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/** * Copyright (c) 2005-2009 springside.org.cn * * Licensed under the Apache License, Version 2.0 (the "License"); * * $Id: ReflectionUtils.java 763 2009-12-27 18:36:21Z calvinxiu $ */ package com.klwork.common.utils; import java.lang.reflect.Field; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; import java.lang.reflect.Modifier; import java.lang.reflect.ParameterizedType; import java.lang.reflect.Type; import java.util.ArrayList; import java.util.Collection; import java.util.Date; import java.util.List; import org.apache.commons.beanutils.ConvertUtils; import org.apache.commons.beanutils.PropertyUtils; import org.apache.commons.lang.StringUtils; import org.apache.commons.lang.builder.ReflectionToStringBuilder; import org.apache.commons.lang.builder.ToStringStyle; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.util.Assert; /** * ??. * * ?????,?Class,????,?Util. * * @author calvin */ public class ReflectionUtils { private static Logger logger = LoggerFactory.getLogger(ReflectionUtils.class); static { /*DateConverter dc = new DateConverter(); dc.setUseLocaleFormat(true); dc.setPatterns(new String[] { "yyyy-MM-dd", "yyyy-MM-dd HH:mm:ss" }); ConvertUtils.register(dc, Date.class);*/ } /** * Getter. */ public static Object invokeGetterMethod(Object target, String propertyName) { String getterMethodName = "get" + StringUtils.capitalize(propertyName); return invokeMethod(target, getterMethodName, new Class[] {}, new Object[] {}); } /** * Setter.valueClass?Setter. */ public static void invokeSetterMethod(Object target, String propertyName, Object value) { invokeSetterMethod(target, propertyName, value, null); } /** * Setter. * * @propertyType Setter,valueClass. */ public static void invokeSetterMethod(Object target, String propertyName, Object value, Class<?> propertyType) { Class<?> type = propertyType != null ? propertyType : value.getClass(); String setterMethodName = "set" + StringUtils.capitalize(propertyName); invokeMethod(target, setterMethodName, new Class[] { type }, new Object[] { value }); } /** * ?, private/protected, ??getter. */ public static Object getFieldValue(final Object object, final String fieldName) { Field field = getDeclaredField(object, fieldName); if (field == null) { throw new IllegalArgumentException( "Could not find field [" + fieldName + "] on target [" + object + "]"); } makeAccessible(field); Object result = null; try { result = field.get(object); } catch (IllegalAccessException e) { logger.error("??{}", e.getMessage()); } return result; } /** * , private/protected, ??setter. */ public static void setFieldValue(final Object object, final String fieldName, final Object value) { Field field = getDeclaredField(object, fieldName); if (field == null) { throw new IllegalArgumentException( "Could not find field [" + fieldName + "] on target [" + object + "]"); } makeAccessible(field); try { field.set(object, value); } catch (IllegalAccessException e) { logger.error("??:{}", e.getMessage()); } } /** * , private/protected. */ public static Object invokeMethod(final Object object, final String methodName, final Class<?>[] parameterTypes, final Object[] parameters) { Method method = getDeclaredMethod(object, methodName, parameterTypes); if (method == null) { throw new IllegalArgumentException( "Could not find method [" + methodName + "] on target [" + object + "]"); } method.setAccessible(true); try { return method.invoke(object, parameters); } catch (Exception e) { throw convertReflectionExceptionToUnchecked(e); } } /** * ?, ?DeclaredField. * * ?Object?, null. */ protected static Field getDeclaredField(final Object object, final String fieldName) { Assert.notNull(object, "object?"); Assert.hasText(fieldName, "fieldName"); for (Class<?> superClass = object.getClass(); superClass != Object.class; superClass = superClass .getSuperclass()) { try { return superClass.getDeclaredField(fieldName); } catch (NoSuchFieldException e) { // Field??,? } } return null; } /** * Field?. */ protected static void makeAccessible(final Field field) { if (!Modifier.isPublic(field.getModifiers()) || !Modifier.isPublic(field.getDeclaringClass().getModifiers())) { field.setAccessible(true); } } /** * ?,?DeclaredMethod. * * ?Object?, null. */ protected static Method getDeclaredMethod(Object object, String methodName, Class<?>[] parameterTypes) { Assert.notNull(object, "object?"); for (Class<?> superClass = object.getClass(); superClass != Object.class; superClass = superClass .getSuperclass()) { try { return superClass.getDeclaredMethod(methodName, parameterTypes); } catch (NoSuchMethodException e) { // Method??,? } } return null; } /** * ??,Class?. * , Object.class. * eg. * public UserDao extends HibernateDao<User> * * @param clazz The class to introspect * @return the first generic declaration, or Object.class if cannot be determined */ @SuppressWarnings("unchecked") public static <T> Class<T> getSuperClassGenricType(final Class clazz) { return getSuperClassGenricType(clazz, 0); } /** * ??,Class?. * , Object.class. * * public UserDao extends HibernateDao<User,Long> * * @param clazz clazz The class to introspect * @param index the Index of the generic ddeclaration,start from 0. * @return the index generic declaration, or Object.class if cannot be determined */ @SuppressWarnings("unchecked") public static Class getSuperClassGenricType(final Class clazz, final int index) { Type genType = clazz.getGenericSuperclass(); if (!(genType instanceof ParameterizedType)) { logger.warn(clazz.getSimpleName() + "'s superclass not ParameterizedType"); return Object.class; } Type[] params = ((ParameterizedType) genType).getActualTypeArguments(); if (index >= params.length || index < 0) { logger.warn("Index: " + index + ", Size of " + clazz.getSimpleName() + "'s Parameterized Type: " + params.length); return Object.class; } if (!(params[index] instanceof Class)) { logger.warn(clazz.getSimpleName() + " not set the actual class on superclass generic parameter"); return Object.class; } return (Class) params[index]; } /** * ????(getter), ??List. * * @param collection ???. * @param propertyName ??????. */ @SuppressWarnings("unchecked") public static List convertElementPropertyToList(final Collection collection, final String propertyName) { List list = new ArrayList(); try { for (Object obj : collection) { list.add(PropertyUtils.getProperty(obj, propertyName)); } } catch (Exception e) { throw convertReflectionExceptionToUnchecked(e); } return list; } /** * ????(getter), ??. * * @param collection ???. * @param propertyName ??????. * @param separator . */ @SuppressWarnings("unchecked") public static String convertElementPropertyToString(final Collection collection, final String propertyName, final String separator) { List list = convertElementPropertyToList(collection, propertyName); return StringUtils.join(list, separator); } /** * ?. * * @param value ? * @param toType ? */ public static Object convertStringToObject(String value, Class<?> toType) { try { return ConvertUtils.convert(value, toType); } catch (Exception e) { throw convertReflectionExceptionToUnchecked(e); } } /** * ??checked exception?unchecked exception. */ public static RuntimeException convertReflectionExceptionToUnchecked(Exception e) { if (e instanceof IllegalAccessException || e instanceof IllegalArgumentException || e instanceof NoSuchMethodException) { return new IllegalArgumentException("Reflection Exception.", e); } else if (e instanceof InvocationTargetException) { return new RuntimeException("Reflection Exception.", ((InvocationTargetException) e).getTargetException()); } else if (e instanceof RuntimeException) { return (RuntimeException) e; } return new RuntimeException("Unexpected Checked Exception.", e); } /** * ?? * * @param object * @return */ public static String toString(Object object) { return new ReflectionToStringBuilder(object, ToStringStyle.DEFAULT_STYLE).toString(); } /** * copy * @param <T> * @param oldObject * @param newObject * @param names * @param types */ public static <T> void copyValueFromOtherObject(T oldObject, T newObject, String[] names, Class[] types) { for (int i = 0; i < names.length; i++) { String name = names[i]; Object value = ReflectionUtils.invokeGetterMethod(newObject, name); ReflectionUtils.invokeSetterMethod(oldObject, name, value, types[i]); } } /** * Determine whether the given field is a "public static final" constant. * @param field the field to check */ public static boolean isPublicStatic(Field field) { int modifiers = field.getModifiers(); return (Modifier.isPublic(modifiers) && Modifier.isStatic(modifiers)); } }