Exception in thread “main” java.lang.NoClassDefFoundError Caused by: java.lang.ClassNotFoundExceptio

[morpheous.sigma]

I am new to Java, although I have several years experience with other langs(e.g. C/C++ etc). I am trying to run an example program, which uses Ant for its build. I have struggled to get rid of the ClassNotFoundException being thrown for the last four days and despite trying various solutions postedelsewhere on the Internet, I have been unable to solve the problem.

I wonder if anyone on here can help.

Here is the stack trace, (as well as my attempts to solve the problem):


$ ./init-og-examples-db.sh
### Creating empty database
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/tools/ant/Task
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:634)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:277)
at java.net.URLClassLoader.access$000(URLClassLoader.java:73)
at java.net.URLClassLoader$1.run(URLClassLoader.java:212)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
at java.lang.ClassLoader.loadClass(ClassLoader.java:321)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:294)
at java.lang.ClassLoader.loadClass(ClassLoader.java:266)
Caused by: java.lang.ClassNotFoundException: org.apache.tools.ant.Task
at java.net.URLClassLoader$1.run(URLClassLoader.java:217)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
at java.lang.ClassLoader.loadClass(ClassLoader.java:321)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:294)
at java.lang.ClassLoader.loadClass(ClassLoader.java:266)
.... 11 more
Could not find the main class: com.opengamma.util.test.DbTool. Program willexit.
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/tools/ant/Task
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:634)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:277)
at java.net.URLClassLoader.access$000(URLClassLoader.java:73)
at java.net.URLClassLoader$1.run(URLClassLoader.java:212)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
at java.lang.ClassLoader.loadClass(ClassLoader.java:321)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:294)
at java.lang.ClassLoader.loadClass(ClassLoader.java:266)
Caused by: java.lang.ClassNotFoundException: org.apache.tools.ant.Task
at java.net.URLClassLoader$1.run(URLClassLoader.java:217)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
at java.lang.ClassLoader.loadClass(ClassLoader.java:321)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:294)
at java.lang.ClassLoader.loadClass(ClassLoader.java:266)
.... 11 more
Could not find the main class: com.opengamma.util.test.DbTool. Program willexit.
### Adding example data
Exception in thread "main" java.lang.NoClassDefFoundError: com/opengamma/examples/tool/ExampleDatabasePopulator
Caused by: java.lang.ClassNotFoundException: com.opengamma.examples.tool.ExampleDatabasePopulator
at java.net.URLClassLoader$1.run(URLClassLoader.java:217)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
at java.lang.ClassLoader.loadClass(ClassLoader.java:321)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:294)
at java.lang.ClassLoader.loadClass(ClassLoader.java:266)
Could not find the main class: com.opengamma.examples.tool.ExampleDatabasePopulator. Program will exit.
### Completed


I am runing on Ubuntu 12.0.4 and my environment settings are as follows:


echo $ANT_HOME
/usr/local/apache-ant-1.9.1
echo $JAVA_HOME
/usr/lib/jvm/java-7-oracle/jre


I have set my CLASSPATH as follows:

export CLASSPATH=$CLASSPATH:/usr/local/apache-ant-1.9.1/etc:/usr/local/apache-ant-1.9.1/lib


Can anyone tell me what I am doing wrong?

 

[markspace]

export CLASSPATH=$CLASSPATH:/usr/local/apache-ant-1.9.1/etc:/usr/local/apache-ant-1.9.1/lib

This is probably your mistake here. Despite the similar names,
CLASSPATH does not work like the PATH environment variables in Unix.
You have to set the classpath to the actual name of the Jar file you
want to use, or use a '*' as the final element of the class path to use
all Jar files in a directory. Doing neither of those, like you have,
actually looks for 'lose' .class files in the file hierarchy.

export
CLASSPATH=$CLASSPATH:/usr/local/apache-ant-1.9.1/etc/*:/usr/local/apache-ant-1.9.1/lib/*

or

export
CLASSPATH=$CLASSPATH:/usr/local/apache-ant-1.9.1/etc/some-ant.jar:/usr/local/apache-ant-1.9.1/lib/another.jar

 

[Lew]

This is probably your mistake here. Despite the similar names,
CLASSPATH does not work like the PATH environment variables in Unix.

All of which is thoroughly explained in the online Java documentation.

You have to set the classpath to the actual name of the Jar file you
want to use, or use a '*' as the final element of the class path to use
all Jar files in a directory. Doing neither of those, like you have,
actually looks for 'lose' .class files in the file hierarchy.

Did you mean "'loose'"?

export
CLASSPATH=$CLASSPATH:/usr/local/apache-ant-1.9.1/etc/*:/usr/local/apache-ant-1.9.1/lib/*

or

export
CLASSPATH=$CLASSPATH:/usr/local/apache-ant-1.9.1/etc/some-ant.jar:/usr/local/apache-ant-1.9.1/lib/another.jar

OP, do read the documentation as this will give you the full story.