我有一个多模块项目：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>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.4.3.RELEASE</version>
</parent>
<groupId>be.bodyreset</groupId>
<artifactId>bodyreset-parent</artifactId>
<version>1.0.0-SNAPSHOT</version>
<packaging>pom</packaging>
<name>Bodyreset Parent</name>
<description>Manages the common properties and dependencies for the child modules</description>
<modules>
<module>bodyreset-commons</module>
<module>messaging-contract</module>
<module>discovery-microservice</module>
<module>api-gateway-microservice</module>
<module>rest-client-microservice</module>
<module>email-commons</module>
<module>security-microservice</module>
<module>user-microservice</module>
<module>point-of-service-microservice</module>
</modules>
<properties>
<docker.image.prefix>bodyreset</docker.image.prefix>
<java.version>1.8</java.version>
<powermock.version>1.6.6</powermock.version>
</properties>
<dependencyManagement>
<dependencies>
...
</dependencies>
</dependencyManagement>
<build>
<pluginManagement>
<plugins>
<plugin>
<groupId>com.spotify</groupId>
<artifactId>docker-maven-plugin</artifactId>
<version>0.4.11</version>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.6.0</version>
<configuration>
<source>${java.version}</source>
<target>${java.version}</target>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>3.0.2</version>
</plugin>
</plugins>
</pluginManagement>
</build>
</project>
rest-client-microservice的POM.xml如下所示：
<?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>be.bodyreset</groupId>
<artifactId>bodyreset-parent</artifactId>
<version>1.0.0-SNAPSHOT</version>
</parent>
<artifactId>rest-client-microservice</artifactId>
<version>1.0.0-SNAPSHOT</version>
<packaging>jar</packaging>
<name>Rest Client Microservice</name>
<description>Manages the REST clients to use for inter-service communication</description>
<dependencies>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</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-hateoas</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-eureka</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-feign</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-hystrix</artifactId>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>com.spotify</groupId>
<artifactId>docker-maven-plugin</artifactId>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>build</goal>
</goals>
</execution>
</executions>
<configuration>
<imageName>${docker.image.prefix}/${project.artifactId}</imageName>
<dockerDirectory>${project.basedir}/src/main/docker</dockerDirectory>
<resources>
<resource>
<targetPath>/</targetPath>
<directory>${project.build.directory}</directory>
<include>${project.build.finalName}.jar</include>
</resource>
</resources>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<executions>
<execution>
<goals>
<goal>test-jar</goal>
</goals>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<executions>
<execution>
<goals>
<goal>repackage</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
</project>
email-commons模块的POM.xml如下所示：
<?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>be.bodyreset</groupId>
<artifactId>bodyreset-parent</artifactId>
<version>1.0.0-SNAPSHOT</version>
</parent>
<artifactId>email-commons</artifactId>
<version>1.0.0-SNAPSHOT</version>
<packaging>jar</packaging>
<name>Email Commons</name>
<description>Enables sending emails via SMPT</description>
<dependencies>
<dependency>
<groupId>be.bodyreset</groupId>
<artifactId>rest-client-microservice</artifactId>
<version>1.0.0-SNAPSHOT</version>
</dependency>
<dependency>
<groupId>be.bodyreset</groupId>
<artifactId>rest-client-microservice</artifactId>
<version>1.0.0-SNAPSHOT</version>
<type>test-jar</type>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</dependency>
<dependency>
<groupId>org.powermock</groupId>
<artifactId>powermock-api-mockito</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.powermock</groupId>
<artifactId>powermock-module-junit4</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-mail</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<executions>
<execution>
<goals>
<goal>test-jar</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
</project>
如果我尝试在父项目上执行maven clean install，我会得到以下结果：
[INFO] ------------------------------------------------------------------------
[INFO] Building Email Commons 1.0.0-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-clean-plugin:2.6.1:clean (default-clean) @ email-commons ---
[INFO] Deleting /home/developer/ideaProjects/bodyreset/email-commons/target
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ email-commons ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 0 resource
[INFO] Copying 2 resources
[INFO]
[INFO] --- maven-compiler-plugin:3.6.0:compile (default-compile) @ email-commons ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 17 source files to /home/developer/ideaProjects/bodyreset/email-commons/target/classes
[INFO] -------------------------------------------------------------
[ERROR] COMPILATION ERROR :
[INFO] -------------------------------------------------------------
[ERROR] /home/developer/ideaProjects/bodyreset/email-commons/src/main/java/be/bodyreset/mail/converter/UserDTOToRecipientConverter.java:[4,29] package be.bodyreset.rest.dto does not exist
[ERROR] /home/developer/ideaProjects/bodyreset/email-commons/src/main/java/be/bodyreset/mail/converter/UserDTOToRecipientConverter.java:[16,63] cannot find symbol
symbol: class UserDTO
[ERROR] /home/developer/ideaProjects/bodyreset/email-commons/src/main/java/be/bodyreset/mail/converter/UserDTOToRecipientConverter.java:[22,30] cannot find symbol
symbol: class UserDTO
location: class be.bodyreset.mail.converter.UserDTOToRecipientConverter
[ERROR] /home/developer/ideaProjects/bodyreset/email-commons/src/main/java/be/bodyreset/mail/converter/UserDTOToSenderConverter.java:[4,29] package be.bodyreset.rest.dto does not exist
[ERROR] /home/developer/ideaProjects/bodyreset/email-commons/src/main/java/be/bodyreset/mail/converter/UserDTOToSenderConverter.java:[5,29] package be.bodyreset.rest.dto does not exist
[ERROR] /home/developer/ideaProjects/bodyreset/email-commons/src/main/java/be/bodyreset/mail/converter/UserDTOToSenderConverter.java:[15,60] cannot find symbol
symbol: class UserDTO
[ERROR] /home/developer/ideaProjects/bodyreset/email-commons/src/main/java/be/bodyreset/mail/converter/UserDTOToSenderConverter.java:[21,27] cannot find symbol
symbol: class UserDTO
location: class be.bodyreset.mail.converter.UserDTOToSenderConverter
[ERROR] /home/developer/ideaProjects/bodyreset/email-commons/src/main/java/be/bodyreset/mail/service/impl/SenderServiceImpl.java:[7,32] package be.bodyreset.rest.client does not exist
[ERROR] /home/developer/ideaProjects/bodyreset/email-commons/src/main/java/be/bodyreset/mail/service/impl/SenderServiceImpl.java:[8,32] package be.bodyreset.rest.client does not exist
[ERROR] /home/developer/ideaProjects/bodyreset/email-commons/src/main/java/be/bodyreset/mail/service/impl/SenderServiceImpl.java:[9,29] package be.bodyreset.rest.dto does not exist
[ERROR] /home/developer/ideaProjects/bodyreset/email-commons/src/main/java/be/bodyreset/mail/service/impl/SenderServiceImpl.java:[10,29] package be.bodyreset.rest.dto does not exist
[ERROR] /home/developer/ideaProjects/bodyreset/email-commons/src/main/java/be/bodyreset/mail/service/impl/SenderServiceImpl.java:[34,13] cannot find symbol
symbol: class PointOfServiceClient
location: class be.bodyreset.mail.service.impl.SenderServiceImpl
[ERROR] /home/developer/ideaProjects/bodyreset/email-commons/src/main/java/be/bodyreset/mail/service/impl/SenderServiceImpl.java:[37,13] cannot find symbol
symbol: class UserClient
location: class be.bodyreset.mail.service.impl.SenderServiceImpl
[ERROR] /home/developer/ideaProjects/bodyreset/email-commons/src/main/java/be/bodyreset/mail/service/impl/SenderServiceImpl.java:[63,13] cannot find symbol
symbol: class PointOfServiceDTO
location: class be.bodyreset.mail.service.impl.SenderServiceImpl
[ERROR] /home/developer/ideaProjects/bodyreset/email-commons/src/main/java/be/bodyreset/mail/service/impl/RecipientServiceImpl.java:[7,32] package be.bodyreset.rest.client does not exist
[ERROR] /home/developer/ideaProjects/bodyreset/email-commons/src/main/java/be/bodyreset/mail/service/impl/RecipientServiceImpl.java:[8,29] package be.bodyreset.rest.dto does not exist
[ERROR] /home/developer/ideaProjects/bodyreset/email-commons/src/main/java/be/bodyreset/mail/service/impl/RecipientServiceImpl.java:[32,13] cannot find symbol
symbol: class UserClient
location: class be.bodyreset.mail.service.impl.RecipientServiceImpl
[INFO] 17 errors
[INFO] -------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary:
[INFO]
[INFO] Bodyreset Parent .................................. SUCCESS [0.690s]
[INFO] Bodyreset Commons ................................. SUCCESS [7.444s]
[INFO] Messaging Contract ................................ SUCCESS [1.751s]
[INFO] Discovery Microservice ............................ SUCCESS [19.925s]
[INFO] API Gateway Microservice .......................... SUCCESS [17.272s]
[INFO] Rest Client Microservice .......................... SUCCESS [15.271s]
[INFO] Email Commons ..................................... FAILURE [1.026s]
[INFO] Security Microservice ............................. SKIPPED
[INFO] User Microservice ................................. SKIPPED
[INFO] Point Of Service Microservice ..................... SKIPPED
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1:04.292s
[INFO] Finished at: Thu Jan 19 11:53:25 CET 2017
[INFO] Final Memory: 63M/656M
[INFO] ------------------------------------------------------------------------
我已经在这个问题上突破了好几天了，但我不知道为什么这不起作用。
答案 0 :(得分：36)
我明白了。 rest-client-microservice是一个Spring Boot项目，使用以下插件：
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<executions>
<execution>
<goals>
<goal>repackage</goal>
</goals>
</execution>
</executions>
</plugin>
重新打包jar，所有包和类都放在BOOT-INF文件夹中。这就是为什么Maven无法找到它们的原因。您可以通过定义插件来解决此问题：
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<executions>
<execution>
<goals>
<goal>repackage</goal>
</goals>
<configuration>
<classifier>exec</classifier>
</configuration>
</execution>
</executions>
</plugin>
使用此配置，Spring Boot Maven插件将创建2个JAR：主要的一个将与通常的Maven项目相同，而第二个将附加分类器并且是可执行的JAR。
答案 1 :(得分：4)
在rest-client-microservice Spring Boot项目中，将此配置添加到spring-boot-maven-plugin。
<configuration>
<classifier>exe</classifier>
</configuration>
所以看起来像这样。
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<classifier>exe</classifier>
</configuration>
</plugin>
答案 2 :(得分：1)
对于此版本及更高版本，我正在使用Spring Boot 2.2.7，并从父pom.xml中删除了以下内容：
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
解决了问题
答案 3 :(得分：0)
对于Spring Boot 2，bootRepackage不再作为任务存在。它由bootJar任务代替。为了使用Gradle构建两个jar，我将其添加到了基本模块中：
jar {
enabled = true
}
答案 4 :(得分：0)
来源：https://spring.io/guides/gs/multi-module/
要告诉Maven不要为Library项目构建可执行jar，必须从Spring Initializr创建的pom.xml中删除以下块：
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>