===javac error===

[solt]

after install jdk

set path=C:\Program Files\Java\jdk1.6.0_17\bin
set classpath=C:\Program Files\Java\jdk1.6.0_17\lib\tools.jar;C:\Program Files\Java\jdk1.6.0_17\lib\dt.jar

when i typed "javac" in command line ,shows the following error:

C:\Documents and Settings\Administrator>javac
Exception in thread "main" java.lang.NoClassDefFoundError: com/sun/tools/javac/Main
used by: java.lang.ClassNotFoundException: com.sun.tools.javac.Main
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)
Could not find the main class: com.sun.tools.javac.Main. Program will exit.

i compile java file,it also show the error above
but when i enter "java",it works

[JosAH]

Get rid of that classpath; javac (as well as java and javaw) are native executable files and they know where to find the core classes.

kind regards,

Jos

[solt]

i try it as you said ,but it doesn't work
same error

[JosAH]

i try it as you said ,but it doesn't work
same error

Are you sure that 'classpath' environment variable is gone? Did you do a default install?

kind regards,

Jos

[solt]

Are you sure that 'classpath' environment variable is gone? Did you do a default install?

kind regards,

Jos

yes,i deleted 'classpath'
and did a default install

[JosAH]

yes,i deleted 'classpath'
and did a default install

What happens when you type "echo %classpath%"? Is it really gone? To make sure, quit your shell/cmd and start a new one.

kind regards,

Jos

[solt]

What happens when you type "echo %classpath%"? Is it really gone? To make sure, quit your shell/cmd and start a new one.

kind regards,

Jos

yes,i entered "echo %classpath%",it returns "%classpath%" only

[JosAH]

yes,i entered "echo %classpath%",it returns "%classpath%" only

Hm, next to the bin directory you'll find a lib directory; does it contain a tools.jar file? If so open it with a zip program (but don't extract anything). Can you find the class com.sun.tools.javac.Main? If that directory (or that file) isn't there your installation might be corrupted by something ...

kind regards,

Jos

[solt]

Hm, next to the bin directory you'll find a lib directory; does it contain a tools.jar file? If so open it with a zip program (but don't extract anything). Can you find the class com.sun.tools.javac.Main? If that directory (or that file) isn't there your installation might be corrupted by something ...

kind regards,

Jos

yes,there is a 'Main.class' there

[JosAH]

yes,there is a 'Main.class' there

I'm running out of ideas ... what happens when you type in "javac.exe"? (including the extension). Try that both in and outside that bin directory.

kind regards,

Jos

[solt]

I'm running out of ideas ... what happens when you type in "javac.exe"? (including the extension). Try that both in and outside that bin directory.

kind regards,

Jos

in the bin directory the "javac.exe" execute success,outside it failures

[JosAH]

in the bin directory the "javac.exe" execute success,outside it failures

Fails how? Does it show those exception stack traces or can't it find an executable file named "javac". If it's the latter check your path variable.

Do you have other java versions installed?

kind regards,

Jos

[solt]

Fails how? Does it show those exception stack traces or can't it find an executable file named "javac". If it's the latter check your path variable.

Do you have other java versions installed?

kind regards,

Jos

it shows the same error above ,and i just have one java version installed.

[JosAH]

it shows the same error above ,and i just have one java version installed.

Let me get this straight: if you type just "javac" in your bin directory you get a listing on the screen that tells you how to use the compiler and its flags, right? But if you type that same outside of your bin directory you get that exception stack trace, right?

If you use your 'search' facility in Microsoft Windows and search for "javac", what are the results?

kind regards,

Jos

[solt]

Let me get this straight: if you type just "javac" in your bin directory you get a listing on the screen that tells you how to use the compiler and its flags, right? But if you type that same outside of your bin directory you get that exception stack trace, right?

If you use your 'search' facility in Microsoft Windows and search for "javac", what are the results?

kind regards,

Jos

just now,i find when i type javac after set path="C:\Program Files\Java\jdk1.6.0_17\bin" ,it works,but it failures after i close the cmd and type javac again

[JosAH]

just now,i find when i type javac after set path="C:\Program Files\Java\jdk1.6.0_17\bin" ,it works,but it failures after i close the cmd and type javac again

Yes, that's what happens: if you define environment variables in your cmd they're only valid during that session (as long as that particular cmd runs) and they're gone when your cmd is gone. Use your control panel to set those environment variables permanently.

But what happened to that mysterious exception stack trace?

kind regards,

Jos

[solt]

Yes, that's what happens: if you define environment variables in your cmd they're only valid during that session (as long as that particular cmd runs) and they're gone when your cmd is gone. Use your control panel to set those environment variables permanently.

But what happened to that mysterious exception stack trace?

kind regards,

Jos

i use control panel set those environment variables from the beginning

[solt]

i reinstall the xp system ,and erverthing is ok
thanks for you help

[JosAH]

i reinstall the xp system ,and erverthing is ok
thanks for you help

What OS did you have installed before? I have installed Java on XP, Vista and 7 without problems ...

kind regards,

Jos

[solt]

What OS did you have installed before? I have installed Java on XP, Vista and 7 without problems ...

kind regards,

Jos

i installed it also on xp before.