我的课程路径出了什么问题？
[英]What's wrong with my classpath?
问题描述
I'm trying to make an applet with jPCT. 
我正在尝试用jPCT做一个applet。 Using jPCT requires that the jPCT jar be added to the classpath. 使用jPCT要求将jPCT jar添加到类路径。 I thought I had it, but I'm still getting a class not found exception about one of jPCT's classes. 我以为自己拥有了，但是我仍然得到一个关于jPCT类之一的类未被发现的异常。
My commands: 我的命令：
$ javac -classpath /var/www/html/jpct.jar:. /var/www/html/HelloWorld.java
$ jar cf /var/www/html/HelloWorld.jar /var/www/html/HelloWorld.class
My HTML: 我的HTML：
<html>
<head>
<title>Hello World</title>
</head>
<body>
<applet code="HelloWorld"
width=640
height=480
archive="http://applet/HelloWorld.jar,http://applet/jpct.jar">
</applet>
</body>
</html>
I'm using Apache and I have verified that my jars are downloadable from the URLs in my code. 我正在使用Apache，并且已经验证可以从代码中的URL下载我的jar。
The exact error message: 确切的错误信息：
$ firefox http://applet/HelloWorld.html
java version "1.6.0_22"
OpenJDK Runtime Environment (IcedTea6 1.10.2) (6b22-1.10.2-0ubuntu1~11.04.1)
OpenJDK Server VM (build 20.0-b11, mixed mode)
(firefox-bin:15296): LIBDBUSMENU-GTK-CRITICAL **: dbusmenu_menuitem_property_set_shortcut: assertion `gtk_accelerator_valid(key, modifier)' failed
Unable to use Firefox's proxy settings. Using "DIRECT" as proxy type.
java.lang.NoClassDefFoundError: com/threed/jpct/World
at HelloWorld.init(HelloWorld.java:18)
at sun.applet.AppletPanel.run(AppletPanel.java:436)
at net.sourceforge.jnlp.NetxPanel.run(NetxPanel.java:69)
at java.lang.Thread.run(Thread.java:679)
Caused by: java.lang.ClassNotFoundException: com.threed.jpct.World
at java.net.URLClassLoader$1.run(URLClassLoader.java:217)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
at net.sourceforge.jnlp.runtime.JNLPClassLoader$CodeBaseClassLoader.findClass(JNLPClassLoader.java:1348)
at java.lang.ClassLoader.loadClass(ClassLoader.java:321)
at java.lang.ClassLoader.loadClass(ClassLoader.java:266)
... 4 more
Exception in thread "TimerQueue" java.lang.IllegalMonitorStateException
at java.util.concurrent.locks.ReentrantLock$Sync.tryRelease(ReentrantLock.java:155)
at java.util.concurrent.locks.AbstractQueuedSynchronizer.release(AbstractQueuedSynchronizer.java:1262)
at java.util.concurrent.locks.ReentrantLock.unlock(ReentrantLock.java:459)
at java.util.concurrent.DelayQueue.take(DelayQueue.java:205)
at javax.swing.TimerQueue.run(TimerQueue.java:167)
at java.lang.Thread.run(Thread.java:679)
What am I doing wrong? 我究竟做错了什么？
2 个解决方案
解决方案1
1 已采纳
You have to put your dependencies on the same web server that is serving the Applet .jar file and give the locations either absolutely or relative to the root context of the Applet. 您必须将依赖项放在提供Applet .jar文件的同一Web服务器上，并给出绝对或相对于Applet根上下文的位置。
And you have to load your Applet into your web browser from the web server, not from the file system. 而且，您必须从Web服务器而不是从文件系统将Applet加载到Web浏览器中。
Here is the relevant reading materials. 这是相关的阅读材料。
ARCHIVE = archiveList ARCHIVE = archiveList
This OPTIONAL attribute describes one or more archives containing classes and other resources that will be "preloaded".
if your applet is at /var/www/html/Applet.jar then the simplest thing to do is put your dependencies in the exact same location /var/www/html/jcpt.jar and then you can just refer to it without having to worry about calculating the relative path. 如果您的小程序位于/var/www/html/Applet.jar那么最简单的方法是将依赖项放在完全相同的位置/var/www/html/jcpt.jar ，然后就可以引用它而不必担心计算相对路径。
Example 例
<applet code="HelloWorld"
width=640
height=480
archive="HelloWorld.jar,jpct.jar">
</applet>
解决方案2
-2 2011-06-20 02:24:58
Have you used any server like Tomcat ? 您是否使用过像Tomcat这样的服务器？ If you have, you may need to assign the path of your jar file to it or copy the jpct.jar to the tomcat/lib/ dir . 如果有，则可能需要为其分配jar文件的路径，或将jpct.jar复制到tomcat / lib / dir。
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