How to unjar, and edit source and jar it back using maven?

Question

I have a situation where i need to Unpack a spring jar and replace a file in that package with my .class file and repackage it back as jar. I understood that this can be done in Maven. So i created a maven project and i added the .java(to be replace in the Spring jar) to it . Here is my Project structure.

here is my pom.xml

    <project>
    <modelVersion>4.0.0</modelVersion>

    <name>repackage</name>
    <groupId>org.springframework</groupId>
    <artifactId>spring</artifactId>
    <version>2.4.6</version>    
    <packaging>pom</packaging>

  <build>
    <plugins>
    <!-- Unpacking -->
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-dependency-plugin</artifactId>
        <version>2.10</version>
        <executions>
          <execution>
            <id>unpack</id>
            <phase>package</phase>
            <goals>
              <goal>unpack</goal>
            </goals>
            <configuration>
              <artifactItems>
                <artifactItem>
                  <groupId>org.springframework</groupId>
                  <artifactId>spring</artifactId>
                  <version>2.5.6.SEC03</version>
                  <type>jar</type>
                  <overWrite>false</overWrite>
                  <outputDirectory>target</outputDirectory>
                </artifactItem>
              </artifactItems>
            </configuration>
          </execution>
        </executions>
      </plugin>

      <!-- Packing -->
<!--      <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-jar-plugin</artifactId>
            <version>2.4</version>
            <executions>
                <execution>
                    <phase>package</phase>
                    <goals>
                        <goal>jar</goal>
                    </goals>
                    <configuration>
                    <classesDirectory>target</classesDirectory>
                        <classifier>sample</classifier>
                    </configuration>
                </execution>
            </executions>
        </plugin>-->
    </plugins>
  </build>
</project>

I am able to unpack the spring jar using maven dependency plugin and i figured out how to pack it back to a jar using maven-jar-plugin. The part i am struggling to understand 1) how convert my .java file into a .class file. As the packaging is pom type <packaging>pom</packaging> I am not able to compile the java file(JdkVersion.java). if successful in creating the class file 2) How to replace this .class file into unpacked spring jar as the file i need to replace is inside the sub directory of /springpackage

Answer 1

You don't have to. Spring is an open source project just clone its source code https://github.com/spring-projects/spring-framework?files=1 and update the code and create a package using simple mvn package command