十三、ContentProvider案例
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
*
* @author jiqinlin
*
*/
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
*
* @author jiqinlin
*
*/
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);
}
}
