1、ContentProviderTestActivity 类中有2个按钮，分别插入数据为查询数据 authorities的值必须与DataBaseConfiguation.AUTHORITY一致
2、DataBaseConfiguation 为程序所用到的配置信息 注：TableConfiguation内部类实现BaseColumns，即声明了_ID 和 _COUNT
3、MyContentProvider 自定义ContentProvider，继承与ContentProvider
其中 uriMatcher 为Uri的匹配器，在静态块中初始化URI。 columnMap为表结构的映射mapping
在getType方法中要根据访问的Uri确定访问资源的类型，以字符串形式返回。格式为："vnd.android.cursor.dir/vnd.catking.userList"、"vnd.android.cursor.item/vnd.catking.userItem";
注释掉，对程序运行无影响。
注意：
static{
//初始化URI
uriMatcher = new UriMatcher(UriMatcher.NO_MATCH); uriMatcher.addURI(DataBaseConfiguation.AUTHORITY, "user", USER_LIST_CODE); uriMatcher.addURI(DataBaseConfiguation.AUTHORITY, "user/#", USER_RECORD_CODE); 红色字体中，的格式为xxx/xx，并不是/xxx/xx，其中*号匹配所有字符，#匹配所有数字 //表结构的映射 columnMap.put(DataBaseConfiguation.TableConfiguation._ID, DataBaseConfiguation.TableConfiguation._ID); columnMap.put(DataBaseConfiguation.TableConfiguation.USER_NAME, DataBaseConfiguation.TableConfiguation.USER_NAME); }
最后在AndroidManifest.xml里配上
<provider android:authorities="com.catking.contentprovider.MyContentProvider" android:name="com.catking.contentprovider.MyContentProvider" />
ContentProviderTestActivity：
import android.app.Activity;
import android.content.ContentValues; import android.database.Cursor; import android.net.Uri; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import com.catking.cfg.DataBaseConfiguation; public class ContentProviderTestActivity extends Activity { private Button insertBtn; private Button queryBtn; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); insertBtn = (Button) findViewById(R.id.insert); queryBtn = (Button) findViewById(R.id.query); insertBtn.setOnClickListener( new InsertOnClickListener()); queryBtn.setOnClickListener( new QueryOnClickListener()); } class InsertOnClickListener implements OnClickListener{ @Override public void onClick(View v) { ContentValues values = new ContentValues(); values.put(DataBaseConfiguation.TableConfiguation.USER_NAME, "张三"); Uri uri = getContentResolver().insert(DataBaseConfiguation.TableConfiguation.CONTENT_URI, values); System.out.println("uri------------------->" + uri); } } class QueryOnClickListener implements OnClickListener{ @Override public void onClick(View v) { Cursor cursor = getContentResolver().query(DataBaseConfiguation.TableConfiguation.CONTENT_URI, null, null, null, null); while (cursor.moveToNext()) { System.out.println(cursor.getString(cursor.getColumnIndex(DataBaseConfiguation.TableConfiguation.USER_NAME))); } } } } DataBaseConfiguation：
package com.catking.cfg; import android.net.Uri; import android.provider.BaseColumns; public class DataBaseConfiguation { public static final String AUTHORITY = "com.catking.contentprovider.MyContentProvider"; public static final String DATABASE_NAME = "cp_db"; public static final int DATABASE_VERSION = 1; public static class TableConfiguation implements BaseColumns{ public static final String TABLE_NAME = "user"; public static final Uri CONTENT_URI = Uri.parse("content://" + DataBaseConfiguation.AUTHORITY + "/" + TABLE_NAME); public static final String CONTENT_TYPE_DIR = "vnd.android.cursor.dir/vnd.catking.userList"; public static final String CONTENT_TYPE_RECORD = "vnd.android.cursor.item/vnd.catking.userItem"; public static final String USER_NAME = "name"; public static final String DEFAULT_SORT_ORDER = "_id desc"; }
}
MyContentProvider：
public class MyContentProvider extends ContentProvider { private static final UriMatcher uriMatcher; private static final int USER_LIST_CODE = 1; private static final int USER_RECORD_CODE = 2; private SQLiteOpenHelper dbh; private static Map<String, String> columnMap = new HashMap<String, String>(); static{ uriMatcher = new UriMatcher(UriMatcher.NO_MATCH); uriMatcher.addURI(DataBaseConfiguation.AUTHORITY, "user", USER_LIST_CODE); uriMatcher.addURI(DataBaseConfiguation.AUTHORITY, "user/#", USER_RECORD_CODE); columnMap.put(DataBaseConfiguation.TableConfiguation._ID, DataBaseConfiguation.TableConfiguation._ID); columnMap.put(DataBaseConfiguation.TableConfiguation.USER_NAME, DataBaseConfiguation.TableConfiguation.USER_NAME); } @Override public boolean onCreate() { dbh = new MySQLiteOpenHelper(getContext(), DataBaseConfiguation.DATABASE_NAME, null, DataBaseConfiguation.DATABASE_VERSION); System.out.println("dbh ������"); return true; } @Override public String getType(Uri uri) { System.out.println("getTypeִ��"); switch (uriMatcher.match(uri)) { case USER_LIST_CODE: return DataBaseConfiguation.TableConfiguation.CONTENT_TYPE_DIR; case USER_RECORD_CODE: return DataBaseConfiguation.TableConfiguation.CONTENT_TYPE_RECORD; default: throw new RuntimeException("unknown uri " + uri.toString()); } } @Override public Uri insert(Uri uri, ContentValues values) { System.out.println("insert ִ��"); SQLiteDatabase db = dbh.getWritableDatabase(); long rowId = db.insert(DataBaseConfiguation.TableConfiguation.TABLE_NAME, null, values); if (rowId > 0) { Uri insertedUri = ContentUris.withAppendedId(DataBaseConfiguation.TableConfiguation.CONTENT_URI, rowId); getContext().getContentResolver().notifyChange(insertedUri, null); return insertedUri; } throw new SQLException("fail to insert row into " + uri.toString()); } @Override public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) { System.out.println(DataBaseConfiguation.TableConfiguation.CONTENT_URI); SQLiteDatabase db = dbh.getReadableDatabase(); SQLiteQueryBuilder qb = new SQLiteQueryBuilder(); qb.setTables(DataBaseConfiguation.TableConfiguation.TABLE_NAME); qb.setProjectionMap(columnMap); switch (uriMatcher.match(uri)) { case USER_LIST_CODE: break; case USER_RECORD_CODE: System.out.println("��ʼ��ѯuri.getPathSegments()����"); for (String s : uri.getPathSegments()) { System.out.println(s); } System.out.println("�����ѯuri.getPathSegments()����"); qb.appendWhere(DataBaseConfiguation.TableConfiguation.USER_NAME + "=" + uri.getPathSegments().get(1)); break; default: throw new RuntimeException("unknown uri " + uri.toString()); } Cursor c = db.query(DataBaseConfiguation.TableConfiguation.TABLE_NAME, projection, selection, selectionArgs, null, null, DataBaseConfiguation.TableConfiguation.DEFAULT_SORT_ORDER); c.setNotificationUri(getContext().getContentResolver(), uri); return c; } @Override public int delete(Uri uri, String selection, String[] selectionArgs) { // TODO Auto-generated method stub return 0; } @Override public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) { // TODO Auto-generated method stub return 0; }
}
MySQLiteOpenHelper：
public class MySQLiteOpenHelper extends SQLiteOpenHelper { public MySQLiteOpenHelper(Context context, String name, CursorFactory factory, int version) { super(context, name, factory, version); } @Override public void onCreate(SQLiteDatabase db) { System.out.println("createDB excuted"); String createSQL = "create table " + DataBaseConfiguation.TableConfiguation.TABLE_NAME + "(" + DataBaseConfiguation.TableConfiguation._ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " + DataBaseConfiguation.TableConfiguation.USER_NAME + " VARCHAR(20)" + ")"; System.out.println(createSQL); db.execSQL(createSQL); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { System.out.println("onUpgrade excuted"); }
}
AndroidManifest：
<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.catking.activity" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="8" /> <application android:icon="@drawable/ic_launcher" android:label="@string/app_name" > <activity android:name=".ContentProviderTestActivity" android:label="@string/app_name" > <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> <provider android:authorities="com.catking.contentprovider.MyContentProvider" android:name="com.catking.contentprovider.MyContentProvider" /> </application>
</manifest>
参考自：