Question：Error when use maven plugin

[twogoods]

I want to modify class when compile

        <plugins>
            <plugin>
                <groupId>net.bytebuddy</groupId>
                <artifactId>byte-buddy-maven-plugin</artifactId>
                <version>1.14.4</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>transform</goal>
                        </goals>
                    </execution>
                </executions>
                <configuration>
                    <transformations>
                        <transformation>
                            <groupId>xxx</groupId>
                            <artifactId>xxx</artifactId>
                            <version>${revision}</version>
                            <plugin>org.xxx.TestPlugin</plugin>
                        </transformation>
                    </transformations>
                </configuration>
            </plugin>

exception is

Caused by: java.lang.AbstractMethodError: org.xxx.Generator.wrap(Lnet/bytebuddy/description/type/TypeDescription;Lnet/bytebuddy/jar/asm/ClassVisitor;Lnet/bytebuddy/implementation/Implementation$Context;Lnet/bytebuddy/pool/TypePool;Lnet/bytebuddy/description/field/FieldList;Lnet/bytebuddy/description/method/MethodList;II)Lnet/bytebuddy/jar/asm/ClassVisitor;
	at net.bytebuddy.asm.AsmVisitorWrapper$Compound.wrap(AsmVisitorWrapper.java:746)
	at net.bytebuddy.dynamic.scaffold.TypeWriter$Default$ForInlining$WithFullProcessing$RedefinitionClassVisitor.visit(TypeWriter.java:5004)
	at net.bytebuddy.jar.asm.ClassReader.accept(ClassReader.java:569)
	at net.bytebuddy.jar.asm.ClassReader.accept(ClassReader.java:424)
	at net.bytebuddy.dynamic.scaffold.TypeWriter$Default$ForInlining.create(TypeWriter.java:4014)
	at net.bytebuddy.dynamic.scaffold.TypeWriter$Default.make(TypeWriter.java:2224)
	at net.bytebuddy.dynamic.DynamicType$Builder$AbstractBase$UsingTypeWriter.make(DynamicType.java:4057)
	at net.bytebuddy.build.Plugin$Engine$Default$Preprocessor$Resolved.call(Plugin.java:4893)
	at net.bytebuddy.build.Plugin$Engine$Default$Preprocessor$Resolved.call(Plugin.java:4850)
	at net.bytebuddy.build.Plugin$Engine$Dispatcher$ForSerialTransformation.accept(Plugin.java:3902)
	at net.bytebuddy.build.Plugin$Engine$Default.apply(Plugin.java:4697)
	at net.bytebuddy.build.maven.ByteBuddyMojo.apply(ByteBuddyMojo.java:468)
	... 23 more

code:

public class TestPlugin implements Plugin {
    @Override
    public DynamicType.Builder<?> apply(DynamicType.Builder<?> builder, TypeDescription typeDescription, ClassFileLocator classFileLocator) {
            Generator generator = new Generator();
            return builder.visit(generator);
    }
}

public class Generator implements AsmVisitorWrapper {

    @Override
    public ClassVisitor wrap(
            TypeDescription instrumentedType,
            ClassVisitor classVisitor,
            Implementation.Context implementationContext,
            TypePool typePool,
            FieldList<FieldDescription.InDefinedShape> fields,
            MethodList<?> methods,
            int writerFlags,
            int readerFlags) {
        return new GenerateMethods(classVisitor);
    }

class AsmVisitorWrapper load by same classloader, why get AbstractMethodError ?

[raphw]

That is not clear to me from the example you provide.

Could you try to debug this by mvnDebug? You could intercept the method within the stack and see what the problem is.

[twogoods]

@raphw here is a sample bytebuddy-maven-plugin-test.
api contains bytebuddy build plugin, dependency has buddy and asm; demo build with byte-buddy-maven-plugin

mvn -X clean package will see error

[raphw]

This is merely a consequence of an underlying: java.lang.ClassNotFoundException: org.objectweb.asm.ClassVisitor. Maven swallows this cause.

Do not use byte-buddy-dep but byte-buddy. Then use ClassVisitorFactory to bridge between different shading concepts of ASM.