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From pgarvie <>
Subject Re: [Digester]How do you populate a map?
Date Tue, 11 Feb 2003 00:57:50 GMT
Embarrassed? Awww man forget it. Your example was well worth it and then 
some. Base on it, here's one way:

public void testLibraryBook() throws SAXException, IOException
         Digester digester = new Digester();
         ClassLoader classLoader = 
         URL resource = classLoader.getResource("library.xml");
         assertNotNull("Resource should not be null!!", resource);

         digester.addObjectCreate("Library", HashMap.class);
         digester.addCallMethod("Library/Book", "put", 2);
         digester.addRule("Library/Book", new 
StringObjectCreateRule(String.class, "title"));
         digester.addCallParam("Library/Book", 0, true);
         digester.addRule("Library/Book", new 
LibraryBookCreateRule(LibraryBook.class, "title"));
         digester.addCallParam("Library/Book", 1, true);
         HashMap map = (HashMap)digester.parse(resource.toString());
         assertNotNull("Hash map should not be null!!", map);
         assertEquals("Based on the xml file, map should have size of 6", 
6, map.size());

     public class LibraryBookCreateRule extends ObjectCreateRule
         private String key;

         public LibraryBookCreateRule(Class aClass, String key)
             this.key = key;

         public void begin(String s, String s1, Attributes attributes) 
throws Exception
             LibraryBook book = new LibraryBook(attributes.getValue(key));

     public class LibraryBook
         private String title;

         public LibraryBook(String title)
             this.title = title;

         public String getTitle()
             return title;

Using library.xml:

<?xml version="1.0" encoding="UTF-8"?>

     <Book title="The Firm"/>
     <Book title="The Cat in the Hat"/>
     <Book title="Green Eggs and Ham"/>
     <Book title="Object Cobol"/>
     <Book title="Anne of Green Gables"/>
     <Book title="Smoke 'Em If Ya Got 'Em"/>

At 03:04 PM 2/10/2003 -0800, you wrote:
>I'm really embarrassed after posting a HowTo on populating a map, but I've
>found that it's not as clear as I thought it was.  I know how to do it with
>the following example:
><?xml version='1.0'?>
>   <key name='The key'/>
>   <value name='The value'/>
>But how to do it with this?
><?xml version='1.0'?>
>   <key name='KeyA'/>
>   <value name='ValueA'/>
>   <key name='KeyB'/>
>   <value name='ValueB'/>
>CallMethodRule is only invoked at the end of <map>, so you can't call it
>twice, once for each key, value pair.
>The situation I have that I actually need to solve looks more like this:
>         <Book title="The Firm" />
>         <Book title="The Cat in the Hat" />
>I would want Library to be a HashMap with titles for keys and Book objects
>for values.  You can't use a CallMethodRule on Book because the put() method
>belongs to Library, not Book.
>BTW, I realize you can do this by creating proxy objects that call put() for
>you.  That's inelegant IMHO and I was hoping that Digester 1.4 had solved
>this issue.

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