如果大厂面试官突然问你FactoryBean+Bean你究竟会多少？

Posted 2020-11-27

如果大厂面试官突然问你FactoryBean+Bean你究竟会多少？

很多Java程序员都在绞尽脑汁的想要进互联网大厂，那进入大厂必备的条件也是大家最想知道的，有很多大厂在面试的过程中会提一些不那么常见的问题，所以我们在去大厂面试的时候就需要提前做好准备。

如果大厂面试官突然问你FactoryBean+Bean你会怎么回答呢？

package com.example.demo10.entity;

//实体

public class Stu {

String name;

public Stu(String name) {

    this.name = name;

}

public Stu() {

}

public String getName() {

    return name;

}

public void setName(String name) {

    this.name = name;

}

}

package com.example.demo10.factory;

import com.example.demo10.entity.Stu;

import org.springframework.beans.factory.FactoryBean;

//创建一个Stu场子

public class StuFactory implements FactoryBean<Stu> {

@Override

public Class<?> getObjectType() {

    return Stu.class;

}

@Override

public boolean isSingleton() {

    return false;

}

@Override

public Stu getObject() throws Exception {

    return new Stu();

}

}

package com.example.demo10.configuration;

import com.example.demo10.factory.StuFactory;

import org.springframework.context.annotation.Bean;

import org.springframework.context.annotation.Configuration;

@Configuration

public class StuConfiguration {

//创建场子Bean

//这里要注意返回的是场子对象，但是正真获取的是Stu对象

@Bean

public StuFactory stuFactory(){

    return  new StuFactory();

}

}

package com.example.demo10;

import com.example.demo10.entity.Stu;

import com.example.demo10.factory.StuFactory;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.context.ConfigurableApplicationContext;

@SpringBootApplication

public class Demo10Application {

public static void main(String[] args) {

    ConfigurableApplicationContext context = SpringApplication.run(Demo10Application.class, args);

    //获取场子里面的产品

    Stu stu1 = context.getBean("stuFactory", Stu.class);

    Stu stu2 = context.getBean("stuFactory", Stu.class);

    System.out.println(stu1.getClass().getName());

    System.out.println(stu1.hashCode());

    System.out.println(stu2.getClass().getName());

    System.out.println(stu2.hashCode());

    //获取工厂自己

    StuFactory stuFactory = context.getBean("&stuFactory", StuFactory.class);

    System.out.println(stuFactory.getClass().getName());

    context.close();

}

}