[FLINK-22639] ClassLoaderUtil cannot print classpath of FlinkUserCodeClassLoader

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.13.0
• Fix Version/s: 1.14.0
• Component/s: Runtime / Configuration
• Labels: Classloader pull-request-available runtime
• Assignee: Yao Zhang
• Reporter: slankka
• Created: 12/May/21 03:40
• Updated: 28/Aug/21 12:12
• Resolved: 25/May/21 08:51

Description

Hello, community.

I found FlinkUserCodeClassLoader is wrapping by 

SafetyNetWrapperClassLoader, but it cut getURL invoking chain.

 

ClassLoaderUtil.getUserCodeClassLoaderInfo:

public static String getUserCodeClassLoaderInfo(ClassLoader loader) {
        if (loader instanceof URLClassLoader) {
            URLClassLoader cl = (URLClassLoader) loader;

            try {
                StringBuilder bld = new StringBuilder();

                if (cl == ClassLoader.getSystemClassLoader()) {
                    bld.append("System ClassLoader: ");
                } else {
                    bld.append("URL ClassLoader:");
                }

                for (URL url : cl.getURLs()) {
                }
}

SafetyNetWrapperClassLoader(FlinkUserCodeClassLoader inner, ClassLoader parent) {
    super(new URL[0], parent);
    this.inner = inner;
}

The constructor passed an empty array to super class, SafetyNetWrapperClassLoader.getURL should dispatch this invocation.

@Override
public URL[] getURLs() {
    return inner.getURLs();
}

Otherwise,  

ClassLoaderUtil.getUserCodeClassLoaderInfo(theJarClassLoader);

will print empty, like below:

URL ClassLoader:

 
 

Issue Links

• links to: GitHub Pull Request #15927