[MCOMPILER-270] Support release=8 on JDK 9

• Type: New Feature
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 3.5.1
• Fix Version/s: 3.6.0
• Assignee: Robert Scholte
• Reporter: Geoffrey De Smet
• Created: 15/Jun/16 13:06
• Updated: 18/Jun/21 07:34
• Resolved: 10/Aug/16 19:15

Description

JDK 9 now supports the the follow argument:

javac -release 7

This replaced both `-source 7` and `-target 7`. And it prevents from using methods introduced in JDK 9 or JDK 8 when compiling for 7 with JDK 9. So `-release 8` basically better in every way than `-source 7 -target 7`.
http://mail.openjdk.java.net/pipermail/jdk9-dev/2015-July/002414.html

Support this in the maven-compiler plugin, something like:

        <plugin>
          <artifactId>maven-compiler-plugin</artifactId>
          <configuration>
            <release>7</release>
          </configuration>
        </plugin>

When compiling with JDK 9, it should just do `javac -release 7`.

When compiling with JDK 8 or lower, it should fallback to `javac -source 7 -target 7`, so it behaves exactly like:

        <plugin>
          <artifactId>maven-compiler-plugin</artifactId>
          <configuration>
            <source>7</source>
            <target>7</target>
          </configuration>
        </plugin>

Issue Links

• is related to: MCOMPILER-468 Introduce parameter to be used for source, target and release