Problem with compiling build.xml ( ANT tools) in Eclipse

Question

I was trying to compile my project thru ANT within eclipse...and it gave me error:
Cannot use classic compiler, as it is not available A common solution is to set the environment variable JAVA_HOME to your jdk directory.
     at org.apache.tools.ant.taskdefs.compilers.Javac12.execute(Javac12.java:96)
     at org.apache.tools.ant.taskdefs.Javac.execute(Javac.java:557)
     at org.apache.tools.ant.Task.perform(Task.java:217)
     at org.apache.tools.ant.Target.execute(Target.java:184)
     at org.apache.tools.ant.Target.performTasks(Target.java:202)
     at org.apache.tools.ant.Project.executeTarget(Project.java:601)
     at org.apache.tools.ant.Project.executeTargets(Project.java:560)
     at org.eclipse.ant.internal.core.ant.InternalAntRunner.run(InternalAntRunner.java:262)
     at java.lang.reflect.Method.invoke(Native Method)
     at org.eclipse.ant.core.AntRunner.run(AntRunner.java:233)
     at org.eclipse.ui.externaltools.internal.core.AntFileRunner.execute(AntFileRunner.java:59)
     at org.eclipse.ui.externaltools.internal.core.DefaultRunnerContext.executeRunner(DefaultRunnerContext.java:413)
     at org.eclipse.ui.externaltools.internal.core.DefaultRunnerContext.run(DefaultRunnerContext.java:464)
     at org.eclipse.ui.externaltools.internal.ui.AntLaunchWizard$1.run(AntLaunchWizard.java:117)
     at org.eclipse.jface.operation.ModalContext$ModalContextThread.run(ModalContext.java:98)
Build exception: E:\MyPrograms\ejb\MEJB\Hello\build.xml:33: Cannot use classic compiler, as it is not available A common solution is to set the environment variable JAVA_HOME to your jdk directory.
I already set my JAVA_HOME with jdk1.3.1, but end up with the same error. JRE 1.3.1_07 is installed on my machine and my project contains the installed jre. It appears in both Project properties dialog box and in Installed JRE tab JAVA BUILD PATH of preferences...
my ANT compilation works fine with command line.
Please Help !!

Answer 1

have you did some wrong with the build output path?
i am dont understand clearful.but i am think so ;
example :
the eclipse's default build out path is 'bin',
so,if you compile by this code:
<target name="compile">
<mkdir dir="./class" />
<javac srcdir="./src" destdir="./class"
classpath="com.Ostermiller.util.*"
encoding="${ENCODING}"
debug="on" optimize="off" deprecation="off" />
</target>
* the "ENCODING" 's value is setting in the properties file.
you will maybe get the 'Cannot use classic compiler' error only.
you can change the build output path ,or use the default path ;
I am sorry ,
I was limited in English and was a bigginer of java ,
so that i cant to talk Clearly.
if it cant working fine ,please mail to me :[email protected]
good luck!
Kou.huang