# Spring Ioc study

**Repository Path**: wgspring/Spring-Ioc-study

## Basic Information

- **Project Name**: Spring Ioc study
- **Description**: Spring中IoC容器的学习
- **Primary Language**: Java
- **License**: Not specified
- **Default Branch**: develop
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2017-02-22
- **Last Updated**: 2020-12-19

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

Spring IoC 练习
---------------
> 1.Spring的配置

在pom.xml中添加spring的依赖

    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>4.3.6.RELEASE</version>
        </dependency>
    </dependencies>

在resources文件夹下新建spring-config.xml

    <?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">
    
    </beans>


>2.bean的基本使用

spring-config添加bean

    <bean id="screwDriver" class="com.study.IoC.ScrewDriver" init-method="init" destroy-method="destroy"/>

其中init-method和destroy-method属性分别指定初始化函数和回收函数， scope="prototype"指定非单例模式，否则默认单例模式

在java文件中获取bean

    //获取上下文
    ApplicationContext context = new ClassPathXmlApplicationContext("spring-config.xml");
    //通过id获取bean
    ScrewDriver screwDriver = context.getBean("screwDriver",ScrewDriver.class);
    screwDriver.useScrew();
    //关闭上下文
    ((ConfigurableApplicationContext)context).close();

>3.构造函数的注入

通过基本类型参数构造

    <bean id="header" class="com.study.IoC.StraightHeader">
        <constructor-arg name="color" value="yellow"/>
        <constructor-arg name="size" value="size"/>
    </bean>

通过配置文件构造
    
    <!--constructor-arg可以用name,index或则type指定对应的参数-->
    <bean id="header" class="com.study.IoC.StraightHeader">
        <constructor-arg name="color" value="${color}"/>
        <constructor-arg name="size" value="${size}"/>
    </bean>
    
    
    <!--配置文件bean-->
    <bean id="headerProperties" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="location" value="header.properties"/>
    </bean>
    
通过复合类型构造

    <bean id="screwDriver" class="com.study.IoC.ScrewDriver" init-method="init" destroy-method="destroy">
        <constructor-arg ref="header"/>
    </bean>
    

>4.set函数的注入

通过基本类型set注入配置

    <bean id="header" class="com.study.IoC.StraightHeader">
        <property name="size" value="18" />
        <property name="color" value="yellow"/>
    </bean>
    
通过复合类型set注入配置

    <bean id="screwDriver" class="com.study.IoC.ScrewDriver" init-method="init" destroy-method="destroy">
        <property name="header" ref="header"/>
    </bean>

通过复合类型set自动注入配置

    <bean id="screwDriver" class="com.study.IoC.ScrewDriver" init-method="init" destroy-method="destroy" autowire="byName"/>

>4.Annotation定义

首先需要在spring-config.xml中添加

    <context:component-scan base-package="com.study.IoC"/>
    
@Component("XXX")用来定义bean
@Value("XXX")用来定义数值
@Autowired用来自动配置
@PostConstruct用来指定初始化函数
@PreDestroy用来指定回收函数