://com.example.dbtest.provider.personprovider/update"); ContentValues values = new ContentValues(); values.put("name", "张三"); resolver.update(uri, values, "id=?", new String[]{"1"}); Toast.makeText(this, "修改成功",0).show(); } public void insert(View view) { ContentResolver resolver = getContentResolver(); Uri uri = Uri.parse("content://com.example.dbtest.provider.personprovider/insert"); ContentValues values = new ContentValues(); values.put("name", "李四"); resolver.insert(uri, values); Toast.makeText(this, "修改成功",0).show(); } @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.main, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { int id = item.getItemId(); if (id == R.id.action_settings) { return true; } return super.onOptionsItemSelected(item); } }
