测试 java反射Reflection中 获取 类属性、方法、构造方法及 调用类方法改变 对象属性

package com.li.test;
/**
 * 实体类User
 * @author Administrator
 */
public class User {
    
    /**
     * name
     */
    private String name;//name
    private int age;//age

    public User() {
    }
    public User(String name,int age) {
        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;
    }
}

package com.li.test;

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

/**
 * 测试 java反射Reflection中 获取 类属性、方法、构造方法及 调用类方法改变 对象属性
 * 
 * @author Administrator
 * 
 */
public class TestReflect {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // 获取 类属性
        Field[] field = User.class.getDeclaredFields();
        System.out.println("User类属性----begin-----");
        for (int i = 0; i < field.length; i++) {
            System.out.println(field[i].getName());
        }
        System.out.println("User类属性----end-----");
        // 获取 类方法
        Method method[] = User.class.getDeclaredMethods();
        System.out.println("User类方法----begin-----");
        for (int i = 0; i < method.length; i++) {
            System.out.println(method[i].getName());
        }
        System.out.println("User类方法----end-----");
        // 获取 构造方法
        Constructor constructor[] = User.class.getDeclaredConstructors();
        System.out.println("User类构造方法----begin-----");
        for (int i = 0; i < constructor.length; i++) {
            System.out.println(constructor[i]);
        }
        System.out.println("User类构造方法----end-----");
        // 改变属性值
        User user1 = new User("A", 1);
        System.out.println("begin " + user1.getName() + user1.getAge());
        Field fieldName = null;
        try {
            fieldName = User.class.getDeclaredField("name");
        } catch (SecurityException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        } catch (NoSuchFieldException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }
        Method setNameMethod = null;
        Method getNameMethod = null;
        Object name = null;
        try {
            setNameMethod = user1.getClass().getDeclaredMethod("setName",new Class[]{fieldName.getType()});
            getNameMethod = user1.getClass().getDeclaredMethod("getName",new Class[]{});
        } catch (SecurityException e) {
            e.printStackTrace();
        } catch (NoSuchMethodException e) {
            e.printStackTrace();
        }
        try {
            setNameMethod.invoke(user1, new Object[]{"B"});
            name = getNameMethod.invoke(user1, new Class[]{});
            
        } catch (IllegalArgumentException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        System.out.println("end " + user1.getName() + user1.getAge());
        System.out.println("end " + (String)name);
    }

}

 

以下是控制台输出：

User类属性----begin-----
name
age
User类属性----end-----
User类方法----begin-----
getAge
setAge
getName
setName
User类方法----end-----
User类构造方法----begin-----
public com.li.test.User()
public com.li.test.User(java.lang.String,int)
User类构造方法----end-----
begin A1
end B1
end B