android 基础一 <Content Provider>

第一步：定义类继承 ContentProvider，实现相关接口

public class MyContentProvider extends ContentProvider 

第二步：定义 UriMatcher

    private final static String AUTHORITY="com.myprovider";//配置文件需要用到这个
    private final static int INSERT_CODE=1;
    private final static int UPDATE_CODE=2;
    private final static int DELETE_CODE=3;
    private final static int SELECT_CODE=4;

    private static final UriMatcher uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
    static {
        Log.e(TAG,"-----uriMatcher--------");
        uriMatcher.addURI(AUTHORITY, "insert", INSERT_CODE);
        uriMatcher.addURI(AUTHORITY, "update", UPDATE_CODE);
        uriMatcher.addURI(AUTHORITY, "delete", DELETE_CODE);
        uriMatcher.addURI(AUTHORITY, "selete", SELECT_CODE);
    }

第三步：匹配 增、删、改、查 URL

 @Override
    public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
        Log.e(TAG,"query");
        if(uriMatcher.match(uri)==SELECT_CODE){
            Log.e(TAG,"query 匹配");
        }else{
            Log.e(TAG,"query fail");
        }
        return null;
    }

 第四步：配置文件

    <application android:allowBackup="true" android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name" 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:exported="true"
            android:authorities="com.myprovider"
            android:name=".MyContentProvider"/>
    </application>

 

源码：

public class MyContentProvider extends ContentProvider {
    static  String TAG="MyContentProvider";
    private final static String AUTHORITY="com.myprovider";
    private final static int INSERT_CODE=1;
    private final static int UPDATE_CODE=2;
    private final static int DELETE_CODE=3;
    private final static int SELECT_CODE=4;

    private static final UriMatcher uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
    static {
        Log.e(TAG,"-----uriMatcher--------");
        uriMatcher.addURI(AUTHORITY, "insert", INSERT_CODE);
        uriMatcher.addURI(AUTHORITY, "update", UPDATE_CODE);
        uriMatcher.addURI(AUTHORITY, "delete", DELETE_CODE);
        uriMatcher.addURI(AUTHORITY, "selete", SELECT_CODE);
    }

    @Override
    public boolean onCreate() {
        return false;
    }

    @Override
    public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
        Log.e(TAG,"query");
        if(uriMatcher.match(uri)==SELECT_CODE){
            Log.e(TAG,"query 匹配");
        }else{
            Log.e(TAG,"query fail");
        }
        return null;
    }

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

    @Override
    public Uri insert(Uri uri, ContentValues values) {
        Log.e(TAG,"insert");
        if(uriMatcher.match(uri)==INSERT_CODE){
            Log.e(TAG,"insert 匹配");
        }else{
            Log.e(TAG,"insert fail");
        }
        return null;
    }

    @Override
    public int delete(Uri uri, String selection, String[] selectionArgs) {
        Log.e(TAG,"delete");
        if(uriMatcher.match(uri)==DELETE_CODE){
            Log.e(TAG,"delete 匹配");
        }else{
            Log.e(TAG,"delete fail");
        }
        return 0;
    }

    @Override
    public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
        Log.e(TAG,"update");
        if(uriMatcher.match(uri)==UPDATE_CODE){
            Log.e(TAG,"update 匹配");
        }else{
            Log.e(TAG,"update fail");
        }
        return 0;
    }
}

 

第三方APP调用 Content Provider

  Uri url = Uri.parse("content://com.myprovider/insert");
  getContentResolver().delete(url,"ss",null);

 

 

 

 

 

查询短信：
Uri uri=Uri.parse("content://sms/");
Cursor cursor=getContenResolver().query(uri,new String[]{"address,"date","body"},null,null,null);
while(cursor.moveToNext()){
     String address=cursor.getString(0);
     String date=cursor.getString(1);
     String body=cursor.getString(2);
}

插入短信：
Uri uri=Uri.parse("content://sms/");
ContentValues values=new ContenValues();
values.put("address","10086");
values.put("body","送话费服务");
values.put("date",System.curentTimeMillis());
getContenResolver().insert(uri,values);

 

----------------------
注册内容观察者：
Uri uri=Uri.parse("content://com.provider.test");
// 第二个参数：false表示完整的uri，匹配整个uri 。  true表示匹配部分uri
getContentResolver().registerContentObserver(uri, true,observer):

public class MyContentObserver extends ContentObserver{
    public MyContentObserver (Handler handler){
          super(handler);
    }
   
    public void onChange(boolean selfChange){
            //发生变化
        }

}