[THRIFT-70] Allow the Java install prefix to be configured.

Systems like Debian expect the thrift jar to be in /usr/share/java, not
the default /usr/local/lib This patch allows configure to be passed a
JAVA_PREFIX= flag.


git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@675821 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/lib/java/Makefile.am b/lib/java/Makefile.am
index e878ae9..45a88e2 100644
--- a/lib/java/Makefile.am
+++ b/lib/java/Makefile.am
@@ -4,7 +4,7 @@
 	$(ANT)
 
 install-exec-hook:
-	$(ANT) install
+	$(ANT) install -Dinstall.path=$(DESTDIR)$(JAVA_PREFIX)
 
 # Make sure this doesn't fail if ant is not configured.
 clean-local: