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import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.URL;

import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

import org.xml.sax.Attributes;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.DefaultHandler;


public class JavaParser extends DefaultHandler{

    private String url="http://www.nasa.gov/rss/dyn/image_of_the_day.rss";
    private boolean inUrl = false;
    private boolean inTitle = false;
    private boolean inDescription = false;
    private boolean inItem = false;
    private boolean inDate = false;
    private String title = null;
    private StringBuffer description = new StringBuffer();
    private String date = null;
    private String imageUrl;

    public void config()
    {
        try {

            InputStream inputStream=new URL(url).openStream();
            Reader reader = new InputStreamReader(inputStream,"UTF-8");

            InputSource is = new InputSource(reader);
            is.setEncoding("UTF-8");

            SAXParserFactory factory = SAXParserFactory.newInstance();
            SAXParser parser = factory.newSAXParser();
            XMLReader xmlReader = parser.getXMLReader();
            //          IotdHandler handler=new IotdHandler();
            xmlReader.setContentHandler(this);
//          InputStream inputStream = new URL(url).openStream(); 
            xmlReader.parse(is);

//          parser.parse(is, this);

        } 
        catch (Exception e)
        {
            e.printStackTrace();
        }
    }



    public void startElement(String uri, String localName, String qName,Attributes attributes) throws SAXException {
        if (localName.equals("enclosure")) 
        { inUrl = true; 
        imageUrl=attributes.getValue("url");
        System.out.println(imageUrl);
        } 
        else { inUrl = false; }
        if (localName.startsWith("item")) 
        { inItem = true; } 
        else if (inItem) { 
            if (localName.equals("title")) 
            { inTitle = true;
            System.out.println("invtitle");} 
            else { inTitle = false; }
            if (localName.equals("description")) 
            { inDescription = true; 
            System.out.println("indiscription");} 
            else { inDescription = false; }
            if (localName.equals("pubDate"))
            { inDate = true;
            System.out.println("dtae");} 
            else { inDate = false; }
        }
    }
    public void characters(char ch[], int start, int length) {
        String chars = new String(ch).substring(start, start + length);

        if (inTitle && title == null) { title = chars; }
        if (inDescription) { description.append(chars); }
        if (inDate && date == null) { date = chars; }
    }


    public String getTitle() { return title; }
    public StringBuffer getDescription() { return description; }
    public String getDate() { return date; }


    public static void main(String[] args) {
        JavaParser parse=new JavaParser();
        parse.config();
        System.out.println(parse.getTitle());
    }

}

我想读取这个 XML 文件并获取 Title 的值，这是我正在尝试的代码，但它返回给我的 title 为 null 值，任何正文都可以帮助我找到这里的问题，我已将其编码为 UTF- 8 因为否则它会抛出 MalformedByteSequenceException。

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0 回答 0