如何在MIDlet程序中解析XML

最新推荐文章于 2026-01-06 22:03:14 发布

翻译最新推荐文章于 2026-01-06 22:03:14 发布 · 643 阅读

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#string #attributes #import #vector #exception #xml

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本文介绍了一个使用JSR172规范中的Java API进行XML文件解析的例子。通过继承DefaultHandler类并实现特定的方法，可以处理XML文档中的元素、属性及文本内容。示例代码展示了如何初始化SAXParser并解析指定的XML文件。

JSR 172实现了Java API来进行XML解析.

下边代码说明了如何解析一个XML文件

import java.io.*;
import org.xml.sax.*;
import javax.xml.parsers.*;
import javax.microedition.midlet.*;
import javax.microedition.io.*;
import javax.microedition.io.file.*;
import javax.microedition.lcdui.*;

public class XMLMidlet extends MIDlet
{
public XMLMidlet() {}

protected void startApp()
{
    try
    {
      SAXParserFactory factory = SAXParserFactory.newInstance();
      SAXParser saxParser = factory.newSAXParser();

      FileConnection fc = (FileConnection) Connector.open(
        "file:///root1/helloworld.xml");
      InputStream is = fc.openInputStream();
      InputSource inputSource = new InputSource(is);
      saxParser.parse(is,new xmlHandler(this));
    }
    catch(Exception ex) {}
}

protected void alert(String msg)
{
    Display display = Display.getDisplay(this);
    Form form = new Form("HelloWorld XML !");
    form.append(msg);
    display.setCurrent(form);
}

protected void pauseApp() {}
protected void destroyApp(boolean bool) {}
}

import org.xml.sax.*;
import org.xml.sax.helpers.*;
import javax.xml.parsers.*;
import java.util.*;

class xmlHandler extends DefaultHandler
{
private XMLMidlet midlet;
private Vector nodes = new Vector();
private Stack tagStack = new Stack();

public xmlHandler (XMLMidlet midlet)
{
this.midlet = midlet;
}

public void startDocument() throws SAXException {}

public void startElement(String uri, String localName, String qName,
    Attributes attributes) throws SAXException
{
    if(qName.equals("node1"))
    {
      Noden node = new Noden();
      nodes.addElement(node);
    }
    tagStack.push(qName);
}

public void characters(char[] ch, int start, int length) throws SAXException
{
String chars = new String(ch, start, length).trim();

    if(chars.length() > 0)
    {
      String qName = (String)tagStack.peek();
      Noden currentnode = (Noden)nodes.lastElement();

      if (qName.equals("name"))
      {
        currentnode.setName(chars);
      }
      else if(qName.equals("type"))
      {
        currentnode.setType(chars);
      }
    }
}

public void endElement(String uri, String localName, String qName,
Attributes attributes) throws SAXException
{
tagStack.pop();
}

public void endDocument() throws SAXException
{
    StringBuffer result = new StringBuffer();
    for (int i=0; i<nodes.size(); i++)
    {
      Noden currentnode = (Noden)nodes.elementAt(i);
      result.append("Name : "currentnode.getName() + " Type : " +
        currentnode.getType() + "/n");
    }
    midlet.alert(result.toString());
}

class Noden
{
private String name;
private String type;

public Noden()
{}

    public void setName(String name)
    {
      this.name = name;
    }

    public void setType(String type)
    {
      this.type = type;
    }

    public String getName()
    {
      return name;
    }

    public String getType()
    {
      return type;
    }
};
}