I can not generate proper WAR file for Tomcat.
I am using MAVEN 3.6.1, Java 12.0.1 and IDE Eclipse. My app is working fine when I run it in eclipse (Run as > Spring Boot App) but the problem is when I am trying to run my WAR file after generate it.
I am doing java -jar .war and I am getting:
Error: Could not find or load main class com.blw.linemanager.Application
Caused by: java.lang.ClassNotFoundException: com.blw.linemanager.Application
I was googling and reading stackoverflow cause I found many post about it but still can not run it. What I am doing wrong?
After some reading I figured out that I have some how configure maven-war-plugin (am I right?) and in pom I did some changes but it does not help.
<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>bwl</groupId>
<artifactId>LineManager</artifactId>
<packaging>war</packaging>
<version>0.0.1-SNAPSHOT</version>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.8.RELEASE</version>
</parent>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-dependencies</artifactId>
<version>2.1.3.RELEASE</version>
<type>pom</type>
<scope>import</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
</dependency>
<dependency>
<groupId>com.jayway.jsonpath</groupId>
<artifactId>json-path</artifactId>
</dependency>
<dependency>
<groupId>com.microsoft.sqlserver</groupId>
<artifactId>mssql-jdbc</artifactId>
</dependency>
<dependency>
<groupId>commons-lang</groupId>
<artifactId>commons-lang</artifactId>
<version>2.1</version>
</dependency>
<dependency>
<groupId>org.codehaus.plexus</groupId>
<artifactId>plexus-utils</artifactId>
<version>1.1</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>
<scope>provided</scope>
</dependency>
</dependencies>
<properties>
<start-class>com.blw.linemanager.Application</start-class>
<maven.compiler.source>12</maven.compiler.source>
<maven.compiler.target>12</maven.compiler.target>
</properties>
<build>
<finalName>LineManager</finalName>
<outputDirectory>${project.build.directory}</outputDirectory>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<release>12</release>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-resources-plugin</artifactId>
<executions>
<execution>
<id>copy-resources</id>
<phase>validate</phase>
<goals>
<goal>copy-resources</goal>
</goals>
<configuration>
<outputDirectory>${project.build.directory}/META-INF</outputDirectory>
<resources>
<resource>
<directory>${basedir}/src/main/resources/META-INF</directory>
</resource>
</resources>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<configuration>
<failOnMissingWebXml>false</failOnMissingWebXml>
<archive>
<manifest>
<classpathPrefix>${project.build.directory}/WEB-INF/classes</classpathPrefix>
<addClasspath>true</addClasspath>
<mainClass>com.blw.linemanager.Application</mainClass>
</manifest>
<manifestFile>${project.build.directory}/META-INF/MANIFEST.MF</manifestFile>
</archive>
</configuration>
</plugin>
</plugins>
</build>
</project>
Also because on the beginning I was getting error 'no main manifest attribute' I add it and now it looks like this
Manifest-Version: 1.0
Created-By: Apache Maven ${maven.version}
Build-Jdk: ${java.version}
Is my way of think wrong? Should I be able to run .war file as java -jar .war or this is missunderstanding?
@SpringBootApplication
public class Application extends org.springframework.boot.web.support.SpringBootServletInitializer {
public static void main(String [] args) {
SpringApplication app = new SpringApplication(Application.class);
app.run(args);
}
protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
return builder.sources(Application.class);
}
}
It is better to get a working spring boot application from here to avoid versions conflicts and the like.
For a war-file deployment (into a local tomcat for example), your application must extend SpringBootServletInitializer:
@SpringBootApplication
public class SpringBootTomcatApplication extends SpringBootServletInitializer {
public static void main(String[] args) {
SpringApplication.run(SpringBootTomcatApplication.class, args);
}
@Override
protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
return builder.sources(SpringBootTomcatApplication.class);
}
}
Change in your pom the packaging to war.
<packaging>war</packaging>
To generate a war-file you need just the spring-boot-maven-plugin:
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
And yes you don't need the maven-war-plugin. Just for testing purposes let's annotate our application with @RestController and introduce a simple endpoint:
@RestController
@SpringBootApplication
public class SpringBootTomcatApplication extends SpringBootServletInitializer {
...
@RequestMapping(value = "/")
public String hello() {
return "Hello World from Tomcat";
}
}
In the Local terminal (in eclipse Ctrl+Alt+T) just enter mvn package than copy the generated war-file from target folder, paste it under the webapps folder of your local Tomcat, request http://localhost:8080/{your-application-name} and you should see the message Hello World from Tomcat.
Now you can add the dependencies you need and continue coding.