spring-boot-maven-plugin spring-boot.run.main-class 被忽略 (Groovy)

Question

我有一个 spring-boot 应用程序，其中包含 2 个主要的 class，如下所示。

package org.arunm.springwebfluxrestservice.client


import org.springframework.boot.autoconfigure.SpringBootApplication
import org.springframework.boot.builder.SpringApplicationBuilder

@SpringBootApplication
class ReactiveClientApplication {

    public static void main(String[] args) {
        new SpringApplicationBuilder(ReactiveClientApplication)
            .properties(Collections.singletonMap("server.port","8081"))
            .run(args)
    }
}

和

package org.arunm.springwebfluxrestservice.webservice


import org.springframework.boot.SpringApplication
import org.springframework.boot.autoconfigure.SpringBootApplication
import org.springframework.web.bind.annotation.RestController

@SpringBootApplication
@RestController
class ReactiveServiceApplication {

    public static void main(String[] args) {
        SpringApplication.run(ReactiveServiceApplication)
    }
}

spring-boot-maven-plugin 已经包含在 pom.xml

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

我正在尝试使用

开始 ReactiveClientApplication

 mvn spring-boot:run -Dspring-boot.run.main-class=org.arunm.springwebfluxrestservice.client.ReactiveClientApplication

我收到错误

[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  4.297 s
[INFO] Finished at: 2020-05-14T16:27:38+10:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.springframework.boot:spring-boot-maven-plugin:2.2.7.RELEASE:run (default-cli) on project spring-webflux-rest-service: Execution default-cli of goal org.springframework.boot:spring-boot-maven-plugin:2.2.7.RELEASE:run failed: Unable to find a single main class from the following candidates [org.arunm.springwebfluxrestservice.webservice.ReactiveServiceApplication, org.arunm.springwebfluxrestservice.client.ReactiveClientApplication] -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.springframework.boot:spring-boot-maven-plugin:2.2.7.RELEASE:run (default-cli) on project spring-webflux-rest-service: Execution default-cli of goal org.springframework.boot:spring-boot-maven-plugin:2.2.7.RELEASE:run failed: Unable to find a single main class from the following candidates [org.arunm.springwebfluxrestservice.webservice.ReactiveServiceApplication, org.arunm.springwebfluxrestservice.client.ReactiveClientApplication]
    at 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 jdk.internal.reflect.NativeMethodAccessorImpl.invoke0 (Native Method)
    at jdk.internal.reflect.NativeMethodAccessorImpl.invoke (NativeMethodAccessorImpl.java:62)
    at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke (DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke (Method.java:566)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced (Launcher.java:282)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launch (Launcher.java:225)
    at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode (Launcher.java:406)
    at org.codehaus.plexus.classworlds.launcher.Launcher.main (Launcher.java:347)
Caused by: org.apache.maven.plugin.PluginExecutionException: Execution default-cli of goal org.springframework.boot:spring-boot-maven-plugin:2.2.7.RELEASE:run failed: Unable to find a single main class from the following candidates [org.arunm.springwebfluxrestservice.webservice.ReactiveServiceApplication, org.arunm.springwebfluxrestservice.client.ReactiveClientApplication]
    at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo (DefaultBuildPluginManager.java:148)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:210)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:156)

我做错了什么？

Answer 1

根据 mainClass 参数的插件 documentation 文档，未指定是否可以从命令行 运行。其他参数已经特别提到了。

因此可以将 Maven 配置文件与主要 class 配置一起使用。

<profiles>
    <profile>
        <id>client</id>
        <properties>
        <spring.boot.mainclass>org.arunm.springwebfluxrestservice.client.ReactiveClientApplication</spring.boot.mainclass>
        </properties>
    </profile>
    <profile>
        <id>service</id>
        <properties>
          <spring.boot.mainclass>org.arunm.springwebfluxrestservice.webservice.ReactiveServiceApplication</spring.boot.mainclass>
        </properties>
    </profile>
</profiles>

Spring 引导 Maven 插件

 <configuration>
          <mainClass>${spring.boot.mainclass}</mainClass>
 </configuration>

控制台

mvn spring-boot:run -P client

尽管这对我也有效，但可能是 Maven 正在 属性 替换配置参数，但我不是 100% 确定

mvn spring-boot:run -Dspring.boot.mainclass=org.arunm.springwebfluxrestservice.client.ReactiveClientApplication

参考资料

https://www.baeldung.com/spring-boot-main-class