Maven循环依赖？

Question

如果我将其添加到POM中，它会创建循环依赖吗？我已经试过了，这似乎是发生了什么。有件事我不明白。不是在构建结束时创建的war文件。

 <dependency>
  <groupId>${project.groupId}</groupId>
  <artifactId>mywebapp</artifactId>
  <version>${project.version}</version>
  <type>war</type>
  <scope>provided</scope>
 </dependency>

我的目录结构是root/functest，root/mywebapp。

有效POM

    [INFO] Scanning for projects...
[INFO] Searching repository for plugin with prefix: 'help'.
[INFO] org.grails: checking for updates from tapestry.javaforge
[WARNING] *** CHECKSUM FAILED - Checksum failed on download: local = 'ee0f52bc37051384f078f9706be9445b550ee4a6'; remote = 'a535436f42caf1ba0f9372328d2920372f30c842' - RETRYING
[WARNING] *** CHECKSUM FAILED - Checksum failed on download: local = 'ee0f52bc37051384f078f9706be9445b550ee4a6'; remote = 'a535436f42caf1ba0f9372328d2920372f30c842' - IGNORING
[INFO] org.apache.maven.plugins: checking for updates from tapestry.javaforge
[INFO] org.codehaus.mojo: checking for updates from tapestry.javaforge
[INFO] artifact org.apache.maven.plugins:maven-help-plugin: checking for updates from tapestry.javaforge
[INFO] ------------------------------------------------------------------------
[INFO] Building functional-tests
[INFO]    task-segment: [help:effective-pom] (aggregator-style)
[INFO] ------------------------------------------------------------------------
[INFO] [help:effective-pom]
[INFO] 
Effective POMs, after inheritance, interpolation, and profiles are applied:

<?xml version="1.0" encoding="UTF-8"?>
<!-- ====================================================================== -->
<!--                                                                        -->
<!-- Generated by Maven Help Plugin on 9/30/09 10:41 AM                     -->
<!-- See: http://maven.apache.org/plugins/maven-help-plugin/                -->
<!--                                                                        -->
<!-- ====================================================================== -->

<!-- ====================================================================== -->
<!--                                                                        -->
<!-- Effective POM for project 'com.mycompany:functest:pom:1.0-SNAPSHOT'    -->
<!--                                                                        -->
<!-- ====================================================================== -->

<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>
  <parent>
    <artifactId>myapp</artifactId>
    <groupId>com.mycompany</groupId>
    <version>1.0-SNAPSHOT</version>
  </parent>
  <groupId>com.mycompany</groupId>
  <artifactId>functest</artifactId>
  <version>1.0-SNAPSHOT</version>
  <packaging>pom</packaging>
  <name>functional-tests</name>
  <url>http://www.mycompany.com/functest</url>
  <organization>
    <name>My Company Inc</name>
    <url>http://www.mycompany.com</url>
  </organization>
  <developers>
    <developer>
      <id>john.doe</id>
      <name>John Doe</name>
      <email>john.doe@mycompany.com</email>
    </developer>
  </developers>
  <build>
    <sourceDirectory>C:\Documents and Settings\ric\AutoSmokeTest\steps\step7\functest\src\main\java</sourceDirectory>
    <scriptSourceDirectory>src/main/scripts</scriptSourceDirectory>
    <testSourceDirectory>C:\Documents and Settings\ric\AutoSmokeTest\steps\step7\functest\src\it</testSourceDirectory>
    <outputDirectory>C:\Documents and Settings\ric\AutoSmokeTest\steps\step7\functest\target\classes</outputDirectory>
    <testOutputDirectory>C:\Documents and Settings\ric\AutoSmokeTest\steps\step7\functest\target\test-classes</testOutputDirectory>
    <resources>
      <resource>
        <mergeId>resource-0</mergeId>
        <directory>C:\Documents and Settings\ric\AutoSmokeTest\steps\step7\functest\src\main\resources</directory>
      </resource>
    </resources>
    <testResources>
      <testResource>
        <mergeId>resource-1</mergeId>
        <directory>C:\Documents and Settings\ric\AutoSmokeTest\steps\step7\functest\src\test\resources</directory>
      </testResource>
    </testResources>
    <directory>C:\Documents and Settings\ric\AutoSmokeTest\steps\step7\functest\target</directory>
    <finalName>functest-1.0-SNAPSHOT</finalName>
    <pluginManagement>
      <plugins>
        <plugin>
          <artifactId>maven-antrun-plugin</artifactId>
          <version>1.3</version>
        </plugin>
        <plugin>
          <artifactId>maven-assembly-plugin</artifactId>
          <version>2.2-beta-2</version>
        </plugin>
        <plugin>
          <artifactId>maven-clean-plugin</artifactId>
          <version>2.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-compiler-plugin</artifactId>
          <version>2.0.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-dependency-plugin</artifactId>
          <version>2.0</version>
        </plugin>
        <plugin>
          <artifactId>maven-deploy-plugin</artifactId>
          <version>2.4</version>
        </plugin>
        <plugin>
          <artifactId>maven-ear-plugin</artifactId>
          <version>2.3.1</version>
        </plugin>
        <plugin>
          <artifactId>maven-ejb-plugin</artifactId>
          <version>2.1</version>
        </plugin>
        <plugin>
          <artifactId>maven-install-plugin</artifactId>
          <version>2.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-jar-plugin</artifactId>
          <version>2.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-javadoc-plugin</artifactId>
          <version>2.5</version>
        </plugin>
        <plugin>
          <artifactId>maven-plugin-plugin</artifactId>
          <version>2.4.3</version>
        </plugin>
        <plugin>
          <artifactId>maven-rar-plugin</artifactId>
          <version>2.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-release-plugin</artifactId>
          <version>2.0-beta-8</version>
        </plugin>
        <plugin>
          <artifactId>maven-resources-plugin</artifactId>
          <version>2.3</version>
        </plugin>
        <plugin>
          <artifactId>maven-site-plugin</artifactId>
          <version>2.0-beta-7</version>
        </plugin>
        <plugin>
          <artifactId>maven-source-plugin</artifactId>
          <version>2.0.4</version>
        </plugin>
        <plugin>
          <artifactId>maven-surefire-plugin</artifactId>
          <version>2.4.3</version>
        </plugin>
        <plugin>
          <artifactId>maven-war-plugin</artifactId>
          <version>2.1-alpha-2</version>
        </plugin>
      </plugins>
    </pluginManagement>
    <plugins>
      <plugin>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>2.0.2</version>
        <executions>
          <execution>
            <goals>
              <goal>testCompile</goal>
            </goals>
          </execution>
        </executions>
        <configuration>
          <source>1.5</source>
          <target>1.5</target>
        </configuration>
      </plugin>
      <plugin>
        <artifactId>maven-surefire-plugin</artifactId>
        <version>2.4.3</version>
        <executions>
          <execution>
            <phase>integration-test</phase>
            <goals>
              <goal>test</goal>
            </goals>
          </execution>
        </executions>
        <configuration>
          <suiteXmlFiles>
            <suiteXmlFile>src/it/testng.xml</suiteXmlFile>
          </suiteXmlFiles>
          <parallel>true</parallel>
          <threadCount>10</threadCount>
        </configuration>
      </plugin>
      <plugin>
        <groupId>org.codehaus.cargo</groupId>
        <artifactId>cargo-maven2-plugin</artifactId>
        <version>1.0.1-alpha-1</version>
        <executions>
          <execution>
            <id>start-container</id>
            <phase>pre-integration-test</phase>
            <goals>
              <goal>start</goal>
              <goal>deploy</goal>
            </goals>
            <configuration>
              <deployer>
                <deployables>
                  <deployable>
                    <groupId>com.mycompany</groupId>
                    <artifactId>mywebapp</artifactId>
                    <type>war</type>
                    <pingURL>http://localhost:8080/mywebapp/index.html</pingURL>
                    <pingTimeout>300000</pingTimeout>
                    <properties>
                      <context>mywebapp</context>
                    </properties>
                  </deployable>
                </deployables>
              </deployer>
            </configuration>
          </execution>
          <execution>
            <id>stop-container</id>
            <phase>post-integration-test</phase>
            <goals>
              <goal>stop</goal>
            </goals>
          </execution>
        </executions>
        <configuration>
          <wait>false</wait>
          <container>
            <containerId>tomcat5x</containerId>
            <zipUrlInstaller>
              <url>http://www.apache.org/dist/tomcat/tomcat-5/v5.5.28/bin/apache-tomcat-5.5.28.zip</url>
              <installDir>${installDir}</installDir>
            </zipUrlInstaller>
            <output>C:\Documents and Settings\ric\AutoSmokeTest\steps\step7\functest\target/tomcat5x.log</output>
            <log>C:\Documents and Settings\ric\AutoSmokeTest\steps\step7\functest\target/cargo.log</log>
          </container>
          <configuration>
            <home>C:\Documents and Settings\ric\AutoSmokeTest\steps\step7\functest\target/tomcat5x/container</home>
            <properties>
              <cargo.logging>high</cargo.logging>
              <cargo.servlet.port>8080</cargo.servlet.port>
            </properties>
          </configuration>
        </configuration>
      </plugin>
      <plugin>
        <artifactId>maven-help-plugin</artifactId>
        <version>2.1</version>
      </plugin>
    </plugins>
  </build>
  <repositories>
    <repository>
      <releases>
        <enabled>false</enabled>
      </releases>
      <snapshots />
      <id>public-snapshots</id>
      <url>http://public-snapshots</url>
    </repository>
    <repository>
      <releases />
      <snapshots />
      <id>openqa-releases</id>
      <url>http://nexus.openqa.org/content/repositories/releases</url>
    </repository>
    <repository>
      <id>openqa</id>
      <url>http://maven.openqa.org</url>
    </repository>
    <repository>
      <snapshots>
        <enabled>false</enabled>
      </snapshots>
      <id>central</id>
      <name>Maven Repository Switchboard</name>
      <url>http://repo1.maven.org/maven2</url>
    </repository>
  </repositories>
  <pluginRepositories>
    <pluginRepository>
      <releases>
        <enabled>false</enabled>
      </releases>
      <snapshots />
      <id>public-snapshots</id>
      <url>http://public-snapshots</url>
    </pluginRepository>
    <pluginRepository>
      <releases />
      <snapshots />
      <id>openqa-plugin</id>
      <url>http://nexus.openqa.org/content/repositories/releases</url>
    </pluginRepository>
    <pluginRepository>
      <releases />
      <snapshots />
      <id>another-plugin</id>
      <url>http://repo1.maven.org/maven2</url>
    </pluginRepository>
    <pluginRepository>
      <releases />
      <id>codehaus.snapshots</id>
      <url>http://snapshots.repository.codehaus.org/</url>
    </pluginRepository>
    <pluginRepository>
      <id>mortbay.repo</id>
      <url>http://www.mortbay.org/maven2/snapshot</url>
    </pluginRepository>
    <pluginRepository>
      <id>tapestry.javaforge</id>
      <url>http://howardlewisship.com/repository</url>
    </pluginRepository>
    <pluginRepository>
      <releases>
        <updatePolicy>never</updatePolicy>
      </releases>
      <snapshots>
        <enabled>false</enabled>
      </snapshots>
      <id>central</id>
      <name>Maven Plugin Repository</name>
      <url>http://repo1.maven.org/maven2</url>
    </pluginRepository>
  </pluginRepositories>
  <dependencies>
    <dependency>
      <groupId>com.mycompany</groupId>
      <artifactId>mywebapp</artifactId>
      <version>1.0-SNAPSHOT</version>
      <type>war</type>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>org.seleniumhq.selenium.server</groupId>
      <artifactId>selenium-server</artifactId>
      <version>1.0.1</version>
    </dependency>
    <dependency>
      <groupId>org.seleniumhq.selenium.client-drivers</groupId>
      <artifactId>selenium-java-client-driver</artifactId>
      <version>1.0.1</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.testng</groupId>
      <artifactId>testng</artifactId>
      <version>5.1</version>
      <classifier>jdk15</classifier>
      <scope>test</scope>
    </dependency>
  </dependencies>
  <reporting>
    <outputDirectory>C:\Documents and Settings\ric\AutoSmokeTest\steps\step7\functest\target/site</outputDirectory>
  </reporting>
</project>

[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESSFUL
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 3 seconds
[INFO] Finished at: Wed Sep 30 10:41:00 CEST 2009
[INFO] Final Memory: 7M/13M
[INFO] ------------------------------------------------------------------------

Answer 1

只有当mywebapp依赖于functest (或传递地依赖于它)时，它才会创建循环依赖。从名称上看，我猜测functest是一个测试组件，因此不会存在这样的依赖。

正如您所看到的，将属性替换到依赖声明中是有效的，如果Maven导致循环，则Maven将导致构建失败。

我猜您对“不是在构建结束时创建的war文件”感到困惑。是因为您希望构建失败，因为functest是在mywebapp之前构建的？请记住，Maven可以访问本地和远程存储库，因此以前构建的任何mywebapp的结果都将在存储库中可用。如果是这种情况，请尝试从本地/远程存储库中删除mywebapp，我怀疑您会看到由于未解析的依赖项而导致构建失败。

Answer 2

如果我把这个添加到一个POM中，它会创建一个循环依赖吗？

如果您所指的pom是functest模块的pom，则仅当mywebapp模块已经依赖于mywebapp模块(这里不应该是这种情况)时，向functest模块添加依赖项才会创建循环依赖项，正如里奇在另一个答案中所述。

我已经试过了，这似乎是发生了什么。

真的吗？你的多模块项目定义好了吗？你能给我们看一下父母的pom吗？您能提供从家长启动maven时获得的跟踪吗？

...war文件不是在构建结束时创建的吗？

好吧..。这取决于你在做什么。

如果您严格遵循Automated Smoke Tests With Selenium, Cargo, TestNG and Maven，请注意，作者并没有真正介绍多模块项目设置(我并不是说他没有这样做，我只是说他没有介绍这一部分)，而只是介绍了功能测试项目设置。他总是从functest目录启动maven，而不是从父pom中作为反应器启动，并且在step 7中由cargo部署的webapp被视为“外部”依赖项。

现在，如果您正在开发自己的are应用程序，那么在对其运行功能测试之前构建它是非常有意义的。实际上，这将是“推荐”的方法。在您的示例中，请确保将mywebapp声明为functest的依赖项，并将两个项目声明为父pom的模块，即类似于此(如果父pom位于父目录中)：

  ...
  <modules>
    <module>mywebapp</module>
    <module>functest</module>
  </modules>
  ...