android - How to reject any incoming call when I have already detected it

Question

Application detects incoming calls and displays a toast when they come. The inner class CallStateListener is responsible for detecting the call:

    private class CallStateListener extends PhoneStateListener {
        @Override
        public void onCallStateChanged(int state, String incomingNumber) {
            switch (state) {
            case TelephonyManager.CALL_STATE_RINGING:
                // called when someone is ringing to this phone

                Toast.makeText(ctx, "Incoming: " + incomingNumber, Toast.LENGTH_LONG).show();           
                break;
            }
        }
    }

but now just after a Toast is shown I would like to cancel/reject this incoming call(any). How to perform cancelling this incoming call?

The full class looks like that:

package com.example.a;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.telephony.PhoneStateListener;
import android.telephony.TelephonyManager;
import android.util.Log;
import android.widget.Toast;


public class CallHelper {

    /**
     * Listener to detect incoming calls.
     */
    private class CallStateListener extends PhoneStateListener {
        @Override
        public void onCallStateChanged(int state, String incomingNumber) {
            switch (state) {
            case TelephonyManager.CALL_STATE_RINGING:
                // called when someone is ringing to this phone

                Toast.makeText(ctx, "Incoming: " + incomingNumber, Toast.LENGTH_LONG).show();           
                break;
            }
        }
    }

    /**
     * Broadcast receiver to detect the outgoing calls.
     */
    public class OutgoingReceiver extends BroadcastReceiver {
        public OutgoingReceiver() {
        }

        @Override
        public void onReceive(Context context, Intent intent) {
            String number = intent.getStringExtra(Intent.EXTRA_PHONE_NUMBER);

            Toast.makeText(ctx, "Outgoing: " + number, Toast.LENGTH_LONG).show();
        }

    }

    private Context ctx;
    private TelephonyManager tm;
    private CallStateListener callStateListener;

    private OutgoingReceiver outgoingReceiver;

    public CallHelper(Context ctx) {
        this.ctx = ctx;

        callStateListener = new CallStateListener();
        outgoingReceiver = new OutgoingReceiver();
    }

    /**
     * Start calls detection.
     */
    public void start() {
        tm = (TelephonyManager) ctx.getSystemService(Context.TELEPHONY_SERVICE);
        tm.listen(callStateListener, PhoneStateListener.LISTEN_CALL_STATE);

        IntentFilter intentFilter = new IntentFilter(Intent.ACTION_NEW_OUTGOING_CALL);
        ctx.registerReceiver(outgoingReceiver, intentFilter);
    }


    /**
     * Stop calls detection.
     */
/*  public void stop() {
        tm.listen(callStateListener, PhoneStateListener.LISTEN_NONE);
        ctx.unregisterReceiver(outgoingReceiver);
    }*/

}

EDIT:

EDIT2 Maybe I lack permissions:

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

    <uses-sdk
        android:minSdkVersion="17"
        android:targetSdkVersion="17" />
    <uses-permission android:name="android.permission.READ_PHONE_STATE" />
    <uses-permission android:name="android.permission.PROCESS_OUTGOING_CALLS" />
    <uses-permission android:name="android.permission.CALL_PHONE" />
    <application
        android:allowBackup="true"
        android:icon="@drawable/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>
         <service
            android:name=".CallDetectService"
            android:enabled="true"
            android:exported="false" >
        </service>
    </application>



</manifest>

UPDATED CLASS

package com.example.a;

import java.lang.reflect.Method;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.telephony.PhoneStateListener;
import android.telephony.TelephonyManager;
import android.widget.Toast;


public class CallHelper {

    /**
     * Listener to detect incoming calls.
     */
    private class CallStateListener extends PhoneStateListener {
        @Override
        public void onCallStateChanged(int state, String incomingNumber) {
            switch (state) {
            case TelephonyManager.CALL_STATE_RINGING:
                // called when someone is ringing to this phone
                Toast.makeText(ctx, "Incoming: " + incomingNumber, Toast.LENGTH_LONG).show();
                 try{
                        TelephonyManager tm = (TelephonyManager) ctx.getSystemService(Context.TELEPHONY_SERVICE);
                        Class c = Class.forName(tm.getClass().getName());
                        Method m = c.getDeclaredMethod("getITelephony");
                        com.android.internal.telephony.ITelephony telephonyService = (com.android.internal.telephony.ITelephony) m.invoke(tm);  

                        telephonyService = (com.android.internal.telephony.ITelephony) m.invoke(tm);
                        telephonyService.silenceRinger();
                        telephonyService.endCall();
                    }catch (Exception e) {
                        e.printStackTrace();

                    }
                break;
            }
        }
    }

    /**
     * Broadcast receiver to detect the outgoing calls.
     */
    public class OutgoingReceiver extends BroadcastReceiver {
        public OutgoingReceiver() {
        }

        @Override
        public void onReceive(Context context, Intent intent) {
            String number = intent.getStringExtra(Intent.EXTRA_PHONE_NUMBER);

            Toast.makeText(ctx, "Outgoing: " + number, Toast.LENGTH_LONG).show();
        }

    }

    private Context ctx;
    private TelephonyManager tm;
    private CallStateListener callStateListener;

    private OutgoingReceiver outgoingReceiver;

    public CallHelper(Context ctx) {
        this.ctx = ctx;

        callStateListener = new CallStateListener();
        outgoingReceiver = new OutgoingReceiver();
    }

    /**
     * Start calls detection.
     */
    public void start() {
        tm = (TelephonyManager) ctx.getSystemService(Context.TELEPHONY_SERVICE);
        tm.listen(callStateListener, PhoneStateListener.LISTEN_CALL_STATE);

        IntentFilter intentFilter = new IntentFilter(Intent.ACTION_NEW_OUTGOING_CALL);
        ctx.registerReceiver(outgoingReceiver, intentFilter);
    }

    /**
     * Stop calls detection.
     */
    /*
     * public void stop() { tm.listen(callStateListener,
     * PhoneStateListener.LISTEN_NONE);
     * ctx.unregisterReceiver(outgoingReceiver); }
     */

}

EDIT 3 Link to project: http://www.speedyshare.com/ccY6T/A1.zip

Answer 1

Import these...

  import java.lang.reflect.Method;
  import android.app.Activity;  
  import android.telephony.TelephonyManager;
  import com.android.internal.telephony.*;

Use this code to reject the phone call.

 try{
    TelephonyManager tm = (TelephonyManager)        context.getSystemService(Context.TELEPHONY_SERVICE);
    Class c = Class.forName(tm.getClass().getName());
    Method m = c.getDeclaredMethod("getITelephony");
    com.android.internal.telephony.ITelephony telephonyService = (ITelephony) m.invoke(tm);  
    telephonyService = (ITelephony) m.invoke(tm);
    telephonyService.silenceRinger();
    telephonyService.endCall();
}catch (Exception e) {
    e.printStackTrace();
      // Some problem occurred while accessing private API
    // TODO: do whatever error handling you want here  

}

Add these permissions into Manifest file.

<uses-permission android:name="android.permission.PROCESS_OUTGOING_CALLS"/>
<uses-permission android:name="android.permission.CALL_PHONE" />
<uses-permission android:name="android.permission.READ_PHONE_STATE" />

The com.android.internal.telephony is not part of the Android SDK. You can get this Java file from here.

Note:

Here we uses Java reflection.These methods are there, but they are marked as "private". Using reflection, we can get lots of information about classes, even the information that is considered "private". Since this is an "unsupported API" it may not work on all devices and it may be changed in a future release of Android