I'm building a simple client-server system. I've built a Java server & an android client which runs on mine device (both connected to the same LAN).
When I'm just trying to setup a connection (by clicking a button) the client fails with the error
-"java.lang.IllegalStateException: Could not execute method of the activity"
In other answers to close problem was said that it might be connected to AsyncTask, but I'm not sure.
server code:
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
public class Server {
public static void startConnection(int portNum)
{
ServerSocket serverSocket=null;
Socket clinetSocket=null;
ObjectOutputStream serverOut=null;
ObjectInputStream serverIn=null;
String message=null;
//create a socket
try{
serverSocket=new ServerSocket(portNum);
}
catch (IOException e) {
e.printStackTrace();
}
System.out.println("Waiting for connection...");
try{
clinetSocket = serverSocket.accept();
}
catch (IOException e){
e.printStackTrace();
}
System.out.println("connected to "+ clinetSocket.getInetAddress().getHostName());
}
Android client code :
Main.java :
package com.example.user_pc.myapplication;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import java.net.Socket;
import java.io.IOException;
import java.net.UnknownHostException;
import java.net.SocketException;
import android.util.Log;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
public class Main extends ActionBarActivity {
TextView text;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
text= (TextView) findViewById(R.id.textView1);
text.setText("");
}
public void pushTheButton(View v)
{
Button button = (Button) findViewById(R.id.button);
createSocket();
}
public void createSocket()
{
Socket sock = null;
String dstIP = "192.168.2.103";//server ip
int dstPort = 9632;
try
{
sock = new Socket(dstIP, dstPort);
}
catch(SocketException ie)
{
Log.wtf("SocketException",ie);
}
catch(UnknownHostException ie)
{
Log.wtf("UnknownHostException",ie);
}
catch(IOException ie)
{
Log.wtf("IOException",ie);
}
}
public static void main(String[] args)
{
int portNum=9632;
startConnection(portNum);
}
``}
manifest.xml:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.user_pc.myapplication" >
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name=".Main"
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>
layout file:
<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:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".Main"
android:onClick="pushTheButton">
<Button
android:layout_width="300dp"
android:layout_height="100dp"
android:text="Click to connect"
android:id="@+id/button"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"
android:layout_marginTop="96dp"
android:onClick="pushTheButton"
/>
</RelativeLayout>
Logcat
01-19 16:28:02.425 10779-10779/com.example.user_pc.myapplication E/AndroidRuntime﹕ FATAL EXCEPTION: main java.lang.IllegalStateException: Could not execute method of the activity at android.view.View$1.onClick(View.java:3599) at android.view.View.performClick(View.java:4204) at android.view.View$PerformClick.run(View.java:17355) at android.os.Handler.handleCallback(Handler.java:725) at android.os.Handler.dispatchMessage(Handler.java:92) at android.os.Looper.loop(Looper.java:137) at android.app.ActivityThread.main(ActivityThread.java:5226) at java.lang.reflect.Method.invokeNative(Native Method) at java.lang.reflect.Method.invoke(Method.java:511) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:795) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:562) at dalvik.system.NativeStart.main(Native Method) Caused by: java.lang.reflect.InvocationTargetException at java.lang.reflect.Method.invokeNative(Native Method) at java.lang.reflect.Method.invoke(Method.java:511) at android.view.View$1.onClick(View.java:3594) at android.view.View.performClick(View.java:4204) at android.view.View$PerformClick.run(View.java:17355) at android.os.Handler.handleCallback(Handler.java:725) at android.os.Handler.dispatchMessage(Handler.java:92) at android.os.Looper.loop(Looper.java:137) at android.app.ActivityThread.main(ActivityThread.java:5226) at java.lang.reflect.Method.invokeNative(Native Method) at java.lang.reflect.Method.invoke(Method.java:511) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:795) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:562) at dalvik.system.NativeStart.main(Native Method) Caused by: android.os.NetworkOnMainThreadException at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1117) at libcore.io.BlockGuardOs.connect(BlockGuardOs.java:84) at libcore.io.IoBridge.connectErrno(IoBridge.java:127) at libcore.io.IoBridge.connect(IoBridge.java:112) at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:192) at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172) at java.net.Socket.startupSocket(Socket.java:566) at java.net.Socket.tryAllAddresses(Socket.java:127) at java.net.Socket.(Socket.java:177) at java.net.Socket.(Socket.java:149) at com.example.user_pc.myapplication.Main.createSocket(Main.java:50) at com.example.user_pc.myapplication.Main.pushTheButton(Main.java:35) at java.lang.reflect.Method.invokeNative(Native Method) at java.lang.reflect.Method.invoke(Method.java:511) at android.view.View$1.onClick(View.java:3594) at android.view.View.performClick(View.java:4204) at android.view.View$PerformClick.run(View.java:17355) at android.os.Handler.handleCallback(Handler.java:725) at android.os.Handler.dispatchMessage(Handler.java:92) at android.os.Looper.loop(Looper.java:137) at android.app.ActivityThread.main(ActivityThread.java:5226) at java.lang.reflect.Method.invokeNative(Native Method) at java.lang.reflect.Method.invoke(Method.java:511) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:795) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:562) at dalvik.system.NativeStart.main(Native Method)
AsyncTask) to do network I/O. – David Wasser