学习打卡--反射（2）

今天没搞太多东西，只是简单地学习了下Swing、以及知道了可以用反射来调用方法、修改成员属性等

package com.sy.reflection;

public class Student {
        public String name;
        private int age;
        public Student(String name,int age) {
        	this.name = name;
        	this.age = age;
        	}
        public void Print() {
        	System.out.println("你妹");
        }
  
}

package com.sy.reflection;
import java.lang.reflect.*;
public class TestStudent {
      public static void main(String[] args)throws Exception {
    	  Student stu = new Student("张三",18);
    	  Class<?> c = stu.getClass();//<>表示泛型，？表示不确定类型
    	 
    	  //通过反射调用方法
    	  Method m = c.getMethod("Print", null);
    	  m.invoke(stu, null);
    	  
    	  Field f1 = c.getField("name");//参数为要从类中得到的字段
    	  String str = (String)f1.get(stu);//参数为要获取的字段值的对象
    	  System.out.println(str);
    	  
    	  Field f2 = c.getDeclaredField("age");
    	  //因为age为私有，所以要设置安全检查
    	  f2.setAccessible(true);
    	  f2.set(stu,20);//通过反射修改属性值
    	  int Age = (int)f2.get(stu);
    	  System.out.println(Age);
      }
}

package swing;

import java.awt.*;

import javax.swing.*;

public class jframe {
	   public jframe() {
		   JFrame f = new JFrame("登录窗口");
		   GridLayout g = new GridLayout(3,1);
		   JPanel p1 = new JPanel();
		   JPanel p2 = new JPanel();
		   JPanel p3 = new JPanel();
		   JLabel l1 = new JLabel("账号：");
		   JLabel l2= new JLabel("密码：");
		   JTextField t1 = new JTextField(10);
		   JPasswordField pw = new JPasswordField(10);
		   pw.setEchoChar('*');
		   JButton b1 = new JButton("确定");
		   f.setVisible(true);
		   f.setSize(400,300);
		   f.setLayout(g);
		   p1.add(l1);
		   p1.add(t1);
		   p2.add(l2);
		   p2.add(pw);
	       p3.add(b1);
		   f.add(p1);
		   f.add(p2);
		   f.add(p3);
	   }
       public static void main(String[] args) {
    	 jframe j = new jframe();
       }
}