服务器端applet用jmf播放声音文件出错

[sanbing]

一个applet例子程序，使用JMF来放语音。
我用Jbuildx在windows xp上编译通过，并可以成功放音。把class/html/wav文件放在web服务器(linux上)上，再在windows Xp上用appletviewer运行出错，客户端在安装jmf4windows的程序前后现象相同。
在windows/linux(web服务器)两个环境下，同一目录下均有class/html/wav三个文件，分别为：SimplePlayerApplet.class/spa.html/test.wav,
Java文件SimplePlayerApplet.java如下：

import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;
import java.lang.String;
import java.net.URL;
import java.net.MalformedURLException;
import java.io.IOException;
import java.util.Properties;
import javax.media.*;
//import com.sun.media.util.JMFSecurity;

/**
* This is a Java Applet that demonstrates how to create a simple
* media player with a media event listener. It will play the
* media clip right away and continuously loop.
*
* <!-- Sample HTML
* <applet code=SimplePlayerApplet width=320 height=300>
* <param name=file value="sun.avi">
* </applet>
* -->
*/
public class SimplePlayerApplet extends Applet implements ControllerListener {

// media Player
Player player = null;
// component in which video is playing
Component visualComponent = null;
// controls gain, position, start, stop
Component controlComponent = null;
// displays progress during download
Component progressBar = null;
boolean firstTime = true;
long CachingSize = 0L;
Panel panel = null;
int controlPanelHeight = 0;
int videoWidth = 0;
int videoHeight = 0;

/**
* Read the applet file parameter and create the media
* player.
*/
public void init() {
//$ System.out.println("Applet.init() is called");
setLayout(null);
setBackground(Color.white);
panel = new Panel();
panel.setLayout( null );
add(panel);
panel.setBounds(0, 0, 320, 240);

// input file name from html param
String mediaFile = null;
// URL for our media file
MediaLocator mrl = null;
URL url = null;

// Get the media filename info.
// The applet tag should contain the path to the
// source media file, relative to the html page.

if ((mediaFile = getParameter("FILE")) == null)
Fatal("Invalid media file parameter");

try {
url = new URL(getDocumentBase(), mediaFile);
mediaFile = url.toExternalForm();
} catch (MalformedURLException mue) {
}

try {
// Create a media locator from the file name
if ((mrl = new MediaLocator(mediaFile)) == null)
Fatal("Can't build URL for " + mediaFile);

/*
try {
JMFSecurity.enablePrivilege.invoke(JMFSecurity.privilegeManager,
JMFSecurity.writePropArgs);
JMFSecurity.enablePrivilege.invoke(JMFSecurity.privilegeManager,
JMFSecurity.readPropArgs);
JMFSecurity.enablePrivilege.invoke(JMFSecurity.privilegeManager,
JMFSecurity.connectArgs);
} catch (Exception e) {}
*/

// Create an instance of a player for this media
try {
player = Manager.createPlayer(mrl);
} catch (NoPlayerException e) {
System.out.println(e);
Fatal("Could not create player for " + mrl);
}

// Add ourselves as a listener for a player's events
player.addControllerListener(this);

} catch (MalformedURLException e) {
Fatal("Invalid media file URL!");
} catch (IOException e) {
Fatal("IO exception creating player for " + mrl);
}

// This applet assumes that its start() calls
// player.start(). This causes the player to become
// realized. Once realized, the applet will get
// the visual and control panel components and add
// them to the Applet. These components are not added
// during init() because they are long operations that
// would make us appear unresposive to the user.
}

[sanbing]

/**
* Start media file playback. This function is called the
* first time that the Applet runs and every
* time the user re-enters the page.
*/

public void start() {
//$ System.out.println("Applet.start() is called");
// Call start() to prefetch and start the player.
if (player != null)
player.start();
}

/**
* Stop media file playback and release resource before
* leaving the page.
*/
public void stop() {
//$ System.out.println("Applet.stop() is called");
if (player != null) {
player.stop();
player.deallocate();
}
}

public void destroy() {
//$ System.out.println("Applet.destroy() is called");
player.close();
}


/**
* This controllerUpdate function must be defined in order to
* implement a ControllerListener interface. This
* function will be called whenever there is a media event
*/
public synchronized void controllerUpdate(ControllerEvent event) {
// If we're getting messages from a dead player,
// just leave
if (player == null)
return;

// When the player is Realized, get the visual
// and control components and add them to the Applet
if (event instanceof RealizeCompleteEvent) {
if (progressBar != null) {
panel.remove(progressBar);
progressBar = null;
}

int width = 320;
int height = 0;
if (controlComponent == null)
if (( controlComponent =
player.getControlPanelComponent()) != null) {

controlPanelHeight = controlComponent.getPreferredSize().height;
panel.add(controlComponent);
height += controlPanelHeight;
}
if (visualComponent == null)
if (( visualComponent =
player.getVisualComponent())!= null) {
panel.add(visualComponent);
Dimension videoSize = visualComponent.getPreferredSize();
videoWidth = videoSize.width;
videoHeight = videoSize.height;
width = videoWidth;
height += videoHeight;
visualComponent.setBounds(0, 0, videoWidth, videoHeight);
}

panel.setBounds(0, 0, width, height);
if (controlComponent != null) {
controlComponent.setBounds(0, videoHeight,
width, controlPanelHeight);
controlComponent.invalidate();
}

} else if (event instanceof CachingControlEvent) {
if (player.getState() > Controller.Realizing)
return;
// Put a progress bar up when downloading starts,
// take it down when downloading ends.
CachingControlEvent e = (CachingControlEvent) event;
CachingControl cc = e.getCachingControl();

// Add the bar if not already there ...
if (progressBar == null) {
if ((progressBar = cc.getControlComponent()) != null) {
panel.add(progressBar);
panel.setSize(progressBar.getPreferredSize());
validate();
}
}
} else if (event instanceof EndOfMediaEvent) {
// We've reached the end of the media; rewind and
// start over
player.setMediaTime(new Time(0));
player.start();
} else if (event instanceof ControllerErrorEvent) {
// Tell TypicalPlayerApplet.start() to call it a day
player = null;
Fatal(((ControllerErrorEvent)event).getMessage());
} else if (event instanceof ControllerClosedEvent) {
panel.removeAll();
}
}

void Fatal (String s) {
// Applications will make various choices about what
// to do here. We print a message
System.err.println("FATAL ERROR: " + s);
throw new Error(s); // Invoke the uncaught exception
// handler System.exit() is another
// choice.

}
}

[sanbing]

spa.html文件如下：
<html>
<head>
<title>SimplePlayerApplet</title>
</head>
<body>
<APPLET NAME="SipAppletPhone"
CODE="SimplePlayerApplet.class"
WIDTH=690 HEIGHT=390>
<param name="FILE" value="test.wav">
</APPLET>

</body>
</html>
另一文件test.wav为wav格式声音文件
在jbuilderx下可以正常运行(播放声音文件)，放在web服务器上，出现以下错误：
C:\Documents and Settings\Owner\jbproject\SimplePlayerApplet\classes>appletviewe
r http://211.71.83.164/test/spa.html
java.lang.NoClassDefFoundError: javax/media/ControllerListener
at java.lang.ClassLoader.defineClass0(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:539)
at java.security.SecureClassLoader.defineClass（SecureClassLoader.java:123)
at sun.applet.AppletClassLoader.findClass(AppletClassLoader.java:157)
at java.lang.ClassLoader.loadClass(ClassLoader.java:289)
at sun.applet.AppletClassLoader.loadClass(AppletClassLoader.java:123)
at java.lang.ClassLoader.loadClass(ClassLoader.java:235)
at sun.applet.AppletClassLoader.loadCode(AppletClassLoader.java:561)
at sun.applet.AppletPanel.createApplet(AppletPanel.java:617)
at sun.applet.AppletPanel.runLoader(AppletPanel.java:546)
at sun.applet.AppletPanel.run(AppletPanel.java:298)
at java.lang.Thread.run(Thread.java:534)
用jbuilder打成JAR包后(把jmf打在包里)，放在服务器上(并改了spa.html)，还是出现同样的错误
如何解决？

[sanbing]

搞定了，原因：
1 程序运行需要JMF包inside，所以打成JAR包且里面有JMF程序就可以
2 改为用JAR发布，html需要进行一些修改，在本例中applet标记中要加入archive标记，如下：
<APPLET NAME="SipAppletPhone"
CODE="SimplePlayerApplet"
ARCHIVE="SimplePlayerApplet.jar"
WIDTH=690 HEIGHT=390>
<param name="FILE" value="test.wav">
</APPLET>
标记不能写错，文件名也不能写错，code里的".class"可以写也可以不写
3 好象和安装JMF没有太大的关系，我把JMF uninstall掉了，没有重启，在windows下还可以用appletviewer访问web server上的applet，感觉不应该

[mituzhishi]

祝贺楼主，您真是自学成材！！