java sax 程序不会转到 startElement() 方法 [英] java sax program doesn't go to startElement() method

问题描述

我正在尝试将 sax 解析器与自定义的 DefaultHandler 一起使用，但奇怪的是从未调用 dHandler 中的 startElement() 方法.endDocument() 正常工作，但它会打印

i'm trying to use the sax parser with customized DefaultHandler, but the strange thing that startElement() method in the dHandler is never invoked. endDocument() works as it should, but it prints

Total elements:0

虽然我的 xml 文件有 11 个状态"类型的元素.

while my xml-file has 11 elements of type "state".

即使我将 total++ 放在 if 语句之外，所以每次调用 startElement() 时它都会递增，它仍然显示 0 个元素.

if even i place total++ outside the if statement, so it gonna increment everytime startElement() is invoked, it still says 0 elements.

请帮帮我，谢谢

if(e.getSource()==open)
    {
        JFileChooser chooseFile=new JFileChooser();
        int returnVal = chooseFile.showOpenDialog(wnd);
         if (returnVal == JFileChooser.APPROVE_OPTION) {
            File file = chooseFile.getSelectedFile();

                //This is where a real application would open the file.
                parser.parse(new InputSource(new FileInputStream(file)));
                DocumentImpl document = (DocumentImpl)parser.getDocument();
                Node root = document.getLastChild();
                AllElements allelements = new AllElements();
                NodeIteratorImpl iterator =(NodeIteratorImpl)document.createNodeIterator(root,
        NodeFilter.SHOW_ELEMENT, (NodeFilter)allelements, true);
                Node n;
                states.removeAll(states);
                while ((n = iterator.nextNode()) != null)
                {

                    if(n.getNodeName().equals("state"))
                    {
                        NamedNodeMap attrs = n.getAttributes();
                        NodeList children=n.getChildNodes();
                        State newState=new State(attrs.item(0).getNodeValue(),
                                attrs.item(1).getNodeValue(),attrs.item(2).getNodeValue(),attrs.item(3).getNodeValue(),children.item(0).getTextContent());
                        states.add(newState);

                    }

                }
                Collections.sort(states,new StateComparator());
                mod.setRowCount(states.size());
                mod.setColumnCount(5);
                for(int i=0;i<states.size();i++)
                {
                    mod.setValueAt(states.get(i).abbr, i, 0);

                    mod.setValueAt(states.get(i).name, i, 1);
                    mod.setValueAt(states.get(i).population_2k10, i, 2);
                    mod.setValueAt(states.get(i).rank_2k, i, 3);
                    mod.setValueAt(states.get(i).census_1990, i, 4);
                }

                mean=0;
                max=MAXIMUM;
                min=MINIMUM;
                count=0;
                  total=0;
                  SAXParserFactory parserFact = SAXParserFactory.newInstance();
        SAXParser parserS = parserFact.newSAXParser();
        DefaultHandler dHandler = new DefaultHandler(){
            public void startElement(String uri, String name, String element, Attributes atri)
                            {
                if (element.equals("state")){
                    total++;
                }
            }
            public void endDocument(){
                System.out.println("Total elements: " + total);
            }
        };
                  parserS.parse(file, dHandler);
                  meanL.setText("mean="+mean);
                  maxL.setText("max="+max);
                  minL.setText("min="+min);
                  countL.setText("count="+total);
        } else {

        }

     } 

推荐答案

请检查Attribute参数的import语句，应该是:

Please check the import statement for the Attribute parameter, it should be:

import org.xml.sax.Attributes;

问候

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