maven工程中导入三方jar包控制引入版本的小知识

<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>com.demo.wx</groupId>
  <artifactId>wx</artifactId>
  <packaging>war</packaging>
  <version>0.0.1-SNAPSHOT</version>
  <name>wx Maven Webapp</name>
  <url>http://maven.apache.org</url>
  <properties>
    <!-- spring版本号 -->
    <spring.version>4.1.2.RELEASE</spring.version>
    <!-- mybatis版本号 -->
    <mybatis.version>3.2.6</mybatis.version>
    <!-- log4j日志文件管理包版本 -->
    <slf4j.version>1.7.7</slf4j.version>
    <log4j.version>1.2.17</log4j.version>
  </properties>

  <dependencies>

        <dependency>  
            <groupId>org.springframework</groupId>  
            <artifactId>spring-core</artifactId>  
            <version>${spring.version}</version>  
        </dependency>  
  
        <dependency>  
            <groupId>org.springframework</groupId>  
            <artifactId>spring-web</artifactId>  
            <version>${spring.version}</version>  
        </dependency>  
        <dependency>  
            <groupId>org.springframework</groupId>  
            <artifactId>spring-oxm</artifactId>  
            <version>${spring.version}</version>  
        </dependency>  
        <dependency>  
            <groupId>org.springframework</groupId>  
            <artifactId>spring-tx</artifactId>  
            <version>${spring.version}</version>  
        </dependency>  
  
        <dependency>  
            <groupId>org.springframework</groupId>  
            <artifactId>spring-jdbc</artifactId>  
            <version>${spring.version}</version>  
        </dependency>  
  
        <dependency>  
            <groupId>org.springframework</groupId>  
            <artifactId>spring-webmvc</artifactId>  
            <version>${spring.version}</version>  
        </dependency>  
        <dependency>  
            <groupId>org.springframework</groupId>  
            <artifactId>spring-aop</artifactId>  
            <version>${spring.version}</version>  
        </dependency>  
  
        <dependency>  
            <groupId>org.springframework</groupId>  
            <artifactId>spring-context-support</artifactId>  
            <version>${spring.version}</version>  
        </dependency>  
  
        <dependency>  
            <groupId>org.springframework</groupId>  
            <artifactId>spring-test</artifactId>  
            <version>${spring.version}</version>  
        </dependency> 

         <dependency>  
            <groupId>org.mybatis</groupId>  
            <artifactId>mybatis</artifactId>  
            <version>${mybatis.version}</version>  
        </dependency> 

        <dependency>  
            <groupId>log4j</groupId>  
            <artifactId>log4j</artifactId>  
            <version>${log4j.version}</version>  
        </dependency>  
          
        <dependency>  
            <groupId>org.slf4j</groupId>  
            <artifactId>slf4j-api</artifactId>  
            <version>${slf4j.version}</version>  
        </dependency>  
  
        <dependency>  
            <groupId>org.slf4j</groupId>  
            <artifactId>slf4j-log4j12</artifactId>  
            <version>${slf4j.version}</version>  
        </dependency>
          
  </dependencies>
  <build>
    <finalName>wx</finalName>
  </build>
</project>