To Compile and Run / Execute a Java File names java_file_name:

To Compile a Java File names java_file_name:
C:\folder_name>javac java_file_name.java

To Execute/Run a Java File names java_file_name:
C:\folder_name>java -classpath .;C:\folder_name\classes12.jar java_file_name

U must have the required JDK and the classes12.jar file on the same directory.