Spring【一，环境搭建】

Spring 大家都不陌生，企业应用中很流行的一个平台。从最开始的 Servlet 控制所有，到 MVC 模式的出现。从 SSH （Struts、Spring、Hibernate） 所谓的三剑客 到 SpringMvc、SpringBoot 等等。技术总是不断在更新，开源框架也越来越多。世界上很多的大公司也慢慢走向了开源的道路，其实这也是必经之路。世界上总有那么多不断挑战权威，不断挑战垄断，不断改变生活的人。好啦，闲话不说了，我们开始搭建最基本，最小型化的 Spring 应用环境。Spring 核心的概念是控制反转，依赖注入。控制反转的意思就是控制权交给 Spring 平台，依赖注入就是程序依赖于 Spring Bean 通过 Java 反射机制将所需对象注入到程序中。

  一、工具 

项目管理 Maven，开发工具 Eclipse Kepler，JDK 1.7。

  二、Jar 包

 spring-context-4.3.8.RELEASE.jar

  三，项目结构

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://java.sun.com/xml/ns/javaee"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
    version="2.5">

    <display-name>mrp</display-name>

</web-app>

application.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" xmlns:context="http://www.springframework.org/schema/context"
    xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop"
    xsi:schemaLocation="
         http://www.springframework.org/schema/beans
         http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
         http://www.springframework.org/schema/context
         http://www.springframework.org/schema/context/spring-context-3.0.xsd
         http://www.springframework.org/schema/tx
         http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
         http://www.springframework.org/schema/aop
         http://www.springframework.org/schema/aop/spring-aop-3.0.xsd">

    <bean id="user" class="com.mrp.www.service.User" />

</beans>  

User 类

package com.mrp.www.service;

public class User {

    private String name = "xxxx";

    public String getName() {
        return name;
    }

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

}

Test 测试类

package com.mrp.www.service;

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

public class Test {

    private static ApplicationContext context;

    public static void main(String[] args) {

        context = new ClassPathXmlApplicationContext("application.xml");

         User u = (User) context.getBean("user");
         System.out.println(u.getName());

    }

}

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>www.mrp.com</groupId>
    <artifactId>mrp</artifactId>
    <packaging>war</packaging>
    <version>0.0.1-SNAPSHOT</version>
    <name>mrp Maven Webapp</name>
    <url>http://maven.apache.org</url>

    <properties>
        <build_path>C:\temp\${project.artifactId}</build_path>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <spring_webmvc_version>3.2.4.RELEASE</spring_webmvc_version>
        <spring_version>4.2.6.RELEASE</spring_version>
        <jstl_version>1.2</jstl_version>
        <standard_version>1.0.6</standard_version>
        <jackson_version>1.9.13</jackson_version>
        <spring_test_version>3.2.4.RELEASE</spring_test_version>
        <hessian_version>4.0.7</hessian_version>
        <servlet_version>2.5</servlet_version>
    </properties>

    <dependencies>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>4.3.8.RELEASE</version>
        </dependency>

    </dependencies>

    <build>
        <finalName>mrp</finalName>
        <plugins>
            <plugin>
                <groupId>org.apache.tomcat.maven</groupId>
                <artifactId>tomcat7-maven-plugin</artifactId>
                <version>2.2</version>
                <configuration>
                    <uriEncoding>${project.build.sourceEncoding}</uriEncoding>
                    <port>8017</port>
                    <path>/${project.artifactId}</path>
                </configuration>
            </plugin>

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.1</version>
                <configuration>
                    <source>1.6</source>
                    <target>1.6</target>
                    <compilerVersion>1.6</compilerVersion>
                    <generatedSourcesDirectory>${build_path}</generatedSourcesDirectory>
                    <generatedTestSourcesDirectory>${build_path}</generatedTestSourcesDirectory>
                </configuration>
            </plugin>

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
                <version>2.4.2</version>
                <configuration>
                    <skipTests>true</skipTests>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

Spring 平台可以集成很多的开源框架，而且 Spring 轻量级，配置简单，上面的例子仅仅配置了一个 User Bean，现实应用当中可就不止一个 Bean 这么简单了。会涉及到 AOP 编程，事务，数据源，缓存，分布式等等一系列的东西。后面在慢慢写出来吧，希望对大家有所帮助，也让自己有所收获。谢谢大家观看！