ContendProvider

package com.itheima28.sqlitedemo.providers;import com.itheima28.sqlitedemo.db.PersonSQLiteOpenHelper;import android.content.ContentProvider;import android.content.ContentUris;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 static final String AUTHORITY = "com.itheima28.sqlitedemo.providers.PersonContentProvider";private static final int PRESON_INSERT_CODE = 0;// 操作person表添加的操作的uri匹配码private static final int PERSON_DELETE_CODE = 1;private static final int PERSON_UPDATE_CODE = 2;private static final int PERSON_QUERY_ALL_CODE = 3;private static final int PERSON_QUERY_ITEM_CODE = 4;private static UriMatcher uriMatcher;private PersonSQLiteOpenHelper mOpenHelper;// person表的数据库帮助对象static {uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);// 添加一些uri(分机号)// content://com.itheima28.sqlitedemo.providers.PersonContentProvider/person/inserturiMatcher.addURI(AUTHORITY, "person/insert", PRESON_INSERT_CODE);// content://com.itheima28.sqlitedemo.providers.PersonContentProvider/person/deleteuriMatcher.addURI(AUTHORITY, "person/delete", PERSON_DELETE_CODE);// content://com.itheima28.sqlitedemo.providers.PersonContentProvider/person/updateuriMatcher.addURI(AUTHORITY, "person/update", PERSON_UPDATE_CODE);// content://com.itheima28.sqlitedemo.providers.PersonContentProvider/person/queryAlluriMatcher.addURI(AUTHORITY, "person/queryAll", PERSON_QUERY_ALL_CODE);// content://com.itheima28.sqlitedemo.providers.PersonContentProvider/person/query/#uriMatcher.addURI(AUTHORITY, "person/query/#", PERSON_QUERY_ITEM_CODE);}@Overridepublic boolean onCreate() {mOpenHelper = new PersonSQLiteOpenHelper(getContext());return true;}@Overridepublic Cursor query(Uri uri, String[] projection, String selection,String[] selectionArgs, String sortOrder) {SQLiteDatabase db = mOpenHelper.getReadableDatabase();switch (uriMatcher.match(uri)) {case PERSON_QUERY_ALL_CODE:  // 查询所有人的uriif(db.isOpen()) {Cursor cursor = db.query("person", projection, selection, selectionArgs, null, null, sortOrder);return cursor;// db.close(); 返回cursor结果集时, 不可以关闭数据库}break;case PERSON_QUERY_ITEM_CODE:// 查询的是单条数据, uri末尾出有一个idif(db.isOpen()) {long id = ContentUris.parseId(uri);Cursor cursor = db.query("person", projection, "_id = ?", new String[]{id + ""}, null, null, sortOrder);return cursor;}break;default:throw new IllegalArgumentException("uri不匹配: " + uri);}return null;}@Overridepublic String getType(Uri uri) {switch (uriMatcher.match(uri)) {case PERSON_QUERY_ALL_CODE: // 返回多条的MIME-typereturn "vnd.android.cursor.dir/person";case PERSON_QUERY_ITEM_CODE: // 返回单条的MIME-TYPEreturn "vnd.android.cursor.item/person";default:break;}return null;}@Overridepublic Uri insert(Uri uri, ContentValues values) {switch (uriMatcher.match(uri)) {case PRESON_INSERT_CODE:// 添加人到person表中SQLiteDatabase db = mOpenHelper.getWritableDatabase();if(db.isOpen()) {long id = db.insert("person", null, values);db.close();return ContentUris.withAppendedId(uri, id);}break;default:throw new IllegalArgumentException("uri不匹配: " + uri);}return null;}@Overridepublic int delete(Uri uri, String selection, String[] selectionArgs) {switch (uriMatcher.match(uri)) {case PERSON_DELETE_CODE:// 在person表中删除数据的操作SQLiteDatabase db = mOpenHelper.getWritableDatabase();if(db.isOpen()) {int count = db.delete("person", selection, selectionArgs);db.close();return count;}break;default:throw new IllegalArgumentException("uri不匹配: " + uri);}return 0;}@Overridepublic int update(Uri uri, ContentValues values, String selection,String[] selectionArgs) {switch (uriMatcher.match(uri)) {case PERSON_UPDATE_CODE: // 更新person表的操作SQLiteDatabase db = mOpenHelper.getWritableDatabase();if(db.isOpen()) {int count = db.update("person", values, selection, selectionArgs);db.close();return count;}break;default:throw new IllegalArgumentException("uri不匹配: " + uri);}return 0;}}