How to build a WAR file with gradle?

I guess that you have applied the spring boot gradle plugin to your project, in addition to the war plugin ? then this behaviour is normal, since the Spring Boot plugin will disable jar and war tasks and replace these with bootWar and bootJar tasks .

With both spring boot and war plugin applied:

./gradlew war
15:35:09: Executing task 'war'...

> Task :compileJava UP-TO-DATE
> Task :processResources UP-TO-DATE
> Task :classes UP-TO-DATE
> Task :war SKIPPED

BUILD SUCCESSFUL in 0s
2 actionable tasks: 2 up-to-date
15:35:10: Task execution finished 'war'.

Note the SKIPPED message

$ ./gradlew bootWar
15:36:35: Executing task 'bootWar'...

> Task :compileJava UP-TO-DATE
> Task :processResources UP-TO-DATE
> Task :classes UP-TO-DATE
> Task :bootWar

BUILD SUCCESSFUL in 1s
3 actionable tasks: 1 executed, 2 up-to-date
15:36:37: Task execution finished 'bootWar'.

Then you will get the expected war file under build/libs.

You can still re-enable the standard jar/war tasks as explained here : https://docs.spring.io/spring-boot/docs/current/gradle-plugin/reference/html/#packaging-executable-wars-deployable (if you need to produce normal archives and not executable archives)

Regarding the Tomcat issue: install Tomcat 8.5.

As rightly said by @M.Ricciuti, the spring boot gradle plugin will disable the jar/war tasks and would only work with bootJar/bootWar tasks. But if you still want your project to be packaged with jar/war tasks just add the below to your build.gradle file

war {
    enabled=true
}

This would enable the gradle war command to generate the war for your project.

Please read: https://docs.gradle.org/current/userguide/war_plugin.html

If using Gradle with IntelliJ, goto build.gradle (or build.gradle.kts for Kotlin) and add

id 'war'

(or just

war

for Kotlin ) under Plugins

Reload Gradle Project and then use gradlew bootWar on the Intellij Terminal.

Add --info or --stackTrace for debugging

I was also facing the same issue.

After a lot of struggle, I figured out that I needed to extend SpringBootServletInitializer in my application. So my effective code looks like

    public class SyncApplication extends SpringBootServletInitializer {

    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
        return application.sources(SyncApplication.class);
    }

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

}

Looks like this SpringBootServletInitializer directs war plugins generate bootstrapping code while building the war, and thus spring context is initialized while deploying the app.

If you are using spring boot with gradle, you should follow the steps below:

1. Edit your build.gradle file adding apply plugin:'war' and then rebuild gradle.

2. With gradle built two (2) files will be created on your root directory: gradlew (for Linux) and gradlew.bat (for windows)

Open your terminal on your current project and run ./gradlew war

Your project will build and generate a .war file in build/libs/