Maven 验证 Spring Boot 应用程序类的 ClassNotFoundException答案

【问题标题】：Maven verify ClassNotFoundException for class of Spring Boot applicationMaven 验证 Spring Boot 应用程序类的 ClassNotFoundException
【发布时间】：2017-06-24 05:47:56
【问题描述】：

当我尝试为我的 Java Spring Boot 项目运行 Maven 的验证生命周期时，我收到了 NoClassDefFoundError。它使用mvn spring-boot:run 编译得很好，但是当我运行mvn clean verify 时它会失败：

$mvn clean verify -Dsurefire.skip=true -X
...
Tests run: 1, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 0.209 sec <<< FAILURE! - in com.fitforger.FitForgerBackendApplicationTests
    initializationError(com.fitforger.FitForgerBackendApplicationTests)  Time elapsed: 0.005 sec  <<< ERROR!
    java.lang.NoClassDefFoundError: com/fitforger/model/GymRat
    Caused by: java.lang.ClassNotFoundException: com.fitforger.model.GymRat

com.fitforger.model.GymRat 是我的应用程序的类之一。

项目结构：

+----src
     +----main
     |    +----java
     |    |    +----com
     |    |         +----fitforger
     |    |              +----controller
     |    |              |    +----GymRatController.java
     |    |              |    +----WorkoutNodeController.java
     |    |              +----dao
     |    |              |    +----GymRatDAO.java
     |    |              +----exception
     |    |              |    +----GymRatCreationFailure.java
     |    |              |    +----GymRatExistsException.java
     |    |              |    +----GymRatNotFound.java
     |    |              |    +----GymRatUpdateFailure.java
     |    |              +----FitForgerBackendApplication.java
     |    |              +----model
     |    |              |    +----FitForgerModel.java
     |    |              |    +----GymRat.java
     |    |              |    +----WorkoutAttribute.java
     |    |              |    +----WorkoutNode.java
     |    |              |    +----WorkoutNodeTypes.java
     |    |              +----repository
     |    |                   +----CouchbaseRepository.java
     |    |                   +----FitForgerRepository.java
     |    +----resources
     |         +----application.properties
     +----test
          +----java
          |    +----com
          |         +----fitforger
          |              +----FitForgerBackendApplicationTests.java
          |              +----GymRatSteps.java
          |              +----repository
          |                   +----CouchbaseRepositoryTest.java
          +----resources
               +----com
                    +----fitforger
                         +----GymRat.feature

我的 pom.xml 的相关部分：

<build>
    <resources>
        <resource>
            <directory>resources</directory>
            <targetPath>${project.build.outputDirectory}</targetPath>
            <includes>
                <include>application.properties</include>
            </includes>
        </resource>
    </resources>

    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.6.1</version>
        </plugin>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-failsafe-plugin</artifactId>
            <version>2.19.1</version>
        </plugin>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-surefire-plugin</artifactId>
        </plugin>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
            <version>1.5.1.RELEASE</version>
        </plugin>
    </plugins>

    <pluginManagement>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>1.5.1.RELEASE</version>
                <executions>
                    <execution>
                        <id>pre-integration-test</id>
                        <goals>
                            <goal>start</goal>
                        </goals>
                    </execution>
                    <execution>
                        <id>post-integration-test</id>
                        <goals>
                            <goal>stop</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <encoding>UTF-8</encoding>
                    <source>${java.version}</source>
                    <target>${java.version}</target>
                </configuration>
            </plugin>

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
                <version>2.19.1</version>
                <configuration>
                    <excludes>
                        <exclude>com.fitforger.FitForgerBackendApplicationTests</exclude>
                    </excludes>
                    <skip>${surefire.skip}</skip>
                </configuration>
            </plugin>

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-failsafe-plugin</artifactId>
                <version>2.19.1</version>
                <configuration>
                    <includes>
                        <include>com.fitforger.FitForgerBackendApplicationTests</include>
                    </includes>
                </configuration>
                <executions>
                    <execution>
                        <goals>
                            <goal>integration-test</goal>
                            <goal>verify</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </pluginManagement>
</build

【问题讨论】：

This(github.com/spring-projects/spring-boot/issues/6254) 看起来与您所面临的相似。你可以试试<plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> <configuration> <classifier>exec</classifier> </configuration> </plugin>
这成功了！非常感谢...可能想添加一个一般性回复，以便我可以将其标记为正确。
很高兴它成功了。我已将其作为答案移动。

标签： java spring-boot maven

【解决方案1】：

通过以下操作解决了OP问题，

This 看起来与您所面临的情况相似。你可以试试

<plugin>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-maven-plugin</artifactId>
   <configuration>
        <classifier>exec</classifier>
   </configuration>
 </plugin>

【讨论】：

【解决方案2】：

此问题也可能表现为集成测试用例未能找到您的 application.properties 资源。

这发生在 because Spring Boot 重新打包的交互中，由 spring-boot-maven-plugin 完成，以及 maven-failsafe-plugin 用于设置集成测试的类路径的逻辑。

Failsafe 插件puts 是类路径上的打包 JAR，而不是保存解压类和资源的目录（由 project.build.outputDirectory 属性给出，通常为 ${basedir}/target/classes）。但是，spring-boot-maven-plugin 完成的重新打包会将应用程序的类和资源放置在 JAR 中一个不寻常的位置，因此尽管 Failsafe 检查 JAR，但它没有找到它要查找的内容。

您可以通过在其配置中使用additionalClasspathElements 明确告诉Failsafe 插件将包含解压缩的类和资源的目录放在使用类路径上来解决此问题：

    <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-failsafe-plugin</artifactId>
        <configuration>
            <additionalClasspathElements>
                <additionalClasspathElement>${basedir}/target/classes</additionalClasspathElement>
            </additionalClasspathElements>
            <includes>
                <include>**/*IT.java</include>
            </includes>
        </configuration>
        <executions>
            <execution>
                <goals>
                    <goal>integration-test</goal>
                    <goal>verify</goal>
                </goals>
            </execution>
        </executions>
    </plugin>

【讨论】：

【解决方案3】：

如果您不扩展spring-boot-starter-parent，则必须在故障安全配置中添加classesDirectory（就像spring-boot-starter-parent pom 一样）：

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-failsafe-plugin</artifactId>
    <executions>
        <execution>
            <goals>
                <goal>integration-test</goal>
                <goal>verify</goal>
            </goals>
        </execution>
    </executions>
    <configuration>
        <!-- this one here! -->
        <classesDirectory>${project.build.outputDirectory}</classesDirectory>
    </configuration>
</plugin>

在JIRA comment 中找到类似问题 (failsafe 2.19+ not working with spring boot 1.4)。

【讨论】：