Class Version Patcher

This plugin allows you to utilize all the new language features of Java while targeting an older version's bytecode.

Usage - Maven

To integrate into your project:

1. Install the plugin locally
2. Add the plugin to your project
   • Update the scope of any dependency that is future-versioned to <scope>provided</scope>
3. Run compile on your project to generate the modified classes in the %PROJECT%/target/classes directory
4. Run any phase you like, such as test (They should now see the modified classes)

Installing the plugin locally

git clone https://github.com/Col-E/Class-Version-Patcher.git
cd Maven-Class-Patcher
mvn install

Using the plugin in your pom.xml

<build>
    <plugins>
        <plugin>
            <groupId>software.coley</groupId>
            <artifactId>class-version-patcher-maven</artifactId>
            <version>2.1.0</version>
            <configuration>
                <!-- Target Java 8, can swap for other version such as 11 -->
                <targetVersion>8</targetVersion>
                <artifacts>
                    <!-- The parameters are the group + artifact identifiers of any dependency separated by a colon ":"
                         You can include any number of values here.
                     -->
                    <param>group_id:artifact_id</param>
                    <param>org.jgroups:jgroups</param>
                </artifacts>
            </configuration>
            <!-- Required to run -->
            <executions>
                <execution>
                    <goals>
                        <goal>patch-compiled</goal>
                        <goal>patch-dependencies</goal>
                        <goal>patch-postprocess</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>

Usage - Gradle

NOTE: The gradle plugin is not yet developed, however you can add the core module of this project as a dependency to your buildscript. From there, you can invoke software.coley.versionpatcher.VersionPatcher as you see fit.

This doesn't properly downgrade Java X's "xyz-feature" to Java Y's version!

Please open an issue with an example of how to replicate your problem.

For example:

• Providing a class file
• Listing a maven dependency
• Listing an open source project