Bad Magic Number” 怎么解决？java报错

Bad Magic Number” 怎么解决？java报错

在编写java的样例代码时出现这种问题。这种情况应该如何解决和避免那？

Java(TM) Plug-in:Version 1.3.1_01

Using JRE version 1.3.1_01 Java HotSpot(TM) Client VM

User home directory = C:\Documentsand Settings\Ankur

Proxy Configuration:Manual Configuration

Proxy: 192.168.11.6:80

java.lang.ClassFormatError:SalesCalculatorAppletBeanInfo (Bad magic number)

at java.lang.ClassLoader.defineClass0(Native Method)

at java.lang.ClassLoader.defineClass(Unknown Source)

at java.security.SecureClassLoader.defineClass(UnknownSource)

at sun.applet.AppletClassLoader.findClass(UnknownSource)

atsun.plugin.security.PluginClassLoader.access$201(Unknown Source)

at sun.plugin.security.PluginClassLoader$1.run(UnknownSource)

at java.security.AccessController.doPrivileged(NativeMethod)

at sun.plugin.security.PluginClassLoader.findClass(UnknownSource)

at java.lang.ClassLoader.loadClass(Unknown Source)

at sun.applet.AppletClassLoader.loadClass(UnknownSource)

at java.lang.ClassLoader.loadClass(Unknown Source)

at java.beans.Introspector.instantiate(Unknown Source)

at java.beans.Introspector.findInformant(UnknownSource)

at java.beans.Introspector.(Unknown Source)

at java.beans.Introspector.getBeanInfo(Unknown Source)

at sun.beans.ole.OleBeanInfo.(Unknown Source)

at sun.beans.ole.StubInformation.getStub(Unknown Source)

at sun.plugin.ocx.TypeLibManager$1.run(Unknown Source)

at java.security.AccessController.doPrivileged(NativeMethod)

at sun.plugin.ocx.TypeLibManager.getTypeLib(UnknownSource)

at sun.plugin.ocx.TypeLibManager.getTypeLib(UnknownSource)

原因是什么，为什么会发生异常，以及下面到底发生了什么。如果有人能帮忙？提前谢谢