Summary

Remove support for argument to javac's -source and -target options for releases earlier than 6.

Problem

Per the policy described in

JEP 182: Policy for Retiring javac -source and -target Options http://openjdk.java.net/jeps/182

Starting in JDK 9, old source and target options will be retired to ease the maintenance of javac.

Solution

In javac, targets

1.1 1.2 1.3 1.4 1.5 / 5

are no longer recognized and target 6 / 1.6 is reported as obsolete.

Source

1.0 1.1 1.2 1.3 1.4 1.5 / 5

are no longer recognized and source 6 / 1.6 is reported as obsolete.

Specification

The javac man page in JDK 9 only lists as supported:

-source

6 / 1.6 (obsolete)
7 / 1.7
8 / 1.8
9 / 1.9

-target

6 / 1.6 (obsolete)
7 / 1.7
8 / 1.8
9 / 1.9