File APIs for Java Developers
Manipulate DOC, XLS, PPT, PDF and many others from your application.
http://aspose.com/file-tools
The moose likes Servlets and the fly likes Error using getParameterValues method Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login


Win a copy of Spring in Action this week in the Spring forum!
JavaRanch » Java Forums » Java » Servlets
Bookmark "Error using getParameterValues method " Watch "Error using getParameterValues method " New topic
Author

Error using getParameterValues method

Scott Updike
Ranch Hand

Joined: Feb 16, 2006
Posts: 92
I have an issue that is probably more in line with a general Java question, but I'm writing a small servlet app and thought I would start here. I have a screen where people can select items to delete and if they don't select anything, I get a java.lang.NullPointerException error. Is there any way to test if my array variable deleteNames is null or not? In looking at the API, I know that if one element is returned, then the array length is equal to 1, but I don't know how to test the length if the original parameter was null.

I'm sure this is a simple thing to do, but I can't seem to find the right way to test if the array is populated or not.

My code snippet is below.

Thanks in advance.

Scott

-------------------------

String[] deleteNames = request.getParameterValues("deleteitems");
try {
Connection conn1 = (Connection) getServletContext().getAttribute("dbconn");
PreparedStatement stmt = conn1.prepareStatement("delete from baissue where issue_name = (?)");
PreparedStatement stmt1 = conn1.prepareStatement("delete from issue_comments where issue_name = (?)");

for (int i=0; i<deleteNames.length;i++) {
//Delete Comments
stmt1.setString(1,deleteNames[i]);
stmt1.executeUpdate();
//Delete Issue
stmt.setString(1,deleteNames[i]);
stmt.executeUpdate();
}

----------------------
Ben Souther
Sheriff

Joined: Dec 11, 2004
Posts: 13410



Java API J2EE API Servlet Spec JSP Spec How to ask a question... Simple Servlet Examples jsonf
Dave Wingate
Ranch Hand

Joined: Mar 26, 2002
Posts: 262
Or if there's nothing to be done when no values are selected, you could try:


[ June 20, 2006: Message edited by: Dave Wingate ]

Fun programming etcetera!
 
I agree. Here's the link: http://aspose.com/file-tools
 
subject: Error using getParameterValues method