Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * KIND, either express or implied. See the License for the * specific language governing permissions and limitations * under the License. */ package org.apache.qpid.disttest.message; import java.beans.PropertyDescriptor; import java.lang.annotation.Annotation; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; import java.util.HashMap; import java.util.Map; import org.apache.commons.beanutils.PropertyUtils; public class ParticipantAttributeExtractor { public static Map<ParticipantAttribute, Object> getAttributes(Object targetObject) { Map<ParticipantAttribute, Object> attributes = new HashMap<ParticipantAttribute, Object>(); PropertyDescriptor[] descriptors = PropertyUtils.getPropertyDescriptors(targetObject); for (PropertyDescriptor propertyDescriptor : descriptors) { final Method readMethod = getPropertyReadMethod(targetObject, propertyDescriptor); for (Annotation annotation : readMethod.getDeclaredAnnotations()) { if (annotation instanceof OutputAttribute) { OutputAttribute outputAttribute = (OutputAttribute) annotation; Object value = getPropertyValue(targetObject, propertyDescriptor.getName()); attributes.put(outputAttribute.attribute(), value); } } } return attributes; } public static Method getPropertyReadMethod(Object targetObject, PropertyDescriptor propertyDescriptor) { final Method readMethod = propertyDescriptor.getReadMethod(); if (readMethod == null) { throw new RuntimeException( "No read method for property " + propertyDescriptor.getName() + " on " + targetObject); } return readMethod; } public static Object getPropertyValue(Object targetObject, String propertyName) { try { return PropertyUtils.getProperty(targetObject, propertyName); } catch (IllegalAccessException e) { throw new RuntimeException("Couldn't get value of property " + propertyName + " from " + targetObject, e); } catch (InvocationTargetException e) { throw new RuntimeException("Couldn't get value of property " + propertyName + " from " + targetObject, e); } catch (NoSuchMethodException e) { throw new RuntimeException("Couldn't get value of property " + propertyName + " from " + targetObject, e); } } }