Unable to find main class with Maven on spring-boot project in Eclipse

Question

I am pretty desperate since I can no longer compile my Maven projects. I have one logical project, broken into 7 maven modules that are still compiled, but today I introduced a function due to which I accidentally created a circular maven dependency. So I reorganized the code and eliminated the cyclic dependency. Since I updated the pom files to reflect the fix, my project is no longer being built. When I run maven with "-X clean install", I get the following java.lang.IllegalStateException: the main class cannot be found

[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] ... 

This is the pom.xml of my parent maven project:

 <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> 

What do I need to do to fix this? Please let me know if you need more information. Thank you in advance.

Answer 1

You must have it

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

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

Answer 2

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

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

Answer 3

I had the same problem. This ended with the announcement of the spring boot mvn plugin in a subproject that does not actually start (there is no main class). I just removed the boot mvn spring module from the submodule and everything went fine

Answer 4

add property to maven properties such as

 <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> 

Answer 5

I decided that

Add the following code to the pom file,

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

Then create an assembly 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> 

Answer 6

Could you just talk about this using the @SpringBootApplication annotation?

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 often used together (especially if you follow the recommendations above), Spring Boot provides a convenient alternative to @SpringBootApplication .

Answer 7

Just for the one who faced a similar problem. I added spring-boot-maven-plugin to the parent POM in the 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 to the modules using it (in the plugin section). The project was successfully built after that.

Answer 8

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

...

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

...

in

...

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

...

Answer 9

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

Answer 10

if you don't have the main class in the springboot project, you can execute spring-boot-maven-plugin as follows

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