为什么Maven会下载不同版本的Spring工件？

Question

在我的 Maven 项目中，我定义了一堆 Spring 依赖项，我注意到在某些情况下它会选择不同版本的工件，即使它们在我的 pom.xml 中指定相同。

这是概述 mvn dependency:tree

[INFO] com.vrutberg.blogping:blogping:war:1.0-SNAPSHOT
[INFO] +- junit:junit:jar:4.7:test
[INFO] +- javax.servlet:servlet-api:jar:2.4:compile
[INFO] +- com.sun.jersey:jersey-server:jar:1.12:compile
[INFO] |  +- asm:asm:jar:3.1:compile
[INFO] |  \- com.sun.jersey:jersey-core:jar:1.12:compile
[INFO] +- com.sun.jersey:jersey-bundle:jar:1.12:compile
[INFO] +- javax.ws.rs:jsr311-api:jar:1.1.1:compile
[INFO] +- org.springframework:spring-core:jar:3.0.0.RC3:compile
[INFO] +- org.springframework:spring-expression:jar:3.0.5.RELEASE:compile
[INFO] +- org.springframework:spring-beans:jar:3.0.0.RC3:compile
[INFO] +- org.springframework:spring-aop:jar:3.0.0.RC3:compile
[INFO] +- org.springframework:spring-context:jar:3.0.0.RC3:compile
[INFO] +- org.springframework:spring-context-support:jar:3.0.5.RELEASE:compile
[INFO] +- org.springframework:spring-tx:jar:3.0.5.RELEASE:compile
[INFO] |  \- aopalliance:aopalliance:jar:1.0:compile
[INFO] +- org.springframework:spring-orm:jar:3.0.5.RELEASE:compile
[INFO] |  \- org.springframework:spring-jdbc:jar:3.0.5.RELEASE:compile
[INFO] +- org.springframework:spring-oxm:jar:3.0.5.RELEASE:compile
[INFO] +- org.springframework:spring-web:jar:3.0.0.RC3:compile
[INFO] +- org.springframework:spring-webmvc:jar:3.0.5.RELEASE:compile
[INFO] |  \- org.springframework:spring-asm:jar:3.0.5.RELEASE:compile
[INFO] +- org.springframework:spring-test:jar:3.0.5.RELEASE:test
[INFO] \- com.sun.jersey.contribs:jersey-spring:jar:1.12:compile
[INFO]    \- com.sun.jersey:jersey-servlet:jar:1.12:compile

在我的 pom.xml 中，我定义了一个用于所有 Spring 工件的属性，它的定义如下：

<org.springframework.version>3.0.5.RELEASE</org.springframework.version>

这些是我的依赖项：

    <!-- spring libraries -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-core</artifactId>
        <version>${org.springframework.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-expression</artifactId>
        <version>${org.springframework.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-beans</artifactId>
        <version>${org.springframework.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-aop</artifactId>
        <version>${org.springframework.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
        <version>${org.springframework.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context-support</artifactId>
        <version>${org.springframework.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-tx</artifactId>
        <version>${org.springframework.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-orm</artifactId>
        <version>${org.springframework.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-oxm</artifactId>
        <version>${org.springframework.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-web</artifactId>
        <version>${org.springframework.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>${org.springframework.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-test</artifactId>
        <version>${org.springframework.version}</version>
        <scope>test</scope>
    </dependency>

为什么它使用不同的版本？

编辑：

好的，所以我刚刚发现了这些警告。我想这与它有关：

Downloading: http://download.java.net/maven/2/org/springframework/spring-core/3.0.0.RC3/spring-core-3.0.0.RC3.pom
Downloading: http://repo1.maven.org/maven2/org/springframework/spring-core/3.0.0.RC3/spring-core-3.0.0.RC3.pom
[WARNING] Missing POM for org.springframework:spring-core:jar:3.0.5.RELEASE
Downloading: http://download.java.net/maven/2/org/springframework/spring-beans/3.0.0.RC3/spring-beans-3.0.0.RC3.pom
Downloading: http://repo1.maven.org/maven2/org/springframework/spring-beans/3.0.0.RC3/spring-beans-3.0.0.RC3.pom
[WARNING] Missing POM for org.springframework:spring-beans:jar:3.0.5.RELEASE
Downloading: http://download.java.net/maven/2/org/springframework/spring-aop/3.0.0.RC3/spring-aop-3.0.0.RC3.pom
Downloading: http://repo1.maven.org/maven2/org/springframework/spring-aop/3.0.0.RC3/spring-aop-3.0.0.RC3.pom
[WARNING] Missing POM for org.springframework:spring-aop:jar:3.0.5.RELEASE
Downloading: http://download.java.net/maven/2/org/springframework/spring-context/3.0.0.RC3/spring-context-3.0.0.RC3.pom
Downloading: http://repo1.maven.org/maven2/org/springframework/spring-context/3.0.0.RC3/spring-context-3.0.0.RC3.pom
[WARNING] Missing POM for org.springframework:spring-context:jar:3.0.5.RELEASE
Downloading: http://download.java.net/maven/2/org/springframework/spring-web/3.0.0.RC3/spring-web-3.0.0.RC3.pom
Downloading: http://repo1.maven.org/maven2/org/springframework/spring-web/3.0.0.RC3/spring-web-3.0.0.RC3.pom
[WARNING] Missing POM for org.springframework:spring-web:jar:3.0.5.RELEASE

为什么有些工件缺少 poms 呢？为什么它回退到使用 3.0.0.RC3？

Answer 1

在 eclipse 中，至少在最后一个版本中，有一个 pom 视图，您可以在其中查看依赖关系树，以便您可以找出为什么添加一个库作为其他库的结果。