类查找android中跨项目的数据库操作ContentProvider的使用

上班之余抽点时间出来写写博文，希望对新接触的朋友有帮助。今天在这里和大家一起学习一下类查找

RuiXin.java类

package com.gtl.data.two;

import android.net.Uri;

public class RuiXin {

public static final String DBNAME = "ruixinonlinedb";
public static final String TNAME = "ruixinonline";
public static final int VERSION = 3;

public static String TID = "tid";
public static final String USERNAME = "username";
public static final String DATE = "date";
public static final String SEX = "sex";

public static final String AUTOHORITY = "com.gtl.data.two";
public static final int ITEM = 1;
public static final int ITEM_ID = 2;

public static final String CONTENT_TYPE = "vnd.android.cursor.dir/vnd.ruixin.login";
public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/vnd.ruixin.login";

public static final Uri CONTENT_URI = Uri.parse("content://" + AUTOHORITY + "/ruixinonline");
}

DBlite.java类

package com.gtl.data.two;

import android.content.ContentValues;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class DBlite extends SQLiteOpenHelper {

public DBlite(Context context) {
super(context, RuiXin.DBNAME, null, RuiXin.VERSION);
}

@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("create table "+RuiXin.TNAME+"(" +
RuiXin.TID+" integer primary key autoincrement not null,"+
RuiXin.USERNAME+" text not null," +
RuiXin.DATE+" interger not null,"+
RuiXin.SEX+" text not null);");

}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS "+RuiXin.TNAME);
onCreate(db);
}

public void add(String username,String date,String sex){
SQLiteDatabase db = getWritableDatabase();
ContentValues values = new ContentValues();
values.put(RuiXin.USERNAME, username);
values.put(RuiXin.DATE, date);
values.put(RuiXin.SEX, sex);
db.insert(RuiXin.TNAME,"",values);
}

public void del(){
SQLiteDatabase db = getWritableDatabase();
db.delete(RuiXin.TNAME,RuiXin.DATE+"=?" , new String[]{"time=1368497000287"});
}

public void update(){
SQLiteDatabase db = getWritableDatabase();
ContentValues values = new ContentValues();
values.put(RuiXin.USERNAME, "louis koo");
values.put(RuiXin.DATE, "today");
values.put(RuiXin.SEX, "男");
db.update(RuiXin.TNAME, values, RuiXin.DATE+"=?" , new String[]{"time=1368497006097"});
}
}

MyProvider.java类

package com.gtl.data.two;
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;

public class MyProvider extends ContentProvider {

DBlite dBlite;
SQLiteDatabase db;
private static final UriMatcher sMatcher;
static{
sMatcher = new UriMatcher(UriMatcher.NO_MATCH);
sMatcher.addURI(RuiXin.AUTOHORITY,RuiXin.TNAME, RuiXin.ITEM);
sMatcher.addURI(RuiXin.AUTOHORITY, RuiXin.TNAME+"/#", RuiXin.ITEM_ID);

}
@Override
public boolean onCreate() {
this.dBlite = new DBlite(this.getContext());
return true;
}

@Override
public Cursor query(Uri uri, String[] projection, String selection,
String[] selectionArgs, String sortOrder) {
db = dBlite.getWritableDatabase();
Cursor c;
switch (sMatcher.match(uri)) {
case RuiXin.ITEM:
c = db.query(RuiXin.TNAME, projection, selection, selectionArgs, null, null, null);
break;
case RuiXin.ITEM_ID:
String id = uri.getPathSegments().get(1);
c = db.query(RuiXin.TNAME, projection,
RuiXin.TID+"="+id+(!TextUtils.isEmpty(selection)?"AND("+selection+')':""),
selectionArgs, null, null, sortOrder);
break;
default:
throw new IllegalArgumentException("Unknown URI"+uri);
}
c.setNotificationUri(getContext().getContentResolver(), uri);
return c;
}

@Override
public String getType(Uri uri) {
switch (sMatcher.match(uri)) {
case RuiXin.ITEM:
return RuiXin.CONTENT_TYPE;
case RuiXin.ITEM_ID:
return RuiXin.CONTENT_ITEM_TYPE;
default:
throw new IllegalArgumentException("Unknown URI"+uri);
}
}

@Override
public Uri insert(Uri uri, ContentValues values) {
db = dBlite.getWritableDatabase();
long rowId;
if(sMatcher.match(uri)!=RuiXin.ITEM){
throw new IllegalArgumentException("Unknown URI"+uri);
}
rowId = db.insert(RuiXin.TNAME,RuiXin.TID,values);
if(rowId>0){
Uri noteUri=ContentUris.withAppendedId(RuiXin.CONTENT_URI, rowId);
getContext().getContentResolver().notifyChange(noteUri, null);
return noteUri;
}
throw new IllegalArgumentException("Unknown URI"+uri);
}

@Override
public int delete(Uri uri, String selection, String[] selectionArgs) {
db = dBlite.getWritableDatabase();
int count = 0;
switch (sMatcher.match(uri)) {
case RuiXin.ITEM:
count = db.delete(RuiXin.TNAME,selection, selectionArgs);
break;
case RuiXin.ITEM_ID:
String id = uri.getPathSegments().get(1);
count = db.delete(RuiXin.TID,
RuiXin.TID+"="+id+(!TextUtils.isEmpty(RuiXin.TID="?")?"AND("+selection+')':""),
selectionArgs);
break;
default:
throw new IllegalArgumentException("Unknown URI"+uri);
}
getContext().getContentResolver().notifyChange(uri, null);
return count;
}

@Override
public int update(Uri uri, ContentValues values, String selection,
String[] selectionArgs) {
SQLiteDatabase db = dBlite.getWritableDatabase();
int count;
switch (sMatcher.match(uri)){
case RuiXin.ITEM:
count = db.update(RuiXin.TNAME, values, selection, selectionArgs);
break;
case RuiXin.ITEM_ID:
String Id = uri.getPathSegments().get(1);
count = db.update(RuiXin.TNAME, values,
RuiXin.TID + "=" + Id + (!TextUtils.isEmpty(selection) ? " AND (" + selection + ')' : ""),
selectionArgs);
break;

default:
throw new IllegalArgumentException("Unknown URI " + uri);
}
getContext().getContentResolver().notifyChange(uri, null);
return count;
}

}

每日一道理

记不清有多少个夜晚，在我翻阅纸张的指间滑落；记不清有多少支蜡烛，在我的凝视中化为灰烬。逝者如斯，我时时刻刻会听见自己对生命承诺的余音，感到岁月的流转在渐渐稀释我的年少无知，我愿自己是一只上足了发条的时钟，在昼夜不停的流转中留下自己充实的每一刻。

主类Test.java类

package com.gtl.data.two;

import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.content.ContentResolver;
import android.database.Cursor;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.Toast;

import com.gtl.R;

public class Test extends Activity implements OnClickListener{

private DBlite dBlite1 ;
private ContentResolver contentResolver;
private Button addbtn,delbtn,querybtn,updatebtn;
private ListView lv;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
dBlite1 = new DBlite(this);
setContentView(R.layout.contentprovide);
addbtn = (Button)findViewById(R.id.btnadd);
delbtn = (Button)findViewById(R.id.btndelete);
querybtn = (Button)findViewById(R.id.btnquery);
updatebtn = (Button)findViewById(R.id.btnupdate);
addbtn.setOnClickListener(this);
delbtn.setOnClickListener(this);
querybtn.setOnClickListener(this);
updatebtn.setOnClickListener(this);
lv = (ListView)findViewById(R.id.lv);

}

private List<String> strlist;
@Override
public void onClick(View v) {
if(v==addbtn){
dBlite1.add("carman lee","time="+System.currentTimeMillis(),"女");
}else if(v==delbtn){
dBlite1.del();
}else if(v==querybtn){
//通过contentResolver停止查找
strlist = new ArrayList<String>();
contentResolver = this.getContentResolver();
Cursor cursor = contentResolver.query(
RuiXin.CONTENT_URI, new String[] {RuiXin.USERNAME,
RuiXin.DATE,RuiXin.SEX }, null, null, null);
while (cursor.moveToNext()) {
strlist.add(cursor.getString(cursor.getColumnIndex(RuiXin.USERNAME))
+ " "+ cursor.getString(cursor.getColumnIndex(RuiXin.DATE))
+ " "+ cursor.getString(cursor.getColumnIndex(RuiXin.SEX)));
}
startManagingCursor(cursor);  //查找后关闭游标
ArrayAdapter<String> adpater = new ArrayAdapter<String>(Test.this,
android.R.layout.simple_expandable_list_item_1,strlist);
lv.setAdapter(adpater);
}else if(v==updatebtn){
dBlite1.update();
}

}

}

接下来在另外一个项目中停止测试，共用一个数据库

MainActivity.java类

package com.example.contentprovidertest;

import java.util.ArrayList;
import java.util.List;
import android.os.Bundle;
import android.app.Activity;
import android.content.ContentResolver;
import android.database.Cursor;
import android.widget.ArrayAdapter;
import android.widget.ListView;

public class MainActivity extends Activity {

private ContentResolver contentResolver;
private List<String> strlist;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
ListView lv = new ListView(this);
//通过contentResolver停止查找
strlist = new ArrayList<String>();
contentResolver = this.getContentResolver();
Cursor cursor = contentResolver.query(
RuiXin.CONTENT_URI, new String[] {RuiXin.USERNAME,
RuiXin.DATE,RuiXin.SEX }, null, null, null);
while (cursor.moveToNext()) {
strlist.add(cursor.getString(cursor.getColumnIndex(RuiXin.USERNAME))
+ " "+ cursor.getString(cursor.getColumnIndex(RuiXin.DATE))
+ " "+ cursor.getString(cursor.getColumnIndex(RuiXin.SEX)));
}
startManagingCursor(cursor);  //查找后关闭游标
ArrayAdapter<String> adpater = new ArrayAdapter<String>(this,
android.R.layout.simple_expandable_list_item_1,strlist);
lv.setAdapter(adpater);
setContentView(lv);

}

}

将参数也复制到该项目工程中去

清单文件AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.gtl"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk android:minSdkVersion="8" />
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

<application
android:icon="@drawable/ic_launcher"
android:label="@string/app_name" >

<activity android:name=".data.two.Test">
<intent-filter >
<action android:name="android.intent.action.MAIN"/>
<category android:name="android.intent.category.LAUNCHER"/>
</intent-filter>
<intent-filter>
<data android:mimeType="vnd.android.cursor.dir/vnd.ruixin.login" />
</intent-filter>
<intent-filter>
<data android:mimeType="vnd.android.cursor.item/vnd.ruixin.login" />
</intent-filter>
</activity>
<provider android:name=".data.two.MyProvider"
android:authorities="com.gtl.data.two"></provider>

</application>

</manifest>

文章结束给大家分享下程序员的一些笑话语录： 很多所谓的牛人也不过如此，离开了你，微软还是微软，Google还是Google，苹果还是苹果，暴雪还是暴雪，而这些牛人离开了公司，自己什么都不是。