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Setting relative URL for javascript (websocket connecting to Spring MVC)

I'm following this tutorial : https://www.baeldung.com/websockets-spring
I tested the app and it works perfectly when running on the embedded-tomcat server. However, when I try to deploy and run the same app on an external tomcat server it breaks, because instead of the URL being
localhost:8080/chat
it becomes
myhostIP:port/spring-boot-web-jsp/chat
So I modified the javascript file adding /spring-boot-web-jsp in front of the existing URLs. When I run the webapp the sockets connect successfully and send data. However now my Spring MVC Controller doesn't work.
My javascript :
var stompClient = null;
function setConnected(connected) {
document.getElementById('connect').disabled = connected;
document.getElementById('disconnect').disabled = !connected;
document.getElementById('conversationDiv').style.visibility
= connected ? 'visible' : 'hidden';
document.getElementById('response').innerHTML = '';
}
function connect() {
var socket = new SockJS('/spring-boot-web-jsp-1.0/chat');
stompClient = Stomp.over(socket);
stompClient.connect({}, function(frame) {
setConnected(true);
console.log('Connected: ' + frame);
stompClient.subscribe('/spring-boot-web-jsp-1.0/topic/messages', function(messageOutput) {
showMessageOutput(JSON.parse(messageOutput.body));
});
});
}
function disconnect() {
if(stompClient != null) {
stompClient.disconnect();
}
setConnected(false);
console.log("Disconnected");
}
function sendMessage() {
var from = document.getElementById('from').value;
var text = document.getElementById('text').value;
stompClient.send("/spring-boot-web-jsp-1.0/app/chat", {},
JSON.stringify({'from':from, 'text':text}));
}
function showMessageOutput(messageOutput) {
var response = document.getElementById('response');
var p = document.createElement('p');
p.style.wordWrap = 'break-word';
p.appendChild(document.createTextNode(messageOutput.from + ": "
+ messageOutput.text + " (" + messageOutput.time + ")"));
response.appendChild(p);
}
My Controller :
#MessageMapping("/chat")
#SendTo("/topic/messages")
public OutputMessage send(Message message) throws Exception {
String time = new SimpleDateFormat("HH:mm").format(new Date());
return new OutputMessage(message.getFrom(), message.getText(), time);
}
My message broker :
#Configuration
#EnableWebSocketMessageBroker
public class WebSocketConfig extends AbstractWebSocketMessageBrokerConfigurer {
#Override
public void configureMessageBroker(MessageBrokerRegistry config) {
config.enableSimpleBroker("/topic");
config.setApplicationDestinationPrefixes("/app");
}
#Override
public void registerStompEndpoints(StompEndpointRegistry registry) {
registry.addEndpoint("/chat");
registry.addEndpoint("/chat").withSockJS();
}
}
I've tried modifying the Controller to :
#MessageMapping("app/chat")
#SendTo("/topic/messages")
public OutputMessage send(Message message) throws Exception {
String time = new SimpleDateFormat("HH:mm").format(new Date());
return new OutputMessage(message.getFrom(), message.getText(), time);
}
#MessageMapping("spring-boot-web-jsp-1.0/app/chat")
#SendTo("spring-boot-web-jsp-1.0/topic/messages")
public OutputMessage send(Message message) throws Exception {
String time = new SimpleDateFormat("HH:mm").format(new Date());
return new OutputMessage(message.getFrom(), message.getText(), time);
}
and a bunch of other variations but none of them work.
How can I modify the Controller and javascript file to work when testing through external Apache Tomcat as well as embedded (setting a relative URL of some sort)? And how can I get this to work properly on the external Tomcat?

Remove your tomcat/webapps/ROOT directory
Rename your final jar/war/ear file to ROOT.jar/war/ear
Deploy it on tomcat
Tomcat will deploy your app under root directory localhost:8080/chat

NullPointerException in JxBrowser when passing null from JavaScript to Java

The following code causes a NullPointerException within the JxBrowser (Version 6.14) java code which i can not debug any further, when passing null as argument to a java-method.
In the documentation it says null converts to null, so i assume it should work and it's a bug: https://jxbrowser.support.teamdev.com/support/solutions/articles/9000013062-calling-java-from-javascript (table at the bottom)
Any ideas how to "fix" this?
import com.teamdev.jxbrowser.chromium.Browser;
import com.teamdev.jxbrowser.chromium.BrowserPreferences;
import com.teamdev.jxbrowser.chromium.JSObject;
import com.teamdev.jxbrowser.chromium.LoggerProvider;
import com.teamdev.jxbrowser.chromium.events.ConsoleEvent;
import com.teamdev.jxbrowser.chromium.events.ConsoleListener;
import com.teamdev.jxbrowser.chromium.events.ScriptContextEvent;
import com.teamdev.jxbrowser.chromium.events.ScriptContextListener;
import com.teamdev.jxbrowser.chromium.swing.BrowserView;
import java.awt.BorderLayout;
import java.util.logging.Level;
import javax.swing.JFrame;
import javax.swing.WindowConstants;
public class SSCCE_JxBrowser {
public static void main(String[] args) {
LoggerProvider.setLevel(Level.INFO); // ALL
BrowserPreferences.setChromiumSwitches("--remote-debugging-port=9222");
Browser browser = new Browser();
BrowserView browserView = new BrowserView(browser);
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
frame.add(browserView, BorderLayout.CENTER);
frame.setSize(700, 500);
frame.setLocationRelativeTo(null);
frame.setTitle("JxBrowser Test");
frame.setVisible(true);
browser.addScriptContextListener(new ScriptContextListener() {
#Override
public void onScriptContextDestroyed(ScriptContextEvent event) {}
#Override
public void onScriptContextCreated(ScriptContextEvent event) {
JSObject window = event.getBrowser().executeJavaScriptAndReturnValue("window").asObject();
window.setProperty("java", new JavaObject());
}
});
browser.addConsoleListener(new ConsoleListener() {
#Override
public void onMessage(ConsoleEvent event) {
System.out.println("log: " + event);
}
});
browser.loadHTML("<html><head>" //
+ "<script>" //
+ "java.log('Ok!');" // this is OK
+ "java.log(null);" // this fails with NullPointerException
+ "</script>" //
+ "<body>page loaded - <a href=\"" + browser.getRemoteDebuggingURL() + "\" target=_blank>debug</a>"
+ "</body></html>");
}
public static class JavaObject {
public void log(String msg) {
System.out.println("msg: " + msg);
}
}
}
Output (html):
Uncaught java.lang.NullPointerException: null
Output (java):
msg: Ok!
log: ConsoleEvent{lineNumber=1, message='Uncaught java.lang.NullPointerException: null', source='about:blank'}
Using an exception breakpoint i found this stacktrace:
Thread [IPC Sync Events Thread] (Suspended (exception java.lang.NullPointerException))
com.teamdev.jxbrowser.chromium.JSContext.a(com.teamdev.jxbrowser.chromium.JSContext, com.teamdev.jxbrowser.chromium.internal.ipc.message.OnInvokeJSJavaMessage) line: 2608
com.teamdev.jxbrowser.chromium.JSContext$a.onMessageReceived(com.teamdev.jxbrowser.chromium.internal.ipc.message.Message) line: 280
com.teamdev.jxbrowser.chromium.internal.ipc.p.a(com.teamdev.jxbrowser.chromium.internal.ipc.p, com.teamdev.jxbrowser.chromium.internal.ipc.message.Message) line: 1082
com.teamdev.jxbrowser.chromium.internal.ipc.q.run() line: 66
com.teamdev.jxbrowser.chromium.internal.q.run() line: 63
java.util.concurrent.Executors$RunnableAdapter<T>.call() line: 511
java.util.concurrent.FutureTask<V>.run() line: 266
java.util.concurrent.ThreadPoolExecutor.runWorker(java.util.concurrent.ThreadPoolExecutor$Worker) line: 1142
java.util.concurrent.ThreadPoolExecutor$Worker.run() line: 617
java.lang.Thread.run() line: 748

This issue has been fixed in JxBrowser 6.19.2-b1-eap build available for download. The fix will be included into the next official release.

You are welcome to download JxBrowser 6.20 with the fix included.

Android main thread blocking WebView thread

I've been working on a problem with doing a synchronous call to JavaScript in a WebView (with a return value) and trying to narrow down the where and why of why it's not working. It seems to be that the WebView thread is blocking while the main thread is waiting for a response from it -- which shouldn't be the case since theWebView runs on a separate thread.
I've put together this small sample that demonstrates it (I hope) fairly clearly:
main.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:weightSum="1">
<WebView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="#+id/webView"/>
</LinearLayout>
MyActivity.java:
package com.example.myapp;
import android.app.Activity;
import android.os.Build;
import android.os.Bundle;
import android.util.Log;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.JavascriptInterface;
import android.webkit.WebViewClient;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
public class MyActivity extends Activity {
public final static String TAG = "MyActivity";
private WebView webView;
private JSInterface JS;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
webView = (WebView)findViewById(R.id.webView);
JS = new JSInterface();
webView.addJavascriptInterface(JS, JS.getInterfaceName());
WebSettings settings = webView.getSettings();
settings.setJavaScriptEnabled(true);
webView.setWebViewClient(new WebViewClient() {
public void onPageFinished(WebView view, String url) {
Log.d(TAG, JS.getEval("test()"));
}
});
webView.loadData("<script>function test() {JSInterface.log(\"returning Success\"); return 'Success';}</script>Test", "text/html", "UTF-8");
}
private class JSInterface {
private static final String TAG = "JSInterface";
private final String interfaceName = "JSInterface";
private CountDownLatch latch;
private String returnValue;
public JSInterface() {
}
public String getInterfaceName() {
return interfaceName;
}
// JS-side functions can call JSInterface.log() to log to logcat
#JavascriptInterface
public void log(String str) {
// log() gets called from Javascript
Log.i(TAG, str);
}
// JS-side functions will indirectly call setValue() via getEval()'s try block, below
#JavascriptInterface
public void setValue(String value) {
// setValue() receives the value from Javascript
Log.d(TAG, "setValue(): " + value);
returnValue = value;
latch.countDown();
}
// getEval() is for when you need to evaluate JS code and get the return value back
public String getEval(String js) {
Log.d(TAG, "getEval(): " + js);
returnValue = null;
latch = new CountDownLatch(1);
final String code = interfaceName
+ ".setValue(function(){try{return " + js
+ "+\"\";}catch(js_eval_err){return '';}}());";
Log.d(TAG, "getEval(): " + code);
// It doesn't actually matter which one we use; neither works:
if (Build.VERSION.SDK_INT >= 19)
webView.evaluateJavascript(code, null);
else
webView.loadUrl("javascript:" + code);
// The problem is that latch.await() appears to block, not allowing the JavaBridge
// thread to run -- i.e., to call setValue() and therefore latch.countDown() --
// so latch.await() always runs until it times out and getEval() returns ""
try {
// Set a 4 second timeout for the worst/longest possible case
latch.await(4, TimeUnit.SECONDS);
} catch (InterruptedException e) {
Log.e(TAG, "InterruptedException");
}
if (returnValue == null) {
Log.i(TAG, "getEval(): Timed out waiting for response");
returnValue = "";
}
Log.d(TAG, "getEval() = " + returnValue);
return returnValue;
}
// eval() is for when you need to run some JS code and don't care about any return value
public void eval(String js) {
// No return value
Log.d(TAG, "eval(): " + js);
if (Build.VERSION.SDK_INT >= 19)
webView.evaluateJavascript(js, null);
else
webView.loadUrl("javascript:" + js);
}
}
}
When running, the following results:
Emulator Nexus 5 API 23:
05-25 13:34:46.222 16073-16073/com.example.myapp D/JSInterface: getEval(): test()
05-25 13:34:50.224 16073-16073/com.example.myapp I/JSInterface: getEval(): Timed out waiting for response
05-25 13:34:50.224 16073-16073/com.example.myapp D/JSInterface: getEval() =
05-25 13:34:50.225 16073-16073/com.example.myapp I/Choreographer: Skipped 239 frames! The application may be doing too much work on its main thread.
05-25 13:34:50.235 16073-16150/com.example.myapp I/JSInterface: returning Success
05-25 13:34:50.237 16073-16150/com.example.myapp D/JSInterface: setValue(): Success
(16073 is 'main'; 16150 is 'JavaBridge')
As you can see, the main thread times out waiting for theWebView to call setValue(), which it doesn't until latch.await() has timed out and main thread execution has continued.
Interestingly, trying with an earlier API level:
Emulator Nexus S API 14:
05-25 13:37:15.225 19458-19458/com.example.myapp D/JSInterface: getEval(): test()
05-25 13:37:15.235 19458-19543/com.example.myapp I/JSInterface: returning Success
05-25 13:37:15.235 19458-19543/com.example.myapp D/JSInterface: setValue(): Success
05-25 13:37:15.235 19458-19458/com.example.myapp D/JSInterface: getEval() = Success
05-25 13:37:15.235 19458-19458/com.example.myapp D/MyActivity: Success
(19458 is 'main'; 19543 is 'JavaBridge')
Things work correctly in sequence, with getEval() causing the WebView to call setValue(), which then exits latch.await() before it times out (as you'd expect/hope).
(I've also tried with an even earlier API level, but things crash out due to what may be, as I understand it, an emulator-only bug in 2.3.3 that never got fixed.)
So I'm at a bit of a loss. In digging around, this seems like the correct approach to doing things. It certainly seems like the correct approach because it works properly on API level 14. But then it's failing on later versions — and I've tested on 5.1 and 6.0 without success.

Look more about migration WebView with Android 4.4.
See description on Android Docs I think you need to use another method for funning your JS action.
For example, base on that doc - Running JS Async Asynchronously evaluates JavaScript in the context of the currently displayed page. If non-null, |resultCallback| will be invoked with any result returned from that execution. This method must be called on the UI thread and the callback will be made on the UI thread.

Android webview, loading javascript file in assets folder

I've seen this question has been asked a lot of times, but still can't manage to get my code working.
I want my webview to load some URL (say www.google.com) and then apply some javascript stored in assets/jstest.js, which contains the following:
function test(){
document.bgColor="#00FF00"; //turns to green the background color
}
And here's where I try to load the JS:
#Override
public void onPageFinished(WebView view, String url){
view.loadUrl("javascript:(function() { "
+ " document.bgColor='#FF0000';" //turns to red the background color
+ " var script=document.createElement('script'); "
+ " script.setAttribute('type','text/javascript'); "
+ " script.setAttribute('src', 'file:///android_asset/jstest.js'); "
+ " script.onload = function(){ "
+ " test(); "
+ " }; "
+ " document.getElementsByTagName('head')[0].appendChild(script); "
+ "})()");
}
I know the javascript here works because the background color actually turns to red, but for some reason it won't load jstest.js. I think the problem might be in file path (I'm certain every other line of the javascript code is correct), but it looks correct to me. And the file is in the right folder.
What am I missing?
EDIT:
Since WebResourceResponse class is available only with API Level 11, here's what I've figured out in the end.
public void onPageFinished(WebView view, String url){
String jscontent = "";
try{
InputStream is = am.open("jstest.js"); //am = Activity.getAssets()
InputStreamReader isr = new InputStreamReader(is);
BufferedReader br = new BufferedReader(isr);
String line;
while (( line = br.readLine()) != null) {
jscontent += line;
}
is.close();
}
catch(Exception e){}
view.loadUrl("javascript:(" + jscontent + ")()");
}
with the jstest.js simply containing:
function() {
document.bgColor="#00FF00";
}

I tried the same thing, loading a bookmarklet (the javascript code in your loadUrl() call) into a third-party page. My bookmarklet also depends on other assets (javascript and css files) which would not load with a file:///android_asset URL.
That's because the security context of the page is still that of, e.g., http://www.google.com, and that's not allowed access to file: URLs. You should be able to see the errors if you supply/override a WebChromeClient.onConsoleMessage().
I ended up with a kludge where I changed the bookmarklet's asset references to a bogus URL scheme, like:
asset:foo/bar/baz.js
and added a WebViewClient.shouldInterceptRequest() override which looks for those and loads them from assets using AssetManager.open().
One thing I don't like about this kludge is that the asset: scheme is open to any third-party HTML/Javascript on any page my view loads, giving them access to my app's assets.
One alternative, which I didn't try, would be to embed the sub-assets in the bookmarklet using data: URLs, but that can get unwieldy.
I'd much prefer it if there was a way to manipulate the security context of just the JS bookmarklet I'm loading in loadUrl(), but I can't find anything like that.
Here's a snippet:
import android.webkit.WebResourceResponse;
...
private final class FooViewClient extends WebViewClient
{
private final String bookmarklet;
private final String scheme;
private FooViewClient(String bookmarklet, String scheme)
{
this.bookmarklet = bookmarklet;
this.scheme = scheme;
}
#Override
public void onPageFinished(WebView view, String url)
{
view.loadUrl(bookmarklet);
}
#Override
public WebResourceResponse shouldInterceptRequest(WebView view, String url)
{
if (url.startsWith(scheme))
try
{
return new WebResourceResponse(url.endsWith("js") ? "text/javascript" : "text/css", "utf-8",
Foo.this.getAssets().open(url.substring(scheme.length())));
}
catch (IOException e)
{
Log.e(getClass().getSimpleName(), e.getMessage(), e);
}
return null;
}
}

I think the iceam cream webview client of cordova does the very thing you want to do.
It would be nice if this was documented somewhere but, as far as I can see, it is not.
Take a look at cordova's android github:
https://github.com/apache/incubator-cordova-android/blob/master/framework/src/org/apache/cordova/IceCreamCordovaWebViewClient.java

Here is how i ended up doing it. I used the Content:// protocol and set up a contentprovider to handle returning a file descriptor to the system
Here is my fileContentProvider:
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import org.apache.commons.io.IOUtils;
import android.content.ContentProvider;
import android.content.ContentValues;
import android.database.Cursor;
import android.net.Uri;
import android.os.ParcelFileDescriptor;
import android.util.Log;
public class FileContentProvider extends ContentProvider {
#Override
public ParcelFileDescriptor openFile(Uri uri, String mode) {
Log.d("FileContentProvider","fetching: " + uri);
ParcelFileDescriptor parcel = null;
String fileNameRequested = uri.getLastPathSegment();
String[] name=fileNameRequested.split("\\.");
String prefix=name[0];
String suffix=name[1];
// String path = getContext().getFilesDir().getAbsolutePath() + "/" + uri.getPath();
//String path=file:///android_asset/"+Consts.FILE_JAVASCRIPT+"
/*check if this is a javascript file*/
if(suffix.equalsIgnoreCase("js")){
InputStream is = null;
try {
is = getContext().getAssets().open("www/"+Consts.FILE_JAVASCRIPT);
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
File file = stream2file(is,prefix,suffix);
try {
parcel = ParcelFileDescriptor.open(file, ParcelFileDescriptor.MODE_READ_ONLY);
} catch (FileNotFoundException e) {
Log.e("FileContentProvider", "uri " + uri.toString(), e);
}
}
return parcel;
}
/*converts an inputstream to a temp file*/
public File stream2file (InputStream in,String prefix,String suffix) {
File tempFile = null;
try {
tempFile = File.createTempFile(prefix, suffix);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
tempFile.deleteOnExit();
FileOutputStream out = null;
try {
out = new FileOutputStream(tempFile);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
IOUtils.copy(in, out);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return tempFile;
}
#Override
public boolean onCreate() {
return true;
}
#Override
public int delete(Uri uri, String s, String[] as) {
throw new UnsupportedOperationException("Not supported by this provider");
}
#Override
public String getType(Uri uri) {
throw new UnsupportedOperationException("Not supported by this provider");
}
#Override
public Uri insert(Uri uri, ContentValues contentvalues) {
throw new UnsupportedOperationException("Not supported by this provider");
}
#Override
public Cursor query(Uri uri, String[] as, String s, String[] as1, String s1) {
throw new UnsupportedOperationException("Not supported by this provider");
}
#Override
public int update(Uri uri, ContentValues contentvalues, String s, String[] as) {
throw new UnsupportedOperationException("Not supported by this provider");
}
}
in the manifest i defined the provider:
<provider android:name="com.example.mypackage.FileContentProvider"
android:authorities="com.example.fileprovider"
/>
Here is the javascript o inject into the webview:
webView.loadUrl("javascript:(function() { "
+ "var script=document.createElement('script'); "
+ " script.setAttribute('type','text/javascript'); "
+ " script.setAttribute('src', 'content://com.example.fileprovider/myjavascriptfile.js'); "
/* + " script.onload = function(){ "
+ " test(); "
+ " }; "
*/ + "document.body.appendChild(script); "
+ "})();");
and here is the myjavascriptfile.js (as an example):
function changeBackground(color) {
document.body.style.backgroundColor = color;
}

Maybe you could have assets as 'html/javascript templates'. You could combine different of these text sources and string logic to compose your desired html to be loaded into the WebViewer. Then, you use .loadData instead of .loadUrl
I'm using it on my own and it seems to work pretty well.
Hope it helps!

With the following two conditions given:
minSdkVersion 21
targetSdkVersion 28
I am able to successfully load any local asset (js, png, css) via the following Java code
#Override
public WebResourceResponse shouldInterceptRequest(WebView view, WebResourceRequest request) {
Uri uri = request.getUrl();
if (uri.getHost().equals("assets")) {
try {
return new WebResourceResponse(
URLConnection.guessContentTypeFromName(uri.getPath()),
"utf-8",
MainActivity.this.getAssets().open(uri.toString().substring(15)));
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
And in the HTML code I can use
<link rel="stylesheet" href="https://assets/material.min.css">
<script src="https://assets/material.min.js"></script>
<script src="https://assets/moment-with-locales.min.js"></script>
<img src="https://assets/stackoverflow.png">
In Java the following then also works (you'd also need to add a favicon.ico to the assets)
webView.loadUrl("https://assets/example.html");
Using https:// as the scheme allows me to load local assets from a page served via HTTPS without security issues due to mixed-content.
None of these require to be set:
webSettings.setMixedContentMode(WebSettings.MIXED_CONTENT_ALWAYS_ALLOW);
webSettings.setDomStorageEnabled(true);
webSettings.setAllowContentAccess(true);
webSettings.setAllowFileAccess(true);
webSettings.setAllowFileAccessFromFileURLs(true);
webSettings.setAllowUniversalAccessFromFileURLs(true);

Flash as a socket gateway for javascript

i just completed a web based chat application based on ajax/php. But the problem with this app is that it has to continuously poll server to check for new messages, which in turn overloads the server if many people are using this app simultaneously.
now i want to implement a socket based chat app in JavaScript. I know there is no support for sockets in JavaScript so i decided to use "Flash as a socket gateway for JavaScript" i am using Linux and and new to flash. can someone help me with how to achieve this.
basically,
1) I want to make a small SWF object that just handles socket logic(minimum width and height so i can hide it easily with -ve margin.
2) I want to access this swf object with JavaScript
i got a code for simple socket in actionscript (from internet) but i cannot get it to compile using mxmlc(free flash compiler).
heres the code...
myXML = new XMLSocket;
myXML.onConnect = handleConnect;
myXML.onXML = handleXML;
myXML.onClose = handleDisconnect;
myXML.connect("http://www.yourServer.com", 12345);
function handleConnect(connectionStatus){
connectionStatus ? trace("Connected.") : trace("Connection failed.");
}
function handleXML(xmlObject){
trace("Object recieved:: "+xmlObject);
}
function sendXML(textToSend){
myXML.send(new XML('"+textToSend+""));
}
function handleDisconnect(){
trace("Connection lost.");
}
function closeConnection(){
trace("Closing connection to server.");
myXML.close();
}
i got a better code but this also does not compile
package
{
import flash.errors.*;
import flash.events.*;
import flash.net.Socket;
public class ChatSocket extends Socket
{
public var host:String;
public var port:uint;
private var socket:Socket;
public static var SOCK_CONNECTED:String = "onSockConnect";
public static var SOCK_IOERROR:String = "onSockIOError";
function ChatSocket(h:String, p:uint)
{
host = h;
port = p;
socket = this;
super(host, port);
initListeners();
}
public function sendMessage(str:String):void
{
if(connected)
{
socket.writeUTFBytes(str + "\n");
}
else
{
trace("Not connected, message not sent!");
}
}
public function readMessage():void
{
if(connected)
{
var str:String = socket.readUTFBytes(socket.bytesAvailable);
trace("Socket Server Response: " + str);
}
else
{
trace("No message read, not connected!");
}
}
private function initListeners():void
{
socket.addEventListener(Event.CLOSE, closeHandler);
socket.addEventListener(Event.CONNECT, connectHandler);
socket.addEventListener(IOErrorEvent.IO_ERROR,
ioErrorHandler);
}
private function closeHandler(event:Event):void
{
trace("Connection to [" + host + "] closed");
}
private function ioErrorHandler(event:IOErrorEvent):void
{
dispatchEvent(new Event(SOCK_IOERROR));
}
private function connectHandler(event:Event):void
{
trace("Connected to [" + host + "]");
dispatchEvent(new Event(SOCK_CONNECTED));
}
private function socketDataHandler(event:ProgressEvent):void
{
readMessage();
}
}
}
var sock:ChatSocket;
sock = new ChatSocket('127.0.0.1', 9990);
sock.addEventListener(ChatSocket.SOCK_CONNECTED, connected);
sock.addEventListener(ChatSocket.SOCK_IOERROR, ioError);
function ioError(e:Event):void
{
trace("Cant connect to " + sock.host + " on port " + sock.port);
}
function connected(e:Event):void
{
sock.sendMessage("are you hungry?");
}
ERROR IS:
localhost bin]$ ./mxmlc ChatSocket.as
Loading configuration file /home/lk/Documents/flex_sdk_3.4/frameworks/flex-config.xml
/home/lk/Documents/flex_sdk_3.4/bin/ChatSocket.as: Error: A file found in a source-path can not have more than one externally visible definition. ChatSocket;sock;ioError;connected

You may wish to check out gimite's web-socket-js. This is a socket gateway that conforms to the work-in-progress Web Socket API, so in future as browsers implement native WebSocket it will automatically switch over to the Flash-free alternative.

The following code lies outside the class and package {} blocks. That is not allowed.
var sock:ChatSocket;
sock = new ChatSocket('127.0.0.1', 9990);
sock.addEventListener(ChatSocket.SOCK_CONNECTED, connected);
sock.addEventListener(ChatSocket.SOCK_IOERROR, ioError);
function ioError(e:Event):void
{
trace("Cant connect to " + sock.host + " on port " + sock.port);
}
function connected(e:Event):void
{
sock.sendMessage("are you hungry?");
}
Declare a document class (that extends Sprite) and move ioError and connected methods to it. Make sock an instance variable instead of a local variable and add the declaration part of sock into its constructor.
//DocClass.as
package
{
public class DocClass
{
private var sock:ChatSocket;
public function DocClass()
{
sock = new ChatSocket('127.0.0.1', 9990);
sock.addEventListener(ChatSocket.SOCK_CONNECTED, connected);
sock.addEventListener(ChatSocket.SOCK_IOERROR, ioError);
}
private function ioError(e:Event):void
{
trace("Cant connect to " + sock.host + " on port " + sock.port);
}
private function connected(e:Event):void
{
sock.sendMessage("are you hungry?");
}
}
}