okay to .include "${PORTSDIR}/Mk/bsd.java.mk"?

[Sam Lawrance]

I'm porting postgis which includes a set of Java classes related to
spatial data types (the rest of the source is C).

I would like to provide an OPTIONS line giving the user the choice
whether to build those classes (WITH_JDBCTYPES).

Problem is, after including bsd.port.pre.mk to get the OPTIONS generated
value of WITH_JDBCTYPES, USE_JAVA has already been read.

Is this okay as a workaround?

.if defined(WITH_JDBCTYPES)
USE_JAVA=	1.4+
.include "${PORTSDIR}/Mk/bsd.java.mk"
.endif

Cheers
Sam.