Maven war has META-INF folder in two places

mavenmeta-infpackagewar

I'm working on a project which uses JAAS and unfortunately for me Tomcat requires a file to be put in a META-INF folder in the root of the war

app.war
  |__META-INF
  |    |___context.xml
 ...

I think that it's already weird since the default META-INF location for WAR's is in the classes folders.

app.war
  |__WEB-INF
  |    |__classes
  |         |__META-INF
 ...

So I'm using Maven, which states that anything in src/main/resources/META-INF will be copied to the appropriate place, which it does. The weird thing is that it is also creating a META-INF folder in the root of the file structure leaving me with 2 META-INF folders.

Project Structure

app
  |__src/main/java
  |__src/main/resources
  |       |__META-INF
  |             |__context.xml
 ...

After mvn package

 app
  |__META-INF [1]
  |__WEB-INF
  |     |__classes
  |           |__META-INF [2]
  |                  |__context.xml
 ...

So, if the war standard states that META-INF should be under classes folder, as in #2, why maven war creates the #1 folder. And is there a way to make it copy files into that folder instead of #2?

Regards

Best Answer

So I found this:

Two Meta-Inf folders - normal structure?

which states that having 2 META-INF folders is not a problem. Digging a little I found:

JAR File Specification

which states about the META-INF folder:

A JAR file is essentially a zip file that contains an optional META-INF directory. ...The META-INF directory, if it exists, is used to store package and extension configuration data, including security, versioning, extension and services.

and this:

JSR-000315 JavaTM Servlet 3.0

which, on section 10.6, states about the WAR file structure:

When packaged into such a form, a META-INF directory will be present which contains information useful to Java archive tools. This directory must not be directly served as content by the container in response to a Web client’s request, though its contents are visible to servlet code via the getResource and getResourceAsStream calls on the ServletContext. Also, any requests to access the resources in META-INF directory must be returned with a SC_NOT_FOUND(404) response.

So from the WAR spec the right place is WEB-INF/classes/META-INF. Yet, since war is a special jar file, it makes sense to have /META-INF as a point for extensions. One can see such different uses in JPA persistence.xml vs. Tomcat context.xml files: the former should be placed in WEB-INF/classes/META-INF while the latter in /META-INF.

Related Solutions

Maven: how to get a war package with resources copied in WEB-INF

either configure the outputDirectory parameter of resources:resources plugin, or put your files under src/main/webapp/WEB-INF/ directory. resource plugin

EDIT:

This configuration is working for me:

  <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-resources-plugin</artifactId>
    <version>2.4.2</version>
    <executions>
      <execution>
        <id>default-copy-resources</id>
        <phase>process-resources</phase>
        <goals>
          <goal>copy-resources</goal>
        </goals>
        <configuration>
          <overwrite>true</overwrite>
          <outputDirectory>${project.build.directory}/${project.artifactId}-${project.version}/WEB-INF/</outputDirectory>
          <resources>
            <resource>
              <directory>${project.basedir}/src/main/resources</directory>
            </resource>
          </resources>
        </configuration>
      </execution>
    </executions>
  </plugin>

you can run a phase in the form somePhase or a goal somePlugin:someGoal. The phase invocations will invoke all plugins goals hooked on phases in interval [validate,phase] in order, so there's no need to explicitly call them.

Java – Maven WebApp META-INF context.xml

Put your META-INF folder within src/main/resources.

Put this on your pom.xml... sorry i missed it before;

<build>
<plugins>
    <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-war-plugin</artifactId>
            <version>3.0.0</version>
            <configuration>


                <archive>
                    <manifest>
                        <addClasspath>true</addClasspath>
                        <classpathPrefix>lib/</classpathPrefix>
                    </manifest>
                </archive>

                <webResources>
                    <resource>
                        <!-- this is relative to the pom.xml directory -->
                        <directory>${project.basedir}/src/main/resources
                        </directory>

                    </resource>
                </webResources>



                <warName>mywar</warName>
            </configuration>
        </plugin>
</plugins>
</build>

the web resources tag is what is important... Hope this helps

Best Answer

Related Solutions

Maven: how to get a war package with resources copied in WEB-INF

Java – Maven WebApp META-INF context.xml

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