httphelper.java

采用JAVA开发

package com.gctech.sms.sp.cms.util;
import java.util.*;
import java.io.InputStream;
import java.io.IOException;
import java.io.OutputStream;
//import javax.microedition.io.Connector;
//import javax.microedition.io.HttpConnection;
import java.net.*;
public class HttpHelper
{
  private static final int MAX_REDIRECTS = 5;
  private static final int MAX_READ_SIZE = 100;//允许从server端读取100个
  public HttpHelper()
  {
  }
  private String getResponse(InputStream in)
  {
    try
    {
      byte[] buf = new byte[ MAX_READ_SIZE ] ;
      int total = 0 ;
      while ( total < MAX_READ_SIZE )
      {
        int count = in.read ( buf , total , MAX_READ_SIZE - total ) ;
        if ( count < 0 )
        {
          break ;
        }
        total += count ;
      }

      return new String ( buf , 0 , total ) ;



    }
    catch ( Exception ex )
    {
      throw new IllegalStateException(ex.getMessage());
    }



  }


  private Hashtable toMap(String response)
{
  int start = 0;
  int end = 0;
  String line = null;
  int lineIndex = 0;
  String key = null;
  String value = null;
  Hashtable t = new Hashtable();
  while ( ( end = response.indexOf ( "\r\n" , start ) ) != -1 )
  {
    line = response.substring(start,end);
    start = end+2;
    if(start>response.length()) break;
    lineIndex = line.indexOf("=",0);
    key = line.substring(0,lineIndex);
    value=line.substring(lineIndex+1);
    t.put(key,value);
  }
  return t;
}

  private String makeQuery(Hashtable map)
  {
    StringBuffer sb = new StringBuffer();
    for(Enumeration e = map.keys();e.hasMoreElements();)
    {
      String key = e.nextElement().toString();
      sb.append(key).append("=").append(map.get(key).toString()).append("&");
    }
    sb.setLength(sb.length()-1);
    //sb.append("\r\n"); 是否需要增加
    return sb.toString();//must encode;
  }

  public Hashtable postMapResponse(String url,Hashtable parameters)
  {
    return toMap(postStringResponse(url,parameters));
  }

  public String postStringResponse(String url,Hashtable parameters)
  {
    InputStream is = null ;
    OutputStream os = null ;
     HttpURLConnection conn = null;
    int redirects = 0 ;
    try
    {

      String query = makeQuery(parameters);//"index=books&field-keywords=" + isbn + "\r\n" ;
      String requestMethod = "POST" ;


      while ( redirects < MAX_REDIRECTS )
      {
        System.out.println("ready connect");

        conn = (HttpURLConnection)new URL(url).openConnection();
        conn.setDoInput(true);
        conn.setDoOutput(true);
        conn.setRequestMethod(requestMethod);


        System.out.println("connect ok");

        conn.setRequestMethod ( requestMethod ) ;
        conn.setRequestProperty ( "Connection" , "Close" ) ;
        if ( requestMethod.equals ( requestMethod ) )
        {
          conn.setRequestProperty ( "Content-Type" ,
                                    "application/x-www-form-urlencoded" ) ;
          os = conn.getOutputStream () ;
          os.write ( query.getBytes () ) ;
          os.close () ;
          os = null ;
        }

        // Read the response from the server
        is = conn.getInputStream () ;
        int code = conn.getResponseCode () ;


        // If we get a redirect, try again at the new location
        if ( ( code >= HttpURLConnection.HTTP_MOVED_PERM &&
               code <= HttpURLConnection.HTTP_SEE_OTHER ) ||
             code == HttpURLConnection.HTTP_MOVED_TEMP)//??
        {
          // Get the URL of the new location (always absolute)
          url = conn.getHeaderField ( "Location" ) ;
          is.close () ;
          conn.disconnect () ;
          is = null ;
          conn = null ;

          if ( ++redirects > MAX_REDIRECTS )
          {
            // Too many redirects - give up.

            break;
          }

          // Choose the appropriate request method
          requestMethod = "POST" ;
          if ( code == HttpURLConnection.HTTP_MOVED_TEMP ||
               code == HttpURLConnection.HTTP_SEE_OTHER )
          {
            requestMethod = "GET" ;
          }
          continue ;
        }
//        String type = conn.getType () ;
        String type="text/html";
        System.out.println("response type "+type);
        if ( code == HttpURLConnection.HTTP_OK &&
             type.indexOf ( "text/html" )!=-1 )
        {
          System.out.println("retrive date from connection");
          return this.getResponse(is);
        }
        else
        {
          throw new IllegalStateException("response error");
        }
      }

      throw new IllegalStateException("can not find the url");
    }
    catch ( Throwable t )
    {
      System.out.println ( t ) ;
      throw new IllegalStateException(t.getMessage());
    }
    finally
    {
      if ( is != null )
      {
        try
        {
          is.close () ;
        }
        catch ( IOException ex )
        {
        }
      }
      if ( os != null )
      {
        try
        {
          os.close () ;
        }
        catch ( IOException ex )
        {
        }
      }
      if ( conn != null )
      {
        try
        {
          conn.disconnect () ;
        }
        catch ( Exception ex )
        {
        }
      }
    }

  }


  public static void main(String[] args)
  {
    HttpHelper h = new HttpHelper();
    Hashtable t = new Hashtable();
    t.put("name","value1");
    System.out.println(h.makeQuery(t));
  }

}