Java反射的两种使用方法(推荐)

package com.tao.test;public class User {  private String name;  private int id;  public User() {  }  public String getName() {    return name;  }  public void setName(String name) {    this.name = name;  }  public int getId() {    return id;  }  public void setId(int id) {    this.id = id;  }}

package com.tao.test;import java.lang.reflect.Constructor;import java.lang.reflect.Field;public class test {  public static void main(String[] args) throws Exception, SecurityException {    //第一种 Constructor<?>方法    Constructor<?> a = User.class.getDeclaredConstructor();    a.setAccessible(true);    User b = (User)a.newInstance();    b.setId(1);//id字段    b.setName("test");//name字段    System.out.println(b.getId()+" "+b.getName());    //第二种 Class<?>方法    Class<?> c = Class.forName("com.tao.test.User");    Field idF = c.getDeclaredField("id");//id字段    idF.setAccessible(true);    Object o = c.newInstance();    idF.set(o, 2);    Field nameF = c.getDeclaredField("name");//name字段    nameF.setAccessible(true);    Object name = c.newInstance();    nameF.set(name, "jack");    System.out.println(idF.get(o)+" "+nameF.get(name));    //普通new    User user = new User();    user.setId(3);    user.setName("tery");    System.out.println(user.getId()+" "+user.getName()+" "+user.getClass());  }}