反射的Utils函数集合
提供访问私有变量 获取泛型类型Class 提取集合中元素的属性等Utils函数
package reflection
import java lang reflect Field 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 List
import mons beanutils PropertyUtils import mons lang StringUtils import slf j Logger import slf j LoggerFactory import springframework util Assert
/** * 反射的Utils函数集合 提供访问私有变量 获取泛型类型Class 提取集合中元素的属性等Utils函数
* * @author lei */ public class ReflectionUtils {
private static Logger logger = LoggerFactory getLogger(ReflectionUtils class)
private ReflectionUtils() { }
/** * 直接读取对象属性值 无视private/protected修饰符 不经过getter函数
*/ 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( 不可能抛出的异常{} e getMessage()) } return result }
/** * 直接设置对象属性值 无视private/protected修饰符 不经过setter函数
*/ 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( 不可能抛出的异常 {} e getMessage()) } }
/** * 循环向上转型 获取对象的DeclaredField */ protected static Field getDeclaredField(final Object object final String fieldName) { Assert notNull(object object不能为空 ) return getDeclaredField(object getClass() fieldName) }
/** * 循环向上转型 获取类的DeclaredField */ @SuppressWarnings( unchecked )
protected static Field getDeclaredField(final Class clazz final String fieldName) { Assert notNull(clazz clazz不能为空 ) Assert hasText(fieldName fieldName ) for (Class superClass = clazz superClass != Object class superClass = superClass getSuperclass()) { try { return superClass getDeclaredField(fieldName) } catch (NoSuchFieldException e) { // Field不在当前类定义 继续向上转型 } } return null }
/** * 强制转换fileld可访问
*/ protected static void makeAccessible(final Field field) { if (!Modifier isPublic(field getModifiers()) || !Modifier isPublic(field getDeclaringClass() getModifiers())) { field setAccessible(true) } }
/** * 通过反射 获得定义Class时声明的父类的泛型参数的类型 如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 Class getSuperClassGenricType(final Class clazz) { return getSuperClassGenricType(clazz ) }
/** * 通过反射 获得定义Class时声明的父类的泛型参数的类型 如public UserDao extends * HibernateDao<User Long>* * @param clazz * clazz The class to introspect * @param index * the Index of the generic ddeclaration start from * @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 <) { 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] }
/** * 提取集合中的对象的属性 组合成List * * @param collection * 来源集合
* @param propertityName * 要提取的属性名
*/ @SuppressWarnings( unchecked )
public static List fetchElementPropertyToList(final Collection collection final String propertyName) throws Exception {
List list = new ArrayList()
for (Object obj collection) { list add(PropertyUtils getProperty(obj propertyName)) }
return list }
/** * 提取集合中的对象的属性 组合成由分割符分隔的字符串
* * @param collection * 来源集合
* @param propertityName * 要提取的属性名
* @param separator * 分隔符
*/ @SuppressWarnings( unchecked )
lishixinzhi/Article/program/Java/hx/201311/26718纯复制:
String 字符串类
System 可得到系统信息
StringBuilder 字符串工具类
Thread 线程类
Math 与数学有关的工具类
ArrayList 底层用数组实现的集合
LinkedList 底层用链表实现的集合
HashMap 接口Map的一个实现类
HashSet 接口Set的一个实现类
Scanner 简单文本扫描器
Calendar 日期类
Date 日期类
File 目录或文件操作类
FileInputStream 输入流
FileOutputStream 输出流
PrintWriter
BufferedInputStream 具有缓冲的输入流
BufferedOutputStream 具有缓冲的输出流
BufferedReader 从字符输入流中读取文本,缓冲各个字符,