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初学JAVA 不知错在哪了?

摘要: 初学JAVA 不知错在哪了?

JAVA_HOME
C:/Java/jdk1.5.0_02

CLASSPATH
C:/Java/jdk1.5.0_02/lib/tools.jar;C:/Java/jdk1.5.0_02/lib/dt.jar;

Path
c:/oracle/ora92/bin;C:/Program Files/Oracle/jre/1.3.1/bin;C:/Program Files/Oracle/jre/1.1.8/bin;%SystemRoot%/system32;%SystemRoot%;%SystemRoot%/System32/Wbem;C:/Program Files/Common Files/Autodesk Shared/;%JAVA_HOME%/bin;%JAVA_HOME%/jre/bin;

运行程序
class JavaProgram{
public static void main(String args[]){
System.out.println("afafakfak");
}
}

javac JavaProgram.java
不会报错,能生成CLASS文件.
运行java JavaProgram 时就要报错.

C:/Java/test>java JavaProgram
Exception in thread "main" java.lang.UnsupportedClassVersionError: JavaProgram (
Unsupported major.minor version 49.0)
at java.lang.ClassLoader.defineClass0(Native Method)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.security.SecureClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.access$100(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClassInternal(Unknown Source)


错在哪了?

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试试这样
CLASSPATH
.;C:/Java/jdk1.5.0_02/lib/tools.jar;C:/Java/jdk1.5.0_02/lib/dt.jar;

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很显然，编译的JDK与运行的JRE 版本不对
javac JavaProgram.java的时候

用的是C:/Java/jdk1.5.0_02的编译器

java JavaProgram的时候

用的是Oracle的jre



这样改

把path里面的

%JAVA_HOME%/bin;%JAVA_HOME%/jre/bin; 放到最前面

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楼上说得有道理

Exception in thread "main" java.lang.UnsupportedClassVersionError: JavaProgram (

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up

path C:/jdk1.5.0_02/bin;

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谢谢各位

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