Android处理POST请求、Android用SAX解析XML

1、处理post请求
public class HttpGet extends Activity {
private boolean isAuthenticated;
private ArrayList<BasicNameValuePair> pairs;
private DefaultHttpClient httpclient;
private HttpPost httppost;
private InputStream content;
private String returnConnection;
@Override
protected void onCreate(Bundle savedInstanceState) {
   super.onCreate(savedInstanceState);
   TextView tv=new TextView(this);
   Map vars=new HashMap();
   vars.put("mydata", "Hello,Android");
   ParameterHttp("http://5billion.com.cn/post.php",vars);
   doPost();
   tv.setText(this.returnConnection);
   this.setContentView(tv);
}

private void ParameterHttp(String url, Map vars) {
   this.httpclient=new DefaultHttpClient();
   this.httppost=new HttpPost(url);
   this.pairs=new ArrayList();
   if(vars!=null){
    Set keys=vars.keySet();
    for(Iterator i=keys.iterator();i.hasNext();){
     String key=(String)i.next();
     pairs.add(new BasicNameValuePair(key,(String) vars.get(key)));
    }
   }
}

private String doPost() {
   try{
    UrlEncodedFormEntity p_entity=new UrlEncodedFormEntity(pairs,"ISO-8859-1");
    httppost.setEntity(p_entity);
    HttpResponse response=httpclient.execute(httppost);
    HttpEntity entity=response.getEntity();
    content=entity.getContent();
    this.returnConnection=convertStreamToString(content);
    Log.d("HttpPostConnection",">>>>>>>>>"+returnConnection);
    int status_code=response.getStatusLine().getStatusCode();
    if(status_code>=300){
     this.isAuthenticated=false;
    }else{
     this.isAuthenticated=true;
    }
  
   }catch (Exception e) {
    // TODO: handle exception
   }
   return returnConnection;
}

private static String convertStreamToString(InputStream is) {
        /*
         * To convert the InputStream to String we use the BufferedReader.readLine()
         * method. We iterate until the BufferedReader return null which means
         * there's no more data to read. Each line will appended to a StringBuilder
         * and returned as String.
         */
        BufferedReader reader = new BufferedReader(new InputStreamReader(is));
        StringBuilder sb = new StringBuilder();

        String line = null;
        try {
            while ((line = reader.readLine()) != null) {
                sb.append(line + "\n");
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                is.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        return sb.toString();
    }
3、SAX解析xml
public class HttpGet extends Activity{

@Override
protected void onCreate(Bundle savedInstanceState) {
   super.onCreate(savedInstanceState);
   TextView tv=new TextView(this);
   try{
    URL url=new URL("http://5billion.com.cn/example.xml");
    //从SAXParserFactor获取SAXParser
    SAXParserFactory spf=SAXParserFactory.newInstance();
    SAXParser sp=spf.newSAXParser();
    //从SAXParser获取XMLReader
    XMLReader xr=sp.getXMLReader();
    //创建文明自己的内容处理器
    ExampleHandler myExampleHandler=new ExampleHandler();
    //用内容处理器处理XMLReader
    xr.setContentHandler(myExampleHandler);
    //XMLReader获取xml文件
    xr.parse(new InputSource(url.openStream()));
    //用ExampleHandle解析XML中数据
    ParsedExampleDataSet parsedExampleDataSet=myExampleHandler.getParsedData();
    //将解析的结果显示到gui
    tv.setText(parsedExampleDataSet.toString());
   }catch (Exception e) {
    tv.setText(e.getMessage());
   }
   this.setContentView(tv);
}


class ExampleHandler extends DefaultHandler {
   private boolean in_outertag=false;
   private boolean in_innertag=false;
   private boolean in_mytag=false;
   private ParsedExampleDataSet myParsedExampleDataSet=new ParsedExampleDataSet();

   public ParsedExampleDataSet getParsedData(){
    return this.myParsedExampleDataSet;
   }

   @Override
   public void characters(char[] ch, int start, int length)
     throws SAXException {
    if(this.in_mytag){
     String str=new String(ch,start,length);
     myParsedExampleDataSet.setExtractedString(str);
     Log.v("ParsingXML","Characters():"+str);
    }
   }

   @Override
   public void startDocument() throws SAXException {
    this.myParsedExampleDataSet=new ParsedExampleDataSet();
    Log.v("ParsingXML","startDocument");
   }
   @Override
   public void endDocument() throws SAXException {
    Log.v("ParsingXML","endDocumnet");
   }
   @Override
   public void startElement(String uri, String localName, String name,
     Attributes attributes) throws SAXException {
    if(localName.equals("outertag")){
     this.in_outertag=true;
    }else if(localName.equals("innertag")){
     this.in_innertag=true;
    }else if(localName.equals("mytag")){
     this.in_mytag=true;
    }else if(localName.equals("tagwithnumber")){
     String attrValue=attributes.getValue("thenumber");
     int i=Integer.parseInt(attrValue);
     this.myParsedExampleDataSet.setExtractedInt(i);
    }
    Log.v("ParsingXML","StartElement():"+localName);
   }
   @Override
   public void endElement(String uri, String localName, String name)
     throws SAXException {
    if(localName.equals("outertag")){
     this.in_outertag=false;
    }else if(localName.equals("innertag")){
     this.in_innertag=false;
    }else if(localName.equals("mytag")){
     this.in_mytag=false;
    }else if(localName.equals("tagwithnumber")){
     //nothing to do
    }
    Log.v("ParsingXML","endElement():"+localName);
   }
}

class ParsedExampleDataSet {
   private String extractedString=null;
   private int extractedInt=0;
   public void setExtractedString(String extractedString) {
    this.extractedString = extractedString;
   }
   public void setExtractedInt(int extractedInt) {
    this.extractedInt = extractedInt;
   }
   @Override
   public String toString() {
    // TODO Auto-generated method stub
    return "String from XML="+this.extractedString+"\n Number from XML="+this.extractedInt;
   }
 
}
}