Java Runtime Environment
Both Apache Solr and PDS Registry tools require Java Runtime Environment to run. Recommended version of Java is 11.
To test if Java is already installed on your system, run the following command from a command prompt:
java -version
If Java is already installed, you will see a message similar to this:
openjdk version "11.0.5" 2019-10-15 OpenJDK Runtime Environment 18.9 (build 11.0.5+10) OpenJDK 64-Bit Server VM 18.9 (build 11.0.5+10, mixed mode)
It is recommended to have JDK 11 installed. JDK/JRE 8 (1.8) might work, but development and testing of PDS Registry and other tools is mostly done with JDK 11.
There are several distributions of Java:
- Open JDK (Free). Can be downloaded from different sites, for example, adoptopenjdk.net. Most Linux distributions have Open JDK in their standard repositories.
- Oracle JDK (Commercial). Can be downloaded from www.oracle.com. You must register and accept a license to download.
If you want to keep several versions of JDK (e.g., 8 and 11), you can download .zip or .tar.gz archives instead of .msi or .pkg files and manually unzip them. Then you can set JAVA_HOME environment variable to choose which version of JDK to run.
Next steps
Java is now available in your environment, you should now deploy the Solr server.