[jdom-interest] Sorting a list of text elements

Ken Rune Helland kenh at csc.no
Fri Mar 16 05:05:02 PST 2001

At 07:42 AM 3/16/2001 -0500, you wrote:
>I am trying to sort a list of text elements within my servlet, which uses 
>JDOM, for a pull down menu and am not getting it to work. Maybe I'm using 
>the sort method (part of the Java 2 Collections framework) 
>incorrectly.  Here is the code snippet:
>     //get root and all first level children (as List)
>     Element root = doc.getRootElement();
>     Element menuItems = root.getChild("Categories");
>     List menuItem = menuItems.getChildren();
>     Collections.sort(menuItem);
>     out.println("       <td><SELECT NAME=\"category\">");
>     for(int i=0;i<menuItem.size();i++){
>     Element elem = (Element)menuItem.get(i);
>     String menuItemText = elem.getTextTrim();
>     out.println("<OPTION>"+menuItemText+"</OPTION>");
>     }
>     out.println("       </SELECT>");
>The Collections.sort(menuItem) line has no effect: the list is not sorted. 
>I am expecting alphabetical sorting as the "natural order." Can someone 
>point out what I need to do?
>Thanks, in advance,

Element does not implement the Comparable interace so it does not
have any "natural order". You must make a class that implements the
Comparator interface so it gives your wanted order and then call

Collections.sort(menuItem, myComparator);


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