Android学习笔记(十七)
ContentProviderDataBaseOpenHelper
package org.wp.service;import org.wp.activity.ContentProviderMetaData;import org.wp.activity.ContentProviderMetaData.UserTableMetaData;import android.content.Context;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteDatabase.CursorFactory;import android.database.sqlite.SQLiteOpenHelper;import android.util.Log;public class DataBaseOpenHelper extends SQLiteOpenHelper {private static final String TAG = "DataBaseOpenHelper";private static final int VERSION = 1;public DataBaseOpenHelper(Context context, String name) {this(context, name, VERSION);}public DataBaseOpenHelper(Context context, String name, int version) {this(context, name, null, version);}public DataBaseOpenHelper(Context context, String name,CursorFactory factory, int version) {super(context, name, factory, version);}@Overridepublic void onCreate(SQLiteDatabase db) {Log.i(TAG, "Create Database");db.execSQL("create table "+ ContentProviderMetaData.DATABASE_TABLE_NAME + "("+ UserTableMetaData._ID + " INTEGER PRIMARY KEY AUTOINCREMENT,"+ UserTableMetaData.USERS_NAME + " varchar(20),"+ UserTableMetaData.USERS_AGE + " int)");}@Overridepublic void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {Log.i(TAG, "Update Database");}}
ContentProviderMetaData
package org.wp.activity;import android.net.Uri;import android.provider.BaseColumns;/** * DATABASE_NAME:数据库名称* DATABASE_VERSION:数据库版本* DATABASE_TABLE_NAME:数据库表名 ** CONTENT_URI:访问该ContentProvider的URI* CONTENT_TYPE:该ContentProvider所返回的数据类型的定义 * CONTENT_TYPE_ITEM:该ContentProvider所返回的数据类型的定义* TABLE_NAME:表名* USERS_NAME:列名 * USERS_AGE:列名* DEFAULT_SORT_ORDER:默认的排序方法 ** @author wp **/public class ContentProviderMetaData {public static final String AUTHORITY = "org.wp.activity.ContentProviderCustom";public static final String DATABASE_NAME = "contentProviderCustom_db";public static final Integer DATABASE_VERSION = 1;public static final String DATABASE_TABLE_NAME = "users";public static final class UserTableMetaData implements BaseColumns {public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/users");public static final String CONTENT_TYPE = "vnd.android.cursor.dir/vnd.contentprovidercustom.user";public static final String CONTENT_TYPE_ITEM = "vnd.android.cursor.item/vnd.contentprovidercustom.user";public static final String TABLE_NAME = "users";public static final String USERS_NAME = "name";public static final String USERS_AGE = "age";public static final String DEFAULT_SORT_ORDER = "_id desc";}}
ContentProviderCustom
package org.wp.activity;import java.util.HashMap;import org.wp.activity.ContentProviderMetaData.UserTableMetaData;import org.wp.service.DataBaseOpenHelper;import android.content.ContentProvider;import android.content.ContentUris;import android.content.ContentValues;import android.content.UriMatcher;import android.database.Cursor;import android.database.SQLException;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteQueryBuilder;import android.net.Uri;import android.text.TextUtils;import android.util.Log;public class ContentProviderCustom extends ContentProvider {private static final String TAG = "ContentProviderCustom";public static final UriMatcher uriMatcher;public static final int INCOMING_USER_COLLECTION = 1;public static final int INCOMINT_USER_SINGER = 2;public static HashMap<String, String> userProjectionMap;private DataBaseOpenHelper dboh;static {uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);uriMatcher.addURI(ContentProviderMetaData.AUTHORITY, "users",INCOMING_USER_COLLECTION);uriMatcher.addURI(ContentProviderMetaData.AUTHORITY, "users/#",INCOMINT_USER_SINGER);userProjectionMap = new HashMap<String, String>();userProjectionMap.put(UserTableMetaData._ID, UserTableMetaData._ID);userProjectionMap.put(UserTableMetaData.USERS_NAME,UserTableMetaData.USERS_NAME);userProjectionMap.put(UserTableMetaData.USERS_AGE,UserTableMetaData.USERS_AGE);}/* * 根据传入的URI，返回该URI所表示的数据类型 */@Overridepublic String getType(Uri uri) {Log.i(TAG, "getType()");switch (uriMatcher.match(uri)) {case INCOMING_USER_COLLECTION:return UserTableMetaData.CONTENT_TYPE;case INCOMINT_USER_SINGER:return UserTableMetaData.CONTENT_TYPE_ITEM;default:throw new IllegalArgumentException("Unknown URI" + uri);}}/* * onCreate()是一个回调方法，在contentProvider创建的时候执行 */@Overridepublic boolean onCreate() {Log.i(TAG, "onCreate()");dboh = new DataBaseOpenHelper(getContext(),ContentProviderMetaData.DATABASE_NAME);return true;}/* * 该函数的返回值是一个Uri，这个Uri表示刚刚使用这个函数所插入的数据 * content://org.wp.activity.ContentProviderCustom/users/1 */@Overridepublic Uri insert(Uri uri, ContentValues values) {Log.i(TAG, "insert()");SQLiteDatabase sdb = dboh.getWritableDatabase();Long rowId = sdb.insert(ContentProviderMetaData.DATABASE_TABLE_NAME,null, values);if (rowId > 0) {Uri insertUserUri = ContentUris.withAppendedId(UserTableMetaData.CONTENT_URI, rowId);getContext().getContentResolver().notifyChange(insertUserUri, null);return insertUserUri;}throw new SQLException("Failed to insert row into" + uri);}@Overridepublic Cursor query(Uri uri, String[] projection, String selection,String[] selectionArgs, String sortOrder) {Log.i(TAG, "query()");SQLiteQueryBuilder sqb = new SQLiteQueryBuilder();switch (uriMatcher.match(uri)) {case INCOMING_USER_COLLECTION:sqb.setTables(UserTableMetaData.TABLE_NAME);sqb.setProjectionMap(userProjectionMap);break;case INCOMINT_USER_SINGER:sqb.setTables(UserTableMetaData.TABLE_NAME);sqb.setProjectionMap(userProjectionMap);sqb.appendWhere(UserTableMetaData._ID + "="+ uri.getPathSegments().get(1));break;}String orderBy;if (TextUtils.isEmpty(sortOrder)) {orderBy = UserTableMetaData.DEFAULT_SORT_ORDER;} else {orderBy = sortOrder;}SQLiteDatabase sdb = dboh.getWritableDatabase();Cursor cur = sqb.query(sdb, projection, selection, selectionArgs, null,null, orderBy);cur.setNotificationUri(getContext().getContentResolver(), uri);return cur;}@Overridepublic int delete(Uri uri, String selection, String[] selectionArgs) {Log.i(TAG, "delete()");return 0;}@Overridepublic int update(Uri uri, ContentValues values, String selection,String[] selectionArgs) {Log.i(TAG, "update()");return 0;}}
ContentProviderActivity
package org.wp.activity;import org.wp.activity.ContentProviderMetaData.UserTableMetaData;import android.app.Activity;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.Toast;public class ContentProviderActivity extends Activity {private static final String TAG = "ContentProviderActivity";private Button insertButton;private Button queryButton;@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);insertButton = (Button) this.findViewById(R.id.insert);queryButton = (Button) this.findViewById(R.id.query);insertButton.setOnClickListener(listener);queryButton.setOnClickListener(listener);Log.i(TAG, getContentResolver().getType(UserTableMetaData.CONTENT_URI));}private View.OnClickListener listener = new View.OnClickListener() {@Overridepublic void onClick(View v) {Button button = (Button) v;switch (button.getId()) {case R.id.insert:ContentValues values = new ContentValues();values.put(UserTableMetaData.USERS_NAME, "张三");values.put(UserTableMetaData.USERS_AGE, 10);Uri uri = getContentResolver().insert(UserTableMetaData.CONTENT_URI, values);Toast.makeText(ContentProviderActivity.this, uri.toString(),Toast.LENGTH_LONG).show();Log.i(TAG, uri.toString());break;case R.id.query:Cursor cur = getContentResolver().query(UserTableMetaData.CONTENT_URI, null, null, null, null);while (cur.moveToNext()) {Log.i(TAG, cur.getString(cur.getColumnIndex(UserTableMetaData.USERS_NAME)));Log.i(TAG,cur.getInt(cur.getColumnIndex(UserTableMetaData.USERS_AGE))+ "");}break;}}};}
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