Java学习之：反射机制（3）通过反射获得对象的成员变量，并给对象的成员变量赋值

代码演示

package 反射;

import java.sql.Struct;

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

    public Student(){

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

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

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

package 反射;

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

public class Main {
    public static void main(String[] args) throws NoSuchMethodException, IllegalAccessException, InvocationTargetException, InstantiationException, NoSuchFieldException {

        Class<Student> studentClass = Student.class;
//        Constructor<Student> constructor = studentClass.getConstructor(String.class, int.class, String.class);
//        Student student = constructor.newInstance("青霞", 30, "西安");
//        System.out.println(student);
        Constructor<Student> con = studentClass.getConstructor();  //采用无参构造的方法创建对象
        Field age = studentClass.getDeclaredField("age");
        
        age.setAccessible(true);

        age.set(con,10);

    }
}

• 这里的 set 是给对象的 age 属性赋值为 10
• getDeclaredField 是为了能获得私有的属性（字段）
• 一定要注意，因为 Student 中的 age 也是私有属性，因此应该设置 setAccessble 为 true