001 // Copyright 2005 The Apache Software Foundation 002 // 003 // Licensed under the Apache License, Version 2.0 (the "License"); 004 // you may not use this file except in compliance with the License. 005 // You may obtain a copy of the License at 006 // 007 // http://www.apache.org/licenses/LICENSE-2.0 008 // 009 // Unless required by applicable law or agreed to in writing, software 010 // distributed under the License is distributed on an "AS IS" BASIS, 011 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 012 // See the License for the specific language governing permissions and 013 // limitations under the License. 014 015 package org.apache.tapestry.annotations; 016 017 import java.beans.Introspector; 018 import java.lang.annotation.Annotation; 019 import java.lang.reflect.Method; 020 021 import org.apache.hivemind.ApplicationRuntimeException; 022 import org.apache.hivemind.Location; 023 import org.apache.hivemind.Resource; 024 import org.apache.tapestry.util.DescribedLocation; 025 026 /** 027 * @author Howard M. Lewis Ship 028 * @since 4.0 029 */ 030 031 public class AnnotationUtils 032 { 033 /** 034 * Determines the property name for a method, by stripping off the is/get/set prefix and 035 * decapitalizing the first name. 036 * 037 * @param method 038 * accessor method (get/set/is) 039 * @return the property name for the method 040 * @throws ApplicationRuntimeException 041 * if the method is not an accessor or mutator method 042 */ 043 public static String getPropertyName(Method method) 044 { 045 String name = method.getName(); 046 047 if (name.startsWith("is")) 048 { 049 checkGetter(method); 050 return Introspector.decapitalize(name.substring(2)); 051 } 052 053 if (name.startsWith("get")) 054 { 055 checkGetter(method); 056 return Introspector.decapitalize(name.substring(3)); 057 } 058 059 if (name.startsWith("set")) 060 { 061 checkSetter(method); 062 return Introspector.decapitalize(name.substring(3)); 063 } 064 065 throw new ApplicationRuntimeException(AnnotationMessages.notAccessor(method)); 066 } 067 068 private static void checkGetter(Method method) 069 { 070 if (method.getParameterTypes().length > 0) 071 throw new ApplicationRuntimeException(AnnotationMessages.noParametersExpected(method)); 072 073 if (method.getReturnType().equals(void.class)) 074 throw new ApplicationRuntimeException(AnnotationMessages.voidAccessor(method)); 075 076 } 077 078 private static void checkSetter(Method method) 079 { 080 if (!method.getReturnType().equals(void.class)) 081 throw new ApplicationRuntimeException(AnnotationMessages.nonVoidMutator(method)); 082 083 if (method.getParameterTypes().length != 1) 084 throw new ApplicationRuntimeException(AnnotationMessages.wrongParameterCount(method)); 085 } 086 087 public static Location buildLocationForAnnotation(Method method, Annotation annotation, 088 Resource classResource) 089 { 090 return new DescribedLocation(classResource, AnnotationMessages.methodAnnotation( 091 annotation, 092 method)); 093 } 094 }