java 的反射

package invocate;

import java.lang.reflect.Constructor;
import java.lang.reflect.Method;


class Persion {
	private String usr = "no";
	private String pwd = "0";
	public Persion(){};
	public Persion(String u , String p){
		this.usr = u ;
		this.pwd = p;
	}
	public String toString(){
		return this.usr + "|" + this.pwd;
	}
	public String getUsr() {
		return usr;
	}
	public void setUsr(String usr) {
		this.usr = usr;
	}
	public String getPwd() {
		return pwd;
	}
	public void setPwd(String pwd) {
		this.pwd = pwd;
	}
	public void prt(String str){
		System.out.println(str);
	}
}


public class T {
	public static void main(String args[]){
		try{
			
			// exam 01
			System.out.println("------------- exam 01 --------------");
			Class c = Class.forName("invocate.Persion");//根据字符串创建一个类	
			Object obj = c.newInstance();//实例化
			Persion p = (Persion)obj;//强制转换
			System.out.println(p);
			
			
			// exam 02
			System.out.println("\n------------- exam 02 --------------");
			Persion p2 = new Persion();
			System.out.println(p2.getClass() == c);
			
			
			// exam 03
			System.out.println("\n------------- exam 03 --------------");
			Class paramType[] = new Class[]{String.class,String.class};//建立一个类数组(构建参数类型数组)
			Constructor ctor = c.getConstructor(paramType);//获取满足参数类型数组的构造函数
			Object params[] = new Object[]{new String("zhangsan"),new String("123456")};//创建一个参数对象数组
			Object instance = ctor.newInstance(params);//实例化对象
			System.out.println(instance);
			
			
			
			// exam 04
			System.out.println("\n------------- exam 04 --------------");
			Class mehtodParamTypes[] = new Class[]{String.class};//创建一个类数组(构建参数类型数组)
			Method method = c.getMethod("prt", mehtodParamTypes);//获取符合参数类型数组的"prt"方法 
			method.invoke(obj,"张三");//调用方法
			
			
		}catch(Exception e){
			e.printStackTrace();
		}
	}
}