Need Spring version# - only have spring.jar file

You cann check it in pom.xml file in <org.springframework-version> tag.

If your project uses Maven, you can run the following at the command line to see it:

$ mvn dependency:tree | grep org.springframework | grep 'spring-core:jar'

This will do it:

import org.springframework.core.SpringVersion;

public class VersionChecker
{
    public static void main(String [] args)
    {
        System.out.println("version: " + SpringVersion.getVersion());
    }
}

Compile and run this with spring.jar in your CLASSPATH and it'll display the version for you. See the javadocs as well.