Question

利用JAVA反射技术执行一个类的方法

求个全代码啊

Answer 1

public class Test {

public Test() {

}

public static void main(String[] args) throws IllegalArgumentException,
SecurityException, IllegalAccessException,
InvocationTargetException, NoSuchMethodException {
Bean bean = new Bean();
System.out.println(bean);
Bean.class.getMethod("setName", String.class).invoke(bean, "Jerry");
Bean.class.getMethod("setAge", int.class).invoke(bean, 25);
System.out.println("After reflection....\n" + bean);
}

}

class Bean {
private String name;
private int age;

public Bean() {
}

public Bean(String name, int age) {
super();
this.name = name;
this.age = age;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public int getAge() {
return age;
}

public void setAge(int age) {
this.age = age;
}

public String toString() {
return "NAME: " + this.getName() + "\nAGE: " + this.getAge();
}
}

Answer 2

try
{
//利用反射调用对应的方法
Class invokeClass = Class.forName( sClassName );
Object invokeObject = invokeClass.newInstance();
Class[] paraType = { Class.forName("javax.servlet.http.HttpServletRequest"),
Class.forName("javax.servlet.http.HttpServletResponse") };
Object[] paraObj = { request, response };
Method invokeMethod = invokeClass.getMethod( sMethodName, paraType );
//sNextPage 为利用反射调用对应的类返回的页面路径
String sNextPage = (String) invokeMethod.invoke( invokeObject, paraObj );

if ( sNextPage != null && !sNextPage.equals("") )
{
response.sendRedirect( "../" + sNextPage );
return;
}
}
catch(Exception e)
{
//页面处理出错，跳转到首页
mySession.invalidate();
response.sendRedirect("../index.htm");
return;
}

Answer 3

package cn;
import java.lang.reflect.*;
public class SimpleClassDesc {

/**
* @param args
*/
public static void main(String[] args) {
Class type=null;
try
{
System.out.println(args[0]);
type=Class.forName(args[0]);

}catch(Exception e)
{
e.printStackTrace();
}

Class superClass=type.getSuperclass();
if(superClass!=null)
{
System.out.println("extends "+superClass.getCanonicalName());
}
Method[] methods=type.getDeclaredMethods();
for(int i=0;i<methods.length;i++)
{
if(Modifier.isPublic(methods[i].getModifiers()))
{
System.out.println(""+methods[i]);
}
}

}
}
利用java反射机制打印出给定类的直接超类，并列出它所声明的public方法。

Answer 4

import java.lang.reflect.InvocationTargetException;

public class SimRef {

public SimRef() {

}

public static void main(String[] args) throws IllegalArgumentException,
SecurityException, IllegalAccessException,
InvocationTargetException, NoSuchMethodException {
Bean bean = new Bean();
System.out.println(bean);
Bean.class.getMethod("setName", String.class).invoke(bean, "Jerry");
Bean.class.getMethod("setAge", int.class).invoke(bean, 25);
System.out.println("After reflection....\n" + bean);
}

}

class Bean {
private String name;
private int age;

public Bean() {
}

public Bean(String name, int age) {
super();
this.name = name;
this.age = age;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public int getAge() {
return age;
}

public void setAge(int age) {
this.age = age;
}

public String toString() {
return "NAME: " + this.getName() + "\nAGE: " + this.getAge();
}
}

Answer 5

// 最简单就是这样
package reflect;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

public class Reflect {
public static void b() {
System.out.println("b is executing...");
}

public static void main(String[] args) throws SecurityException, NoSuchMethodException, IllegalArgumentException, IllegalAccessException, InvocationTargetException {
Method m = Reflect.class.getMethod("b", null);
m.invoke(null, null);
}
}