SpringBoot: Defining the main class in pom.xml file
I've generated a Spring Boot web application using Spring Initializer, embedded Tomcat, Thymeleaf template engine.Technologies used: Spring Boot 1.4.2.RELEASE, Spring 4.3.4.RELEASE, Thymeleaf 2.1.5.RELEASE, Tomcat Embed 8.5.6, Maven 3, Java 8. I have this pom.xml file,
and I generate the war using this command
mvn clean package -DskipTests -Dspring.profiles.active=pebloc,war -DAPPKEY=pebloc
pom.xml:
<?xml version="1.0" encoding="UTF-8"?>
<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.bookcloud</groupId>
<artifactId>bookcloud</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>
<name>bookcloud</name>
<description>Book Cloud </description>
<profiles>
<profile>
<id>jar</id>
<properties>
<spring.boot.mainclass>com.bookcloud.iot.BookCloudApplication</spring.boot.mainclass>
</properties>
</profile>
<profile>
<id>war</id>
<properties>
<spring.boot.mainclass>com.bookcloud.iot.BookCloudApplicationWar</spring.boot.mainclass>
</properties>
</profile>
</profiles>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.2.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>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-aop</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-mail</artifactId>
</dependency>
<dependency>
<groupId>it.ozimov</groupId>
<artifactId>spring-boot-email-core</artifactId>
<version>0.5.1</version>
</dependency>
<dependency>
<groupId>it.ozimov</groupId>
<artifactId>spring-boot-thymeleaf-email</artifactId>
<version>0.5.1</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-security</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-batch</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/com.icegreen/greenmail -->
<dependency>
<groupId>com.icegreen</groupId>
<artifactId>greenmail</artifactId>
<version>1.5.3</version>
<optional>true</optional>
<scope>test</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpclient -->
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
</dependency>
<!-- hot swapping, disable cache for template, enable live reload -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.hsqldb</groupId>
<artifactId>hsqldb</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>Camden.SR5</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<executions>
<execution>
<goals>
<goal>repackage</goal>
</goals>
<configuration>
<mainClass>${spring.boot.mainclass}</mainClass>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
</project>
but I still got this error:
[ERROR] Failed to execute goal org.springframework.boot:spring-boot-maven-plugin:1.5.2.RELEASE:repackage (default) on project bookcloud: Execution default of goal org.springframework.boot:spring-boot-maven-plugin:1.5.2.RELEASE:repackage failed: Unable to find a single main class from the following candidates [com.bookcloud.iot.BookCloudApplication, com.bookcloud.iot.BookCloudApplicationWar] -> [Help 1]
BookCloudApplication.java
@Profile("!war")
@SpringBootApplication
@Import({SecurityConfig.class ,PersistenceConfig.class, ServiceConfig.class})
public class BookCloudApplication {
public static void main(String[] args) {
SpringApplication.run(BookCloudApplication.class, args);
}
}
BookCloudApplicationWar.java
@Profile("war")
@Import({SecurityConfig.class ,PersistenceConfig.class})
@SpringBootApplication
public class BookCloudApplicationWar extends SpringBootServletInitializer {
@Override
protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
return application.sources(BookCloudApplicationWar.class);
}
public static void main(String[] args) throws Exception {
SpringApplication.run(BookCloudApplicationWar.class, args);
}
}
Answer
Maven profiles has no relation to Spring profiles.
You have two Maven profiles: jar, war
You either use:
mvn clean package -Pjar
or
mvn clean package -Pwar
The error you are getting is while building the artifact because pom needs:
<start-class>your.app.entry.point.Main</start-class>
inside the properties element.
I would suggest to have only one start class regardless of the Maven profile.
something like:
pom.xml:
...
<modelVersion>4.0.0</modelVersion>
<groupId>com.asimio.cloud</groupId>
<artifactId>zuul-server</artifactId>
<version>0-SNAPSHOT</version>
<packaging>${packaging.type}</packaging>
...
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
<start-class>your.app.entry.point.Main</start-class>
<packaging.type>jar</packaging.type>
...
<profiles>
<profile>
<id>war</id>
<properties>
<packaging.type>war</packaging.type>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>
<scope>provided</scope>
</dependency>
</dependencies>
...
</profile>
</profiles>
...
Main.java:
package your.app.entry.point;
...
@SpringBootApplication
@Import({SecurityConfig.class ,PersistenceConfig.class, ServiceConfig.class})
public class App extends SpringBootServletInitializer {
@Override
protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
return builder.sources(App.class);
}
public static void main(String[] args) {
SpringApplication.run(App.class, args);
}
}
No need for Spring profiles. This artifact can now be built using either Maven profile and will run either using:
java -jar .....
when building this artifact as a jar
or
as a war file deployed to a servlet container when built using the -Pwar Maven profile.