import otherpackage.OtherPackageClass; import java.lang.reflect.AccessibleObject; import java.lang.reflect.Constructor; import java.lang.reflect.Field; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; import java.lang.reflect.Type; public class ClassAttrs { ClassAttrs() { /* local, not anonymous, not member */ class ConsInnerNamed { public void showMe() { printClassAttrs(this.getClass()); } } ConsInnerNamed cinner = new ConsInnerNamed(); cinner.showMe(); } public static void main() { printClassAttrs(ClassAttrs.class); printClassAttrs(OtherClass.class); printClassAttrs(OtherPackageClass.class); /* local, not anonymous, not member */ class InnerNamed { public void showMe() { printClassAttrs(this.getClass()); } } InnerNamed inner = new InnerNamed(); inner.showMe(); ClassAttrs attrs = new ClassAttrs(); /* anonymous, not local, not member */ printClassAttrs((new OtherClass() { int i = 5; }).getClass()); /* member, not anonymous, not local */ printClassAttrs(MemberClass.class); try { Constructor cons; cons = MemberClass.class.getConstructor( new Class[] { MemberClass.class }); System.out.println("constructor signature: " + getSignatureAttribute(cons)); Method meth; meth = MemberClass.class.getMethod("foo", (Class[]) null); System.out.println("method signature: " + getSignatureAttribute(meth)); Field field; field = MemberClass.class.getField("mWha"); System.out.println("field signature: " + getSignatureAttribute(field)); } catch (NoSuchMethodException nsme) { System.err.println("FAILED: " + nsme); } catch (NoSuchFieldException nsfe) { System.err.println("FAILED: " + nsfe); } catch (RuntimeException re) { System.err.println("FAILED: " + re); re.printStackTrace(); } } /* to call the (out-of-scope) <code>getSignatureAttribute</code> methods */ public static String getSignatureAttribute(Object obj) { Method method; try { if (obj instanceof AccessibleObject) { method = AccessibleObject.class.getDeclaredMethod( "getSignatureAttribute"); } else { // Should be a Class. method = Class.class.getDeclaredMethod( "getSignatureAttribute"); } method.setAccessible(true); } catch (NoSuchMethodException ex) { System.err.println("getSignatureAttribute() not defined."); ex.printStackTrace(); return "<unknown>"; } try { return (String) method.invoke(obj); } catch (IllegalAccessException ex) { throw new RuntimeException(ex); } catch (InvocationTargetException ex) { throw new RuntimeException(ex); } } /* for reflection testing */ static class MemberClass<XYZ> { public MemberClass<XYZ> mWha; public MemberClass(MemberClass<XYZ> memb) { mWha = memb; } public Class<XYZ> foo() throws NoSuchMethodException { return null; } } /* for reflection testing (getClasses vs getDeclaredClasses) */ static public class PublicMemberClass { float mBlah; } /* * Dump a variety of class attributes. */ public static void printClassAttrs(Class clazz) { final boolean WORKING = false; Class clazz2; System.out.println("***** " + clazz + ":"); System.out.println(" name: " + clazz.getName()); System.out.println(" canonical: " + clazz.getCanonicalName()); System.out.println(" simple: " + clazz.getSimpleName()); System.out.println(" genericSignature: " + getSignatureAttribute(clazz)); System.out.println(" super: " + clazz.getSuperclass()); if (WORKING) System.out.println(" genericSuperclass: " + clazz.getGenericSuperclass()); System.out.println(" declaring: " + clazz.getDeclaringClass()); System.out.println(" enclosing: " + clazz.getEnclosingClass()); System.out.println(" enclosingCon: " + clazz.getEnclosingConstructor()); System.out.println(" enclosingMeth: " + clazz.getEnclosingMethod()); System.out.println(" modifiers: " + clazz.getModifiers()); System.out.println(" package: " + clazz.getPackage()); System.out.println(" declaredClasses: " + stringifyTypeArray(clazz.getDeclaredClasses())); System.out.println(" member classes: " + stringifyTypeArray(clazz.getClasses())); System.out.println(" isAnnotation: " + clazz.isAnnotation()); System.out.println(" isAnonymous: " + clazz.isAnonymousClass()); System.out.println(" isArray: " + clazz.isArray()); System.out.println(" isEnum: " + clazz.isEnum()); System.out.println(" isInterface: " + clazz.isInterface()); System.out.println(" isLocalClass: " + clazz.isLocalClass()); System.out.println(" isMemberClass: " + clazz.isMemberClass()); System.out.println(" isPrimitive: " + clazz.isPrimitive()); System.out.println(" isSynthetic: " + clazz.isSynthetic()); if (WORKING) System.out.println(" genericInterfaces: " + stringifyTypeArray(clazz.getGenericInterfaces())); } /* * Convert an array of Type into a string. Start with an array count. */ private static String stringifyTypeArray(Type[] types) { StringBuilder stb = new StringBuilder(); boolean first = true; stb.append("[" + types.length + "]"); for (Type t: types) { if (first) { stb.append(" "); first = false; } else { stb.append(", "); } stb.append(t.toString()); } return stb.toString(); } }