Eclipse Ant ClassPath问题

Question

Using Eclipse Juno on Java 1.8

    eclipse.buildId=M20130204-1200
    java.version=1.8.0_45
    java.vendor=Oracle Corporation
    BootLoader constants: OS=win32, ARCH=x86, WS=win32, NL=en_US
    Command-line arguments:  -os win32 -ws win32 -arch x86



    Error
    Tue Jul 21 10:25:12 EDT 2015
    Could not find one or more classes: "org.apache.tools.ant.BuildException". Please check the Ant classpath.

java.lang.NoClassDefFoundError: org/apache/tools/ant/BuildException
    at java.lang.Class.getDeclaredConstructors0(Native Method)
    at java.lang.Class.privateGetDeclaredConstructors(Class.java:2671)
    at java.lang.Class.getConstructor0(Class.java:3075)
    at java.lang.Class.newInstance(Class.java:412)
    at org.eclipse.ant.core.AntRunner.run(AntRunner.java:324)
    at org.eclipse.ant.internal.launching.launchConfigurations.AntLaunchDelegate$1.run(AntLaunchDelegate.java:298)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.ClassNotFoundException: org.apache.tools.ant.BuildException
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at org.eclipse.ant.internal.core.AntClassLoader.findClass(AntClassLoader.java:54)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)

Answer 1

Juno ships with a version of ANT which doesn't work with Java 8, you'll need to manually install a version that works.

It's detailed here

https://wiki.eclipse.org/Ant/Java8

https://bugs.eclipse.org/bugs/show_bug.cgi?id=395421

So you need to move to Luna or upgrade Ant manually.

Answer 2

There can be two possibilities: First Your ANT_HOME has the default enties and has the older version of ANT.

Go and manually change the entry there and include the required JAR

Preferences > Ant > Runtime > Classpath > Ant Home Entries (Default)

2. Check if the ANT jars are present in the LIB folder.
3. Your ANT_HOME has not been configured. Go in the above path and configure.