企业官网建设流程全解析

、定义一个Student类#

为了方便看到生命周期过程，我直接使用print大法;

另外，将类交给Spring容器管理可以通过xml文件形式和注解形式，接下来我都实现一下

1、xml形式#

package com.goahead.bean;

public class Student1 {

private String name;

public Student1() {

System.out.println("1、实例化");

}

public Student1(String name) {

this.name = name;

}

public void setName(String name) {

System.out.println("2、依赖注入");

this.name = name;

}

public void myInit() {

System.out.println("3、初始化");

}

public void myDestroy() {

System.out.println("5、销毁");

}

}

2、注解形式#

package com.goahead.bean;

import org.springframework.stereotype.Component;

import org.springframework.beans.factory.annotation.Value;

import javax.annotation.PostConstruct;

import javax.annotation.PreDestroy;

@Component

public class Student2 {

private String name;

public Student2() {

System.out.println("1、实例化");

}

public Student2(String name) {

this.name = name;

}

@Value("goahead")

public void setName(String name) {

System.out.println("2、依赖注入");

this.name = name;

}

@PostConstruct

public void myInit() {

System.out.println("3、初始化");

}

@PreDestroy

public void myDestroy() {

System.out.println("5、销毁");

}

}

二、将Student类交给Spring容器#

1、xml文件形式#

需要在resource文件夹下定义一个xml文件

<?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="http://www.springframework.org/schema/beans

http://www.springframework.org/schema/beans/spring-beans.xsd">

<bean id="student" class="com.goahead.bean.Student" init-method="myInit" destroy-method="myDestroy">

<property name="name" value="goahead"/>

</bean>

</beans>

2、注解形式（推荐）#

注解形式我们只需在Student2类上加相应的注解，然后加一个配置类

在config目录下创建一个 AppConfig类

package com.goahead.config;

import org.springframework.context.annotation.ComponentScan;

import org.springframework.context.annotation.Configuration;

@Configuration

@ComponentScan("com.goahead.bean") // 扫描包路径

public class AppConfig {

}

三、测试#

由于我们第二步实现了两种方式，所以测试也对应两种方式

1、对应xml形式#

import com.goahead.bean.Student1;

import org.junit.Test;

import org.springframework.context.ApplicationContext;

import org.springframework.context.support.ClassPathXmlApplicationContext;

public class AppTest1 {

@Test

public void test1() {

ApplicationContext context = new ClassPathXmlApplicationContext("spring.xml");

Student1 student1 = context.getBean(Student1.class);

System.out.println("4、使用Bean");

((ClassPathXmlApplicationContext)context).close();

}

}

2、注解形式#

import com.goahead.bean.Student2;

import com.goahead.config.AppConfig;

import org.junit.Test;

import org.springframework.context.annotation.AnnotationConfigApplicationContext;

public class AppTest2 {

@Test

public void test2() {

// 使用AnnotationConfigApplicationContext替代ClassPathXmlApplicationContext

AnnotationConfigApplicationContext context =

new AnnotationConfigApplicationContext(AppConfig.class);

Student2 student = context.getBean(Student2.class);

System.out.println("4、使用Bean");

context.close(); // 触发销毁方法

}

}

四、测试结果#

1、xml形式#

image

2、注解形式#

image