First, uninstall java from your system
$ sudo apt-get update && sudo apt-get remove openjdk*
Next we need a place for java
$ sudo mkdir /opt/java
$ cd /opt/java
Download java from https://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html
$ sudo tar zxvf ~/Downloads/jdk-8u221-linux-x64.tar.gz
$ sudo update-alternatives --install "/usr/bin/java" "java" "/opt/java/jdk1.8.0_221/bin/java" 1
$ sudo update-alternatives --set java /opt/java/jdk1.8.0_221/bin/java
$ java -version
java version "1.8.0_221"
Java(TM) SE Runtime Environment (build 1.8.0_221-b11)
Java HotSpot(TM) 64-Bit Server VM (build 25.221-b11, mixed mode)
Download SAP JAVA from marketplace
$ cd 50144807_7/BD_NW_7.0_Presentation_7.50_Comp._2_/PRES2/GUI/JAVA
$ sudo java -jar PlatinGUI750Linux_1.JAR
$ cd /opt/SAPClients/SAPGUI/bin
$ ./guilogon
You can create a new launcher with the next information.
Name: SAP
command: /bin/sh "/opt/SAPClients/SAPGUI7.50rev1/bin/guilogon"