使用Java SAX解析XML文档时出现问题

时间:2010-08-27 04:32:39

标签: java xml parsing sax

我正在解析XML文档。我之前已经做了好几千次了,但是我不知道为什么我会遇到以下问题:

以下是我正在解析的XML文档的相关部分:

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

所以,我试图搞砸user_rating,predict_rating和id。我成功地这样做了。但是,我注意到当user_rating不包含任何值时,predict_rating将自动取值,而不是它自己的值4.8。但是,当user_rating确实有值时,predict_rating将具有正确的值。这是我的解析代码:

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;
}

 }

是否与user_rating具有属性“value”的事实有关?我将不胜感激任何帮助。谢谢!

1 个答案:

答案 0 :(得分:3)

我建议你等一下

endElement(String uri, String localName, String qName)
在将元素标记为传递之前

inSomething = false

我可以想象当元素为空时,

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

将不会被调用,您的标志将不会被清除,并且您将遇到两个inSomething标志设置为true的不一致状态。