在Windows命令行中将Jar文件添加到Buildpath

Question

Im quite annoyed at having to ask this but I cant get it to work. Currently I have a project with:

5 Classes in the src/ folder

2 JARS named profiles.jar and classifier.jar in the root folder

I want to create a "makefile?" or "batch file?" to compile and run these classes FROM THE WINDOWS COMMAND LINE , but first add the jars to the buildpath? Im not sure how I go about this

When I try to do it, it says that the class is not found, most likely due to me not adding the jars to the buildpath correctly. What are the commands I need to use to run this in command prompt?

Thanks Philip

EDIT

Thanks for the help, Im having alot of trouble getting it to work tho Currently I have a project with 5 classes in the src folder, and 2 jars in the jar folder

Here are the commands Im running:

set CLASSPATH=C:\\wamp\\www\\news\\UserProfiling\\jars\\classifier.jar ;C:\\wamp\\www\\news\\UserProfiling\\jars\\profiles.jar

Then from the root folder, Im running:

javac src/*.java

Then:

java -cp ./src:./jars/* src/Interaction

Interaction is the main class, Im getting all sorts of noclassfound errors, am I doing something wrong? Many thanks Philip

THE ERROR

java -cp ./src:./jars/* Interaction Exception in thread "main" java.lang.NoClassDefFoundError: Interaction Caused by: java.lang.ClassNotFoundException: Interaction at java.net.URLClassLoader$1.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClassInternal(Unknown Source) Could not find the main class: Interaction. Program will exit.

Answer 1

In version older than or equal to Java version 5 you must specify each jar individually, and the root of your source, on your classpath eg

java -cp a.jar:b.jar:c.jar:./src MainClass

In version 6 you can use wildcards for the jars eg

java -cp ./src:* MainClass

but it might be cleaner putting your jars into a sub directory eg

java -cp ./src:./jars/* MainClass

So basically, your makefile or start script needs to construct a command like one of the above.

More info - Sun docs (v6)

Update - in response to your second edit, you need to specify the full main class name, so if the class is in a package called 'com.mypackage.MainClass' then you need to do:

java -cp ./src:./jars/* com.mypackage.MainClass

I'd also suggest getting the command working as a standalone command first, before getting the whole script running. By removing moving parts it will be faster to debug and easier to see what's going on.

Answer 2

I would suggest you take a look at ant or maven . Ant is a solution to do pretty much straightforward what you want to do, maven is not as straightforward but has its advantages when it comes to managing dependencies.

Answer 3

About your second question : if you use

java -cp ./src:./jars/* src/Interaction

it will try to launch the class src/Interaction, which does not exists. src is already in your classpath, so you just have to do

java -cp ./src:./jars/* Interaction

Answer 4

Found your problem, I think.

javac src/*.java

java -cp ./src:./jars/* src/Interaction

This problem plagues many beginners: You need to run javac and java from the directory where your source tree starts. In your case, that directory is src . Since src does not appear in your package names, it should also not appear in your compile/execution paths.

So you should

cd UserProfiling/src 

and run

javac *.java 

and

java -cp .:../jars Interaction 

from there.