解析网络 xml 流程

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import android.os.Environment;

public class FileUtils
{
private String SDPATH;

public String getSDPATH()
    {
return SDPATH;
    }

public FileUtils()
    {
//得到当前外部存储设备的目录/SDCARD
        SDPATH = Environment.getExternalStorageDirectory() + "/";
    }

/**
     * 在SD卡上创建文件
     * 
     * @throws IOException
*/
public File creatSDFile(String fileName) throws IOException
    {
        File file = new File(SDPATH + fileName);
        file.createNewFile();
return file;
    }

/**
     * 在SD卡上创建目录
     * 
     * @param dirName
*/
public File creatSDDir(String dirName)
    {
        File dir = new File(SDPATH + dirName);
        dir.mkdir();
return dir;
    }

/**
     * 判断SD卡上的文件夹是否存在
*/
public boolean isFileExist(String fileName)
    {
        File file = new File(SDPATH + fileName);
return file.exists();
    }

/**
     * 将一个InputStream里面的数据写入到SD卡中
*/
public File write2SDFromInput(String path, String fileName,
            InputStream input)
    {
        File file = null;
        OutputStream output = null;
try
        {
            creatSDDir(path);
            file = creatSDFile(path + fileName);
            output = new FileOutputStream(file);
byte buffer[] = new byte[4 * 1024];
while ((input.read(buffer)) != -1)
            {
                output.write(buffer);
            }
            output.flush();
        }
catch (Exception e)
        {
            e.printStackTrace();
        }
finally
        {
try
            {
                output.close();
            }
catch (Exception e)
            {
                e.printStackTrace();
            }
        }
return file;
    }

}

package my.utils;

import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

public class HttpDownloader
{
private URL url = null;

/**
     * 根据URL下载文件，前提是这个文件当中的内容是文本，函数的返回值就是文件当中的内容
     * 1.创建一个URL对象
     * 2.通过URL对象，创建一个HttpURLConnection对象
     * 3.得到InputStram
     * 4.从InputStream当中读取数据
     * @param urlStr
     * @return
*/
public String download(String urlStr)
    {
        StringBuffer sb = new StringBuffer();
        String line = null;
        BufferedReader buffer = null;
try
        {
// 创建一个URL对象
            url = new URL(urlStr);
// 创建一个Http连接
            HttpURLConnection urlConn = (HttpURLConnection) url
                    .openConnection();
// 使用IO流读取数据
            buffer = new BufferedReader(new InputStreamReader(urlConn
                    .getInputStream()));
while ((line = buffer.readLine()) != null)
            {
                sb.append(line);
            }
        }
catch (Exception e)
        {
            e.printStackTrace();
        }
finally
        {
try
            {
                buffer.close();
            }
catch (Exception e)
            {
                e.printStackTrace();
            }
        }
return sb.toString();
    }

/**
     * 该函数返回整形 -1：代表下载文件出错 0：代表下载文件成功 1：代表文件已经存在
*/
public int downFile(String urlStr, String path, String fileName)
    {
        InputStream inputStream = null;
try
        {
            FileUtils fileUtils = new FileUtils();

if (fileUtils.isFileExist(path + fileName))
            {
return 1;
            }
else
            {
                inputStream = getInputStreamFromUrl(urlStr);
                File resultFile = fileUtils.write2SDFromInput(path, fileName,
                        inputStream);
if (resultFile == null)
                {
return -1;
                }
            }
        }
catch (Exception e)
        {
            e.printStackTrace();
return -1;
        }
finally
        {
try
            {
                inputStream.close();
            }
catch (Exception e)
            {
                e.printStackTrace();
            }
        }
return 0;
    }

/**
     * 根据URL得到输入流
     * 
     * @param urlStr
     * @return
     * @throws MalformedURLException
     * @throws IOException
*/
public InputStream getInputStreamFromUrl(String urlStr)
throws MalformedURLException, IOException
    {
        url = new URL(urlStr);
        HttpURLConnection urlConn = (HttpURLConnection) url.openConnection();
        InputStream inputStream = urlConn.getInputStream();
return inputStream;
    }
}

package my.xml;

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

import android.util.Log;

public class MyContentHandler extends DefaultHandler
{
    String hisname, address, money, sex, status;
    String tagName;

/**
     * 开始解析xml
     * @throws SAXException
*/
public void startDocument() throws SAXException
    {
        System.out.println("````````begin````````");
    }

/**
     * 结束解析xml
     * @throws SAXException
*/
public void endDocument() throws SAXException
    {
        System.out.println("````````end````````");
    }

/**
     * 开始解析元素属性
     * 
     * @param namespaceURI 命名空间，防止命名重复
     * @param localName            不带前缀的名字
     * @param qName        带前缀的名字
     * @param attr         代表标签里所有的属性
     * @throws SAXException
*/
public void startElement(String namespaceURI, String localName,
            String qName, Attributes attr) throws SAXException
    {
        tagName = localName;//把当前正在解析的无前缀的名字传给tagName

if (localName.equals("worker"))
        {
//获取标签的全部属性
            for (int i = 0; i < attr.getLength(); i++)
            {
                Log.e("@@@", (attr.getLocalName(i) + "=" + attr.getValue(i)));//得到第i个属性的名字和值
            }
        }
    }

/**
     * 结束元素解析
     * 
     * @param namespaceURI
     * @param localName
     * @param qName
     * @throws SAXException
*/
public void endElement(String namespaceURI, String localName, String qName)
throws SAXException
    {
//在workr标签解析完之后，会打印出所有得到的数据
        tagName = "";
if (localName.equals("worker"))
        {
this.printout();
        }
    }

/**
     * 具体解析标签里的内容
     * 
     * @param ch        所有读取到的内容，都会放到char[]类型的数组里
     * @param start     读取的内容是从char[]数组的哪一位开始
     * @param length    从start开始，一共有多长的内容
     * @throws SAXException
*/
public void characters(char[] ch, int start, int length)
throws SAXException
    {
if (tagName.equals("name"))
            hisname = new String(ch, start, length);
else if (tagName.equals("sex"))
            sex = new String(ch, start, length);
else if (tagName.equals("status"))
            status = new String(ch, start, length);
else if (tagName.equals("address"))
            address = new String(ch, start, length);
else if (tagName.equals("money"))
            money = new String(ch, start, length);
    }

private void printout()
    {
        System.out.print("name: ");
        System.out.println(hisname);
        System.out.print("sex: ");
        System.out.println(sex);
        System.out.print("status: ");
        System.out.println(status);
        System.out.print("address: ");
        System.out.println(address);
        System.out.print("money: ");
        System.out.println(money);
        System.out.println();
    }

}

package my.xml;

import java.io.StringReader;

import javax.xml.parsers.SAXParserFactory;

import my.utils.HttpDownloader;
import my.xml.R;

import org.xml.sax.InputSource;
import org.xml.sax.XMLReader;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class XMLActitity extends Activity
{
/** Called when the activity is first created. */
private Button parseButton;

    @Override
public void onCreate(Bundle savedInstanceState)
    {
super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        parseButton = (Button) findViewById(R.id.parseButton);
        parseButton.setOnClickListener(new ParseButtonListener());
    }

class ParseButtonListener implements OnClickListener
    {
        @Override
public void onClick(View v)
        {
            HttpDownloader hd = new HttpDownloader();//new一个HttpDownloader对象
            String resultStr = hd
                    .download("http://192.168.1.112/test.xml");//把下载的字符串放在resultStr
            try
            {
/**
                 * 创建一个SAXParserFactory,再用这个工厂来创建一个XMLReader，以此来读取XML
                 * 这个方法就是这样写的，没有什么为什么，只是规定的格式罢了。
*/
                SAXParserFactory factory = SAXParserFactory.newInstance();
                XMLReader reader = factory.newSAXParser().getXMLReader();

//为XMLReader设置内容处理器，MyContentHandler()为具体处理的类
                reader.setContentHandler(new MyContentHandler());
//开始解析文件
                reader.parse(new InputSource(new StringReader(resultStr)));
            }
catch (Exception e)
            {
                e.printStackTrace();
            }
        }

    }
}