java compile error: Source/Target option 1.5 is not supported since jdk 9
error: Source option 1.5 is no longer supported. Use 1.6 or later.
error: Target option 1.5 is no longer supported. Use 1.6 or later.
With the release of jdk 9(which now the default in Debian testing/unstable), Source/Target option 1.5 is not supported.
Not sure is there any better way than hard code the version. JEP 182 suggests since jdk 9:
JDK 9 will implement a "one plus three back" support policy meaning that 1.9/9, 1.8/8, 1.7/7, and 1.6/6 will be recognized in that release. That policy will continue in JDK 10.