Java tutorial
/** * Copyright (c) 2013-2015 www.javahih.com * * Licensed under the Apache License, Version 2.0 (the "License"); */ package com.hihframework.core.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.beanutils.converters.DateConverter; import org.apache.commons.lang.StringUtils; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.util.Assert; /** * <p> Title:??</p> * <p> Description:springside</p> * <p> Copyright: Copyright (c) 2013 </p> * <p> Company:hihsoft.co.,ltd </p> * @author hihsoft.co.,ltd * @version 1.0 */ public final class ReflectUtil { private static Logger logger = LoggerFactory.getLogger(ReflectUtil.class); /** * @param obj * @param cmpModifier * @return */ private static String[] getFieldsName(Object obj, int cmpModifier) { String[] retValue; Class<?> objClass = obj.getClass(); Field[] fields = objClass.getDeclaredFields(); if (fields != null && !(fields.length < 1)) { int j = 0; for (int i = 0; i < fields.length; i++) { int modifier = fields[i].getModifiers(); if (modifier == cmpModifier) j++; } retValue = new String[j]; j = 0; for (int i = 0; i < fields.length; i++) { int modifier = fields[i].getModifiers(); if (modifier == cmpModifier) { retValue[j] = fields[i].getName(); j++; } } return retValue; } else return null; } public static final String[] getPrivateFieldsName(Object obj) { return getFieldsName(obj, Modifier.PRIVATE); } public static final String[] getProtectedFieldsName(Object obj) { return getFieldsName(obj, Modifier.PROTECTED); } public static final String[] getPublicFieldsName(Object obj) { return getFieldsName(obj, Modifier.PUBLIC); } public static final String[] getAllFieldsName(Object obj) { String[] retValue; Class<?> objClass = obj.getClass(); Field[] fields = objClass.getDeclaredFields(); if (fields != null && !(fields.length < 1)) { retValue = new String[fields.length]; for (int i = 0; i < fields.length; i++) { retValue[i] = fields[i].getName(); } return retValue; } else return null; } private static String[] getMethodsName(Object obj, int cmpModifier, String prefix) { String[] retValue; Class<?> objClass = obj.getClass(); Method[] methods = objClass.getDeclaredMethods(); if (methods != null && !(methods.length < 1)) { int j = 0; for (int i = 0; i < methods.length; i++) { int modifier = methods[i].getModifiers(); if (prefix != null && !prefix.equals("")) { if (modifier == cmpModifier && methods[i].getName().startsWith(prefix)) j++; } else if (modifier == cmpModifier) j++; } retValue = new String[j]; j = 0; for (int i = 0; i < methods.length; i++) { int modifier = methods[i].getModifiers(); if (prefix != null && !prefix.equals("")) { if (modifier == cmpModifier && methods[i].getName().startsWith(prefix)) { retValue[j] = methods[i].getName(); j++; } } else if (modifier == cmpModifier) { retValue[j] = methods[i].getName(); j++; } } return retValue; } else return null; } public static final String[] getPrivateMethodsName(Object obj) { return getMethodsName(obj, Modifier.PRIVATE, null); } public static final String[] getProtectedMethodsName(Object obj) { return getMethodsName(obj, Modifier.PROTECTED, null); } public static final String[] getPublicMethodsName(Object obj) { return getMethodsName(obj, Modifier.PUBLIC, null); } public static final String[] filterPublicMethodsName(Object obj, String prefix) { return getMethodsName(obj, Modifier.PUBLIC, prefix); } private static Method[] getMethods(Object obj, int cmpModifier, String prefix) { Method[] retMethod = null; Class<?> objClass = obj.getClass(); Method[] methods = objClass.getDeclaredMethods(); if (methods != null && !(methods.length < 1)) { int j = 0; for (int i = 0; i < methods.length; i++) { int modifier = methods[i].getModifiers(); if (prefix != null && !prefix.equals("")) { if (modifier == cmpModifier && methods[i].getName().startsWith(prefix)) j++; } else if (modifier == cmpModifier) j++; } retMethod = new Method[j]; j = 0; for (int i = 0; i < methods.length; i++) { int modifier = methods[i].getModifiers(); if (prefix != null && !prefix.equals("")) { if (modifier == cmpModifier && methods[i].getName().startsWith(prefix)) { retMethod[j] = methods[i]; j++; } } else if (modifier == cmpModifier) retMethod[j] = methods[i]; } return retMethod; } else return null; } public static final Method[] getPrivateMethods(Object obj, String prefix) { return getMethods(obj, Modifier.PRIVATE, prefix); } public static final Method[] getProtectedMethods(Object obj, String prefix) { return getMethods(obj, Modifier.PROTECTED, prefix); } public static final Method[] getPublicMethods(Object obj, String prefix) { return getMethods(obj, Modifier.PUBLIC, prefix); } /** * ?, 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 (Exception e) { } } 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 (SecurityException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (NoSuchMethodException e) { // TODO Auto-generated catch block e.printStackTrace(); } } 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(Class<?> clazz) { return (Class<T>) 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 */ 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 ??????. */ public static List<Object> convertElementPropertyToList(final Collection<?> collection, final String propertyName) { List<Object> list = new ArrayList<Object>(); 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 . */ public static String convertElementPropertyToString(final Collection<?> collection, final String propertyName, final String separator) { List<Object> list = convertElementPropertyToList(collection, propertyName); return StringUtils.join(list, separator); } /** * ?clazzproperty. * * @param value ? * @param clazz ???Class * @param propertyName ???Class. */ public static Object convertValue(Object value, Class<?> toType) { try { 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); 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 || e instanceof InvocationTargetException) return new IllegalArgumentException("Reflection Exception.", e); else return new RuntimeException(e); } /** * * @param obj * @param fieldName * @return * @author Xiaojf * @since 2011-9-9 */ public static Class<?> getGenericType(Class<?> obj, String fieldName) { try { Field field = getDeclaredField(obj, fieldName); if (field != null) { ParameterizedType pt = (ParameterizedType) field.getGenericType(); if (pt != null && pt.getActualTypeArguments() != null) { Type[] types = pt.getActualTypeArguments(); if (types.length > 0) { return (Class<?>) types[0]; } } } } catch (Exception e) { } return null; } public static String getRootClassName(Class<?> clazz) { String name = clazz.getName(); int index = name.lastIndexOf("."); return name.substring(index + 1); } }