Since your question was very short I am going to guess at what you wanted. Are you installing the Splunk for Database Connectivity? If so, install JRE or JDK and the location of where Java is installed is your JAVA_HOME. If you then install the Database Connectivity app, and in the app you run configure/setup and set JAVA_HOME to this value. Save the settings and the Java JDBC Bridge should be active.
Since your question was very short I am going to guess at what you wanted. Are you installing the Splunk for Database Connectivity? If so, install JRE or JDK and the location of where Java is installed is your JAVA_HOME. If you then install the Database Connectivity app, and in the app you run configure/setup and set JAVA_HOME to this value. Save the settings and the Java JDBC Bridge should be active.
Please be much more specific in your questions. Post details about what you're trying to achieve, where you got stuck, what errors you are seeing, etc etc. We shouldn't have to guess what your question is about.