Java -classpath option

Question

Will the use of -classpath option with java, add to or replace the contents of the CLASSPATH env variable?

Answer 1

Yes. Quoted from the java(1) man page:

   -classpath classpath
   -cp classpath
          Specifies a list of directories, JAR archives, and ZIP archives to search  for  class  files.   Class
          path  entries  are separated by colons (:). Specifying -classpath or -cp overrides any setting of the
          CLASSPATH environment variable.

          If -classpath and -cp are not used and CLASSPATH is not set, the user class path consists of the cur-
          rent directory (.).

Answer 2

Either one of the options is used, not both.

Specifying -classpath or -cp overrides any setting of the CLASSPATH environment variable.

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The -classpath option is preferred because you can set it individually for each application without affecting other applications and without other applications modifying its value.

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Setting the CLASSPATH variable or using the -classpath command-line option overrides that default, so if you want to include the current directory in the search path, you must include "." in the new settings.

Answer 3

Using the classpath variable it overrides the CLASSPATH of Environment variable but only for that session. If you restart the application you need to again set the classpath variable.