反射的作用：绕过编译阶阶段

package reflect_framework;

/**
 * FileName: ReflectDemo
 * Author:   lps
 * Date:     2022/4/22 10:32
 * Sign:刘品水 Q：1944900433
 */
public class ReflectDemo {
    public static void main(String[] args) {
        Student s = new Student();
        s.setName("刘品水");
        s.setClassName("物联网1913");
        s.setAge(21);
        s.setSex('男');
        s.setHobby("敲键盘");
        MybatisUtil.save(s);

        Teacher t = new Teacher();
        t.setName("仲老师");
        t.setSex('男');
        t.setSalary(28888.88);
        MybatisUtil.save(t);


    }
}

package reflect_framework;

import java.io.FileOutputStream;
import java.io.PrintStream;
import java.lang.reflect.Field;

/**
 * FileName: MybatisUtil
 * Author:   lps
 * Date:     2022/4/22 10:46
 * Sign:刘品水 Q：1944900433
 */
public class MybatisUtil {
    public static void save(Object obj) {

        //1.提取这个对象的全部成员变量
        try (PrintStream ps = new PrintStream(new FileOutputStream("F:\\JavaProject\\Code\\src\\data.txt",true));){
            Class<?> c = obj.getClass();
            //String getSimpleName() 返回源代码中给出的基础类的简单名称。
            ps.println("========"+c.getSimpleName()+"========");
            //提取全部成员变量
            Field[] fields = c.getDeclaredFields();
            //获取成员变量的信息
            for (Field field : fields) {
                String name = field.getName();
                //提取本成员变量在obj对象的值
                field.setAccessible(true);
                String value= field.get(obj)+"";
                ps.println(name+"="+value);

            }
        } catch (Exception e) {
            e.printStackTrace();
        }


    }
}

package reflect_framework;

/**
 * FileName: Student
 * Author:   lps
 * Date:     2022/4/22 10:31
 * Sign:刘品水 Q：1944900433
 */
public class Student {
    private String name;
    private char sex;
    private  int age;
    private String className;
    private String hobby;

    public Student() {
    }

    public Student(String name, char sex, int age, String className, String hobby) {
        this.name = name;
        this.sex = sex;
        this.age = age;
        this.className = className;
        this.hobby = hobby;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public char getSex() {
        return sex;
    }

    public void setSex(char sex) {
        this.sex = sex;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getClassName() {
        return className;
    }

    public void setClassName(String className) {
        this.className = className;
    }

    public String getHobby() {
        return hobby;
    }

    public void setHobby(String hobby) {
        this.hobby = hobby;
    }
}

package reflect_framework;

/**
 * FileName: Teacher
 * Author:   lps
 * Date:     2022/4/22 10:31
 * Sign:刘品水 Q：1944900433
 */
public class Teacher {
    private String name;
    private char sex;
    private double salary;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public char getSex() {
        return sex;
    }

    public void setSex(char sex) {
        this.sex = sex;
    }

    public double getSalary() {
        return salary;
    }

    public void setSalary(double salary) {
        this.salary = salary;
    }

    public Teacher() {
    }

    public Teacher(String name, char sex, double salary) {
        this.name = name;
        this.sex = sex;
        this.salary = salary;
    }
}