Question

我刚刚使用全新的Java9官方版本升级了我的Java8项目。

该项目使用Maven插件org.apache.maven.plugins:maven-jar-plugin 2.6版。当我运行mvn clean install时，我现在得到以下异常：

ERROR] Failed to execute goal org.apache.maven.plugins:maven-jar-plugin:2.6:jar (default-jar) on project my-test-utils: Execution default-jar of goal org.apache.maven.plugins:maven-jar-plugin:2.6:jar failed: An API incompatibility was encountered while executing org.apache.maven.plugins:maven-jar-plugin:2.6:jar: java.lang.ExceptionInInitializerError: null
[ERROR] -----------------------------------------------------
[ERROR] realm =    plugin>org.apache.maven.plugins:maven-jar-plugin:2.6
[ERROR] strategy = org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy
[ERROR] urls[0] = file:/Users/jeanvaljean/.m2/repository/org/apache/maven/plugins/maven-jar-plugin/2.6/maven-jar-plugin-2.6.jar
[ERROR] urls[1] = file:/Users/jeanvaljean/.m2/repository/org/slf4j/slf4j-jdk14/1.5.6/slf4j-jdk14-1.5.6.jar
[ERROR] urls[2] = file:/Users/jeanvaljean/.m2/repository/org/slf4j/jcl-over-slf4j/1.5.6/jcl-over-slf4j-1.5.6.jar
[ERROR] urls[3] = file:/Users/jeanvaljean/.m2/repository/org/apache/maven/reporting/maven-reporting-api/2.2.1/maven-reporting-api-2.2.1.jar
[ERROR] urls[4] = file:/Users/jeanvaljean/.m2/repository/org/apache/maven/doxia/doxia-sink-api/1.1/doxia-sink-api-1.1.jar
[ERROR] urls[5] = file:/Users/jeanvaljean/.m2/repository/org/apache/maven/doxia/doxia-logging-api/1.1/doxia-logging-api-1.1.jar
[ERROR] urls[6] = file:/Users/jeanvaljean/.m2/repository/junit/junit/3.8.1/junit-3.8.1.jar
[ERROR] urls[7] = file:/Users/jeanvaljean/.m2/repository/commons-cli/commons-cli/1.2/commons-cli-1.2.jar
[ERROR] urls[8] = file:/Users/jeanvaljean/.m2/repository/org/codehaus/plexus/plexus-interactivity-api/1.0-alpha-4/plexus-interactivity-api-1.0-alpha-4.jar
[ERROR] urls[9] = file:/Users/jeanvaljean/.m2/repository/backport-util-concurrent/backport-util-concurrent/3.1/backport-util-concurrent-3.1.jar
[ERROR] urls[10] = file:/Users/jeanvaljean/.m2/repository/org/sonatype/plexus/plexus-sec-dispatcher/1.3/plexus-sec-dispatcher-1.3.jar
[ERROR] urls[11] = file:/Users/jeanvaljean/.m2/repository/org/sonatype/plexus/plexus-cipher/1.4/plexus-cipher-1.4.jar
[ERROR] urls[12] = file:/Users/jeanvaljean/.m2/repository/org/codehaus/plexus/plexus-interpolation/1.11/plexus-interpolation-1.11.jar
[ERROR] urls[13] = file:/Users/jeanvaljean/.m2/repository/org/apache/maven/maven-archiver/2.6/maven-archiver-2.6.jar
[ERROR] urls[14] = file:/Users/jeanvaljean/.m2/repository/org/apache/maven/shared/maven-shared-utils/0.7/maven-shared-utils-0.7.jar
[ERROR] urls[15] = file:/Users/jeanvaljean/.m2/repository/com/google/code/findbugs/jsr305/2.0.1/jsr305-2.0.1.jar
[ERROR] urls[16] = file:/Users/jeanvaljean/.m2/repository/org/codehaus/plexus/plexus-utils/3.0.20/plexus-utils-3.0.20.jar
[ERROR] urls[17] = file:/Users/jeanvaljean/.m2/repository/org/codehaus/plexus/plexus-archiver/2.9/plexus-archiver-2.9.jar
[ERROR] urls[18] = file:/Users/jeanvaljean/.m2/repository/org/codehaus/plexus/plexus-io/2.4/plexus-io-2.4.jar
[ERROR] urls[19] = file:/Users/jeanvaljean/.m2/repository/commons-io/commons-io/2.2/commons-io-2.2.jar
[ERROR] urls[20] = file:/Users/jeanvaljean/.m2/repository/org/apache/commons/commons-compress/1.9/commons-compress-1.9.jar
[ERROR] Number of foreign imports: 1
[ERROR] import: Entry[import  from realm ClassRealm[maven.api, parent: null]]
[ERROR]

有关如何解决此问题的任何提示？

我使用 Maven 3.3.9 。 mvn -version输出：

 Apache Maven 3.3.9 (bb52d8502b132ec0a5a3f4c09453c07478323dc5; 2015-11-10T17:41:47+01:00)
Maven home: /Users/jeanvaljean/Applications/maven/apache-maven-3.3.9
Java version: 9, vendor: Oracle Corporation
Java home: /Library/Java/JavaVirtualMachines/jdk-9.jdk/Contents/Home
Default locale: en_IT, platform encoding: UTF-8
OS name: "mac os x", version: "10.12.3", arch: "x86_64", family: "mac"

失败的模块实际上是父pom的第一个子模块。令人惊讶的是空洞：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://maven.apache.org/POM/4.0.0"
         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>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.7.RELEASE</version>
    </parent>

    <groupId>my.group</groupId>
    <artifactId>my-parent</artifactId>
    <version>0.1.0-SNAPSHOT</version>
    <packaging>pom</packaging>


    <modules>
        <module>test-utils</module>
        <module>commons</module>
        <module>validation</module>
    </modules>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>9</java.version>
        <tomcat.version>8.5.5</tomcat.version>
        <unit-tests.skip>true</unit-tests.skip>
        <integration-tests.skip>true</integration-tests.skip>

        <!-- PLUGINS -->
        <maven-compiler-plugin>3.6.2</maven-compiler-plugin>
        <maven-surefire-plugin>2.20.1</maven-surefire-plugin>
        <nexus-staging-maven-plugin>1.6.8</nexus-staging-maven-plugin>
        <maven-source-plugin>3.0.1</maven-source-plugin>
        <maven-javadoc-plugin>3.0.0-M1</maven-javadoc-plugin>
        <maven-gpg-plugin>1.6</maven-gpg-plugin>
        <versions-maven-plugin>2.4</versions-maven-plugin>
        <maven-scm-plugin>1.9.5</maven-scm-plugin>
    </properties>



    <prerequisites>
        <maven>3.0.4</maven>
    </prerequisites>

    <dependencies>
        <!-- SPRING BOOT -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-hystrix</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.retry</groupId>
            <artifactId>spring-retry</artifactId>
        </dependency>
    </dependencies>

    <build>

        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.6.2</version>
                <configuration>
                    <source>9</source>
                    <target>9</target>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-deploy-plugin</artifactId>
                <version>2.8.2</version>
                <configuration>
                    <skip>true</skip>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>**/*AcceptanceTest.java</exclude>
                        <exclude>**/*IT.java</exclude>
                    </excludes>
                </configuration>
                <executions>
                    <execution>
                        <id>integration-test</id>
                        <goals>
                            <goal>test</goal>
                        </goals>
                        <phase>integration-test</phase>
                        <configuration>
                            <excludes>
                                <exclude>none</exclude>
                            </excludes>
                            <includes>
                                <include>**/*IT.java</include>
                            </includes>
                        </configuration>
                    </execution>
                    <execution>
                        <id>acceptance-test</id>
                        <goals>
                            <goal>test</goal>
                        </goals>
                        <phase>verify</phase>
                        <configuration>
                            <excludes>
                                <exclude>none</exclude>
                            </excludes>
                            <includes>
                                <include>**/*AcceptanceTest.java</include>
                            </includes>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>org.jacoco</groupId>
                <artifactId>jacoco-maven-plugin</artifactId>
                <version>0.7.5.201505241946</version>
                <executions>
                    <execution>
                        <id>default-prepare-agent</id>
                        <goals>
                            <goal>prepare-agent</goal>
                        </goals>
                    </execution>
                    <execution>
                        <id>default-check</id>
                        <phase>prepare-package</phase>
                        <goals>
                            <goal>report</goal>
                            <goal>check</goal>
                        </goals>
                        <configuration>
                            <rules>
                                <rule>
                                    <element>CLASS</element>
                                    <excludes>
                                        <!--<exclude>it.ozimov</exclude>-->
                                    </excludes>
                                    <limits>
                                        <limit>
                                            <counter>BRANCH</counter>
                                            <value>COVEREDRATIO</value>
                                            <minimum>0</minimum>
                                        </limit>
                                        <limit>
                                            <counter>LINE</counter>
                                            <value>COVEREDRATIO</value>
                                            <minimum>0</minimum>
                                        </limit>
                                    </limits>
                                </rule>
                            </rules>
                        </configuration>
                    </execution>
                </executions>
            </plugin>

            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>versions-maven-plugin</artifactId>
                <version>2.3</version>
                <configuration>
                    <generateBackupPoms>false</generateBackupPoms>
                </configuration>
            </plugin>



            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-assembly-plugin</artifactId>
                <version>2.4.1</version>
                <dependencies>
                    <dependency>
                        <groupId>org.codehaus.plexus</groupId>
                        <artifactId>plexus-archiver</artifactId>
                        <version>2.4.4</version>
                    </dependency>
                </dependencies>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-jar-plugin</artifactId>
                <version>2.6</version>
                <dependencies>
                    <dependency>
                        <groupId>org.codehaus.plexus</groupId>
                        <artifactId>plexus-archiver</artifactId>
                        <version>2.4.4</version>
                    </dependency>
                </dependencies>
            </plugin>

        </plugins>
    </build>

</project>

Answer 1

在您的模块中，机会主要是不兼容的 maven-plugin 版本。您可以尝试将父模块中的插件配置更新为以下内容并进行测试：

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.7.0</version>
            <configuration>
                <source>1.9</source>
                <target>1.9</target>
                <jdkToolchain>
                    <version>9</version>
                </jdkToolchain>
            </configuration>
        </plugin>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-jar-plugin</artifactId>
            <version>3.0.2</version>
        </plugin>
    </plugins>
</build>

有关所有插件的兼容版本列表，请参阅Maven#Java9+Jigsaw

Answer 2

我拥有最新的Maven版本3.6.3。但是我意识到环境路径配置中设置的Java版本与IDE（IntelliJ）中安装的Java版本不匹配。

我在IDE中将最新的JDK版本（用于1.8）配置为1.8.0_265

我将环境路径设置为相同版本

您可以在此处配置JAVA_HOME，JRE_HOME，JDK_HOME。另外，请确保已添加路径。

有关如何设置环境变量的参考：https://stackoverflow.com/a/26640589/2889297

Maven主页为您提供了有关兼容的Java版本https://maven.apache.org/install.html

的高级建议

注意：在更新环境路径之后和运行mvn clean install之前，请确保版本正确反映在IDE终端中。您必须关闭并重新打开IDE，以反映更改。

JDK9和maven-jar-plugin

2 个答案: