ContentProvider的基本使用

ContentProvider：内容提供者。她主要完成这么一件事：共享数据。将一个应用的数据共享给其他应用

代码如下：

1、SQLiteProvider

package com.njupt.practice_contentprovider1.provider;

import com.njupt.practice_contentprovider1.dao.DBOpenHelper;

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 SQliteProvider extends ContentProvider{

	private UriMatcher matcher = new UriMatcher(UriMatcher.NO_MATCH);
	private DBOpenHelper helper;
	public static final int PERSON = 1;
	public static final int PERSON_ID = 2;
	
	@Override
	public boolean onCreate() {
		helper = new DBOpenHelper(getContext());
		matcher.addURI("jd_love_ztmm","person",PERSON);
		matcher.addURI("jd_love_ztmm", "person/#", PERSON_ID);
		return true;
	}
	
	@Override
	public Cursor query(Uri uri, String[] projection, String selection,
			String[] selectionArgs, String sortOrder) {
		
		SQLiteDatabase db = helper.getReadableDatabase();
		switch(matcher.match(uri)){
		case PERSON_ID:
			long id = ContentUris.parseId(uri);
			selection = selection == null ? "id = " + id : selection + " AND id = " + id;
		case PERSON:
			return db.query("person", null, selection, selectionArgs, null, null, sortOrder);
		default:
			throw new RuntimeException("Uri不能识别: " + uri);
		}
	}
	
	@Override
	public Uri insert(Uri uri, ContentValues values) {
		SQLiteDatabase db =  helper.getWritableDatabase();
		switch(matcher.match(uri)){
		case PERSON:
			long id = db.insert("person", "id", values);
			return ContentUris.withAppendedId(uri, id);
		default:
			throw new RuntimeException("Uri不能识别: " + uri);
		}
		
	}
	
	@Override
	public int delete(Uri uri, String selection, String[] selectionArgs) {
		
		SQLiteDatabase db = helper.getWritableDatabase();
		switch(matcher.match(uri)){
			case PERSON_ID:
				long id = ContentUris.parseId(uri);
				selection = selection == null ? "id = " + id : selection + " AND id = " + id;
			case PERSON:
				return db.delete("person", selection, selectionArgs);
			default:
				throw new RuntimeException("Uri不能识别: " + uri);
		}
	}
	
	
	@Override
	public int update(Uri uri, ContentValues values, String selection,
			String[] selectionArgs) {
		SQLiteDatabase db = helper.getWritableDatabase();
		switch(matcher.match(uri)){
		case PERSON_ID:
			long id = ContentUris.parseId(uri);
			selection = selection == null ? "id = " + id : selection + "AND id = " + id; 
		case PERSON:
			return db.update("person", values, selection, selectionArgs);
		default:
			throw new RuntimeException("Uri不能识别: " + uri);
		}
	}
	
	
	@Override
	public String getType(Uri uri) {
		// TODO Auto-generated method stub
		return null;
	}
}

2、ProviderTest

测试类

package com.njupt.pc1;

import android.content.ContentProvider;
import android.content.ContentResolver;
import android.content.ContentValues;
import android.database.Cursor;
import android.net.Uri;
import android.test.AndroidTestCase;

public class ProviderTest extends AndroidTestCase{

	public void testQuery(){
		
		ContentResolver resolver = getContext().getContentResolver();
		Uri uri = Uri.parse("content://jd_love_ztmm/person");
		Cursor c = resolver.query(uri,null,null,null,null);
	    
		while(c.moveToNext()){
			Integer id = c.getInt(0);
			String name = c.getString(1);
			Integer balance = c.getInt(2);
			
			System.out.println(new Person(id,name,balance));
		}
	}
	
	public void testDelete(){
		
	   ContentResolver resolver =  getContext().getContentResolver();
	   Uri uri = Uri.parse("content://jd_love_ztmm/person/1");
	   resolver.delete(uri, null, null);
	}
	
	public void testUpdate(){
		ContentResolver resolver = getContext().getContentResolver();
		Uri uri = Uri.parse("content://jd_love_ztmm/person/2");
		ContentValues values = new ContentValues();
		values.put("name", "刘诗诗是java程序员的女神");
		values.put("balance", "65000");
		resolver.update(uri, values, null, null);
	}
	
	public void testInsert(){
		
		ContentResolver resolver =  getContext().getContentResolver();
		Uri uri = Uri.parse("content://jd_love_ztmm/person");
		ContentValues values = new ContentValues();
		values.put("name","刘诗诗是C++程序员的女神" );
		values.put("balance", "70000");
		resolver.insert(uri, values);
	}
}

3、DBTest

package com.njupt.practice_contentprovider1.dao;

import java.util.List;
import java.util.Random;

import com.njupt.practice_contentprovider1.domain.Person;

import android.test.AndroidTestCase;

public class DBTest extends AndroidTestCase {

	public void testCreateDataBase() {
		DBOpenHelper helper = new DBOpenHelper(getContext());
		helper.getWritableDatabase();
	}

	public void testInsert() {
		PersonDao dao = new PersonDao(getContext());
		Person p = new Person("我爱章泽天", 55000);
		dao.insert(p);
	}

	public void testDelete() {
		PersonDao dao = new PersonDao(getContext());
		dao.delete(104);
	}

	public void testUpdate() {
		PersonDao dao = new PersonDao(getContext());
		Person p = new Person(105, "章泽天爱我", 46000);
		dao.update(p);
	}

	public void testQuery() {
		PersonDao dao = new PersonDao(getContext());
		Person p = dao.query(105);
		System.out.println(p);
	}

	public void testInsertMany() {

		PersonDao dao = new PersonDao(getContext());
		String strs[] = new String[]{"天天","章泽天","我爱天天","天天爱我"};
		
		for(int i = 0 ; i < 100 ; ++i){
			dao.insert(new Person(strs[new Random().nextInt(50) %4]+ i , new Random().nextInt(10000)));
		}
	}
	
	public void testQueryAll(){
		PersonDao dao = new PersonDao(getContext());
		
		List<Person> persons = dao.queryAll();
		
	   for(Person p : persons){
		   System.out.println(p);
	   }
	}
	
	public void testQueryCount(){
		PersonDao dao = new PersonDao(getContext());
		
		System.out.println(dao.queryCount());
	}
	
	public void testQueryPage(){
		PersonDao dao = new PersonDao(getContext());
		
		List<Person> persons = dao.queryPage(2, 20);
		
		for(Person p : persons){
			System.out.println(p);
		}
	}
	
	public void testRemit(){
		PersonDao dao = new PersonDao(getContext());
		dao.remit(4, 3, 3000);
	}
}

4、AndroidManifest.xml

在编写完ContentProvider的代码以后，别忘了在清单文件AndroidManifest.xml中进行注册

<provider android:name="com.njupt.practice_contentprovider1.provider.SQliteProvider"
            android:authorities="jd_love_ztmm"
            android:exported="true"/>