KwCheng's blog

When we write many program , we also need to manage these program in order to avoid confuse.

Java has provide two method for us to manage these program , Package and Jar.

We will describe these two method follow.

Package , for example:

package MyLibrary;

public class PackageDemo

{

//the code body

} 

After finishing our program , we need to type the command as below:

javac -d . PackageDemo.java

Jar , for example:

We need to type the command as below to construct a jar file.

jar cvf myLibrary.jar MyLibrary

We also can add new class to existing jar file.

jar uvf myLibrary.jar MyLibrary

Meaning of options:

c : create a new archive.

u : update an existing file named xxx.jar.

v : Generate verbose output to standard output.

f : specifies the name of jar file.

ref : http://docs.oracle.com/javase/1.4.2/docs/tooldocs/windows/jar.html