springboot 使用java+kotlin混合开发，基于maven打包失败

布满荆棘的人生 2022-02-01 05:17 516阅读 0赞

## 背景 ##

鉴于springboot的快速开发以及kotlin的简介语法，公司新项目使用kotlin进行开发。开发工具使用IDEA，本地运行正常，但是通过maven进行项目打包的时候出现异常

## 工具 ##

springboot 【2.1.2】  kotlin【1.2.7】jdk【1.8】maven【3.5】

## 问题分析 ##

查阅网上资料说 运行

mvn clean kotlin:compile package -Dmaven.test.skip=true，然而并没有什么卵用；

**分析：**打包问题基本可以先猜测是pom的配置问题，先查看build这块的内容

pom.xml内容如下

。。。省略部分
        <dependency>
    		<groupId>com.fasterxml.jackson.module</groupId>
    		<artifactId>jackson-module-kotlin</artifactId>
    	</dependency>
    	<dependency>
    		<groupId>org.jetbrains.kotlin</groupId>
    		<artifactId>kotlin-reflect</artifactId>
    	</dependency>
    	<dependency>
    		<groupId>org.jetbrains.kotlin</groupId>
    		<artifactId>kotlin-stdlib-jdk8</artifactId>
    	</dependency>
     
    <build>
            <sourceDirectory>${project.basedir}/src/main/kotlin</sourceDirectory>
            <testSourceDirectory>${project.basedir}/src/test/kotlin</testSourceDirectory>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                </plugin>
                <plugin>
                    <groupId>org.jetbrains.kotlin</groupId>
                    <artifactId>kotlin-maven-plugin</artifactId>
                    <configuration>
                        <args>
                            <arg>-Xjsr305=strict</arg>
                        </args>
                        <compilerPlugins>
                            <plugin>spring</plugin>
                        </compilerPlugins>
                        <jvmTarget>1.8</jvmTarget>
                    </configuration>
                    <dependencies>
                        <dependency>
                            <groupId>org.jetbrains.kotlin</groupId>
                            <artifactId>kotlin-maven-allopen</artifactId>
                            <version>${kotlin.version}</version>
                        </dependency>
                    </dependencies>
                </plugin>
            </plugins>
        </build>

**执行mvn package 打包操作**，控制台报错：

[ERROR] Failed to execute goal org.springframework.boot:spring-boot-maven-plugin:2.1.2.RELEASE:repackage (default) on project srv-base: Execution default of goal org.springframework.boot:spring-boot-maven-plugin:2.1.2.RELEASE:repackage failed: Unable to find main class -> [Help 1]
    [ERROR] 
    [ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
    [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/PluginExecutionException

**Unable to find main class -> \[Help 1\] ：**说明未指定运行主类，spring-boot-maven-plugin中指定启动类路径**（注意：启动类为Kotlin的.kt文件时，指定的类名后需要加上Kt，【com.xxx.xxx.ApplicationKt】否则包启动无法还是无法找到主类）**

<plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                    <executions>
                        <execution>
                            <goals>
                                <goal>repackage</goal>
                            </goals>
                        </execution>
                    </executions>
                    <configuration>
                        <mainClass>com.xxx.xxx.ApplicationKt</mainClass>
                    </configuration>
                </plugin>

再次打包没有报错，但是运行时还是找不到主类。。。。。查看生成的包内容发现只有java编写的类有生成到包目录下，kotlin文件都未正常生成到包目录中

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2h1YW5nXzU1MA_size_16_color_FFFFFF_t_70][]

一脸懵逼，应该是kotlin编译器配置有问题，网上查阅后发现需要指定kotlin编译的项目路径，修改pom中kotlin-maven-plugin 指定资源路径

<plugin>
                    <groupId>org.jetbrains.kotlin</groupId>
                    <artifactId>kotlin-maven-plugin</artifactId>
                    <configuration>
                        <args>
                            <arg>-Xjsr305=strict</arg>
                        </args>
                        <jvmTarget>1.8</jvmTarget>
                    </configuration>
                    <executions>
                        <execution>
                            <id>compile</id>
                            <goals>
                                <goal>compile</goal>
                            </goals>
                            <configuration>
                                <sourceDirs>
                                    <sourceDir>${project.basedir}/src/main/kotlin</sourceDir>
                                    
                                </sourceDirs>
                            </configuration>
                        </execution>
                        <execution>
                            <id>test-compile</id>
                            <goals>
                                <goal>test-compile</goal>
                            </goals>
                            <configuration>
                                <sourceDirs>
                                    <sourceDir>${project.basedir}/src/test/kotlin</sourceDir>
                                    
                                </sourceDirs>
                            </configuration>
                        </execution>
                    </executions>
                </plugin>

再次打包-》运行，一切正常

已经被maven玩了好几次，这次又被kkotlin-maven-plugin玩了一次，记录一下避免忘记

参考链接：[http://www.kotlincn.net/docs/reference/using-maven.html][http_www.kotlincn.net_docs_reference_using-maven.html]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2h1YW5nXzU1MA_size_16_color_FFFFFF_t_70]: /images/20220201/e299f88142134b68bac62aab3c9751b4.png
[http_www.kotlincn.net_docs_reference_using-maven.html]: http://www.kotlincn.net/docs/reference/using-maven.html