在 Eclipse 的 spring-boot 项目中使用 Maven“ Unable to find main class”

我非常绝望，因为我不再能够编译我的 Maven 项目。我有一个逻辑项目分为7个 maven 模块，到目前为止编译良好，但今天我引入了一个功能，由此我意外地生成了一个循环 maven 依赖。因此，我重构了代码并消除了循环依赖关系。自从我更新了 pom 文件以反映我的项目不再构建的修复程序。当我使用“-X clean install”运行 maven 时，我得到以下 java.lang。IllegalStateException: 无法找到主类

[INFO] Error stacktraces are turned on.
[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Build Order:
[INFO]
[INFO] agiletunes-parent
[INFO] agiletunes-util
[INFO] agiletunes-security-common
[INFO] agiletunes-marketing-persistence
[INFO] agiletunes-common-ui
[INFO] agiletunes-security-client
[INFO] agiletunes-marketing-application
[INFO] agiletunes-security-server
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building agiletunes-parent 0.0.1
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- spring-boot-maven-plugin:1.5.2.RELEASE:repackage (default) @ agiletunes-parent ---
[INFO]
[INFO] --- maven-install-plugin:2.5.2:install (default-install) @ agiletunes-parent ---
[INFO] Installing C:\Users\Alexander\Documents\Development\agileTunes\agiletunes-parent\pom.xml to C:\Users\Alexander\Documents\Development\mavenArtifacts\com\agiletunes\agiletunes-parent\0.0.1\agiletunes-parent-0.0.1.pom
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building agiletunes-util 0.0.1
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ agiletunes-util ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory C:\Users\Alexander\Documents\Development\agileTunes\agiletunes-util\src\main\resources
[INFO] skip non existing resourceDirectory C:\Users\Alexander\Documents\Development\agileTunes\agiletunes-util\src\main\resources
[INFO]
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ agiletunes-util ---
[INFO] Nothing to compile - all classes are up to date
[INFO]
[INFO] --- maven-resources-plugin:2.6:testResources (default-testResources) @ agiletunes-util ---
[INFO] Not copying test resources
[INFO]
[INFO] --- maven-compiler-plugin:3.1:testCompile (default-testCompile) @ agiletunes-util ---
[INFO] Not compiling test sources
[INFO]
[INFO] --- maven-surefire-plugin:2.18.1:test (default-test) @ agiletunes-util ---
[INFO] Tests are skipped.
[INFO]
[INFO] --- maven-jar-plugin:2.6:jar (default-jar) @ agiletunes-util ---
[INFO]
[INFO] --- spring-boot-maven-plugin:1.5.2.RELEASE:repackage (default) @ agiletunes-util ---
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary:
[INFO]
[INFO] agiletunes-parent .................................. SUCCESS [  1.492 s]
[INFO] agiletunes-util .................................... FAILURE [  1.095 s]
[INFO] agiletunes-security-common ......................... SKIPPED
[INFO] agiletunes-marketing-persistence ................... SKIPPED
[INFO] agiletunes-common-ui ............................... SKIPPED
[INFO] agiletunes-security-client ......................... SKIPPED
[INFO] agiletunes-marketing-application ................... SKIPPED
[INFO] agiletunes-security-server ......................... SKIPPED
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 3.674 s
[INFO] Finished at: 2017-03-21T21:53:04+01:00
[INFO] Final Memory: 31M/309M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.springframework.boot:spring-boot-maven-plugin:1.5.2.RELEASE:repackage (default) on project agiletunes-util: Execution default of goal org.springframework.boot:spring-boot-maven-plugin:1.5.2.RELEASE:repackage failed: Unable to find main class -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.springframework.boot:spring-boot-maven-plugin:1.5.2.RELEASE:repackage (default) on project agiletunes-util: Execution default of goal org.springframework.boot:spring-boot-maven-plugin:1.5.2.RELEASE:repackage failed: Unable to find main class
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:212)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:116)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:80)
at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51)
at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:307)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:193)
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:106)
at org.apache.maven.cli.MavenCli.execute(MavenCli.java:863)
at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:288)
at org.apache.maven.cli.MavenCli.main(MavenCli.java:199)
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.PluginExecutionException: Execution default of goal org.springframework.boot:spring-boot-maven-plugin:1.5.2.RELEASE:repackage failed: Unable to find main class
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:145)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:207)
... 20 more
Caused by: java.lang.IllegalStateException: Unable to find main class
at org.springframework.boot.loader.tools.Repackager.buildManifest(Repackager.java:354)
at org.springframework.boot.loader.tools.Repackager.repackage(Repackager.java:273)
at org.springframework.boot.loader.tools.Repackager.repackage(Repackager.java:258)
at org.springframework.boot.loader.tools.Repackager.repackage(Repackager.java:190)
at org.springframework.boot.maven.RepackageMojo.repackage(RepackageMojo.java:212)
at org.springframework.boot.maven.RepackageMojo.execute(RepackageMojo.java:199)
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:134)
... 21 more
[ERROR]
...

这是我的 maven 父项目的 pom.xml:

<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>


<groupId>com.agiletunes</groupId>
<artifactId>agiletunes-parent</artifactId>
<version>0.0.1</version>


<packaging>pom</packaging>
<name>agiletunes-parent</name>
<description>Maven parent project of agiletunes</description>


<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.2.RELEASE</version>
<relativePath></relativePath>
</parent>


<modules>
<module>../agiletunes-common-ui</module>
<module>../agiletunes-marketing-application</module>
<module>../agiletunes-marketing-persistence</module>
<module>../agiletunes-security-client</module>
<module>../agiletunes-security-common</module>
<module>../agiletunes-security-server</module>
<module>../agiletunes-util</module>
</modules>


<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>


<!-- Java -->
<java.version>1.8</java.version>


<!-- Spring -->
<spring.boot.version>1.5.2.RELEASE</spring.boot.version>


<!-- persistence -->
<mysql-connector-java.version>6.0.5</mysql-connector-java.version>


<!-- util -->
<guava.version>17.0</guava.version>


<!-- testing -->
<mockito.version>1.9.5</mockito.version>


</properties>


<dependencies>


<!-- Spring -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>${mysql-connector-java.version}</version><!--$NO-MVN-MAN-VER$ -->
<scope>runtime</scope>
</dependency>


<!-- utils -->
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
<version>${guava.version}</version>
</dependency>


<!-- unit test framework -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>


<dependency>
<groupId>org.mockito</groupId>
<artifactId>mockito-core</artifactId>
<version>${mockito.version}</version>
<scope>test</scope>
</dependency>


</dependencies>


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

我需要做什么，弥补这一切吗？请让我知道，如果你需要更多的信息。先谢谢你。

160312

小开

You can try adding this in the properties section of your pom

<start-class>your.package.main</start-class>

小开

You should have this

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

only in those modules that you want to run, but not in the parent pom.

小开

add property to maven properties like this

<properties>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
<start-class>org.roshan.Application</start-class>
</properties>

小开

Wouldn't you simply tell it by using the annotation @SpringBootApplication?

https://docs.spring.io/spring-boot/docs/current/reference/html/using-boot-using-springbootapplication-annotation.html

Many Spring Boot developers always have their main class annotated with @Configuration, @EnableAutoConfiguration and @ComponentScan. Since these annotations are so frequently used together (especially if you follow the best practices above), Spring Boot provides a convenient @SpringBootApplication alternative.

小开

I had the same problem. It ended being a spring boot mvn plugin declaration on a subproject that does not actually run (no main class). I just removed the spring boot mvn plugin from the submodule and everything ran fine

小开

I solved that,

Add the following code to pom file,

<profiles>
<profile>
<id>profile1</id>
<properties>
<spring.boot.mainclass>com.detaysoft.Application</spring.boot.mainclass>
</properties>
</profile>
</profiles>

Then build the build tag as follows,

    <build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<executions>
<execution>
<goals>
<goal>repackage</goal>
</goals>
<configuration>
<mainClass>${spring.boot.mainclass}</mainClass>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>

小开

In my case I had to add the "sourceDirectory" and my pom.xml changed from:

...

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

...

<build>
<sourceDirectory>src</sourceDirectory>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>

...

小开

最佳答案

Just for someone who faced with similar problem. I added spring-boot-maven-plugin in parent POM in section pluginManagement section like this:

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

Then I added the plugin only in the modules using it (in plugin section).The project has been successfully built after that.

小开

If you manually build your Sprint Boot project by using maven then make sure your project has a class like " class Application extends SpringBootServletInitializer " with main method in that.

小开

if you don't have a main class in springboot project, you can execution spring-boot-maven-plugin by follow

 <build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<skip>true</skip>
</configuration>
</plugin>
</plugins>
</build>

小开

I also had same issue, and solved by adding Application class as

@SpringBootApplication
public class Application {


public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
}

i missed adding application start point during configuration of project.

小开

In project agiletunes-util pom.xml add

<properties>
<spring-boot.repackage.skip>true</spring-boot.repackage.skip>
</properties>

小开

There are 2 ways to solve the issue:

Create Main class:

public class Main {public static void main(String[] args){}}

Remove plugin from pom.xml:

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

小开

In my case, I had a code source file named java even though I was explicitly using kotlin:

<sourceDirectory>${project.basedir}/src/main/kotlin</sourceDirectory>
<testSourceDirectory>${project.basedir}/src/test/kotlin</testSourceDirectory>

小开

I also stumbled across this issue, and it turned out that packaging type was wrong. When I changed packaging from pom to jar, everything started to work correctly.

小开

I had a similar problem in the pom.xml created for separating my data model into a new module.

Reading this tread I discovered I had accidentally put the <configuration><skip>true</skip></configuration> inside the <executions> block. Below is my corrected pom.xml build section. FYI, there is no <packaging> entry in my pom.xml.

Using Ubuntu 20.04 LTS, Java 11.0.7, maven 3.6.3, Spring Starter 2.3.2.RELEASE, IntelliJ 2020.2

Working build configuration for pom.xml of my data model module

    <build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<executions>
<execution>
<goals>
<goal>repackage</goal>
</goals>
</execution>
</executions>
<configuration>
<skip>true</skip>
</configuration>
</plugin>
</plugins>
</build>

小开

If you have multi modules maven project, as first workaround simply disable repackage to avoid this exception :

<properties>
<spring-boot.repackage.skip>true</spring-boot.repackage.skip>
</properties>

Other workarouds :

<executions>
<execution>
<goals>
<goal>repackage</goal>
</goals>
</execution>
</executions>
<configuration>
<skip>true</skip>
</configuration>

As solution:

  <properties>
<spring.boot.mainclass>ir.shaparak.Application</spring.boot.mainclass>
</properties>

Another solution: In parent POM do as follows:

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

In sub modules(runable moudles) should be as follows

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

小开

With Maven you can tell which is the main class by:

<build>
<plugins>
<plugin>
<configuration>
<mainClass>com.xxx.yyy.mainApplication<mainClass>
<configuration>
<plugin>
<plugins>
</build>

小开

I was also facing the same issue is resolved by adding <id>repackage</id>.

 <plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<executions>
<execution>
<id>repackage</id>
<goals>
<goal>repackage</goal>
</goals>
<configuration>
<skip>true</skip>
</configuration>
</execution>
</executions>
</plugin>
</plugins>

小开

In my case, I had missed bellow tag in progect pom:

<packaging>jar</packaging>

<packaging>war</packaging>

so, I added and it worked fine.

小开

I had the same issue for multi module project and I added <mainClass>package-name-in-which-main-method-resides</mainClass> and it worked.

<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<mainClass>package-name-where-@SpringBootApplication-main-method-is(com.agiletunes)</mainClass>
</configuration>
</plugin>
</plugins>
</build>

小开

In my case, I had a kotlin project but the src dir was named java instead of kotlin by the IDE. refactoring the name fixed the issue.

小开

under

<artifactId></artifactId>

tag write this property

<properties>
<spring-boot.repackage.skip>true</spring-boot.repackage.skip>
</properties>

it is helped me

小开

<properties>
<spring-boot.repackage.skip>true</spring-boot.repackage.skip>
</properties>

This will work for your pom.xml as your program is trying to find a main class so that it can repackage all the dependencies into a single fat jar but if your module does not contain a main class then you need to specify it with the above code in your module's pom file.