Maven工具链未在构建中触发

Question

我正在使用最新的maven 3.3.9,它强制执行java 8,并尝试使用java 7 maven工具链在java 7中编译项目.

按照: maven指南我已经放入maven工具链插件尝试告诉它使用java 7来编译应用程序.我的项目设置如下:

• top_module - >(在这个pom.xml中放入了maven工具链插件)

  --- submodule1

  --- submodule2

这是我的父pom.xml:

<?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>

    <parent>
        <groupId>parent</groupId>
        <artifactId>build-base</artifactId>
        <version>1.0.17</version>
    </parent>

    <groupId>top_module</groupId>
    <artifactId>top_module</artifactId>
    <version>1</version>
    <packaging>pom</packaging>
    <name>${project.artifactId}</name>

    <modules>
        <module>submodule1</module>
        <module>submodule2</module>
    </modules>

    <properties>


        ...

    </properties>

    <dependencyManagement>
        <dependencies>

            <dependency>
                ...
            </dependency>
            <dependency>
                ...
            </dependency>
        </dependencies>
    </dependencyManagement>

    <dependencies>
        <dependency>
            ...
        </dependency>
    </dependencies>

    <build>
        <pluginManagement>
            <plugins>
                <!-- Ensure we compile as the correct jdk version -->
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <version>3.1</version>
                </plugin>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-toolchains-plugin</artifactId>
                    <version>1.1</version>
                    <executions>
                        <execution>
                            <goals>
                                <goal>toolchain</goal>
                            </goals>
                        </execution>
                    </executions>
                    <configuration>
                        <toolchains>
                            <jdk>
                                <version>1.7</version>
                                <vendor>sun</vendor>
                            </jdk>
                        </toolchains>
                    </configuration>
                </plugin>

                <!-- Maven WAR Plugin -->
                <plugin>
                    <artifactId>maven-war-plugin</artifactId>
                    <version>${maven.war.plugin.version}</version>
                    <inherited>true</inherited>
                    <configuration>
                        <archiveClasses>true</archiveClasses>
                    </configuration>
                </plugin>

                <plugin>
                    <groupId>org.eclipse.m2e</groupId>
                    <artifactId>lifecycle-mapping</artifactId>
                    <version>1.0.0</version>
                    <configuration>
                        <lifecycleMappingMetadata>
                            <pluginExecutions>
                                <pluginExecution>
                                    <pluginExecutionFilter>
                                        <groupId>org.apache.maven.plugins</groupId>
                                        <artifactId>maven-enforcer-plugin</artifactId>
                                        <versionRange>[1.0.0,)</versionRange>
                                        <goals>
                                            <goal>enforce</goal>
                                        </goals>
                                    </pluginExecutionFilter>
                                    <action>
                                        <ignore />
                                    </action>
                                </pluginExecution>
                            </pluginExecutions>
                        </lifecycleMappingMetadata>
                    </configuration>
                </plugin>

            </plugins>
        </pluginManagement>
    </build>

    ...

</project>

mvn clean install由于插件与java 8不兼容,构建不运行任何工具链相关的步骤并在运行时调出,这显然意味着工具链没有运行.我还需要pom中的其他东西吗？

这是我的M2_HOME中的toolchains.xml文件:

<?xml version="1.0" encoding="UTF8"?>
    <toolchains>
      <!-- JDK toolchains -->
      <toolchain>
        <type>jdk</type>
        <provides>
          <version>1.6</version>
          <vendor>sun</vendor>
        </provides>
        <configuration>
          <jdkHome>C:\Java\jdk1.6.0_45</jdkHome>
        </configuration>
      </toolchain>

            <toolchain>
        <type>jdk</type>
        <provides>
          <version>1.7</version>
          <vendor>sun</vendor>
        </provides>
        <configuration>
          <jdkHome>C:\Java\jdk1.7.0_79</jdkHome>
        </configuration>
      </toolchain>
    </toolchains>

Answer 1

问题只是你已经定义了所有插件,pluginManagement但你需要像这样定义它们:

<build>
  <pluginManagement>
    <plugins>
      <!-- Ensure we compile as the correct jdk version -->
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>3.1</version>
      </plugin>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-toolchains-plugin</artifactId>
        <version>1.1</version>
      </plugin>

      <!-- Maven WAR Plugin -->
      <plugin>
        <artifactId>maven-war-plugin</artifactId>
        <version>${maven.war.plugin.version}</version>
        <inherited>true</inherited>
        <configuration>
          <archiveClasses>true</archiveClasses>
        </configuration>
      </plugin>

      <plugin>
        <groupId>org.eclipse.m2e</groupId>
        <artifactId>lifecycle-mapping</artifactId>
        <version>1.0.0</version>
        <configuration>
          <lifecycleMappingMetadata>
            <pluginExecutions>
              <pluginExecution>
                <pluginExecutionFilter>
                  <groupId>org.apache.maven.plugins</groupId>
                  <artifactId>maven-enforcer-plugin</artifactId>
                  <versionRange>[1.0.0,)</versionRange>
                  <goals>
                    <goal>enforce</goal>
                  </goals>
                </pluginExecutionFilter>
                <action>
                  <ignore />
                </action>
              </pluginExecution>
            </pluginExecutions>
          </lifecycleMappingMetadata>
        </configuration>
      </plugin>

    </plugins>
  </pluginManagement>
  <plugins>
    <plugin>
      <groupId>org.apache.maven.plugins</groupId>
      <artifactId>maven-toolchains-plugin</artifactId>
      <executions>
        <execution>
          <goals>
            <goal>toolchain</goal>
          </goals>
          <configuration>
            <toolchains>
              <jdk>
                <version>1.7</version>
                <vendor>sun</vendor>
              </jdk>
            </toolchains>
          </configuration>
        </execution>
      </executions>
    </plugin>
  </plugins>


</build>

...

</project>

pluginManagement用于定义版本和默认配置,但不绑定到您需要为maven-toolchains-plugin执行的生命周期.在pluginManagement中你应该定义你正在使用的版本的所有插件,这些插件意味着maven-resources-plugin,maven-install-plugin,maven-deploy-plugin,maven-enforcer-plugin等.这可能是公司的一个很好的候选者.父pom定义了所有这些东西.并且您将最佳方式分离Maven使用的JDK和代码使用的JDK.

除此之外,Maven 3.3.9至少需要JDK 7而不是 JDK 8