android中数据存储的ContentProvider的使用方法

元数据接口

packagecom.example.contentproviderprojecrt;

importandroid.net.Uri;

importandroid.provider.BaseColumns;

publicinterfaceMLDNbatabaseMetaData{

//外部访问，content地址://com.example.contentproviderproject

publicstaticfinalStringAUTHORITY="com.example.contentproviderproject";

//数据库的名称

publicstaticfinalStringDATABASE_NAME="mldn.db";

//数据库的版本

publicstaticfinalintVERSION=1;

//member表的元素定义，直接继承与_ID和_COUNT静态变量

publicstaticinterfaceMemberTableMetaDataextendsBaseColumns{

//数据表的名称

publicstaticfinalStringTABLE_NAME="member";

//外部访问的URI地址

publicstaticfinalUriCONTENT_URI=Uri.parse("content://"+

AUTHORITY+"/"+TABLE_NAME);

//取得member表中的所有数据

publicstaticfinalStringCONTACT_LIST="vnd.android.cursor.dir/vnd.contentproviderproject.member";

//取得一个member信息

publicstaticfinalStringCONTACT_ITEM="vnd.android.cursor.item/vnd.contentproviderproject.member";

//字段名称

publicstaticfinalStringMEMBER_NAME="name";

publicstaticfinalStringMEMBER_AGE="age";

publicstaticfinalStringMEMBER_BIRTHDAY="birthday";

//显示时候的排序字段

publicstaticfinalStringSORT_ORDER="_idDESC";

}

定义数据库操作类助手

packagecom.example.contentproviderprojecrt;

importandroid.content.Context;

importandroid.database.sqlite.SQLiteDatabase;

importandroid.database.sqlite.SQLiteDatabase.CursorFactory;

importandroid.database.sqlite.SQLiteOpenHelper;

publicclassMyDatabaseHelperextendsSQLiteOpenHelper{

publicMyDatabaseHelper(Contextcontext){

//创建数据库

super(context,MLDNbatabaseMetaData.DATABASE_NAME,null,MLDNbatabaseMetaData.VERSION);

}

@Override

publicvoidonCreate(SQLiteDatabasedb){

//创建表

Stringsql="CREATETABLE"+MLDNbatabaseMetaData.MemberTableMetaData.TABLE_NAME+"("

+MLDNbatabaseMetaData.MemberTableMetaData._ID+"INTEGERPRIMARYKEY,"

+MLDNbatabaseMetaData.MemberTableMetaData.MEMBER_NAME+"VARCHAR(50)NOTNULL,"

+MLDNbatabaseMetaData.MemberTableMetaData.MEMBER_AGE+"INTEGERNOTNULL,"

+MLDNbatabaseMetaData.MemberTableMetaData.MEMBER_BIRTHDAY+"DATENOTNULL"

+")";

db.execSQL(sql);//执行SQL语句

}

@Override

publicvoidonUpgrade(SQLiteDatabasedb,intoldVersion,intnewVersion){

//更新表

Stringsql="DROPTABLEIFEXISTS"+MLDNbatabaseMetaData.MemberTableMetaData.TABLE_NAME;

db.execSQL(sql);//执行SQL语句

this.onCreate(db);//更新数据库

}

定义表操作contentProvider类

packagecom.example.contentproviderprojecrt;

importandroid.content.ContentProvider;

importandroid.content.ContentUris;

importandroid.content.ContentValues;

importandroid.content.UriMatcher;

importandroid.database.Cursor;

importandroid.database.sqlite.SQLiteDatabase;

importandroid.net.Uri;

publicclassMemberContentProviderextendsContentProvider{

privatestaticUriMatcheruriMatcher=null;//定义UriMatcher对象

privatestaticfinalintGET_MEMBER_LIST=1;//查询全部的常量标记

privatestaticfinalintGET_MEMBER_ITEM=2;//根据ID查询的常量标记

privateMyDatabaseHelperhelper=null;//数据库操作类对象

static{

uriMatcher=newUriMatcher(uriMatcher.NO_MATCH);//实例化UriMatcher

uriMatcher.addURI(MLDNbatabaseMetaData.AUTHORITY,

MLDNbatabaseMetaData.MemberTableMetaData.TABLE_NAME,GET_MEMBER_LIST);//增加匹配项

uriMatcher.addURI(MLDNbatabaseMetaData.AUTHORITY,

MLDNbatabaseMetaData.MemberTableMetaData.TABLE_NAME+"/#",GET_MEMBER_ITEM);//增加匹配项

}

//删除数据操作

@Override

publicintdelete(Uriuri,Stringselection,String[]selectionArgs){

SQLiteDatabasedb=this.helper.getWritableDatabase();//以写的方式打开

intresult=0;//操作结果

switch(uriMatcher.match(uri)){//匹配传入的Uri

caseGET_MEMBER_LIST:

result=db.delete(MLDNbatabaseMetaData.MemberTableMetaData.TABLE_NAME,selection,selectionArgs);

break;

caseGET_MEMBER_ITEM:

longid=ContentUris.parseId(uri);

Stringwhere="_id="+id;

result=db.delete(MLDNbatabaseMetaData.MemberTableMetaData.TABLE_NAME,where,selectionArgs);

break;

default:

thrownewUnsupportedOperationException("NOTSUPPORTOPERATION"+uri);

}

returnresult;

}

@Override

publicStringgetType(Uriuri){

switch(uriMatcher.match(uri)){//匹配传入的Uri

caseGET_MEMBER_LIST:

returnMLDNbatabaseMetaData.MemberTableMetaData.CONTACT_LIST;

caseGET_MEMBER_ITEM:

returnMLDNbatabaseMetaData.MemberTableMetaData.CONTACT_ITEM;

default:

thrownewUnsupportedOperationException("NOTSUPPORTOPERATION"+uri);//抛出异常

}

@Override

publicUriinsert(Uriuri,ContentValuesvalues){

SQLiteDatabasedb=this.helper.getWritableDatabase();//以写的方式打开

longid=0;//增加之后的ID

switch(uriMatcher.match(uri)){//匹配传入的Uri

caseGET_MEMBER_LIST:

id=db.insert(MLDNbatabaseMetaData.MemberTableMetaData.TABLE_NAME,

MLDNbatabaseMetaData.MemberTableMetaData._ID,values);

StringuriPath=uri.toString();//取出地址

Stringpath=uriPath+"/"+id;//建立新的URI地址

returnUri.parse(path);

caseGET_MEMBER_ITEM:

returnnull;

default:

thrownewUnsupportedOperationException("NOTSUPPORTOPERATION"+uri);

}

@Override

publicbooleanonCreate(){

this.helper=newMyDatabaseHelper(super.getContext());//实例化DatabaseHelper

returntrue;//操作成功

}

@Override

publicCursorquery(Uriuri,String[]projection,Stringselection,

String[]selectionArgs,StringsortOrder){

SQLiteDatabasedb=this.helper.getReadableDatabase();//以读的方式打开

switch(uriMatcher.match(uri)){//匹配传入的Uri

caseGET_MEMBER_LIST:

returndb.query(MLDNbatabaseMetaData.MemberTableMetaData.TABLE_NAME,

projection,selection,selectionArgs,null,null,sortOrder);

caseGET_MEMBER_ITEM:

longid=ContentUris.parseId(uri);

Stringwhere="_id="+id;

returndb.query(MLDNbatabaseMetaData.MemberTableMetaData.TABLE_NAME,projection,where,selectionArgs,null,null,sortOrder);

default:

thrownewUnsupportedOperationException("NOTSUPPORTOPERATION"+uri);

}

@Override

publicintupdate(Uriuri,ContentValuesvalues,Stringselection,

String[]selectionArgs){

SQLiteDatabasedb=this.helper.getWritableDatabase();//以写的方式打开

intresult=0;//操作结果

switch(uriMatcher.match(uri)){//匹配传入的Uri

caseGET_MEMBER_LIST:

result=db.update(MLDNbatabaseMetaData.MemberTableMetaData.TABLE_NAME,values,null,null);

break;

caseGET_MEMBER_ITEM:

longid=ContentUris.parseId(uri);

Stringwhere="_id="+id;

result=db.update(MLDNbatabaseMetaData.MemberTableMetaData.TABLE_NAME,values,where,selectionArgs);

break;

default:

thrownewUnsupportedOperationException("NOTSUPPORTOPERATION"+uri);

}

returnresult;

}

Acitivity程序

packagecom.example.contentproviderprojecrt;

importjava.text.SimpleDateFormat;

importjava.util.ArrayList;

importjava.util.Date;

importjava.util.HashMap;

importjava.util.List;

importjava.util.Map;

importandroid.net.Uri;

importandroid.os.Bundle;

importandroid.app.Activity;

importandroid.content.ContentResolver;

importandroid.content.ContentUris;

importandroid.content.ContentValues;

importandroid.database.Cursor;

importandroid.view.Menu;

importandroid.view.View;

importandroid.view.View.OnClickListener;

importandroid.widget.Button;

importandroid.widget.ListView;

importandroid.widget.SimpleAdapter;

importandroid.widget.Toast;

publicclassMainActivityextendsActivity{

privateButtoninsertBut=null;

privateButtonupdateBut=null;

privateButtondeleteBut=null;

privateButtonqueryBut=null;

privateListViewmemberList=null;

@Override

protectedvoidonCreate(BundlesavedInstanceState){

super.onCreate(savedInstanceState);

super.setContentView(R.layout.activity_main);

this.insertBut=(Button)super.findViewById(R.id.insertBut);//获取按钮

this.insertBut.setOnClickListener(newInsertOnClickListener());//设置按钮单击事件

this.updateBut=(Button)super.findViewById(R.id.updateBut);//获取按钮

this.updateBut.setOnClickListener(newUpdateOnClickListener());//设置按钮单击事件

this.deleteBut=(Button)super.findViewById(R.id.deleteBut);//获取按钮

this.deleteBut.setOnClickListener(newDeleteOnClickListener());//设置按钮单击事件

this.queryBut=(Button)super.findViewById(R.id.queryBut);//获取按钮

this.queryBut.setOnClickListener(newQueryOnClickListener());//设置按钮单击事件

this.memberList=(ListView)super.findViewById(R.id.memberList);//获取ListView

}

privateclassQueryOnClickListenerimplementsOnClickListener{//查询按钮事件

@Override

publicvoidonClick(Viewv){

Cursorresult=MainActivity.this.textQuery(null);//查询的结果集

List<Map<String,Object>>list=newArrayList<Map<String,Object>>();//用于设置SimpleAdapter

for(result.moveToFirst();!result.isAfterLast();result.moveToNext()){//循环取出数据

Map<String,Object>map=newHashMap<String,Object>();

map.put("_id",result.getInt(0));

map.put("name",result.getString(1));

map.put("age",result.getInt(2));

map.put("birthday",result.getString(3));

list.add(map);//保存取出的数据

}

MainActivity.this.memberList.setAdapter(newSimpleAdapter(

MainActivity.this,//将数据包装

list,//数据集合

R.layout.member,//显示的布局文件

newString[]{"_id","name","age","birthday"},//匹配的Mapkey

newint[]{R.id._id,R.id.name,R.id.age,R.id.birthday}));//布局文件里面对应的ID

}

privateclassDeleteOnClickListenerimplementsOnClickListener{//删除按钮事件

@Override

publicvoidonClick(Viewv){

longresult=0;//返回删除了多少条数据

result=MainActivity.this.textDelete(String.valueOf(2));

Toast.makeText(MainActivity.this,"result="+result,Toast.LENGTH_LONG).show();

}

privateclassUpdateOnClickListenerimplementsOnClickListener{//更新按钮事件

@Override

publicvoidonClick(Viewv){

longresult=0;//返回更新了多少条数据

result=MainActivity.this.textUpdate("1","李元静",18,"1998-01-01");

Toast.makeText(MainActivity.this,"result="+result,Toast.LENGTH_LONG).show();

}

privateclassInsertOnClickListenerimplementsOnClickListener{//增加按钮事件

@Override

publicvoidonClick(Viewv){

longid=0;//保存接受ID

id=MainActivity.this.textInsert("李元静",21,newSimpleDateFormat("yyyy-MM-dd").format(newDate()));

Toast.makeText(MainActivity.this,"id="+id,Toast.LENGTH_LONG).show();

}

privateCursortextQuery(String_id){

if(_id==null||"".equals(_id)){//查询全部数据

returnsuper.getContentResolver().query(

MLDNbatabaseMetaData.MemberTableMetaData.CONTENT_URI

,null,null,null,

MLDNbatabaseMetaData.MemberTableMetaData.SORT_ORDER);

}else{//查询指定ID数据

returnsuper.getContentResolver().query(

Uri.withAppendedPath(MLDNbatabaseMetaData.MemberTableMetaData.CONTENT_URI,_id)

,null,null,null,

MLDNbatabaseMetaData.MemberTableMetaData.SORT_ORDER);

}

privatelongtextDelete(String_id){

ContentResolvercontentSesolver=super.getContentResolver();//定义取得ContentResolver对象

intresult=0;

if(_id==null||"".equals(_id)){//删除全部数据

result=contentSesolver.delete(MLDNbatabaseMetaData.MemberTableMetaData.CONTENT_URI,null,null);

}else{//删除指定数据

result=contentSesolver.delete(Uri.withAppendedPath(MLDNbatabaseMetaData.MemberTableMetaData.CONTENT_URI,_id),null,null);

}

returnresult;

}

privatelongtextInsert(Stringname,intage,Stringbirthday){

ContentResolvercontentSesolver=null;//定义ContentResolver

contentSesolver=super.getContentResolver();//取得contentSesolver

ContentValuesvalues=newContentValues();//设置内容

values.put(MLDNbatabaseMetaData.MemberTableMetaData.MEMBER_NAME,name);

values.put(MLDNbatabaseMetaData.MemberTableMetaData.MEMBER_AGE,age);

values.put(MLDNbatabaseMetaData.MemberTableMetaData.MEMBER_BIRTHDAY,birthday);

UriresultUri=contentSesolver.insert(MLDNbatabaseMetaData.MemberTableMetaData.CONTENT_URI,values);

returnContentUris.parseId(resultUri);//解析ID返回

}

privatelongtextUpdate(String_id,Stringname,intage,Stringbirthday){

longresult=0;

ContentResolvercontentSesolver=null;//定义ContentResolver

contentSesolver=super.getContentResolver();//取得contentSesolver

ContentValuesvalues=newContentValues();//设置内容

values.put(MLDNbatabaseMetaData.MemberTableMetaData.MEMBER_NAME,name);

values.put(MLDNbatabaseMetaData.MemberTableMetaData.MEMBER_AGE,age);

values.put(MLDNbatabaseMetaData.MemberTableMetaData.MEMBER_BIRTHDAY,birthday);

if(_id==null||"".equals(_id)){//更新全部

result=contentSesolver.update(MLDNbatabaseMetaData.MemberTableMetaData.CONTENT_URI,values,null,null);

}else{//更新制定数据

result=contentSesolver.update(

Uri.withAppendedPath(MLDNbatabaseMetaData.MemberTableMetaData.CONTENT_URI,

_id),values,null,null);

}

UriresultUri=contentSesolver.insert(MLDNbatabaseMetaData.MemberTableMetaData.CONTENT_URI,values);

returnresult;

}

@Override

publicbooleanonCreateOptionsMenu(Menumenu){

//Inflatethemenu;thisaddsitemstotheactionbarifitispresent.

getMenuInflater().inflate(R.menu.main,menu);

returntrue;

}

Layout:activity_mail.xml

<LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"

android:orientation="vertical"

android:layout_width="fill_parent"

android:layout_height="fill_parent">

<LinearLayout

android:orientation="horizontal"

android:layout_width="fill_parent"

android:layout_height="wrap_content">

<Button

android:id="@+id/insertBut"