记一次maven打包报错Compilation failure:[找不到符号] [程序包XXX不存在]的处理过程

问题描述

[INFO] Reactor Summary for Demo 1.0:
[INFO]
[INFO] Demo ............................................... SUCCESS [  0.166 s]
[INFO] core ............................................... SUCCESS [  7.119 s]
[INFO] webAPI ............................................. FAILURE [  0.545 s]
[INFO] adminAPI ........................................... SKIPPED
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  8.188 s
[INFO] Finished at: 2019-11-28T15:31:53+08:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.8.1:compile (default-compile) on project webAPI: Compilation failure: Compilation failure:
[ERROR] /E:/workspace-git/Demo/WebAPI/src/main/java/com/demo/webapi/controller/CitysController.java:[4,26] 程序包com.demo.core.anno不存在
[ERROR] /E:/workspace-git/Demo/WebAPI/src/main/java/com/demo/webapi/controller/CitysController.java:[5,26] 程序包com.demo.core.anno不存在
[ERROR] /E:/workspace-git/Demo/WebAPI/src/main/java/com/demo/webapi/controller/CitysController.java:[6,26] 程序包com.demo.core.bean不存在
[ERROR] /E:/workspace-git/Demo/WebAPI/src/main/java/com/demo/webapi/controller/CitysController.java:[7,31] 程序包com.demo.core.component不存在
[ERROR] /E:/workspace-git/Demo/WebAPI/src/main/java/com/demo/webapi/controller/CitysController.java:[8,32] 程序包com.demo.core.controller不存在
[ERROR] /E:/workspace-git/Demo/WebAPI/src/main/java/com/demo/webapi/controller/CitysController.java:[9,29] 程序包com.demo.core.service不存在
[ERROR] /E:/workspace-git/Demo/WebAPI/src/main/java/com/demo/webapi/controller/CitysController.java:[29,38] 找不到符号
[ERROR]   符号: 类 BaseController
[ERROR] /E:/workspace-git/Demo/WebAPI/src/main/java/com/demo/webapi/controller/CitysController.java:[29,53] 找不到符号
[ERROR]   符号: 类 CitysService
[ERROR] /E:/workspace-git/Demo/WebAPI/src/main/java/com/demo/webapi/controller/CitysController.java:[27,2] 找不到符号
[ERROR]   符号: 类 RequiredToken
[ERROR] /E:/workspace-git/Demo/WebAPI/src/main/java/com/demo/webapi/controller/CitysController.java:[31,13] 找不到符号
[ERROR]   符号:   类 CitysService
[ERROR]   位置: 类 com.demo.webapi.controller.CitysController
[ERROR] /E:/workspace-git/Demo/WebAPI/src/main/java/com/demo/webapi/controller/CitysController.java:[37,13] 找不到符号
[ERROR]   符号:   类 FanoutProducer
[ERROR]   位置: 类 com.demo.webapi.controller.CitysController
[ERROR] /E:/workspace-git/Demo/WebAPI/src/main/java/com/demo/webapi/controller/CitysController.java:[40,12] 找不到符号
[ERROR]   符号:   类 ResponseBean
[ERROR]   位置: 类 com.demo.webapi.controller.CitysController
[ERROR] /E:/workspace-git/Demo/WebAPI/src/main/java/com/demo/webapi/controller/CitysController.java:[48,12] 找不到符号
[ERROR]   符号:   类 ResponseBean
[ERROR]   位置: 类 com.demo.webapi.controller.CitysController
[ERROR] /E:/workspace-git/Demo/WebAPI/src/main/java/com/demo/webapi/controller/CitysController.java:[54,12] 找不到符号
[ERROR]   符号:   类 ResponseBean
[ERROR]   位置: 类 com.demo.webapi.controller.CitysController
[ERROR] /E:/workspace-git/Demo/WebAPI/src/main/java/com/demo/webapi/controller/CitysController.java:[60,12] 找不到符号
[ERROR]   符号:   类 ResponseBean
[ERROR]   位置: 类 com.demo.webapi.controller.CitysController
[ERROR] /E:/workspace-git/Demo/WebAPI/src/main/java/com/demo/webapi/controller/CitysController.java:[66,12] 找不到符号
[ERROR]   符号:   类 ResponseBean
[ERROR]   位置: 类 com.demo.webapi.controller.CitysController
[ERROR] /E:/workspace-git/Demo/WebAPI/src/main/java/com/demo/webapi/controller/CitysController.java:[76,12] 找不到符号
[ERROR]   符号:   类 ResponseBean
[ERROR]   位置: 类 com.demo.webapi.controller.CitysController
[ERROR] /E:/workspace-git/Demo/WebAPI/src/main/java/com/demo/webapi/controller/CitysController.java:[54,32] 找不到符号
[ERROR]   符号:   类 MultiRequestBody
[ERROR]   位置: 类 com.demo.webapi.controller.CitysController
[ERROR] /E:/workspace-git/Demo/WebAPI/src/main/java/com/demo/webapi/controller/CitysController.java:[54,71] 找不到符号
[ERROR]   符号:   类 MultiRequestBody
[ERROR]   位置: 类 com.demo.webapi.controller.CitysController
[ERROR] -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.8.1:compile (default-compile) on project webAPI: Comp
ilation failureat org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:215)at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:156)at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:148)at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:117)at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:81)at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build (SingleThreadedBuilder.java:56)at org.apache.maven.lifecycle.internal.LifecycleStarter.execute (LifecycleStarter.java:128)at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:305)at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:192)at org.apache.maven.DefaultMaven.execute (DefaultMaven.java:105)at org.apache.maven.cli.MavenCli.execute (MavenCli.java:956)at org.apache.maven.cli.MavenCli.doMain (MavenCli.java:288)at org.apache.maven.cli.MavenCli.main (MavenCli.java:192)at sun.reflect.NativeMethodAccessorImpl.invoke0 (Native Method)at sun.reflect.NativeMethodAccessorImpl.invoke (NativeMethodAccessorImpl.java:62)at sun.reflect.DelegatingMethodAccessorImpl.invoke (DelegatingMethodAccessorImpl.java:43)at java.lang.reflect.Method.invoke (Method.java:498)at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced (Launcher.java:289)at org.codehaus.plexus.classworlds.launcher.Launcher.launch (Launcher.java:229)at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode (Launcher.java:415)at org.codehaus.plexus.classworlds.launcher.Launcher.main (Launcher.java:356)
Caused by: org.apache.maven.plugin.compiler.CompilationFailureException: Compilation failureat org.apache.maven.plugin.compiler.AbstractCompilerMojo.execute (AbstractCompilerMojo.java:1220)at org.apache.maven.plugin.compiler.CompilerMojo.execute (CompilerMojo.java:187)at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo (DefaultBuildPluginManager.java:137)at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:210)at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:156)at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:148)at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:117)at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:81)at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build (SingleThreadedBuilder.java:56)at org.apache.maven.lifecycle.internal.LifecycleStarter.execute (LifecycleStarter.java:128)at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:305)at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:192)at org.apache.maven.DefaultMaven.execute (DefaultMaven.java:105)at org.apache.maven.cli.MavenCli.execute (MavenCli.java:956)at org.apache.maven.cli.MavenCli.doMain (MavenCli.java:288)at org.apache.maven.cli.MavenCli.main (MavenCli.java:192)at sun.reflect.NativeMethodAccessorImpl.invoke0 (Native Method)at sun.reflect.NativeMethodAccessorImpl.invoke (NativeMethodAccessorImpl.java:62)at sun.reflect.DelegatingMethodAccessorImpl.invoke (DelegatingMethodAccessorImpl.java:43)at java.lang.reflect.Method.invoke (Method.java:498)at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced (Launcher.java:289)at org.codehaus.plexus.classworlds.launcher.Launcher.launch (Launcher.java:229)at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode (Launcher.java:415)at org.codehaus.plexus.classworlds.launcher.Launcher.main (Launcher.java:356)
[ERROR]
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException
[ERROR]
[ERROR] After correcting the problems, you can resume the build with the command
[ERROR]   mvn <goals> -rf :webAPI

业务背景：项目是使用的spring boot 模块化开发，分为三个模块：即webAPI，core，adminAPI，其中core是其他两个的核心依赖包，本身不提供任何接口服务。

POM文件

这里只展示和打包相关的配置

父POM

<modelVersion>4.0.0</modelVersion><groupId>com.demo</groupId>
<artifactId>Demo</artifactId>
<packaging>pom</packaging>
<version>1.0</version><modules><module>Core</module><module>WebAPI</module><module>AdminAPI</module>
</modules><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>2.1.6.RELEASE</version><relativePath/> <!-- lookup parent from repository -->
</parent><properties><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding><project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding><java.version>1.8</java.version>
</properties>

core POM文件

<modelVersion>4.0.0</modelVersion><artifactId>core</artifactId>
<packaging>jar</packaging>
<!--<version>1.0</version>-->
<name>core</name>
<description>Demo project for Spring Boot</description><parent><artifactId>Demo</artifactId><groupId>com.demo</groupId><version>1.0</version>
</parent>
<profiles><profile><id>dev</id><properties><profiles.active>dev</profiles.active></properties><activation><activeByDefault>true</activeByDefault></activation></profile><profile><!-- 生产环境 --><id>pro</id><properties><profiles.active>pro</profiles.active></properties></profile>
</profiles>
<build><finalName>core</finalName><plugins><!--这里注意下，这是出问题源头--><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin></plugins><resources><resource><directory>src/main/resources</directory><excludes><exclude>src/main/resources/dev</exclude><exclude>src/main/resources/pro</exclude></excludes></resource><resource><directory>src/main/resources/${profiles.active}</directory></resource></resources>
</build>

webAPI POM文件

<dependencies><dependency><groupId>com.demo</groupId><artifactId>core</artifactId><version>1.0</version><exclusions><exclusion><groupId>org.slf4j</groupId><artifactId>slf4j-log4j12</artifactId></exclusion></exclusions><type>jar</type></dependency><dependency><groupId>org.springframework.retry</groupId><artifactId>spring-retry</artifactId></dependency>
</dependencies><build><finalName>webAPI</finalName><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin></plugins>
</build>

amdinAPI就不贴了，和webAPI大同小异。
这时候执行打包命令：

mvn clean package  -Dmaven.test.skip=true

结果就是出现上述错误。但是core打包正常，到了打webAPI包才出的问题。一度让我认为是webAPI出现的问题。

问题原因

问题就出在spring-boot-maven-plugin这个打包方式上，就是core POM文件里的这段代码

<plugins><!--这里注意下，这是出问题源头--><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin>
</plugins>

**上面的这种打包方式是把core打包成可执行jar。无法当做普通依赖包被其他工程使用 **

说明：可执行jar包与依赖jar包中包含的内容是不一样的，大小上看，依赖jar包更小，可执行jar包更大。原因是，依赖jar包中主要包含了生产的代码，而可执行jar包中则包含了相关的底层库。
可执行jar作为依赖，会报出程序包或符号不存在的问题。

解决方式

解决方法其实有两种：

第一种：

把打包方式更换为maven-compiler-plugin插件。具体操作就是把core pom文件修改为：

<plugins><!--这里注意下，这是出问题源头--><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin><plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-compiler-plugin</artifactId><configuration><source>8</source><target>8</target></configuration></plugin>
</plugins>

执行打包命令。

[INFO] Reactor Summary for Demo 1.0:
[INFO]
[INFO] Demo ............................................... SUCCESS [  0.308 s]
[INFO] core ............................................... SUCCESS [  6.830 s]
[INFO] webAPI ............................................. SUCCESS [  6.561 s]
[INFO] adminAPI ........................................... SUCCESS [  8.675 s]
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  22.857 s
[INFO] Finished at: 2019-11-29T14:58:00+08:00
[INFO] ------------------------------------------------------------------------

结果没问题。

第二种：

增加classifier属性，具体core pom文件：

<plugins><!--这里注意下，这是出问题源头--><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId><!--新增--><configuration><classifier>exec</classifier></configuration></plugin>
</plugins>

这里为什么要加一个classifier标签：
spring-boot-maven-plugin在打包时会打两个包，一个.jar一个.jar.original，默认第一个.jar是一个可执行jar。classifier是用来区分两个jar包的，这是第一个就是普通的依赖包，第二个就是名字为exec的可执行jar。

这种方式的使用场景：就是这个模块即要作为普通依赖的jar，也要作为可执行jar使用。不过这种情况很少出现。

总结

这次问题的涉及点就是两种打包方式和两种jar的区别。说明了对于maven及pom配置文件的了解不够。