Beginner question about external java libraries

Question

This command compiles:

javac -classpath google-collections.jar Test.java

What's the command to run Test.class?

Answer 1

java -classpath google-collections.jar:. Test

The ":." adds the current directory to the classpath so java can find Test.class

Answer 2

The following will have the current directory and the google-colletions.jar as the classpath:

java -cp .;google-collections.jar Test

This will run the main method in the Test class with the following signature:

public static void main(String[])

Note:

As noted by Paul Tomblin in the comments, the separator character for the classpath is different depending on the platform on which javac is run on.

For Solaris/Linux (and apparently Mac OS), the separator character is a colon ( : ), while on Windows, it is a semi-colon ( ; ).

Reference:

• Setting the classpath (Solaris)
• Setting the classpath (Windows)