Pour avoir la description d'une méthode version bytecode :

import java.lang.reflect.Constructor;
import java.lang.reflect.Executable;
import java.lang.reflect.Method;
import java.util.concurrent.ThreadPoolExecutor;

public class ByteCodeDescriptor {

    public static void main(String... args) {

        Class clazz = ThreadPoolExecutor.class;

        String result=     ByteCodeDescriptor.getDescriptorForClass(clazz);
        System.out.println("class = " + result);

        for (Method m : ThreadPoolExecutor.class.getMethods()) {
            String resultM= ByteCodeDescriptor.getDescriptor(m);
            System.out.println("method = " + m);
            System.out.println("method result = " + m.getName() + resultM);
        }

        for (Constructor c :     ThreadPoolExecutor.class.getConstructors()) {
        String resultM= ByteCodeDescriptor.getDescriptor(c);
        System.out.println("constructor = " + c);
        System.out.println("constructor result = " + resultM);
    }

}

static String getDescriptorForClass(final Class c)
{
    if(c.isPrimitive())
    {
        if(c==byte.class)
            return "B";
        if(c==char.class)
            return "C";
        if(c==double.class)
            return "D";
        if(c==float.class)
            return "F";
        if(c==int.class)
            return "I";
        if(c==long.class)
            return "J";
        if(c==short.class)
            return "S";
        if(c==boolean.class)
            return "Z";
        if(c==void.class)
            return "V";
        throw new RuntimeException("Unrecognized primitive "+c);
    }
    if(c.isArray()) return c.getName().replace('.', '/');
    return ('L'+c.getName()+';').replace('.', '/');
}

static String getDescriptor(Executable e) {
    String s = "(";
    for (final Class c : e.getParameterTypes())
        s += getDescriptorForClass(c);
    s += ')';
    if (e instanceof Method) {
        Method m = (Method) e;
        return m.getName() + s + getDescriptorForClass(m.getReturnType());
    } else if (e instanceof Constructor) {
        Constructor c = (Constructor) e;
        return "<init>" + s + getDescriptorForClass(void.class);
    }
    throw new RuntimeException("Unrecognized primitive "+e);
}
}