Maven: javac: source release 1.6 requires target release 1.6

Question

NOTE: This appears to be a limit in the \"javac\" program.

I have Java 6 code that needs to be built for a Java 5 JVM. My previous work with the javac ant target (

Answer 1

I believe you need to set -bootclasspath as well so that javac compiles against JDK 1.5 bootstrap classes.

Try:

javac -source 1.6 -target 1.5 -bootclasspath /path/to/jdk1.5/lib/rt.jar -extdirs "" Foo.java

UPDATE:

Try removing the -source option, but keep the -target option.

I just tested it out:

# no source, only target => COMPILES to 1.5
$ javac -target 1.5 Foo.java
$ javap -v  Foo | grep version
  minor version: 0
  major version: 49

# no source, no target => COMPILES to 1.6
$ javac Foo.java
$ javap -v  Foo | grep version
  minor version: 0
  major version: 50

# both source and target => ERROR
$ javac -source 1.6 -target 1.5 Foo.java
javac: source release 1.6 requires target release 1.6

$ javac -version
javac 1.6.0_21