Spring入门(一) 环境搭建及IOC示例

一. 环境搭建

1. 安装jdk

2. 安装maven

3. 下载Spring Tool Suite 3.7.0: https://spring.io/tools/sts/all  或者安装其插件

二. helloworld: 演示IOC

1. 创建一个maven项目

2. 引入依赖

<dependencies>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
        <version>4.2.4.RELEASE</version>
    </dependency>
</dependencies>

 3. 创建类：

package com.spring.bean;


public class HelloWorld {
	private String name;

	public String getName() {
		return name;
	}

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

	public void hello(){
		System.out.println("hello " + this.name);
	}
	
	@Override
	public String toString() {
		return "HelloWorld [name=" + name + "]";
	}
	
	
}

 4. 创建spring 配制文件

<?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="helloWorld" class="com.spring.bean.HelloWorld">
		<property name="name" value="Spring"></property>
	</bean>
</beans>

 5.创建运行类

package com.spring.bean;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Main {

	public static void main(String[] args) {
		//1. 创建Spring 的IOC容器对象
		//ApplicationContext 代表IOC对象
		ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
		//2.从IOC容器中取出bean实例
		//利用id定位到IOC容器中的bean
		HelloWorld hello = (HelloWorld) ctx.getBean("helloWorld");
		//3, 调用hello方法
		hello.hello();
		
		//利用类型定位到IOC容器中的bean,如果applicationConfig.xml里配制多个HelloWorld的bean,bean不唯一，会出错
		HelloWorld hello1 = ctx.getBean(HelloWorld.class);
		System.out.println(hello1 == hello);
	}

}

6.运行main类

得到结果：

十二月 26, 2015 9:34:14 上午 org.springframework.context.support.ClassPathXmlApplicationContext prepareRefresh
信息: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@2e0fa5d3: startup date [Sat Dec 26 09:34:14 CST 2015]; root of context hierarchy
十二月 26, 2015 9:34:14 上午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
信息: Loading XML bean definitions from class path resource [applicationContext.xml]
hello Spring
true

成功。