[Java基础]反射获取成员方法并使用练习

Posted 2021-08-15 Wecccccccc

代码如下:

package ClassObjectPack;

public class Student {
    private String name;
    int age;
    public String address;

    public Student(String name, int age, String address) {
        this.name = name;
        this.age = age;
        this.address = address;
    }

    public Student() {
    }

    private Student(String name) {
        this.name = name;
    }

    Student(String name, int age) {
        this.name = name;
        this.age = age;
    }

    private void function()
    {
        System.out.println("function");
    }

    public void method1()
    {
        System.out.println("method");
    }

    public void method2(String s)
    {
        System.out.println("method:"+s);
    }

    public String method3(String s,int i)
    {
        return s+","+i;
    }

    @Override
    public String toString() {
        return "Student{" +
                "name='" + name + '\\'' +
                ", age=" + age +
                ", address='" + address + '\\'' +
                '}';
    }
}

package ClassObjectPack01;

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

public class ReflectDemo06 {
    public static void main(String[] args) throws ClassNotFoundException, NoSuchMethodException, InvocationTargetException, InstantiationException, IllegalAccessException {
        Class<?> c = Class.forName("ClassObjectPack.Student");

        Constructor<?> con = c.getConstructor();
        Object obj = con.newInstance();

        Method m1 = c.getMethod("method1");
        m1.invoke(obj);

        Method m2 = c.getMethod("method2", String.class);
        m2.invoke(obj,"林青霞");

        Method m3 = c.getMethod("method3", String.class, int.class);
        Object o = m3.invoke(obj, "林青霞", 30);
        System.out.println(o);

//        Method m4 = c.getMethod("function");
        Method m4 = c.getDeclaredMethod("function");
        m4.setAccessible(true);

        m4.invoke(obj);
        System.out.println(m4);
    }
}

测试结果: