通过反射API构造对象,并使用反射调用方式访问对象的public/private方法和字段。 package lavasoft.test; /** * 测试的业务类 * * @author leizhimin 2010-5-6 20:16:10 */ public class MyService { private String msg; public MyService() { System.out.println("log: 无参构造方法lavasoft.test.MyService.MyService()被调用过了!"); } public MyService(String msg) { System.out.println("log: 有参构造方法lavasoft.test.MyService.MyService()被调用过了!"); this.msg = msg; } public String doSomething(String person, String something) { System.out.println("log: 业务方法lavasoft.test.MyService.doSomething()被调用过了!"); return person + " is doing " + something + "! " + "附加消息:" + msg; } public String getMsg() { System.out.println("log: lavasoft.test.MyService.getMsg()被调用过了!"); return msg; } public void setMsg(String msg) { System.out.println("log: lavasoft.test.MyService.setMsg()被调用过了!"); this.msg = msg; } private String doPrivate() { System.out.println("log: 私有方法lavasoft.test.MyService.doPrivate()被调用过了!"); return "私有方法doPrivate()被调用了!"; } } package lavasoft.test; import java.lang.reflect.Constructor; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.*; /** * Java反射深度测试 * * @author leizhimin 2010-5-6 20:26:49 */ public class TestReflect { public static void main(String[] args) throws NoSuchMethodException, InvocationTargetException, IllegalAccessException, InstantiationException, NoSuchFieldException { //通过反射方式创建对象 Class clazz = MyService.class; MyService sv = (MyService)clazz.getConstructor().newInstance(); sv.setMsg("通过Class方式创建一个对象,并调用对象上的方法!"); //通过反射方式调用对象的public方法 Method m_setMsg = clazz.getMethod("setMsg",String.class); m_setMsg.invoke(sv,"通过反射调用了sv对象上的一个方法!"); Method m_do = clazz.getMethod("doSomething",String.class ,String.class); String re = (String)m_do.invoke(sv,"张三" ,"吃饭"); System.out.println(re); //通过反射方式调用对象的private方法 Method m_doPrivate = clazz.getDeclaredMethod("doPrivate"); m_doPrivate.setAccessible(true); m_doPrivate.invoke(sv); //通过反射方式访问对象private字段 Field f_msg = clazz.getDeclaredField("msg"); f_msg.setAccessible(true); f_msg.set(sv,"hahahahahahahaha"); System.out.println(sv.getMsg()); } } log: 无参构造方法lavasoft.test.MyService.MyService()被调用过了! log: lavasoft.test.MyService.setMsg()被调用过了! log: lavasoft.test.MyService.setMsg()被调用过了! log: 业务方法lavasoft.test.MyService.doSomething()被调用过了! 张三 is doing 吃饭! 附加消息:通过反射调用了sv对象上的一个方法! log: 私有方法lavasoft.test.MyService.doPrivate()被调用过了! log: lavasoft.test.MyService.getMsg()被调用过了! hahahahahahahaha Process finished with exit code 0