java
java
You can run both versions together. I have Java 8 and Java 7 set up, but I mainly use Java for programming. The JVM that becomes default seems to depend on which one you install last.
Restart Java 8, then adjust your system environment variables. Locate JAVA_HOME and change its path to point to Java 7.
These variables exist in environmental data collected from various sources such as sensors, satellites, and field measurements.
Search for instructions on customizing your Java home setup and implement them step by step.