以前发过一个自己编写的通过类反射机制实现的非常好用的JAVA动态类处理源码，后来在网上又看到一个同样通过反射完成动态类处理的Java类，感觉在代码简洁与程序处理上都较我的强，就在其基础上做了些修改完善，共享给大家。
ClassReflect.java
import java.lang.reflect.Array;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
/**
* Java Reflection Cookbook
*
* @author Michael Lee
* @author sidac modified at 2007-9-7
* @since 2006-8-23
* @version 0.1a
*/
public class ClassReflect {
/**
* 得到某个对象的公共属性
* @param owner 对象
* @param fieldName 属性
* @return 该属性对象
* @throws ReflectionErrorException 反射操作抛出例外
*/
public static Object getProperty(Object owner, String fieldName) throws ReflectionErrorException{
try {
Class ownerClass = owner.getClass();
Object property = null;
try{
//优先处理提供Getter方法的(非)公共属性(为POJO类的属性处理提供方便)
property = invokeMethod(owner, "get" + upperFirstChar(fieldName), null);
} catch (ReflectionErrorException e){
//按Getter方法没提取到再按Public属性提取下
Field field = ownerClass.getField(fieldName);
property = field.get(owner);
}
return property;
} catch (Exception e) {
//May happen Exception:
//SecurityException, NoSuchFieldException, IllegalArgumentException, IllegalAccessException
throw new ReflectionErrorException("Get object property error.", e);
}
}
/**
* 设置某个对象的公共属性
* @param owner 对象
* @param fieldName 属性
* @param value 设置值
* @return 该属性对象
* @throws ReflectionErrorException 反射操作抛出例外
*/
public static void setProperty(Object owner, String fieldName, Object value) throws ReflectionErrorException{
try {
Class ownerClass = owner.getClass();
try{
//优先处理提供Setter方法的(非)公共属性(为POJO类的属性处理提供方便)
invokeMethod(owner, "set" + upperFirstChar(fieldName), new Object[]{value});
} catch (ReflectionErrorException e){
//按Getter方法没提取到再按Public属性提取下
Field field = ownerClass.getField(fieldName);
field.set(owner, value);
}
} catch (Exception e) {
//May happen Exception:
//SecurityException, NoSuchFieldException, IllegalArgumentException, IllegalAccessException
throw new ReflectionErrorException("Set object property error.", e);
}
}
/**
* 得到某类的静态公共属性
* @param className 类名
* @param fieldName 属性名
* @return 该属性对象
* @throws ReflectionErrorException 反射操作抛出例外
*/
public static Object getStaticProperty(String className, String fieldName) throws ReflectionErrorException {
try {
Class ownerClass = Class.forName(className);
Field field = ownerClass.getField(fieldName);
Object property = field.get(ownerClass);
return property;
} catch (Exception e) {
//May happen Exception:
//ClassNotFoundException, SecurityException, NoSuchFieldException, IllegalArgumentException, IllegalAccessException
throw new ReflectionErrorException("Get static object property error.", e);
}
}
/**
* 执行某对象方法
* @param owner 对象
* @param methodName 方法名
* @param args 参数
* @return 方法返回值
* @throws ReflectionErrorException 反射操作抛出例外
*/
public static Object invokeMethod(Object owner, String methodName, Object[] args) throws ReflectionErrorException {
try {
Class ownerClass = owner.getClass();
Method method = null;
if(args == null) {
method = ownerClass.getMethod(methodName, null);
} else {
Class[] argsClass = new Class[args.length];
for (int i = 0, j = args.length; i < j; i++) {
argsClass[i] = args[i].getClass();
}
method = ownerClass.getMethod(methodName, argsClass);
}
return method.invoke(owner, args);
} catch (Exception e) {
//May happen Exception:
//SecurityException, NoSuchMethodException, IllegalArgumentException, IllegalAccessException, InvocationTargetException
throw new ReflectionErrorException("Invoke object method error.", e);
}
}
/**
* 执行某类的静态方法
* @param className 类名
* @param methodName 方法名
* @param args 参数数组
* @return 执行方法返回的结果
* @throws ReflectionErrorException 反射操作抛出例外
*/
public static Object invokeStaticMethod(String className, String methodName, Object[] args) throws ReflectionErrorException {
try {
Class ownerClass = Class.forName(className);
Method method = null;
if(args == null) {
method = ownerClass.getMethod(methodName, null);
} else {
Class[] argsClass = new Class[args.length];
for (int i = 0, j = args.length; i < j; i++) {
argsClass[i] = args[i].getClass();
}
method = ownerClass.getMethod(methodName, argsClass);
}
return method.invoke(null, args);
} catch (Exception e) {
//May happen Exception:
//ClassNotFoundException, SecurityException, NoSuchMethodException, IllegalArgumentException, IllegalAccessException, InvocationTargetException
throw new ReflectionErrorException("Invoke static object method error.", e);
}
}
/**
* 新建类实例
* @param className 类名
* @param args 构造函数的参数
* @return 新建的实例
* @throws ReflectionErrorException 反射操作抛出例外
*/
public static Object newInstance(String className, Object[] args) throws ReflectionErrorException {
try {
Class newoneClass = Class.forName(className);
Class[] argsClass = new Class[args.length];
for (int i = 0, j = args.length; i < j; i++) {
argsClass[i] = args[i].getClass();
}
Constructor cons = newoneClass.getConstructor(argsClass);
return cons.newInstance(args);
} catch (Exception e) {
//May happen Exception:
//ClassNotFoundException, SecurityException, NoSuchMethodException, IllegalArgumentException, InstantiationException, IllegalAccessException, InvocationTargetException
throw new ReflectionErrorException("Create new object instance error.", e);
}
}
/**
* 是不是某个类的实例
* @param obj 实例
* @param cls 类
* @return 如果 obj 是此类的实例，则返回 true
*/
public static boolean isInstance(Object obj, Class cls) {
return cls.isInstance(obj);
}
/**
* 得到数组中的某个元素
* @param array 数组
* @param index 索引
* @return 返回指定数组对象中索引组件的值
*/
public static Object getByArray(Object array, int index) {
return Array.get(array, index);
}
/**
* 大写单词首字母
* @param str 单词
* @return 大写首字母后的单词
*/
public static String upperFirstChar(String str) {
if (str == null || str.equals("")) {
return str;
} else {
StringBuffer result = new StringBuffer(str.substring(0, 1).toUpperCase());
result.append(str.substring(1).toLowerCase());
return result.toString();
}
}
}
反射处理例外声明类
ReflectionErrorException.java
/**
* @author sidac
* Reflection 动态处理时错误时统一抛出的例外
*/
public class ReflectionErrorException extends Exception {
/**
*
*/
private static final long serialVersionUID = 346011547748517512L;
/**
* throw Exception in the method RunClass of DynamicRunClass
* when can't find the method to runed which the user specified
*/
private Throwable ex;
public ReflectionErrorException() {
super((Throwable)null); // Disallow initCause
}
public ReflectionErrorException(String s) {
super(s, null); // Disallow initCause
}
public ReflectionErrorException(String s, Throwable ex) {
super(s, null); // Disallow initCause
this.ex = ex;
}
public Throwable getException() {
return ex;
}
public Throwable getCause() {
return ex;
}
}
下面是原来的代码：
Java反射经典实例 Java Reflection Cookbook <script src="" type=text/javascript></script>
import java.lang.reflect.Array;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
/**
* Java Reflection Cookbook
*
* @author Michael Lee
* @since 2006-8-23
* @version 0.1a
*/
public class Reflection {
/**
* 得到某个对象的公共属性
*
* @param owner, fieldName
* @return 该属性对象
* @throws Exception
*
*/
public Object getProperty(Object owner, String fieldName) throws Exception {
Class ownerClass = owner.getClass();
Field field = ownerClass.getField(fieldName);
Object property = field.get(owner);
return property;
}
/**
* 得到某类的静态公共属性
*
* @param className 类名
* @param fieldName 属性名
* @return 该属性对象
* @throws Exception
*/
public Object getStaticProperty(String className, String fieldName)
throws Exception {
Class ownerClass = Class.forName(className);
Field field = ownerClass.getField(fieldName);
Object property = field.get(ownerClass);
return property;
}
/**
* 执行某对象方法
*
* @param owner
* 对象
* @param methodName
* 方法名
* @param args
* 参数
* @return 方法返回值
* @throws Exception
*/
public Object invokeMethod(Object owner, String methodName, Object[] args)
throws Exception {
Class ownerClass = owner.getClass();
Class[] argsClass = new Class[args.length];
for (int i = 0, j = args.length; i < j; i++) {
argsClass[i] = args[i].getClass();
}
Method method = ownerClass.getMethod(methodName, argsClass);
return method.invoke(owner, args);
}
/**
* 执行某类的静态方法
*
* @param className
* 类名
* @param methodName
* 方法名
* @param args
* 参数数组
* @return 执行方法返回的结果
* @throws Exception
*/
public Object invokeStaticMethod(String className, String methodName,
Object[] args) throws Exception {
Class ownerClass = Class.forName(className);
Class[] argsClass = new Class[args.length];
for (int i = 0, j = args.length; i < j; i++) {
argsClass[i] = args[i].getClass();
}
Method method = ownerClass.getMethod(methodName, argsClass);
return method.invoke(null, args);
}
/**
* 新建实例
*
* @param className
* 类名
* @param args
* 构造函数的参数
* @return 新建的实例
* @throws Exception
*/
public Object newInstance(String className, Object[] args) throws Exception {
Class newoneClass = Class.forName(className);
Class[] argsClass = new Class[args.length];
for (int i = 0, j = args.length; i < j; i++) {
argsClass[i] = args[i].getClass();
}
Constructor cons = newoneClass.getConstructor(argsClass);
return cons.newInstance(args);
}
/**
* 是不是某个类的实例
* @param obj 实例
* @param cls 类
* @return 如果 obj 是此类的实例，则返回 true
*/
public boolean isInstance(Object obj, Class cls) {
return cls.isInstance(obj);
}
/**
* 得到数组中的某个元素
* @param array 数组
* @param index 索引
* @return 返回指定数组对象中索引组件的值
*/
public Object getByArray(Object array, int index) {
return Array.get(array,index);
}
}
