Bug 528926 – [gtk] build.sh should find java on it's own if not
specified.

Bug: https://bugs.eclipse.org/bugs/show_bug.cgi?id=528926
Change-Id: I23e3d9d7aed0ea7702329e7e705120539420f5dc
Signed-off-by: Leo Ufimtsev <lufimtse@redhat.com>
diff --git a/features/org.eclipse.equinox.executable.feature/library/gtk/build.sh b/features/org.eclipse.equinox.executable.feature/library/gtk/build.sh
index 6cd9ca8..691eb40 100755
--- a/features/org.eclipse.equinox.executable.feature/library/gtk/build.sh
+++ b/features/org.eclipse.equinox.executable.feature/library/gtk/build.sh
@@ -86,6 +86,17 @@
 				defaultOSArch="x86_64"
 				defaultJava=DEFAULT_JAVA_EXEC
 				[ -d /bluebird/teamswt/swt-builddir/JDKs/x86_64/jdk1.5.0 ] && defaultJavaHome="/bluebird/teamswt/swt-builddir/JDKs/x86_64/jdk1.5.0"
+
+				# Automatically figure out where java is installed on the system if it was not found/given otherwise.
+				if [ "$defaultJavaHome" = "" ]; then
+					DYNAMIC_JAVA_HOME=`readlink -f /usr/bin/java | sed "s:jre/::" | sed "s:bin/java::"`
+                                 	if [ -a "${DYNAMIC_JAVA_HOME}include/jni.h" ]; then
+        	                		echo "Info: Java automatically set to: $DYNAMIC_JAVA_HOME "
+						defaultJavaHome="$DYNAMIC_JAVA_HOME"
+					else
+						echo "Warning, java not found on system. Please specify JAVA_HOME manually"
+					fi
+				fi
 				OUTPUT_DIR="$EXEC_DIR/bin/$defaultWS/$defaultOS/$defaultOSArch"
 				;;
 			i?86 | "x86")