Sample Application: Unit Testing Java

package net.unicon;
import javax.servlet.http.*;

public class Thing2 {
    
    public int testMe(HttpServletRequest request, String name) {
        try {
            return Integer.parseInt((String)request.getAttribute(name));
        } catch (NumberFormatException e) {
	    return 0;
        }
    }
}

package net.unicon;
import javax.servlet.http.HttpServletRequest;

class ThingTest2 extends GroovyTestCase { 

  void testTestMe() {
    String name = "x";    //attribute name
    String value = "42";  //attribute value
    //This is the mock object
    HttpServletRequest request = [ getAttribute : { n -> ( n == name ? value : null) } ] as HttpServletRequest;
    Thing2 thing = new Thing2();  
    //I have a feeling there's an easier way than "Integer.parseInt"
    assertEquals(Integer.parseInt(value), thing.testMe(request, name));
    assertEquals(0, thing.testMe(request, "phonyname"));
  }
}