ContentProvider案例

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PersonContentProvider内容提供者类

package com.ljq.db;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;import android.text.TextUtils;/** * 内容提供者 *  * 作用：统一数据访问方式，方便外部调用 *  */public class PersonContentProvider extends ContentProvider {    // 数据集的MIME类型字符串则应该以vnd.android.cursor.dir/开头    public static final String PERSONS_TYPE = "vnd.android.cursor.dir/person";    // 单一数据的MIME类型字符串应该以vnd.android.cursor.item/开头    public static final String PERSONS_ITEM_TYPE = "vnd.android.cursor.item/person";    public static final String AUTHORITY = "com.ljq.provider.personprovider";// 主机名    /* 自定义匹配码 */    public static final int PERSONS = 1;    /* 自定义匹配码 */    public static final int PERSON = 2;    public static final Uri PERSONS_URI = Uri.parse("content://" + AUTHORITY + "/person");    private DBOpenHelper dbOpenHelper = null;    // UriMatcher类用来匹配Uri，使用match()方法匹配路径时返回匹配码    private static final UriMatcher uriMatcher;    static {        // 常量UriMatcher.NO_MATCH表示不匹配任何路径的返回码        uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);        // 如果match()方法匹配content://com.ljq.provider.personprovider/person路径，返回匹配码为PERSONS        uriMatcher.addURI(AUTHORITY, "person", PERSONS);        // 如果match()方法匹配content://com.ljq.provider.personprovider/person/230路径，返回匹配码为PERSON        uriMatcher.addURI(AUTHORITY, "person/#", PERSON);    }        @Override    public boolean onCreate() {        dbOpenHelper = new DBOpenHelper(this.getContext());        return true;    }        @Override    public Uri insert(Uri uri, ContentValues values){        SQLiteDatabase db = dbOpenHelper.getWritableDatabase();        long id = 0;        switch (uriMatcher.match(uri)) {        case PERSONS:            id = db.insert("person", "name", values);// 返回的是记录的行号，主键为int，实际上就是主键值            return ContentUris.withAppendedId(uri, id);        case PERSON:            id = db.insert("person", "name", values);            String path = uri.toString();            return Uri.parse(path.substring(0, path.lastIndexOf("/"))+id); // 替换掉id        default:            throw new IllegalArgumentException("Unknown URI " + uri);        }    }        @Override    public int delete(Uri uri, String selection, String[] selectionArgs) {        SQLiteDatabase db = dbOpenHelper.getWritableDatabase();        int count = 0;        switch (uriMatcher.match(uri)) {        case PERSONS:            count = db.delete("person", selection, selectionArgs);            break;        case PERSON:            // 下面的方法用于从URI中解析出id，对这样的路径content://com.ljq.provider.personprovider/person/10            // 进行解析，返回值为10            long personid = ContentUris.parseId(uri);            String where = "id=" + personid;// 删除指定id的记录            where += !TextUtils.isEmpty(selection) ? " and (" + selection + ")" : "";// 把其它条件附加上            count = db.delete("person", where, selectionArgs);            break;        default:            throw new IllegalArgumentException("Unknown URI " + uri);        }        db.close();        return count;    }    @Override    public int update(Uri uri, ContentValues values, String selection,            String[] selectionArgs) {        SQLiteDatabase db = dbOpenHelper.getWritableDatabase();        int count = 0;        switch (uriMatcher.match(uri)) {        case PERSONS:            count = db.update("person", values, selection, selectionArgs);            break;        case PERSON:            // 下面的方法用于从URI中解析出id，对这样的路径content://com.ljq.provider.personprovider/person/10            // 进行解析，返回值为10            long personid = ContentUris.parseId(uri);            String where = "id=" + personid;// 获取指定id的记录            where += !TextUtils.isEmpty(selection) ? " and (" + selection + ")" : "";// 把其它条件附加上            count = db.update("person", values, where, selectionArgs);            break;        default:            throw new IllegalArgumentException("Unknown URI " + uri);        }        db.close();        return count;    }        @Override    public String getType(Uri uri) {        switch (uriMatcher.match(uri)) {        case PERSONS:            return PERSONS_TYPE;        case PERSON:            return PERSONS_ITEM_TYPE;        default:            throw new IllegalArgumentException("Unknown URI " + uri);        }    }    @Override    public Cursor query(Uri uri, String[] projection, String selection,            String[] selectionArgs, String sortOrder) {        SQLiteDatabase db = dbOpenHelper.getReadableDatabase();        switch (uriMatcher.match(uri)) {        case PERSONS:            return db.query("person", projection, selection, selectionArgs, null, null, sortOrder);        case PERSON:            // 下面的方法用于从URI中解析出id，对这样的路径content://com.ljq.provider.personprovider/person/10            // 进行解析，返回值为10            long personid = ContentUris.parseId(uri);            String where = "id=" + personid;// 获取指定id的记录            where += !TextUtils.isEmpty(selection) ? " and (" + selection + ")" : "";// 把其它条件附加上            return db.query("person", projection, where, selectionArgs, null, null, sortOrder);        default:            throw new IllegalArgumentException("Unknown URI " + uri);        }    }}

文件清单

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.ljq.sql" android:versionCode="1"    android:versionName="1.0">    <application android:icon="@drawable/icon"        android:label="@string/app_name">        <uses-library android:name="android.test.runner" />        <activity android:name=".SqlActivity"            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:name="com.ljq.db.PersonContentProvider"               android:authorities="com.ljq.provider.personprovider" />    </application>    <uses-sdk android:minSdkVersion="7" />    <instrumentation        android:name="android.test.InstrumentationTestRunner"        android:targetPackage="com.ljq.sql" android:label="Tests for My App" /></manifest>

PersonContentProviderTest内容提供者测试类

package com.ljq.test;import android.content.ContentResolver;import android.content.ContentValues;import android.database.Cursor;import android.net.Uri;import android.test.AndroidTestCase;import android.util.Log;/** * 外部访问内容提供者 *  * */public class PersonContentProviderTest extends AndroidTestCase{    private static final String TAG = "PersonContentProviderTest";        public void testSave() throws Throwable{        ContentResolver contentResolver = this.getContext().getContentResolver();        Uri insertUri = Uri.parse("content://com.ljq.provider.personprovider/person");        ContentValues values = new ContentValues();        values.put("name", "ljq");        values.put("phone", "1350000009");        Uri uri = contentResolver.insert(insertUri, values);        Log.i(TAG, uri.toString());    }        public void testUpdate() throws Throwable{        ContentResolver contentResolver = this.getContext().getContentResolver();        Uri updateUri = Uri.parse("content://com.ljq.provider.personprovider/person/1");        ContentValues values = new ContentValues();        values.put("name", "linjiqin");        contentResolver.update(updateUri, values, null, null);    }     public void testFind() throws Throwable{        ContentResolver contentResolver = this.getContext().getContentResolver();        //Uri uri = Uri.parse("content://com.ljq.provider.personprovider/person");        Uri uri = Uri.parse("content://com.ljq.provider.personprovider/person");        Cursor cursor = contentResolver.query(uri, null, null, null, "id asc");        while(cursor.moveToNext()){            int personid = cursor.getInt(cursor.getColumnIndex("id"));            String name = cursor.getString(cursor.getColumnIndex("name"));            String phone = cursor.getString(cursor.getColumnIndex("phone"));            Log.i(TAG, "personid="+ personid + ",name="+ name+ ",phone="+ phone);        }        cursor.close();    }        public void testDelete() throws Throwable{        ContentResolver contentResolver = this.getContext().getContentResolver();        Uri uri = Uri.parse("content://com.ljq.provider.personprovider/person/1");        contentResolver.delete(uri, null, null);    }}

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