Step 2: To download the Java JDK, click on Download JDK (1 in the image) button. These applets allow you to have a much richer experience online than simply. I'm sure that other applications have the same problem, and the root cause is probably the same. Then open another command prompt and type java –version, you will see: That means you have successfully setup OpenJDK 11 on your computer. To open this web start application you need to download the java runtime environment JRE ( Java Runtime Environment ) 1.