javains

#!/bin/sh


J_INSTALL_DIR=/usr/lib/jvm/java-8-oracle
URL=$(curl -s http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html | \
    awk "/downloads\['/ && ! /demos/ && /\['files'\]/ && /linux-x64/ && /\.tar\.gz/" | \
    grep -o 'http.*\.tar\.gz') 

AVAILABLE=$(echo $URL | grep -o -P 'jdk-8u.{0,2}' | cut -d "u" -f 2)
CURRENT=$("$J_INSTALL_DIR"/bin/java -version 2>&1 | awk '/version/ {print $3}' | cut -d_ -f 2 | tr -d '"')

if [ -z $CURRENT ] || [ $AVAILABLE -gt $CURRENT ]; then
	cd /var/cache/oracle-jdk8-installer
	rm -f jdk-8u"$CURRENT"-linux-x64.tar.gz
	wget --no-check-certificate --no-cookies --header "Cookie: oraclelicense=accept-securebackup-cookie" $URL
	tar -xzf jdk-8u"$AVAILABLE"-linux-x64.tar.gz
	rm -rf $J_INSTALL_DIR
	mv jdk1.8.0_"$AVAILABLE"/ $J_INSTALL_DIR

	LATEST=$(LANG=C update-alternatives --display java | grep ^/ | sed -e 's/.* //g' | sort -n | tail -1)
	if [ -z $LATEST ]; then
		LATEST=1
	else
		J_PATH=$(LANG=C update-alternatives --display java | grep "priority "$LATEST"" | awk '{print $1}')
		[ $J_PATH = "$J_INSTALL_DIR"/jre/bin/java ] || LATEST=$((LATEST+1))
	fi	
	
	#link JRE files
	for f in $J_INSTALL_DIR/jre/bin/*; do
		name=`basename $f`;
		if [ ! -f "/usr/bin/$name" -o -L "/usr/bin/$name" ]; then  #some files, like jvisualvm might not be links
			if [ -f "$J_INSTALL_DIR/man/man1/$name.1.gz" ]; then
						
				update-alternatives --install /usr/bin/$name $name $J_INSTALL_DIR/jre/bin/$name $LATEST --slave /usr/share/man/man1/$name.1.gz $name.1.gz $J_INSTALL_DIR/man/man1/$name.1.gz
			fi
		else     
	    		update-alternatives --install /usr/bin/$name $name $J_INSTALL_DIR/jre/bin/$name $LATEST
	    	
	    	fi
	done

	echo "Oracle Java 8 installed"
	
fi

if [ $AVAILABLE -eq $CURRENT ]; then
	echo "Java is up to date"
fi