java - Clear cache of apps in android programitiically Not for images -

in android application, want make app has button named cleancache , inside code list down applications cache , clear toast message cache cleared. looked @ different questions , answers didn't find interesting. i'd implemented consists of errors.

here mainactivity.java file:

package com.example.ahsankhan.cache; import android.app.activity; import android.content.context; import android.os.bundle; import android.view.view; import android.view.view.onclicklistener; import android.widget.button;  import java.io.file;  public class mainactivity extends activity {      @override public void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.activity_main);      addlisteneronbutton();  }  public void addlisteneronbutton() {      //select specific button bundle action want     button button = (button) findviewbyid(r.id.button1);      button.setonclicklistener(new onclicklistener() {          @override         public void onclick(view view) {              @override             public void oncreate(bundle *) {                 super.oncreate(*);                 setcontentview(r.layout.activity_main);             }              @override             protected void onstop(){                 super.onstop();             }              //fires after onstop() state             @override             protected void ondestroy() {                 super.ondestroy();                 try {                     trimcache(this);                 } catch (exception e) {                     // todo auto-generated catch block                     e.printstacktrace();                 }             }              public static void trimcache(context context) {                 try {                     file dir = context.getcachedir();                     if (dir != null && dir.isdirectory()) {                         deletedir(dir);                     }                 } catch (exception e) {                     // todo: handle exception                 }             }              public static boolean deletedir(file dir) {                 if (dir != null && dir.isdirectory()) {                     string[] children = dir.list();                     (int = 0; < children.length; i++) {                         boolean success = deletedir(new file(dir,     children[i]));                         if (!success) {                             return false;                         }                     }                 }                  // directory empty delete                 return dir.delete();             }         }      });  }  } 

activity_main.xml file

<?xml version="1.0" encoding="utf-8"?> <linearlayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" >  <button     android:id="@+id/button1"     android:layout_width="wrap_content"     android:layout_height="wrap_content"     android:text="button - go mkyong.com" />  </linearlayout> 

androidmanifest.xml file

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.ahsankhan.cache" >  <application     android:allowbackup="true"     android:icon="@mipmap/ic_launcher"     android:label="@string/app_name"     android:theme="@style/apptheme" >     <activity         android:name=".mainactivity"         android:label="@string/app_name" >         <intent-filter>             <action android:name="android.intent.action.main" />              <category android:name="android.intent.category.launcher" />         </intent-filter>     </activity> </application>  </manifest> 

take @ line:

public void oncreate(bundle *) {    super.oncreate(*); 

you can't use * variable name. has sane this:

public void oncreate(bundle b) {    super.oncreate(b);