Class loading issue for code located in buildSrc

Help/Discuss
1

Hi,

I will use a custom subclass of DefaultTemplateBasedStartScriptGenerator in my project build. The class source code is located somewhere under the buildSrc directory. My script generator class provides a method similar to DefaultTemplateBasedStartScriptGenerator.utf8ClassPathResource(), in particular that method also makes use of class com.google.common.io.CharSource:

public class StartScriptGenerator extends DefaultTemplateBasedStartScriptGenerator {
    
    public StartScriptGenerator(File templateFile) {
        super(
                TextUtil.getUnixLineSeparator(),
                StartScriptTemplateBindingFactory.unix(),
                utf8FileResource(templateFile)
        );
    }
    
    private static TextResource utf8FileResource(final File file) {
        return new CharSourceBackedTextResource(new CharSource() {
            @Override
            public Reader openStream() throws IOException {
                InputStream stream = new FileInputStream(file);
                return new BufferedReader(new InputStreamReader(stream, CharsetUtil.UTF_8));
            }
        });
    }
}

In order to get rid of a NoClassDefFoundError for class CharSource I needed to explicitly add guava to the dependencies of the buildSrc subproject:

dependencies {
    compile gradleApi()
    compile localGroovy()
    compile 'com.google.guava:guava:18.0'
}

However now I run into the following exception which I am unable to resolve:

Caused by: java.lang.LinkageError: loader constraint violation: when resolving method "org.gradle.api.internal.resources.CharSourceBackedTextResource.<init>(Lcom/google/common/io/CharSource;)V" the class loader (instance of java/net/URLClassLoader) of the current class, xyz/StartScriptGenerator, and the class loader (instance of org/gradle/internal/classloader/MutableURLClassLoader) for the method's defining class, org/gradle/api/internal/resources/CharSourceBackedTextResource, have different Class objects for the type com/google/common/io/CharSource used in the signature

Question: is there a way to get the guava libraries included in the compile class path that does not produce the linkage error?

2

I think the reason for this exception is, that you use a different guava
version than gradle does. try this one instead:

‘com.google.guava:guava-jdk5:17.0@jar’,

This is the version which is currently used in gradle master.

3

Rene,

thanks for your response. Using that dependency doesn’t solve the problem. I even killed the build daemon just to be sure, but the same linkage error persists. I am using gradle 2.5.