Ant can be used to automate compiling and creating JAR files, but Ant itself will not create a distributable file. You need to tell Ant to create one for you, usually using JAR.
I believe most IDEs (Eclipse, Netbeans, etc) allow you to create JAR files quite easily, but I suggest you read
this so you know at least how it all works. You'll be glad when you need to create JAR files and you don't have an
IDE available.