Re: [jboss-dev] Small boottime improvement

It's this piece of code: package org.jboss.hack; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; /** * Fast method finder. * * @author <a href="mailto:cdewolf@redhat.com">Carlo de Wolf</a> */ public class ClassHack { private static Method COPY; private static Method PRIVATE_GET_DECLARED_METHODS; private static Method SEARCH_METHODS; static { try { COPY = Method.class.getDeclaredMethod("copy"); COPY.setAccessible(true); PRIVATE_GET_DECLARED_METHODS = Class.class.getDeclaredMethod("privateGetDeclaredMethods", Boolean.TYPE); PRIVATE_GET_DECLARED_METHODS.setAccessible(true); SEARCH_METHODS = Class.class.getDeclaredMethod("searchMethods", Method[].class, String.class, Class[].class); SEARCH_METHODS.setAccessible(true); } catch (SecurityException e) { throw new RuntimeException(e); } catch (NoSuchMethodException e) { throw new RuntimeException(e); } } /** * Returns a safe copy of the method. * * @param unsafeMethod * @return */ private static Method copy(Method unsafeMethod) { // TODO: should really use ReflectAccess / LangReflectAccess try { return (Method) COPY.invoke(unsafeMethod); } catch (IllegalArgumentException e) { throw new RuntimeException(e); } catch (IllegalAccessException e) { throw new RuntimeException(e); } catch (InvocationTargetException e) { throw new RuntimeException(e); } } public static Method findMethod(Class<?> cls, String name, Class<?>... parameterTypes) { if(cls == null) return null; Method unsafeMethods[] = getDeclaredMethods(cls, false); Method unsafeMethod = searchMethods(unsafeMethods, name, parameterTypes); if(unsafeMethod != null) return copy(unsafeMethod); return findMethod(cls.getSuperclass(), name, parameterTypes); } /** * Very unsafe, returns references to the cache. * * @param publicOnly * @return */ private static Method[] getDeclaredMethods(Class<?> cls, boolean publicOnly) { try { return (Method[]) PRIVATE_GET_DECLARED_METHODS.invoke(cls, publicOnly); } catch (IllegalArgumentException e) { throw new RuntimeException(e); } catch (IllegalAccessException e) { throw new RuntimeException(e); } catch (InvocationTargetException e) { throw new RuntimeException(e); } } public static Method searchMethods(Method[] methods, String name, Class<?>[] parameterTypes) { try { return (Method) SEARCH_METHODS.invoke(null, methods, name, parameterTypes); } catch (IllegalArgumentException e) { throw new RuntimeException(e); } catch (IllegalAccessException e) { throw new RuntimeException(e); } catch (InvocationTargetException e) { throw new RuntimeException(e); } } } I never committed it, because as Bill says it's a Bad Thing. Not only does it abuse internal methods it also exposes Methods from a cache that lead to huge security holes. So don't commit it, ever. :-) The important bit is that scanning annotations using reflection is extremely slow, so never do that either. Carlo On 02/16/2010 02:20 PM, Kabir Khan wrote: