深入实践Spring Boot1.3.1　Maven依赖管理

1.3.1　Maven依赖管理

使用Maven，通过导入Spring Boot的starter模块，可以将许多程序依赖包自动导入工程中。使用Maven的parent POM，还可以更容易地管理依赖的版本和使用默认的配置，工程中的模块也可以很方便地继承它。例如，使用1.2.1节创建的工程，修改pom.xml文件，使用如代码清单1-1所示的简单Maven配置，基本上就能为一个使用Spring Boot开发框架的Web项目开发提供所需的相关依赖。

代码清单1-1　Spring Boot Web基本依赖配置

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

<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/xsd/maven-4.0.0.xsd">

    <modelVersion>4.0.0</modelVersion>

    <groupId>springboot.example</groupId>

    <artifactId>spring-boot-hello</artifactId>

    <version>1.0-SNAPSHOT</version>

    <parent>

        <groupId>org.springframework.boot</groupId>

        <artifactId>spring-boot-starter-parent</artifactId>

        <version>1.3.2.RELEASE</version>

    </parent>

    <dependencies>

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-web</artifactId>

        </dependency>

    </dependencies>

</project>

这里只使用了一个依赖配置spring-boot-starter-web和一个parent配置spring-boot-starter-parent，在工程的外部库（External Libraries）列表中，它自动引入的依赖包如代码清单1-2所示。

代码清单1-2　Maven加载的依赖列表

<orderEntry type="library" name="Maven: org.springframework.boot:spring-boot-starter-web:1.3.2.RELEASE" level="project" />

<orderEntry type="library" name="Maven: org.springframework.boot:spring-boot-starter:1.3.2.RELEASE" level="project" />

<orderEntry type="library" name="Maven: org.springframework.boot:spring-boot:1.3.2.RELEASE" level="project" />

<orderEntry type="library" name="Maven: org.springframework.boot:spring-boot-autoconfigure:1.3.2.RELEASE" level="project" />

<orderEntry type="library" name="Maven: org.springframework.boot:spring-boot-starter-logging:1.3.2.RELEASE" level="project" />

<orderEntry type="library" name="Maven: ch.qos.logback:logback-classic:1.1.3" level="project" />

<orderEntry type="library" name="Maven: ch.qos.logback:logback-core:1.1.3" level="project" />

<orderEntry type="library" name="Maven: org.slf4j:slf4j-api:1.7.13" level="project" />

<orderEntry type="library" name="Maven: org.slf4j:jcl-over-slf4j:1.7.13" level="project" />

<orderEntry type="library" name="Maven: org.slf4j:jul-to-slf4j:1.7.13" level="project" />

<orderEntry type="library" name="Maven: org.slf4j:log4j-over-slf4j:1.7.13" level="project" />

<orderEntry type="library" name="Maven: org.springframework:spring-core:4.2.4.RELEASE" level="project" />

<orderEntry type="library" scope="RUNTIME" name="Maven: org.yaml:snakeyaml:1.16" level="project" />

<orderEntry type="library" name="Maven: org.springframework.boot:spring-boot-starter-tomcat:1.3.2.RELEASE" level="project" />

<orderEntry type="library" name="Maven: org.apache.tomcat.embed:tomcat-embed-core:8.0.30" level="project" />

<orderEntry type="library" name="Maven: org.apache.tomcat.embed:tomcat-embed-el:8.0.30" level="project" />

<orderEntry type="library" name="Maven: org.apache.tomcat.embed:tomcat-embed-logging-juli:8.0.30" level="project" />

<orderEntry type="library" name="Maven: org.apache.tomcat.embed:tomcat-embed-websocket:8.0.30" level="project" />

<orderEntry type="library" name="Maven: org.springframework.boot:spring-boot-starter-validation:1.3.2.RELEASE" level="project" />

<orderEntry type="library" name="Maven: org.hibernate:hibernate-validator:5.2.2.Final" level="project" />

<orderEntry type="library" name="Maven: javax.validation:validation-api:1.1.0.Final" level="project" />

<orderEntry type="library" name="Maven: org.jboss.logging:jboss-logging:3.3.0.Final" level="project" />

<orderEntry type="library" name="Maven: com.fasterxml:classmate:1.1.0" level="project" />

<orderEntry type="library" name="Maven: com.fasterxml.jackson.core:jackson-databind:2.6.5" level="project" />

<orderEntry type="library" name="Maven: com.fasterxml.jackson.core:jackson-annotations:2.6.5" level="project" />

<orderEntry type="library" name="Maven: com.fasterxml.jackson.core:jackson-core:2.6.5" level="project" />

<orderEntry type="library" name="Maven: org.springframework:spring-web:4.2.4.RELEASE" level="project" />

<orderEntry type="library" name="Maven: org.springframework:spring-aop:4.2.4.RELEASE" level="project" />

<orderEntry type="library" name="Maven: aopalliance:aopalliance:1.0" level="project" />

<orderEntry type="library" name="Maven: org.springframework:spring-beans:4.2.4.RELEASE" level="project" />

<orderEntry type="library" name="Maven: org.springframework:spring-context:4.2.4.RELEASE" level="project" />

<orderEntry type="library" name="Maven: org.springframework:spring-webmvc:4.2.4.RELEASE" level="project" />

<orderEntry type="library" name="Maven: org.springframework:spring-expression:4.2.4.RELEASE" level="project" />

在工程的外部库列表中，Spring Boot已经导入了整个springframework依赖，以及autoconf?igure、logging、slf4j、jackson、tomcat插件等，所有这些都是一个Web项目可能需要用到的东西（包括你已经考虑到的和没有考虑到的），它真是一个聪明的助手。