Jmf on web start

Question

Hi friends,
Currently I am dealing with a project which includes distribution of JMF(java media framework) over the web. For this purpose, web start seems a nice approach.
Moreover, JMF requires some native libraries which should be deployed from web start. I had problems at this point and strongly need help. I could not achieve deploying these libraries from web start hence running JMF from web start.
I had no problem at running JMF from local JRE in standard java desktop applications. This means that required dlls can be successfully loaded and linked from standard applications but not from web start applications.
I have read lots of forums and web sites and did what is said (at least I think I did), but could not solve the problem. Most probably, I need to do some simple configurations but at this point I totally don�t know what to do. Below, I want to mention shortly what I did to deploy JMF over the web start and the exceptions and error I faced with. I will be very happy if you find something wrong in these steps and tell me what to do:
1. I jared all dlls related with the JMF : To do that, from Eclipse ee, I selected about 15 jmf dlls, right clicked them, chose �export� as jar, and obtained a jar from these dlls.
2. Then, I signed them using keytool and jarsigner tools of java to give the project unrestricted access for media processing.
3. Then, I added this jar to the webcontent folder of the project with other jars and files.
4. After that, I added following tag to the jnlp file of the project: <nativelib href="http://193.140.214.29:8080/jmfproject/jmf-native-all.jar"/>
5. I also added required System.loadLibrary() methods to my code in the order which gives no problem. (In the forums I read previously, these codes are required to load native dlls to the environment in which project will be run.)
Note: I deployed project on Apache Tomcat Server.
Below, I give my complete jnlp file;
<?xml version="1.0" encoding="utf-8"?>
<jnlp spec="1.0" codebase="http://193.140.214.29:8080/jmfproject" href="http://193.140.214.29:8080/jmfproject/jmfproject.jnlp">
<information>
<title>jmfproject</title>
<vendor>Techneon ltd.</vendor>
<icon href="http://193.140.214.29:8080/jmfproject/techneon.jpg" kind="default"/>
<icon href="http://193.140.214.29:8080/jmfproject/techneon.jpg" kind="splash"/>
</information>
<security>
<all-permissions/>
</security>
<resources OS = "Windows">
<j2se version="1.6.0_03" href="http://java.sun.com/products/autodl/j2se"/>
<jar href="http://193.140.214.29:8080/jmfproject/jmf.jar"/>
<nativelib href="http://193.140.214.29:8080/jmfproject/jmfnative.jar"/>
</resources>
<application-desc main-class="JmfprojectStarter"/>
</jnlp>
And below is the cronical exception I faced with:
java.lang.NullPointerException
at Jmfproject.<init>(Jmfproject.java:241)
at JmfprojectStarter.main(JmfprojectStarter.java:9)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.sun.javaws.Launcher.executeApplication(Unknown Source)
at com.sun.javaws.Launcher.executeMainClass(Unknown Source)
at com.sun.javaws.Launcher.doLaunchApp(Unknown Source)
at com.sun.javaws.Launcher.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)

Answer 1

Hi Andrew,
Thank you very much for your attention,
My simple project contains 2 classes: JmfprojectStarter, which contains only main method and Jmfproject which is a swing GUI
Below is JmfprojectStarter:
+public class JmfprojectStarter {+
+     /**+
+     * @param args+
+     */+
+     public static void main(String[] args) {+
+          +
+          new Jmfproject();+
+     }+
+}+
And below is the System.loadlibrary part of the Jmfproject class:
+/*+
* Java(TM) SE 6 version.
some import statements
+@SuppressWarnings("serial")+
+public class Jmfproject extends JFrame implements ControllerListener {+
+     some gui component declarations+
+     +
+public Jmfproject() {+
+     +
+     System.loadLibrary("jmacm");+
+     System.loadLibrary("jmdaudc");+
+     System.loadLibrary("jmmpegv");+
+     System.loadLibrary("jmutil");+
+     System.loadLibrary("jmvcm");+
+     System.loadLibrary("jmvfw");+
+     System.loadLibrary("jmmpa");+
+     System.loadLibrary("jmmci");+
+     System.loadLibrary("jmdaud");+
+     System.loadLibrary("jmcvid");+
+     System.loadLibrary("jmam");+
+     System.loadLibrary("jmjpeg");+
+     System.loadLibrary("jmh263enc");+
+     System.loadLibrary("jmh261");+
+     System.loadLibrary("jmgdi");+
+     System.loadLibrary("jmg723");+
+     System.loadLibrary("jmddraw");+
+     System.loadLibrary("jmvh263");+
+     System.loadLibrary("jmfjawt");+
+     System.loadLibrary("jmgsm");+
+.+
+.+
+.+
some gui component initiliazations
+.+
+.+
+.+
below is code block where I got the exception(statement in bold throws the exception)
+try {+
+          URL mediaURL = getClass().getResource("media/ungreedy.wav");+
+          player = Manager.createPlayer(mediaURL);+
+          player.addControllerListener(this);+
+     }catch (Exception e) {e.printStackTrace();statusField.setText("player error");}+
player.start();+
As you see, System.loadlibrary methods are not called from main method(although from the same thread). Moreover, I guess there is no problem in the order of method calls since I changed the order untill I do not get "dependency" errors which are thrown when one dll depends on some other one. But in some way, these dlls can not be used by web start according to the part of exception thrown :
at sun.reflect.*NativeMethodAccessorImpl.invoke0*(Native Method)
at sun.reflect.*NativeMethodAccessorImpl.invoke*(Unknown Source)
at sun.reflect.*DelegatingMethodAccessorImpl.invoke*(Unknown Source)
I have no idea at this point:(
Thank you very much again
Edited by: alperyesilyurt on Jan 9, 2008 5:35 AM