创建StudentContentProvider项目
MyProvider类；
package com.mycontent;
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.net.Uri;
import android.text.TextUtils;
import android.util.Log;
public class MyProvider extends ContentProvider {
//共享数据源
private StudentData sd;
//匹配器
private static final UriMatcher sMatcher;
/**
* 当类被加载时需要创建的类对象
*/
static {
//其中authorities类似于域名或IP，用来标识操作哪个ContentProvider
////创建一个URI匹配器，参数为不匹配时的返回值
// 传入匹配码如果大于0表示匹配根路径或传入-1，即常量UriMatcher.NO_MATCH表示不匹配根路径
// addURI()方法是用来增加其他URI匹配路径的：
// 第一个参数代表传入标识ContentProvider的AUTHORITY字符串
// 第二个参数是要匹配的路径，#代表任意数字，另外还可以用*来匹配任意文本
// 第三个参数必须传入一个大于零的匹配码，用于match()方法对相匹配的URI返回相对应的匹配码
sMatcher = new UriMatcher(UriMatcher.NO_MATCH);
sMatcher.addURI(StudentData.AUTHORITY, "item", StudentData.ITEM);
sMatcher.addURI(StudentData.AUTHORITY, "item/#", StudentData.ITEM_ID);
}
/*
* 每当ContentProvider启动时都会回调onCreate()方法。此方法主要执行一些ContentProvider初始化
* 的工作，返回true表示初始化成功，返回false则初始化失败。
*/
@Override
public boolean onCreate() {
sd = new StudentData(this.getContext());
SQLiteDatabase sdb = sd.getWritableDatabase();
ContentValues values = new ContentValues();
for(int i=1;i<=30;i++){
values.put("name", "hello"+i);
sdb.insert(StudentData.TABLE_NAME, StudentData.SID, values);
}
sdb.close();
sdb=null;
return true;
}
/*
* 如果操作集合，则必须以vnd.android.cursor.dir开头
* 如果操作非集合，则必须以vnd.android.cursor.item开头
* */
// getType()是用来返回数据的MIME类型的方法。使用sMatcher对URI进行匹配，并返回相应的MIME类型字符串
@Override
public String getType(Uri uri) {
switch (sMatcher.match(uri)) {
case StudentData.ITEM:
return StudentData.CONTENT_TYPE;
case StudentData.ITEM_ID:
return StudentData.CONTENT_ITEM_TYPE;
default:
throw new IllegalArgumentException("Unknown URI " + uri);
}
}
/*
* 插入数据，返回新插入数据的URI，只接受数据集的URI，即指向表的URI
*/
@Override
public Uri insert(Uri uri, ContentValues values) {
SQLiteDatabase sdb = sd.getWritableDatabase();
long rowId;
if (sMatcher.match(uri) != StudentData.ITEM) {
sdb.close();
sdb=null;
throw new IllegalArgumentException("Unknow URI " + uri);
}
rowId = sdb.insert(StudentData.TABLE_NAME, StudentData.SID, values);
if (rowId > 0) {
Uri noteUri = ContentUris.withAppendedId(StudentData.CONTENT_URI,
rowId);
this.getContext().getContentResolver().notifyChange(noteUri, null);
return noteUri;
}
sdb.close();
sdb=null;
throw new SQLException("Failed to insert row into " + uri);
}
/*
* 用于数据的删除，返回的是所影响数据的数目，首先利用数据库辅助对象获取一个SQLiteDatabase对象
* 然后根据传入Uri用sMatcher进行匹配，对单个数据或数据集进行删除或修改。notifyChange()方法
* 用来通知注册在次URI上的观察者（observer）数据发生了改变。
*/
@Override
public int delete(Uri uri, String selection, String[] selectionArgs) {
SQLiteDatabase sdb = sd.getWritableDatabase();
int count;
switch (sMatcher.match(uri)) {
case StudentData.ITEM:
count = sdb.delete(StudentData.TABLE_NAME, selection, selectionArgs);
break;
case StudentData.ITEM_ID:
//String id = uri.getPathSegments().get(1);
long id = ContentUris.parseId(uri);
count = sdb.delete(StudentData.TABLE_NAME, StudentData.SID
+ "="
+ id
+ (!TextUtils.isEmpty(selection) ? " AND (" + selection
+ ")" : ""), selectionArgs);
break;
default:
throw new IllegalArgumentException("Unknown URI " + uri);
}
sdb.close();
sdb=null;
this.getContext().getContentResolver().notifyChange(uri, null);
return count;
}
/*
* 查询数据，将数据装入一个Cursor对象并返回
*/
@Override
public Cursor query(Uri uri, String[] projection, String selection,
String[] selectionArgs, String sortOrder) {
SQLiteDatabase sdb = sd.getReadableDatabase();
Cursor c;
switch (sMatcher.match(uri)) {
case StudentData.ITEM:
c = sdb.query(StudentData.TABLE_NAME, projection, selection,
selectionArgs, null, null, sortOrder);
break;
case StudentData.ITEM_ID:
// String id = uri.getPathSegments().get(1);
long id = ContentUris.parseId(uri);
c = sdb.query(StudentData.TABLE_NAME, projection, StudentData.SID
+ "="
+ id
+ (!TextUtils.isEmpty(selection) ? " AND (" + selection
+ ")" : ""), selectionArgs, null, null, sortOrder);
break;
default:
Log.i("sMatcher.match(uri)", String.valueOf(sMatcher.match(uri)));
throw new IllegalArgumentException("Query with unknown URI: " + uri);
}
sdb.close();
sdb=null;
c.setNotificationUri(getContext().getContentResolver(), uri);
return c;
}
// 更新，与删除类方法类似
@Override
public int update(Uri uri, ContentValues values, String selection,
String[] selectionArgs) {
SQLiteDatabase sdb = sd.getWritableDatabase();
int count;
switch (sMatcher.match(uri)) {
case StudentData.ITEM:
count = sdb.update(StudentData.TABLE_NAME, values, selection,
selectionArgs);
break;
case StudentData.ITEM_ID:
String id = uri.getPathSegments().get(1);
count = sdb.update(StudentData.TABLE_NAME, values, StudentData.SID
+ "="
+ id
+ (!TextUtils.isEmpty(selection) ? " AND (" + selection
+ ")" : ""), selectionArgs);
break;
default:
throw new IllegalArgumentException("Unknown URI " + uri);
}
sdb.close();
sdb=null;
this.getContext().getContentResolver().notifyChange(uri, null);
return count;
}
}
数据共享对象StudentData
package com.mycontent;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.net.Uri;
public class StudentData extends SQLiteOpenHelper {
/*
* 分别定义了数据库和表的名称、表中各个字段的名称、数据库的版本号
*/
private final static String DB_NAME = "student";
public final static String TABLE_NAME = "hero";
private final static String SNAME = "name";
// public final static String Age = "age";
public final static String SID = "_id";
public final static int DB_VERSION = 1;
/*
* AUTHORITY:定义了标识ContentProvider的字符串 ;
* ITEM和ITEM_ID分别用于UriMatcher(资源标识符匹配器)中对路径item和item/id的匹配号码
* CONTENT_TYPE和CONTENT_ITEM_TYPE定义了数据的MIME类型。需要注意的是： 单一数据的MIME 类型字符串应该以
* vnd.android.cursor.item/开头，数据集的MIME类型字符串应该以vnd.android.cursor.dir开头
* CONTENT_URI定义的是查询当前表数据的content://样式URI
*/
public static final String AUTHORITY = "com.myapp.provider.studentdata";
public static final int ITEM = 1;
public static final int ITEM_ID = 2;
public static final String CONTENT_TYPE = "vnd.android.cursor.dir/hero";
public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/hero";
public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY
+ "/item");
public StudentData(Context context) {
super(context, DB_NAME, null, DB_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE " + TABLE_NAME + "(" + SID
+ " INTEGER PRIMARY KEY AUTOINCREMENT," + SNAME + " VARCHAR NOT NULL);");
}
@Override
public void onUpgrade(SQLiteDatabase db, int arg1, int arg2) {
db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
}
}
数据共享声明；
<provider android:name=".MyProvider" android:authorities="com.myapp.provider.studentdata"/>
创建测试工程TestStudentCon
package com.mycontent.test;
import com.mycontent.StudentData;
import android.content.ContentResolver;
import android.content.ContentValues;
import android.database.Cursor;
import android.net.Uri;
import android.test.AndroidTestCase;
import android.util.Log;
public class TestStuConPro extends AndroidTestCase {
public void testInsert()throws Exception{ //插入记录
Uri uri = Uri.parse("content://" + "com.myapp.provider.studentdata"
+ "/item");
ContentResolver resolver = this.getContext().getContentResolver();
ContentValues values = new ContentValues();
values.put("name", "ddd1");
values.put("name", "eee1");
resolver.insert(uri, values);
}
public void testUpdate()throws Exception{ //更新id=2的记录
Uri uri = Uri.parse("content://" + "com.myapp.provider.studentdata"
+ "/item/2");
ContentResolver resolver = this.getContext().getContentResolver();
ContentValues values = new ContentValues();
values.put("name", "aaa");
resolver.update(uri, values, null, null);
}
public void testDelete()throws Exception{ //删除id=1的记录
Uri uri = Uri.parse("content://" + "com.myapp.provider.studentdata"
+ "/item/1"); //删除id=1的记录
ContentResolver resolver = this.getContext().getContentResolver();
resolver.delete(uri, null, null);
}
public void testQuery()throws Exception{ //插入全部记录并显示
Uri uri = Uri.parse("content://" + "com.myapp.provider.studentdata"
+ "/item"); //查询所有记录
ContentResolver resolver = this.getContext().getContentResolver();
Cursor cursor = resolver.query(uri, null, null, null, null);
while(cursor.moveToNext()){
// StudentData person = new StudentData(cursor.getInt(cursor.getColumnIndex("id")),cursor.getString(cursor.getColumnIndex("name")),cursor.getInt(cursor.getColumnIndex("age")));
Log.v("ContentProvider", cursor.getInt((cursor.getColumnIndex("_id")))+"");
}
}
}
ok，完事。