Using the following code I get a NoClassDefFoundError caused by ClassNotFoundException:
File file = new File( "C:\\prototype.core.bl.xmodelval.xmodel-1.0.0.jar" );
URL url = file.toURI().toURL();
URL[] urls = new URL[] { url };
ClassLoader cl = new URLClassLoader( urls );
Class cls = cl.loadClass("de.zeb.control.prototype.core.bl.xmodelval.xmodel.entity.EntityNameLengthXModelValidationRule" );
The jar and the class in the jar are definitely available. The following exception is thrown by cl.loadClass. The full exception stack trace follows:
Exception in thread "main" java.lang.NoClassDefFoundError: de/zeb/control/prototype/core/bl/xmodelval/XModelValidationRule
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631)
at java.lang.ClassLoader.defineClass(ClassLoader.java:615)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631)
at java.lang.ClassLoader.defineClass(ClassLoader.java:615)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
at de.zeb.control.prototype.core.bl.xmodelval.jarwelfare.loader.XModelJarLoader.load(XModelJarLoader.java:32)
at de.zeb.control.prototype.core.bl.xmodelval.jarwelfare.supplier.Runner.main(Runner.java:29)
Caused by: java.lang.ClassNotFoundException: de.zeb.control.prototype.core.bl.xmodelval.XModelValidationRule
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
... 24 more
It seems strange for me that the full class name of the ClassNotFoundException doesn't match the name of the cl.loadClass.
Thank you for your help.
You might need to provide parent classloader, because otherwise the classloader you define won't be able to access any classes already present in your application. Eg:
ClassLoader cl = new URLClassLoader( urls , getClass().getClassLoader());
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