The mJRE (short for Multiple JRE) feature was previously used to specify a specific JRE version, or range of versions, for launching our applications. We would accomplish this via the command-line option -version or with an entry in the JAR file's manifest. The following flowchart illustrates what happens based on our selection:
Multiple JRE flow
This functionality was introduced with JDK 5 and was not fully documented in that release or any subsequent release prior to JDK 9.
The following specific changes were introduced with the modern platform:
- The mJRE feature has been removed.
- The launcher will now produce an error whenever the -version command-line option is used. This is a Terminal error in that processing will not continue.
- In Java 9, a warning will be produced if there is a -version entry in a JAR's manifest. The warning will not stop the execution.
- In Java 10 and 11, the presence of a -version entry in a manifest file will result in a Terminal error.