【发布时间】：2013-04-28 20:29:12
【问题描述】：
我正在为我的第一个 java 类完成一个项目，我正在创建一个 要嵌入到 HTML 中的小程序。我得到一个调用目标异常，但我不能 想办法。我所有的类与 HTML 文件和 jar 文件都在同一个目录中。它们都在我保存所有 java 项目的文件中，如果位置与它有关的话。
这是一个有两个子类的程序，它们是主按钮的事件监听器 班级。它旨在与听众一起计算选票，它正常运行，但不是作为 HTML 小程序。我不认为程序的代码会成为问题，但这里是：
import java.awt.*;
import java.awt.event.*;
public class votes {
static int A;
static int B;
static TextField yescount;
static TextField nocount;
public static void main(String[] args) {
yeslistener yus = new yeslistener();
nolistener nos = new nolistener();
A = 0;
B = 0;
Frame frame = new Frame("Votes");
frame.setSize(600, 600);
frame.setVisible(true);
Label label = new Label("Is java a fun programming language?");
label.setBounds(50, 50, 400, 50);
frame.add(label);
nocount = new TextField("0");
nocount.setBounds(450, 400, 100, 50);
nocount.setForeground(Color.red);
frame.add(nocount);
yescount = new TextField("0");
yescount.setBounds(50, 400, 100, 50);
yescount.setForeground(Color.green);
frame.add(yescount);
Button yes = new Button("Yes");
yes.setBounds(50, 500, 100, 50);
yes.addMouseListener(yus);
frame.add(yes);
Button no = new Button("No");
no.setBounds(450, 500, 100, 50);
no.addMouseListener(nos);
frame.add(no);
Label lbl = new Label();
frame.add(lbl);
}
static class yeslistener extends MouseAdapter {
public void mouseClicked(MouseEvent me) {
A++;
yescount.setText(A + " Votes");
}
}
static class nolistener extends MouseAdapter {
public void mouseClicked(MouseEvent me) {
B++;
nocount.setText(B + " Votes");
}
}
}
我将所有三个类打包到一个 jar 文件中用作存档。 这是我用来调用类和归档 jar 文件的 HTML 文件：
<HTML>
<Head> <title> Votes </title> </head>
<body>
<applet Code= "votes.class"
archive= "votes.jar"
width="600" height="600">
</applet>
</body>
</HTML>
我的 Java 控制台异常如下所示：
basic: exception: java.lang.reflect.InvocationTargetException.
java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at com.sun.deploy.uitoolkit.impl.awt.AWTAppletAdapter.runOnEDTAndWait(Unknown Source)
at com.sun.deploy.uitoolkit.impl.awt.AWTAppletAdapter.instantiateApplet(Unknown Source)
at sun.plugin2.applet.Plugin2Manager.initAppletAdapter(Unknown Source)
at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.reflect.InvocationTargetException
at com.sun.deploy.uitoolkit.impl.awt.OldPluginAWTUtil.invokeAndWait(Unknown Source)
... 5 more
Caused by: java.lang.ClassCastException: votes cannot be cast to java.applet.Applet
at com.sun.deploy.uitoolkit.impl.awt.AWTAppletAdapter$1.run(Unknown Source)
at java.awt.event.InvocationEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$200(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
basic: Removed progress listener: sun.plugin.util.ProgressMonitorAdapter@17c9937
我一直在寻找答案一段时间，我觉得异常没有给我足够的信息来解决所有问题。您能给我的任何帮助将不胜感激，谢谢。
【问题讨论】：
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“我正在为我的第一个 java 类完成一个项目，并且我正在创建一个小程序”（警钟）请参阅 Why CS teachers should stop teaching Java applets 了解为什么我认为在您制作了几个（基于
JFrame的）应用程序之后再制作一个小程序是雄心勃勃的。
标签： java html exception applet awt