How to use jar files without package information?

Question

I have a jar called "MyTools". The jar is in c:\data folder. I created a new file in the same folder called "UseTools.java". Now I would like to use some of the classes from the MyTools.jar in my UseTools.java. I tried this but it doesnt seem to work:

import MyTools.*;    
public class UseTools
{
  public static void main(String[] args) 
  {
    MyTools.SomeClass foo = new SomeClass();
    SomeClass.doSomething();
  }
}

I tried to compile this with:

javac -cp . UseTools.java

and got this error message:

UseTools.java:1: package MyTools does not exist
import MyTools.*;
^
UseTools.java:7: package MyTools does not exist
        MyTools.SomeClass foo = new SomeClass()
                                     ^
2 errors

I did not set the package name in any class.

Do I have to set a package name in my jar classes?

Answer 1

You need to add -cp file.jar instead of -cp .

The latter one will pick up .class files only. BTW: why not using an IDE like netbeans, eclipse or intelliJ?

Answer 2

In your MyTools.jar there should be a package with the name MyTools. And before compiling you should add the jar to the classpath.