[JAVA] What is a Spring Boot .original file?

When you create a Spring Boot project and execute the mvn clean package command, the .original file is created in the target directory as shown below.

I tried to find out what this was.

The .original file is just a Jar or War

Yes, it's just a Jar file, a War file.

Spring Boot can create an Executable Jar (War). This format is for Jar and War that are not .original.

.original is not an Executable, it's just a Jar or War.

As you can see by unzipping the Jar and War and comparing the contents, the Executive Jar (War) contains the Spring Boot related classes required for execution, and the directory structure is different.

Details are explained in the official documentation. https://docs.spring.io/spring-boot/docs/current/reference/html/executable-jar.html

Made by Spring Boot Maven Plugin

This file is created by Spring Boot Maven Plugin. This Plugin has a goal of spring-boot: repackage, where we create an Executable Jar (War) and rename the Jar and War originally packaged in Maven to the name .original.

The reason why it is created even though spring-boot: repackage is not specified like mvn clean package is that the following settings are set in pom.xml of spring-boot-starter-parent. Is being done.

pom.xml(Excerpt)

<plugin>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-maven-plugin</artifactId>
  <executions>
    <execution>
      <id>repackage</id>
      <goals>
        <goal>repackage</goal>
      </goals>
    </execution>
  </executions>
  <configuration>
    <mainClass>${start-class}</mainClass>
  </configuration>
</plugin>

repackage is executed in the package phase, so if you do mvn clean package, repackage will also be executed.

To avoid creating a .original file

If you need to create an Executable Jar (War), the .original file will always be created. However, if you just want to create a Jar or War, you can skip creating an Executable Jar (War) with one of the following:

• When specified as a command argument

mvn clean package -Dspring-boot.repackage.skip=true

• When setting in pom.xml

pom.xml

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

How to use the .original file

If the operation is to deploy the War file to the application server without using the embedded Tomcat, it does not need to be an Executable War. (Of course, you can also deploy in Executable War.)

Executable War also includes the Spring Boot classes needed to run it, as well as Maven-provided scoped libraries, so it tends to be larger than a regular War file. Therefore, if you are doing this kind of operation, you can reduce the file size by deploying the .original file or making the above settings so that Executable War is not created. I will.

However, I think the good thing about Spring Boot is that it can be executed quickly with the java command.