I am transferring a message from one emulator instance on a machine to another

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Asked: May 27, 20262026-05-27T04:50:29+00:00 2026-05-27T04:50:29+00:00

I am transferring a message from one emulator instance on a machine to another

0

I am transferring a message from one emulator instance on a machine to another emulator instance on same machine.

A server runs on the machine A. It runs perfectly (I guess)
The client runs ok. But when I click a button to transfer data from client to server I get
Null pointer exception in (scoket,getoutputstream())

PrintWriter out = new PrintWriter(new BufferedWriter(
                         new OutputStreamWriter(socket.getOutputStream())),
                         true);

I also sometimes get the permission dined error in client

I have done all redirections, and added INTERNET tag in android manifest file too,

I got the server crashing with permission denied error but after I added the Internet allow tag server worked..
But when I added the the same tag to client’s manifest file the client crashes

SO am not able to remove the permission denied error by adding the INTERNET tag
At the same time am not able to clear the NULLPOINTER exception

Also the client and local machine have different timezone.
The android emulator doesn’t take Local TZ by default.

So I set up the -timezone option and even that doesn’t change the timzone zone
AFAIK i guess am doing things right w.r.t to ports and ips.
There is no error when creating socket but only when using the socket.ouputstream?
Are there any firewall problem. ?

I have searched extensively and not sure what the problem is.
Looking forward to your help.
Thanks.

EDIT:

I am using the client server Code from here by NickT
Connecting 2 Emulator instances In Android
and have modified a little
Am getting the error3
and when I print the error:

11-25 18:59:06.185: W/System.err(388): java.net.SocketException: Permission denied
11-25 18:59:06.185: W/System.err(388):  at org.apache.harmony.luni.platform.OSNetworkSystem.socket(Native Method)
11-25 18:59:06.185: W/System.err(388):  at dalvik.system.BlockGuard$WrappedNetworkSystem.socket(BlockGuard.java:347)
11-25 18:59:06.185: W/System.err(388):  at org.apache.harmony.luni.net.PlainSocketImpl.create(PlainSocketImpl.java:220)
11-25 18:59:06.185: W/System.err(388):  at java.net.Socket.startupSocket(Socket.java:618)
11-25 18:59:06.185: W/System.err(388):  at java.net.Socket.<init>(Socket.java:258)
11-25 18:59:06.185: W/System.err(388):  at net.wipp.ece.ClAct.onCreate(ClAct.java:40)
11-25 18:59:06.185: W/System.err(388):  at android.app.Activity.performCreate(Activity.java:4397)
11-25 18:59:06.185: W/System.err(388):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1048)
11-25 18:59:06.185: W/System.err(388):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1779)
11-25 18:59:06.185: W/System.err(388):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1831)
11-25 18:59:06.185: W/System.err(388):  at android.app.ActivityThread.access$500(ActivityThread.java:122)
11-25 18:59:06.185: W/System.err(388):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1024)
11-25 18:59:06.185: W/System.err(388):  at android.os.Handler.dispatchMessage(Handler.java:99)
11-25 18:59:06.185: W/System.err(388):  at android.os.Looper.loop(Looper.java:132)
11-25 18:59:06.185: W/System.err(388):  at android.app.ActivityThread.main(ActivityThread.java:4123)
11-25 18:59:06.185: W/System.err(388):  at java.lang.reflect.Method.invokeNative(Native Method)
11-25 18:59:06.185: W/System.err(388):  at java.lang.reflect.Method.invoke(Method.java:491)
11-25 18:59:06.185: W/System.err(388):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
11-25 18:59:06.185: W/System.err(388):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
11-25 18:59:06.185: W/System.err(388):  at dalvik.system.NativeStart.main(Native Method)
11-25 19:00:14.045: W/System.err(388): java.lang.NullPointerException
11-25 19:00:14.055: W/System.err(388):  at net.wipp.ece.ClAct$1.onClick(ClAct.java:54)
11-25 19:00:14.055: W/System.err(388):  at android.view.View.performClick(View.java:3110)
11-25 19:00:14.065: W/System.err(388):  at android.view.View$PerformClick.run(View.java:11934)
11-25 19:00:14.065: W/System.err(388):  at android.os.Handler.handleCallback(Handler.java:587)
11-25 19:00:14.065: W/System.err(388):  at android.os.Handler.dispatchMessage(Handler.java:92)
11-25 19:00:14.065: W/System.err(388):  at android.os.Looper.loop(Looper.java:132)
11-25 19:00:14.065: W/System.err(388):  at android.app.ActivityThread.main(ActivityThread.java:4123)
11-25 19:00:14.065: W/System.err(388):  at java.lang.reflect.Method.invokeNative(Native Method)
11-25 19:00:14.065: W/System.err(388):  at java.lang.reflect.Method.invoke(Method.java:491)
11-25 19:00:14.065: W/System.err(388):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
11-25 19:00:14.065: W/System.err(388):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
11-25 19:00:14.065: W/System.err(388):  at dalvik.system.NativeStart.main(Native Method)
11-25 19:19:45.285: D/dalvikvm(388): GC_CONCURRENT freed 349K, 7% free 6380K/6791K, paused 10ms+2ms
11-25 19:26:27.115: I/dalvikvm(388): Jit: resizing JitTable from 512 to 1024
11-25 19:49:48.055: D/dalvikvm(388): GC_CONCURRENT freed 419K, 8% free 6378K/6919K, paused 7ms+2ms
11-25 20:19:58.565: D/dalvikvm(388): GC_CONCURRENT freed 419K, 8% free 6378K/6919K, paused 7ms+2ms
11-25 20:45:27.594: I/dalvikvm(388): Jit: resizing JitTable from 1024 to 2048
11-25 20:50:09.304: D/dalvikvm(388): GC_CONCURRENT freed 419K, 8% free 6378K/6919K, paused 7ms+3ms
11-25 21:20:19.785: D/dalvikvm(388): GC_CONCURRENT freed 419K, 8% free 6378K/6919K, paused 4ms+2ms
11-25 21:50:29.924: D/dalvikvm(388): GC_CONCURRENT freed 419K, 8% free 6378K/6919K, paused 8ms+5ms
11-25 22:20:40.565: D/dalvikvm(388): GC_CONCURRENT freed 419K, 8% free 6378K/6919K, paused 8ms+3ms
11-25 22:50:50.675: D/dalvikvm(388): GC_CONCURRENT freed 419K, 8% free 6378K/6919K, paused 7ms+2ms
11-25 23:21:00.474: D/dalvikvm(388): GC_CONCURRENT freed 419K, 8% free 6378K/6919K, paused 5ms+4ms
11-25 23:51:10.485: D/dalvikvm(388): GC_CONCURRENT freed 419K, 8% free 6378K/6919K, paused 11ms+3ms
11-26 00:21:20.725: D/dalvikvm(388): GC_CONCURRENT freed 419K, 8% free 6378K/6919K, paused 8ms+2ms
11-26 00:51:30.835: D/dalvikvm(388): GC_CONCURRENT freed 419K, 8% free 6378K/6919K, paused 8ms+3ms
11-26 01:21:41.254: D/dalvikvm(388): GC_CONCURRENT freed 419K, 8% free 6378K/6919K, paused 12ms+4ms
11-26 01:48:27.275: W/System.err(388): java.lang.NullPointerException
11-26 01:48:27.275: W/System.err(388):  at net.wipp.ece.ClAct$1.onClick(ClAct.java:54)
11-26 01:48:27.275: W/System.err(388):  at android.view.View.performClick(View.java:3110)
11-26 01:48:27.275: W/System.err(388):  at android.view.View$PerformClick.run(View.java:11934)
11-26 01:48:27.275: W/System.err(388):  at android.os.Handler.handleCallback(Handler.java:587)
11-26 01:48:27.275: W/System.err(388):  at android.os.Handler.dispatchMessage(Handler.java:92)
11-26 01:48:27.285: W/System.err(388):  at android.os.Looper.loop(Looper.java:132)
11-26 01:48:27.285: W/System.err(388):  at android.app.ActivityThread.main(ActivityThread.java:4123)
11-26 01:48:27.285: W/System.err(388):  at java.lang.reflect.Method.invokeNative(Native Method)
11-26 01:48:27.285: W/System.err(388):  at java.lang.reflect.Method.invoke(Method.java:491)
11-26 01:48:27.295: W/System.err(388):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
11-26 01:48:27.295: W/System.err(388):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
11-26 01:48:27.295: W/System.err(388):  at dalvik.system.NativeStart.main(Native Method)
11-26 01:48:32.734: W/System.err(388): java.lang.NullPointerException
11-26 01:48:32.744: W/System.err(388):  at net.wipp.ece.ClAct$1.onClick(ClAct.java:54)
11-26 01:48:32.744: W/System.err(388):  at android.view.View.performClick(View.java:3110)
11-26 01:48:32.744: W/System.err(388):  at android.view.View$PerformClick.run(View.java:11934)
11-26 01:48:32.744: W/System.err(388):  at android.os.Handler.handleCallback(Handler.java:587)
11-26 01:48:32.744: W/System.err(388):  at android.os.Handler.dispatchMessage(Handler.java:92)
11-26 01:48:32.744: W/System.err(388):  at android.os.Looper.loop(Looper.java:132)
11-26 01:48:32.744: W/System.err(388):  at android.app.ActivityThread.main(ActivityThread.java:4123)
11-26 01:48:32.744: W/System.err(388):  at java.lang.reflect.Method.invokeNative(Native Method)
11-26 01:48:32.744: W/System.err(388):  at java.lang.reflect.Method.invoke(Method.java:491)
11-26 01:48:32.744: W/System.err(388):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
11-26 01:48:32.754: W/System.err(388):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
11-26 01:48:32.754: W/System.err(388):  at dalvik.system.NativeStart.main(Native Method)
11-26 01:48:32.945: W/System.err(388): java.lang.NullPointerException
11-26 01:48:32.945: W/System.err(388):  at net.wipp.ece.ClAct$1.onClick(ClAct.java:54)
11-26 01:48:32.945: W/System.err(388):  at android.view.View.performClick(View.java:3110)
11-26 01:48:32.945: W/System.err(388):  at android.view.View$PerformClick.run(View.java:11934)
11-26 01:48:32.945: W/System.err(388):  at android.os.Handler.handleCallback(Handler.java:587)
11-26 01:48:32.955: W/System.err(388):  at android.os.Handler.dispatchMessage(Handler.java:92)
11-26 01:48:32.955: W/System.err(388):  at android.os.Looper.loop(Looper.java:132)
11-26 01:48:32.955: W/System.err(388):  at android.app.ActivityThread.main(ActivityThread.java:4123)
11-26 01:48:32.955: W/System.err(388):  at java.lang.reflect.Method.invokeNative(Native Method)
11-26 01:48:32.955: W/System.err(388):  at java.lang.reflect.Method.invoke(Method.java:491)
11-26 01:48:32.955: W/System.err(388):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
11-26 01:48:32.955: W/System.err(388):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
11-26 01:48:32.955: W/System.err(388):  at dalvik.system.NativeStart.main(Native Method)
11-26 01:48:33.116: W/System.err(388): java.lang.NullPointerException
11-26 01:48:33.116: W/System.err(388):  at net.wipp.ece.ClAct$1.onClick(ClAct.java:54)
11-26 01:48:33.116: W/System.err(388):  at android.view.View.performClick(View.java:3110)
11-26 01:48:33.116: W/System.err(388):  at android.view.View$PerformClick.run(View.java:11934)
11-26 01:48:33.116: W/System.err(388):  at android.os.Handler.handleCallback(Handler.java:587)
11-26 01:48:33.116: W/System.err(388):  at android.os.Handler.dispatchMessage(Handler.java:92)
11-26 01:48:33.116: W/System.err(388):  at android.os.Looper.loop(Looper.java:132)
11-26 01:48:33.125: W/System.err(388):  at android.app.ActivityThread.main(ActivityThread.java:4123)
11-26 01:48:33.125: W/System.err(388):  at java.lang.reflect.Method.invokeNative(Native Method)
11-26 01:48:33.125: W/System.err(388):  at java.lang.reflect.Method.invoke(Method.java:491)
11-26 01:48:33.125: W/System.err(388):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
11-26 01:48:33.125: W/System.err(388):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
11-26 01:48:33.155: W/System.err(388):  at dalvik.system.NativeStart.main(Native Method)
11-26 01:48:33.195: D/dalvikvm(388): GC_CONCURRENT freed 415K, 8% free 6382K/6919K, paused 4ms+2ms
11-26 01:48:33.305: W/System.err(388): java.lang.NullPointerException
11-26 01:48:33.305: W/System.err(388):  at net.wipp.ece.ClAct$1.onClick(ClAct.java:54)
11-26 01:48:33.305: W/System.err(388):  at android.view.View.performClick(View.java:3110)
11-26 01:48:33.305: W/System.err(388):  at android.view.View$PerformClick.run(View.java:11934)
11-26 01:48:33.305: W/System.err(388):  at android.os.Handler.handleCallback(Handler.java:587)
11-26 01:48:33.305: W/System.err(388):  at android.os.Handler.dispatchMessage(Handler.java:92)
11-26 01:48:33.305: W/System.err(388):  at android.os.Looper.loop(Looper.java:132)
11-26 01:48:33.305: W/System.err(388):  at android.app.ActivityThread.main(ActivityThread.java:4123)
11-26 01:48:33.305: W/System.err(388):  at java.lang.reflect.Method.invokeNative(Native Method)
11-26 01:48:33.305: W/System.err(388):  at java.lang.reflect.Method.invoke(Method.java:491)
11-26 01:48:33.305: W/System.err(388):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
11-26 01:48:33.315: W/System.err(388):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
11-26 01:48:33.315: W/System.err(388):  at dalvik.system.NativeStart.main(Native Method)
11-26 01:48:33.455: W/System.err(388): java.lang.NullPointerException
11-26 01:48:33.465: W/System.err(388):  at net.wipp.ece.ClAct$1.onClick(ClAct.java:54)
11-26 01:48:33.465: W/System.err(388):  at android.view.View.performClick(View.java:3110)
11-26 01:48:33.465: W/System.err(388):  at android.view.View$PerformClick.run(View.java:11934)
11-26 01:48:33.465: W/System.err(388):  at android.os.Handler.handleCallback(Handler.java:587)
11-26 01:48:33.465: W/System.err(388):  at android.os.Handler.dispatchMessage(Handler.java:92)
11-26 01:48:33.475: W/System.err(388):  at android.os.Looper.loop(Looper.java:132)
11-26 01:48:33.475: W/System.err(388):  at android.app.ActivityThread.main(ActivityThread.java:4123)
11-26 01:48:33.475: W/System.err(388):  at java.lang.reflect.Method.invokeNative(Native Method)
11-26 01:48:33.475: W/System.err(388):  at java.lang.reflect.Method.invoke(Method.java:491)
11-26 01:48:33.475: W/System.err(388):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
11-26 01:48:33.475: W/System.err(388):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
11-26 01:48:33.475: W/System.err(388):  at dalvik.system.NativeStart.main(Native Method)
11-26 01:48:33.764: W/System.err(388): java.lang.NullPointerException
11-26 01:48:33.764: W/System.err(388):  at net.wipp.ece.ClAct$1.onClick(ClAct.java:54)
11-26 01:48:33.764: W/System.err(388):  at android.view.View.performClick(View.java:3110)
11-26 01:48:33.764: W/System.err(388):  at android.view.View$PerformClick.run(View.java:11934)
11-26 01:48:33.764: W/System.err(388):  at android.os.Handler.handleCallback(Handler.java:587)
11-26 01:48:33.764: W/System.err(388):  at android.os.Handler.dispatchMessage(Handler.java:92)
11-26 01:48:33.774: W/System.err(388):  at android.os.Looper.loop(Looper.java:132)
11-26 01:48:33.774: W/System.err(388):  at android.app.ActivityThread.main(ActivityThread.java:4123)
11-26 01:48:33.774: W/System.err(388):  at java.lang.reflect.Method.invokeNative(Native Method)
11-26 01:48:33.774: W/System.err(388):  at java.lang.reflect.Method.invoke(Method.java:491)
11-26 01:48:33.774: W/System.err(388):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
11-26 01:48:33.774: W/System.err(388):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
11-26 01:48:33.774: W/System.err(388):  at dalvik.system.NativeStart.main(Native Method)
11-26 01:50:49.035: W/System.err(472): java.net.SocketException: Permission denied
11-26 01:50:49.035: W/System.err(472):  at org.apache.harmony.luni.platform.OSNetworkSystem.socket(Native Method)
11-26 01:50:49.035: W/System.err(472):  at dalvik.system.BlockGuard$WrappedNetworkSystem.socket(BlockGuard.java:347)
11-26 01:50:49.035: W/System.err(472):  at org.apache.harmony.luni.net.PlainSocketImpl.create(PlainSocketImpl.java:220)
11-26 01:50:49.045: W/System.err(472):  at java.net.Socket.startupSocket(Socket.java:618)
11-26 01:50:49.045: W/System.err(472):  at java.net.Socket.<init>(Socket.java:258)
11-26 01:50:49.045: W/System.err(472):  at net.wipp.ece.ClAct.onCreate(ClAct.java:40)
11-26 01:50:49.045: W/System.err(472):  at android.app.Activity.performCreate(Activity.java:4397)
11-26 01:50:49.045: W/System.err(472):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1048)
11-26 01:50:49.045: W/System.err(472):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1779)
11-26 01:50:49.045: W/System.err(472):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1831)
11-26 01:50:49.045: W/System.err(472):  at android.app.ActivityThread.access$500(ActivityThread.java:122)
11-26 01:50:49.045: W/System.err(472):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1024)
11-26 01:50:49.055: W/System.err(472):  at android.os.Handler.dispatchMessage(Handler.java:99)
11-26 01:50:49.055: W/System.err(472):  at android.os.Looper.loop(Looper.java:132)
11-26 01:50:49.055: W/System.err(472):  at android.app.ActivityThread.main(ActivityThread.java:4123)
11-26 01:50:49.055: W/System.err(472):  at java.lang.reflect.Method.invokeNative(Native Method)
11-26 01:50:49.055: W/System.err(472):  at java.lang.reflect.Method.invoke(Method.java:491)
11-26 01:50:49.055: W/System.err(472):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
11-26 01:50:49.055: W/System.err(472):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
11-26 01:50:49.055: W/System.err(472):  at dalvik.system.NativeStart.main(Native Method)
11-26 01:50:54.375: E/Client(472): java.lang.NullPointerException
11-26 01:50:54.375: E/Client(472):  at net.wipp.ece.ClAct$1.onClick(ClAct.java:54)
11-26 01:50:54.375: E/Client(472):  at android.view.View.performClick(View.java:3110)
11-26 01:50:54.375: E/Client(472):  at android.view.View$PerformClick.run(View.java:11934)
11-26 01:50:54.375: E/Client(472):  at android.os.Handler.handleCallback(Handler.java:587)
11-26 01:50:54.375: E/Client(472):  at android.os.Handler.dispatchMessage(Handler.java:92)
11-26 01:50:54.375: E/Client(472):  at android.os.Looper.loop(Looper.java:132)
11-26 01:50:54.375: E/Client(472):  at android.app.ActivityThread.main(ActivityThread.java:4123)
11-26 01:50:54.375: E/Client(472):  at java.lang.reflect.Method.invokeNative(Native Method)
11-26 01:50:54.375: E/Client(472):  at java.lang.reflect.Method.invoke(Method.java:491)
11-26 01:50:54.375: E/Client(472):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
11-26 01:50:54.375: E/Client(472):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
11-26 01:50:54.375: E/Client(472):  at dalvik.system.NativeStart.main(Native Method)
11-26 01:50:54.375: W/System.err(472): java.lang.NullPointerException
11-26 01:50:54.375: W/System.err(472):  at net.wipp.ece.ClAct$1.onClick(ClAct.java:54)
11-26 01:50:54.375: W/System.err(472):  at android.view.View.performClick(View.java:3110)
11-26 01:50:54.375: W/System.err(472):  at android.view.View$PerformClick.run(View.java:11934)
11-26 01:50:54.375: W/System.err(472):  at android.os.Handler.handleCallback(Handler.java:587)
11-26 01:50:54.385: W/System.err(472):  at android.os.Handler.dispatchMessage(Handler.java:92)
11-26 01:50:54.385: W/System.err(472):  at android.os.Looper.loop(Looper.java:132)
11-26 01:50:54.385: W/System.err(472):  at android.app.ActivityThread.main(ActivityThread.java:4123)
11-26 01:50:54.385: W/System.err(472):  at java.lang.reflect.Method.invokeNative(Native Method)
11-26 01:50:54.385: W/System.err(472):  at java.lang.reflect.Method.invoke(Method.java:491)
11-26 01:50:54.385: W/System.err(472):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
11-26 01:50:54.385: W/System.err(472):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
11-26 01:50:54.385: W/System.err(472):  at dalvik.system.NativeStart.main(Native Method)

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1 Answer

Editorial Team · Answer 1 · 2026-05-27T04:50:30+00:00

Editorial Team

2026-05-27T04:50:30+00:00Added an answer on May 27, 2026 at 4:50 am

The exception log tells you exactly where the error is:

at net.wipp.ece.ClAct$1.onClick(ClAct.java:54)

That means that in your ClAct class, in the onClick method, on line 54 something is null. If you set a breakpoint and debug all the way up to that point, you will see that something is null on that line.

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