Problem parsing XML document with Java SAX

Question

Hello everyone,

I am parsing an XML document. I have done this thousands of times before, but I can't see why I am getting the following issue:

Here is the relevant part of the XML document that I am parsing:

XML: <?xml version="1.0" standalone="yes"?>
<ratings>
<url_template>http://api.netflix.com/users/T1BlCJtdcWMuF6gJEfue96_W.kZ_gW81h59KqLEfT1AzE-/ratings/title?{-join|&amp;amp;|title_refs}&lt;/url_template&gt;
<ratings_item>
    <user_rating value="not_interested"></user_rating>
    <predicted_rating>4.8</predicted_rating>
    <id>http://api.netflix.com/users/T1BlCJtdcWMuF6gJEfue96_W.kZ_gW81h59KqLEfT1AzE-/ratings/title/70112530&lt;/id&gt;
    <link href="http://api.netflix.com/catalog/titles/series/70112530/seasons/70112530" rel="http://schemas.netflix.com/catalog/title" title="Castle: Season 1">
    </link>
    .
    .
    .

So, I am trying to pase out the user_rating, the predicted_rating, and the id. I am doing this successfully. However, I am noticing that when user_rating contains no value, then the predicted_rating will automatically take the value of , rather than it's own value of 4.8. When user_rating does have value, however, then the predicted_rating will have the correct value. Here is my parsing code:

public class RatingsHandler extends DefaultHandler {

Vector vector;
Ratings ratings;

boolean inUserRating;
boolean inPredictedRating;
boolean inAverageRating;
boolean inID;

public void startDocument() throws SAXException {
    vector = new Vector();
    ratings = new Ratings();
}

public void startElement(String uri, String localName, String qName,
        Attributes attributes) throws SAXException {

    if (localName.equals("user_rating")) {
        inUserRating = true;

    } else if (localName.equals("predicted_rating")) {
        inPredictedRating = true;

    } else if (localName.equals("average_rating")) {
        inAverageRating = true;

    } else if (localName.equals("id")) {
        inID = true;

    }

}

public void characters(char ch[], int start, int length)
        throws SAXException {

    if (inUserRating) {
        ratings.setUserRating(new String(ch, start, length));
        inUserRating = false;
    } else if (inPredictedRating) {
        ratings.setPredRating(new String(ch, start, length));
        inPredictedRating = false;
    } else if (inAverageRating) {
        ratings.setAvgRating(new String(ch, start, length));
        inAverageRating = false;
    } else if (inID) {
        Const.rating_id = new String(ch, start, length);
        inID = false;
    }
}

public void endDocument() throws SAXException {

    if (ratings != null) {
        vector.addElement(ratings);
    }
}

public Vector getRatings() {
    return vector;
}

 }

Does it have something to do with the fact that user_rating has an attribute "value"? I would appreciate any help. Thanks!

Answer 1

I would suggest you to wait for the

endElement(String uri, String localName, String qName)

before you mark the element as passed by:

inSomething = false

I can imagine that when the element is empty, the

public void characters(char[] ch, int start, int length)

won't be called, your flag won't be cleared and you will run into inconsitent state having two inSomething flags set to true.