一、保存信息

 Student类：

package testpackage;

import java.io.IOException;

public class Student {
    private String name;
    private String area;
    public String testfield;
    private int age;

    public Student() {
    }

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

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

    /**
     * 获取
     * @return name
     */
    public String getName() {
        return name;
    }

    /**
     * 设置
     * @param name
     */
    public void setName(String name) {
        this.name = name;
    }

    /**
     * 获取
     * @return area
     */
    public String getArea() {
        return area;
    }

    /**
     * 设置
     * @param area
     */
    public void setArea(String area) {
        this.area = area;
    }

    /**
     * 获取
     * @return age
     */
    public int getAge() {
        return age;
    }

    /**
     * 设置
     * @param age
     */
    public void setAge(int age) {
        this.age = age;
    }

    public String toString() {
        return "Student";
    }

    public void eat(String something) throws IOException,NullPointerException {
        System.out.println("在吃"+something);
    }
    public void eat(int number){
        System.out.println("吃了"+number+"个东西");
    }
}

Teacher类：

package testpackage;

public class Teacher {
    private String name;
    private  String job;
    private int age;
    private String area;

    public Teacher() {
    }

    public Teacher(String name, String job, int age, String area) {
        this.name = name;
        this.job = job;
        this.age = age;
        this.area = area;
    }

    /**
     * 获取
     * @return name
     */
    public String getName() {
        return name;
    }

    /**
     * 设置
     * @param name
     */
    public void setName(String name) {
        this.name = name;
    }

    /**
     * 获取
     * @return job
     */
    public String getJob() {
        return job;
    }

    /**
     * 设置
     * @param job
     */
    public void setJob(String job) {
        this.job = job;
    }

    /**
     * 获取
     * @return age
     */
    public int getAge() {
        return age;
    }

    /**
     * 设置
     * @param age
     */
    public void setAge(int age) {
        this.age = age;
    }

    /**
     * 获取
     * @return area
     */
    public String getArea() {
        return area;
    }

    /**
     * 设置
     * @param area
     */
    public void setArea(String area) {
        this.area = area;
    }

    public String toString() {
        return "Teacher";
    }
}

主函数：

import testpackage.Student;
import testpackage.Teacher;

import java.io.*;
import java.lang.reflect.Field;

public class Test {
    public static void main(String[] args) throws IllegalAccessException, IOException {

        Teacher teacher=new Teacher("历山","班主任",20,"南京");
        Student stu=new Student("张三","北京",16);
        SaveObject(teacher);
        SaveObject(stu);
    }

    public static void SaveObject(Object object) throws IllegalAccessException, IOException {
        //将对象的所有成员变量及对应属性保存到本地文件中去   name=XX
        //针对对象来创建.class文件
        Class clazz = object.getClass();

        //将每一个信息存入本地文件中
        String str=object+"";
        BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(new FileOutputStream(str+".txt")));

        //先获取对象所有的成员变量
        Field[] declaredFields = clazz.getDeclaredFields();
        for (Field declaredfield : declaredFields) {
            //遍历所有的成员变量
            //临时取消权限检验
            declaredfield.setAccessible(true);
            //获取成员变量的名字
            String name = declaredfield.getName();
            //获取成员变量对应的值
            Object o = declaredfield.get(object);
            String info=name+"="+o;

            bw.write(info);
            bw.newLine();
            bw.flush();
        }
        bw.close();
    }
}

二、跟配置文件结合动态创建

配置文件：

import java.io.*;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Properties;

public class Test2 {
    public static void main(String[] args) throws IOException, ClassNotFoundException, NoSuchMethodException, InvocationTargetException, InstantiationException, IllegalAccessException {
        //动态创建对象并调用方法

        //读取配置文件
        BufferedReader br=new BufferedReader(new InputStreamReader(new FileInputStream("prop.properties")));
        String b;
        //创建prop集合
        Properties prop=new Properties();
        //读取配置文件
        prop.load(br);
        br.close();

        System.out.println(prop); //{classname=testpackage.Student, method=study}

        //查找对应键的值（全类名）
        //方法返回值是Object类
        System.out.println(prop.get("classname"));  //testpackage.Student
        Class clazz = Class.forName((String) prop.get("classname"));

        //查找对应键的值（方法名）
        String method =(String)prop.get("method");
        Method declaredMethod = clazz.getDeclaredMethod(method);
        //临时取消权限检验
        declaredMethod.setAccessible(true);
        //利用Clazz对象创建对应类的对象
        //获取构造方法
       /* Constructor[] declaredConstructors = clazz.getDeclaredConstructors();
        for (Constructor d : declaredConstructors) {
            System.out.println(d);
        }
        */
        //获取无参构造方法
        Constructor cons = clazz.getDeclaredConstructor();

        //根据返回的构造方法创建对象
        //临时取消权限检验
        cons.setAccessible(true);
        Object o = cons.newInstance();
        //调用方法 使用newInstance创建的对象进行调用
         declaredMethod.invoke(o);

    }
}