As a developer, you may have come across the error message "BUILD FAILURE: Failed to execute goal org.apache.maven.plugins:maven-war-plugin:2.2:war" when trying to build your web application. This error message is usually accompanied by the message "web.xml is missing," and it can be frustrating to figure out what's causing it. In this guide, we'll explore what the setting does and how to troubleshoot this error message in your Maven project.
What is ?
The setting is a configuration option in the Maven WAR plugin that tells Maven what to do if the web.xml file is missing from your project. By default, this setting is set to "true," which means that Maven will fail the build if it can't find the web.xml file.
This can be a useful feature because the web.xml file is a critical component of any Java EE web application. It's responsible for configuring the web application's servlets, filters, and other components. If the web.xml file is missing, the web application won't be able to start correctly.
However, in some cases, you may want to disable this feature. For example, if you're working on a new web application and haven't created the web.xml file yet, you don't want Maven to fail the build just because the file is missing.
How to Troubleshoot the "web.xml is missing" Error Message
If you're seeing the "web.xml is missing" error message when running the Maven build, there are a few things you can try to troubleshoot the issue.
Check that the web.xml File Exists
The first thing to check is that the web.xml file actually exists in your project. The file should be located in the src/main/webapp/WEB-INF/ directory. If it's not there, you'll need to create it.
Check that the Maven WAR Plugin is Configured Correctly
Next, you should check that the Maven WAR plugin is configured correctly in your pom.xml file. Make sure that the plugin is included in the build section and that the setting is set to the value you want.
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<version>3.3.1</version>
<configuration>
<failOnMissingWebXml>false</failOnMissingWebXml>
</configuration>
</plugin>
</plugins>
</build>
In the example above, the setting is set to "false," which means that Maven won't fail the build if the web.xml file is missing.
Clean and Rebuild the Project
If you've checked that the web.xml file exists and the Maven WAR plugin is configured correctly, but you're still seeing the error message, try cleaning and rebuilding the project. Sometimes, Maven can get confused, and a clean build can help fix the issue.
You can clean the project by running the following command:
mvn clean
And then rebuild the project by running:
mvn install
Check for Maven or Plugin Updates
Finally, if none of the above solutions work, you may want to check for updates to Maven or the Maven WAR plugin. Sometimes, bugs or issues in these tools can cause strange behavior. Updating to the latest version may help fix the problem.
FAQ
Q1: Can I disable the setting globally for all my Maven projects?
Yes, you can disable the setting globally by adding the following to your settings.xml file:
<settings>
<pluginGroups>
<pluginGroup>org.apache.maven.plugins</pluginGroup>
</pluginGroups>
<profiles>
<profile>
<id>disable-failonmissingwebxml</id>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<configuration>
<failOnMissingWebXml>false</failOnMissingWebXml>
</configuration>
</plugin>
</plugins>
</build>
</profile>
</profiles>
<activeProfiles>
<activeProfile>disable-failonmissingwebxml</activeProfile>
</activeProfiles>
</settings>
Q2: What's the difference between and ?
is a setting specific to the Maven WAR plugin that controls whether Maven should fail the build if the web.xml file is missing. is a setting that controls whether Maven should fail if there are no projects in the build reactor. These are two separate settings with different purposes.
Q3: Can I use the setting with other Maven plugins?
No, the setting is specific to the Maven WAR plugin and won't work with other plugins.
Q4: Can I set the setting to "true" for specific Maven profiles?
Yes, you can override the setting for specific Maven profiles by adding the following to your pom.xml file:
<profiles>
<profile>
<id>profile1</id>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<configuration>
<failOnMissingWebXml>true</failOnMissingWebXml>
</configuration>
</plugin>
</plugins>
</build>
</profile>
</profiles>
In this example, the setting is set to "true" for the "profile1" profile.
Q5: Can I set the setting to a variable in my Maven project?
Yes, you can set the setting to a variable in your Maven project by adding the following to your pom.xml file:
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<version>3.3.1</version>
<configuration>
<failOnMissingWebXml>${myVariable}</failOnMissingWebXml>
</configuration>
</plugin>
</plugins>
</build>
In this example, the setting is set to the value of the "myVariable" variable. You can set this variable in your pom.xml file or in your Maven settings.xml file.