ذخیره محتوا در اندروید

public class My Application extends  ContentProvider {

}

<pfix>://<authority>/<data_type>/<id>

package com.example.MyApplication;

 

import android.net.Uri;

import android.os.Bundle;

import android.app.Activity;

 

import android.content.ContentValues;

import android.content.CursorLoader;

 

import android.database.Cursor;

 

import android.view.Menu;

import android.view.View;

 

import android.widget.EditText;

import android.widget.Toast;

 

public class MainActivity extends Activity {

 

   @Override

   protected void onCreate(Bundle savedInstanceState) {

      super.onCreate(savedInstanceState);

      setContentView(R.layout.activity_main);

   }

   public void onClickAddName(View view) {

      // Add a new student record

      ContentValues values = new ContentValues();

      values.put(StudentsProvider.NAME,

         ((EditText)findViewById(R.id.editText2)).getText().toString());

 

      values.put(StudentsProvider.GRADE,

         ((EditText)findViewById(R.id.editText3)).getText().toString());

 

      Uri uri = getContentResolver().insert(

         StudentsProvider.CONTENT_URI, values);

 

      Toast.makeText(getBaseContext(),

         uri.toString(), Toast.LENGTH_LONG).show();

   }

   public void onClickRetrieveStudents(View view) {

      // Retrieve student records

      String URL = "content://com.example.MyApplication.StudentsProvider";

 

      Uri students = Uri.parse(URL);

      Cursor c = managedQuery(students, null, null, null, "name");

 

      if (c.moveToFirst()) {

         do{

            Toast.makeText(this,

               c.getString(c.getColumnIndex(StudentsProvider._ID)) +

                  ", " +  c.getString(c.getColumnIndex( StudentsProvider.NAME)) +

                     ", " + c.getString(c.getColumnIndex( StudentsProvider.GRADE)),

            Toast.LENGTH_SHORT).show();

         } while (c.moveToNext());

      }

   }

}

package com.example.MyApplication;

 

import java.util.HashMap;

 

import android.content.ContentProvider;

import android.content.ContentUris;

import android.content.ContentValues;

import android.content.Context;

import android.content.UriMatcher;

 

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.Uri;

import android.text.TextUtils;

 

public class StudentsProvider extends ContentProvider {

   static final String PROVIDER_NAME = "com.example.MyApplication.StudentsProvider";

   static final String URL = "content://" + PROVIDER_NAME + "/students";

   static final Uri CONTENT_URI = Uri.parse(URL);

 

   static final String _ID = "_id";

   static final String NAME = "name";

   static final String GRADE = "grade";

 

   private static HashMap<String, String> STUDENTS_PROJECTION_MAP;

 

   static final int STUDENTS = 1;

   static final int STUDENT_ID = 2;

 

   static final UriMatcher uriMatcher;

   static{

      uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);

      uriMatcher.addURI(PROVIDER_NAME, "students", STUDENTS);

      uriMatcher.addURI(PROVIDER_NAME, "students/#", STUDENT_ID);

   }

 

   /**

      * Database specific constant declarations

   */

  

   private SQLiteDatabase db;

   static final String DATABASE_NAME = "College";

   static final String STUDENTS_TABLE_NAME = "students";

   static final int DATABASE_VERSION = 1;

   static final String CREATE_DB_TABLE =

      " CREATE TABLE " + STUDENTS_TABLE_NAME +

         " (_id INTEGER PRIMARY KEY AUTOINCREMENT, " +

         " name TEXT NOT NULL, " +

         " grade TEXT NOT NULL);";

 

   /**

      * Helper class that actually creates and manages

      * the provider's underlying data repository.

   */

  

   private static class DatabaseHelper extends SQLiteOpenHelper {

      DatabaseHelper(Context context){

         super(context, DATABASE_NAME, null, DATABASE_VERSION);

      }

 

      @Override

      public void onCreate(SQLiteDatabase db) {

         db.execSQL(CREATE_DB_TABLE);

      }

 

      @Override

      public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

         db.execSQL("DROP TABLE IF EXISTS " +  STUDENTS_TABLE_NAME);

         onCreate(db);

      }

   }

 

   @Override

   public boolean onCreate() {

      Context context = getContext();

      DatabaseHelper dbHelper = new DatabaseHelper(context);

 

      /**

         * Create a write able database which will trigger its

         * creation if it doesn't already exist.

      */

        

      db = dbHelper.getWritableDatabase();

      return (db == null)? false:true;

   }

 

   @Override

   public Uri insert(Uri uri, ContentValues values) {

      /**

         * Add a new student record

      */

      long rowID = db.insert(    STUDENTS_TABLE_NAME, "", values);

 

      /**

         * If record is added successfully

      */

      if (rowID > 0) {

         Uri _uri = ContentUris.withAppendedId(CONTENT_URI, rowID);

         getContext().getContentResolver().notifyChange(_uri, null);

         return _uri;

      }

       

      throw new SQLException("Failed to add a record into " + uri);

   }

 

   @Override

   public Cursor query(Uri uri, String[] projection,

      String selection,String[] selectionArgs, String sortOrder) {

      SQLiteQueryBuilder qb = new SQLiteQueryBuilder();

      qb.setTables(STUDENTS_TABLE_NAME);

 

      switch (uriMatcher.match(uri)) {

         case STUDENTS:

            qb.setProjectionMap(STUDENTS_PROJECTION_MAP);

         break;

 

         case STUDENT_ID:

            qb.appendWhere( _ID + "=" + uri.getPathSegments().get(1));

         break;

        

         default:  

      }

 

      if (sortOrder == null || sortOrder == ""){

         /**

            * By default sort on student names

         */

         sortOrder = NAME;

      }

     

      Cursor c = qb.query(db,    projection,      selection,

         selectionArgs,null, null, sortOrder);

      /**

         * register to watch a content URI for changes

      */

      c.setNotificationUri(getContext().getContentResolver(), uri);

      return c;

   }

 

   @Override

   public int delete(Uri uri, String selection, String[] selectionArgs) {

      int count = 0;

      switch (uriMatcher.match(uri)){

         case STUDENTS:

            count = db.delete(STUDENTS_TABLE_NAME, selection, selectionArgs);

         break;

 

         case STUDENT_ID:

            String id = uri.getPathSegments().get(1);

            count = db.delete( STUDENTS_TABLE_NAME, _ID +  " = " + id +

               (!TextUtils.isEmpty(selection) ? "

               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) {

      int count = 0;

      switch (uriMatcher.match(uri)) {

         case STUDENTS:

            count = db.update(STUDENTS_TABLE_NAME, values, selection, selectionArgs);

         break;

 

         case STUDENT_ID:

            count = db.update(STUDENTS_TABLE_NAME, values,

               _ID + " = " + uri.getPathSegments().get(1) +

               (!TextUtils.isEmpty(selection) ? "

               AND (" +selection + ')' : ""), selectionArgs);

            break;

         default:

            throw new IllegalArgumentException("Unknown URI " + uri );

      }

       

      getContext().getContentResolver().notifyChange(uri, null);

      return count;

   }

 

   @Override

   public String getType(Uri uri) {

      switch (uriMatcher.match(uri)){

         /**

            * Get all student records

         */

         case STUDENTS:

            return "vnd.android.cursor.dir/vnd.example.students";

         /**

            * Get a particular student

         */

         case STUDENT_ID:

            return "vnd.android.cursor.item/vnd.example.students";

         default:

            throw new IllegalArgumentException("Unsupported URI: " + uri);

      }

   }

}

<?xml version="1.0" encoding="utf-8"?>

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

    package="com.example.MyApplication">

 

   <application

      android:allowBackup="true"

      android:icon="@mipmap/ic_launcher"

      android:label="@string/app_name"

      android:supportsRtl="true"

      android:theme="@style/AppTheme">

         <activity android:name=".MainActivity">

            <intent-filter>

               <action android:name="android.intent.action.MAIN" />

               <category android:name="android.intent.category.LAUNCHER" />

            </intent-filter>

         </activity>

       

      <provider android:name="StudentsProvider"

         android:authorities="com.example.MyApplication.StudentsProvider"/>

   </application>

</manifest>

<?xml version="1.0" encoding="utf-8"?>

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

   xmlns:tools="http://schemas.android.com/tools"

   android:layout_width="match_parent"

   android:layout_height="match_parent"

   android:paddingBottom="@dimen/activity_vertical_margin"

   android:paddingLeft="@dimen/activity_horizontal_margin"

   android:paddingRight="@dimen/activity_horizontal_margin"

   android:paddingTop="@dimen/activity_vertical_margin"

   tools:context="com.example.MyApplication.MainActivity">

 

   <TextView

      android:id="@+id/textView1"

      android:layout_width="wrap_content"

      android:layout_height="wrap_content"

      android:text="Content provider"

      android:layout_alignParentTop="true"

      android:layout_centerHorizontal="true"

      android:textSize="30dp" />

 

   <TextView

      android:id="@+id/textView2"

      android:layout_width="wrap_content"

      android:layout_height="wrap_content"

      android:text="Tutorials point "

      android:textColor="#ff87ff09"

      android:textSize="30dp"

      android:layout_below="@+id/textView1"

      android:layout_centerHorizontal="true" />

 

   <ImageButton

      android:layout_width="wrap_content"

      android:layout_height="wrap_content"

      android:id="@+id/imageButton"

      android:src="@drawable/abc"

      android:layout_below="@+id/textView2"

      android:layout_centerHorizontal="true" />

 

   <Button

      android:layout_width="wrap_content"

      android:layout_height="wrap_content"

      android:id="@+id/button2"

      android:text="Add Name"

      android:layout_below="@+id/editText3"

      android:layout_alignRight="@+id/textView2"

      android:layout_alignEnd="@+id/textView2"

      android:layout_alignLeft="@+id/textView2"

      android:layout_alignStart="@+id/textView2"

      android:onClick="onClickAddName"/>

 

   <EditText

      android:layout_width="wrap_content"

      android:layout_height="wrap_content"

      android:id="@+id/editText"

      android:layout_below="@+id/imageButton"

      android:layout_alignRight="@+id/imageButton"

      android:layout_alignEnd="@+id/imageButton" />

 

   <EditText

      android:layout_width="wrap_content"

      android:layout_height="wrap_content"

      android:id="@+id/editText2"

      android:layout_alignTop="@+id/editText"

      android:layout_alignLeft="@+id/textView1"

      android:layout_alignStart="@+id/textView1"

      android:layout_alignRight="@+id/textView1"

      android:layout_alignEnd="@+id/textView1"

      android:hint="Name"

      android:textColorHint="@android:color/holo_blue_light" />

 

   <EditText

      android:layout_width="wrap_content"

      android:layout_height="wrap_content"

      android:id="@+id/editText3"

      android:layout_below="@+id/editText"

      android:layout_alignLeft="@+id/editText2"

      android:layout_alignStart="@+id/editText2"

      android:layout_alignRight="@+id/editText2"

      android:layout_alignEnd="@+id/editText2"

      android:hint="Grade"

      android:textColorHint="@android:color/holo_blue_bright" />

 

   <Button

      android:layout_width="wrap_content"

      android:layout_height="wrap_content"

      android:text="Retrive student"

      android:id="@+id/button"

      android:layout_below="@+id/button2"

      android:layout_alignRight="@+id/editText3"

      android:layout_alignEnd="@+id/editText3"

      android:layout_alignLeft="@+id/button2"

      android:layout_alignStart="@+id/button2"

      android:onClick="onClickRetrieveStudents"/>

</RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>

<resources>

    <string name="app_name">My Application</string>

</resources>;