尝试使用外部库运行Java时出现NoClassDefFound

Question

I have problem with running my java project.

E:\Workspace\compiled>java -classpath server\libraries\log4j-1.2.16.jar;E:\Workspace\compiled\server\service-1.0-SNAPSHOT.jar;E:\Workspace\compiled\server\libraries\log4j-1.2.16.jar -Djava.security.policy=E:\Workspace\compiled\socket.policy -Djava.rmi.server.codebase=file:///E:\Workspace\compiled\server\service-1.0-SNAPSHOT.jar -jar E:\Workspace\compiled\server\service-1.0-SNAPSHOT.jar E:\Workspace\compiled\log4j.properties
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/log4j/PropertyConfigurator
    at pwr.mgr.server.service.Launcher.main(Launcher.java:18)
Caused by: java.lang.ClassNotFoundException: org.apache.log4j.PropertyConfigurator
    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)
    ... 1 more

It's compiled using maven and I end up with .jar file. I decided today, that I'll use log4j for logging instead of wimple System.out... Before this change it was working fine

here's how I run it

java -cp .;%SRV_ADDR%;%SRV_LIBS% -Djava.security.policy=%POLICY_FILE% -Djava.rmi.server.codebase=file:///%SRV_ADDR% pwr.mgr.server.service.Launcher %CD%\log4j.properties

SRV_ADDR points to my service.jar (with Launcher class)

SRV_LIBS points to log4j-1.2.16.jar

I added ".;" at the begining hoping it would help, because mentioned files are in child directory to the one from I am trying to launch this.

I should also mention that I need to haev log4j library somewhere here, because I will be moving my app onto another machine and I don't know what libraries to expect there, maybe only pure java, so I need to deliver everything in one package.

If anyone is interested in Launcher class it's very simple:

public class Launcher {

public static void main(String args[]) {
    PropertyConfigurator.configure(args[0]);
    if (System.getSecurityManager() == null) {
        System.setSecurityManager(new SecurityManager());
    }

    try {
        Runtime.getRuntime().exec("rmiregistry");
        ServerIntf obj = new Server();
        Registry registry = LocateRegistry.getRegistry();
        registry.rebind("Server", obj);
        System.out.println("Server bound in registry");
    } catch (Exception e) {
        System.out.println("Server err: " + e.getMessage());
        e.printStackTrace();
    }
}
}

Does anyone have any idea what am I doing wrong? Maybe adding only this one log4j jar file is not enough? I copied it from my maven repository.

EDIT1 already changed jar i'm pointing to from log4j-1.2.16-javadoc.jar to log4j-1.2.16.jar but it didn't help

Answer 1

When using java -jar ... , the -classpath argument is ignored . Either specify all necessary jars in the manifest of your main jar (but you can only use relative paths there), or add your main jar to the -classpath and mention the main class on the command line.

Yes, I don't like this, too.

Answer 2

SRV_LIBS points to log4j-1.2.16-javadoc.jar

Usually the "-javadoc" in the name means that the jar contains no code - only javadoc documentation. Try log4j-1.2.16.jar instead.

Answer 3

It looks like you're pointing to the wrong log4j jar.

You currently have -classpath server\\libraries\\log4j-1.2.16-javadoc.jar; which tries to load the javadoc jar file.

Try using -classpath server\\libraries\\log4j-1.2.16.jar; instead.

Answer 4

For starters, you are using the log4j javadoc jar. That only contains javadoc documentation and not any class files. You need to be using log4j-1.2.16.jar.