When you download Java from Oracle, there are two flavors of downloads, the JRE and the JDK.
- Java Runtime Environment (JRE), which contains enough java to execute programs.
- Java Development Kit (JDK), which contains the compiler and other development tools. It may also be called the Software Development Kit (SDK).
You need the JDK to do the deployment. If you're seeing this error, it means that you don't have the JDK installed, or maybe you have it installed but Eclipse doesn't where it is.
Once you have the JDK installed, go into the Eclipse preferences under Java and "Installed JREs" and make sure your JDK is installed and set as the default. May also need to define a JAVA_HOME environment variable in your operating system that points to your installed JDK.