Create contentprovider and use contentresolver

1. Create contentprovider

 

Define (content required for client calls) Interface

package com.gogler.content;import android.net.Uri;import android.provider.BaseColumns;public class Users {public static final String AUTHORITY = "com.gogler.content";public static final class User implements BaseColumns{public static final Uri CONTENT_URI  = Uri.parse("content://com.gogler.content");       public static final String  USER_NAME  = "USER_NAME"; }}

 

Implement content providers

 

Package COM. gogler. content; import android. content. contentprovider; import android. content. contenturis; import android. content. contentvalues; import android. content. context; import android. database. cursor; import android. database. sqlexception; import android. database. SQLite. sqlitedatabase; import android. database. SQLite. sqliteopenhelper; import android. database. SQLite. sqlitequerybuilder; import android.net. u Ri; public class sumarycontentprovider extends contentprovider {private sqlitedatabase sqldb; private databasehelper dbhelper; Private Static final string database_name = "users. DB "; Private Static final int database_version = 1; Private Static final string table_name =" user "; Private Static final string tag =" sumarycontentprovider "; Private Static class databasehelper extends sqliteopenhelper {databa Sehelper (context) {super (context, database_name, null, database_version) ;}@ override public void oncreate (sqlitedatabase dB) {// create a table db.exe csql ("create table" + table_name + "(_ id integer primary key autoincrement," + "user_name text );");} @ override public void onupgrade (sqlitedatabase dB, int oldversion, int newversion) {db.exe csql ("Drop table if exists" + table_name); oncr Eate (db) ;}@ overridepublic int Delete (URI Uri, string S, string [] as) {return 0 ;}@ overridepublic string GetType (URI) {return NULL ;}@ overridepublic URI insert (URI Uri, contentvalues) {sqldb = dbhelper. getwritabledatabase (); long rowid = sqldb. insert (table_name, "", contentvalues); If (rowid> 0) {URI rowuri = contenturis. appendid (users. user. content_uri.buildupon (), rowid ). bui LD (); getcontext (). getcontentresolver (). policychange (rowuri, null); Return rowuri;} Throw new sqlexception ("failed to insert row into" + URI);} @ overridepublic Boolean oncreate () {dbhelper = new databasehelper (getcontext (); Return (dbhelper = NULL )? False: true;} @ overridepublic cursor query (URI Uri, string [] projection, string selection, string [] selectionargs, string sortorder) {sqlitequerybuilder QB = new sqlitequerybuilder (); sqlitedatabase DB = dbhelper. getreadabledatabase (); QB. settables (table_name); cursor c = QB. query (dB, projection, selection, null, sortorder); C. setnotificationuri (getcontext (). getcontentresolver (), Uri); Return C ;}@ overridepublic int Update (URI Uri, contentvalues, string S, string [] as) {return 0 ;}}

 

2. Use the content provider contentresolver (client)

 

package com.gogler.content;import android.app.Activity;import android.content.ContentValues;import android.database.Cursor;import android.net.Uri;import android.os.Bundle;import android.widget.Toast;public class ContentSumaryActivity extends Activity {@Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);        for(int i =1; i<=10; i++){        insertRecord("User"+i);        }        displayRecords();    }       private void insertRecord(String userName) {        ContentValues values = new ContentValues();        values.put(Users.User.USER_NAME, userName);        getContentResolver().insert(Users.User.CONTENT_URI, values);    }   private void displayRecords() {        String columns[] = new String[] { Users.User._ID, Users.User.USER_NAME };        Uri myUri = Users.User.CONTENT_URI;        Cursor cur = managedQuery(myUri, columns,null, null, null );        if (cur.moveToFirst()) {            String id = null;            String userName = null;            do {                id = cur.getString(cur.getColumnIndex(Users.User._ID));                userName = cur.getString(cur.getColumnIndex(Users.User.USER_NAME));                Toast.makeText(this, id + " " + userName, Toast.LENGTH_LONG).show();           } while (cur.moveToNext());       }    }}

 

3. Reference

Android basics: Android content provider