http请求工具类

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.util.Map;
import java.util.Properties;
/**  
 * HTTP GET/POST 请求工具                                                                     
 *                                                                                          
 * @author
 * @version 1.0
*/ 
public abstract class NetUtils {
  public static final String CHARACTER_ENCODING = "UTF-8";   
     public static final String PATH_SIGN = "/";   
     public static final String METHOD_POST = "POST";   
     public static final String METHOD_GET = "GET";   
     public static final String CONTENT_TYPE = "Content-Type";   
   
     /**  
      * 以POST方式向指定地址发送数据包请求,并取得返回的数据包      * @param urlString                                                                                            

      * @param requestData                                                                                          

      * @return 返回数据包                                                                                          

      * @throws Exception                                                                                           

      */                                                                                                            

     public static byte[] requestPost(String urlString, byte[] requestData)   
             throws Exception {   
         Properties requestProperties = new Properties();   
         requestProperties.setProperty(CONTENT_TYPE,"application/octet-stream; charset=utf-8");  
         return requestPost(urlString, requestData, requestProperties);   
     }                                                                                                              

     /**  
      * 以POST方式向指定地址发送数据包请求,并取得返回的数据包                                                       

      *                                                                                                             

      * @param urlString                                                                                            

      * @param requestData                                                                                          

      * @param requestProperties                                                                                    

      * @return 返回数据包                                                                                          

      * @throws Exception                                                                                           

      */                                                                                                            

     public static byte[] requestPost(String urlString, byte[] requestData,   
             Properties requestProperties) throws Exception {   
         byte[] responseData = null;   
         HttpURLConnection con = null;   
         try {   
             URL url = new URL(urlString);   
             con = (HttpURLConnection) url.openConnection();                                                        

             if ((requestProperties != null) && (requestProperties.size() > 0)) {  
                 for (Map.Entry<Object, Object> entry : requestProperties.entrySet()) {                             

                     String key = String.valueOf(entry.getKey());                                                   

                     String value = String.valueOf(entry.getValue());                                               

                     con.setRequestProperty(key, value);                                                            

                 }                                                                                                  

             }                                                                                                      

             con.setRequestMethod(METHOD_POST); // 置为POST方法   
             con.setDoInput(true); // 开启输入流   
             con.setDoOutput(true); // 开启输出流   
//             con.setConnectTimeout(10000); //超时时间
             // 如果请求数据不为空，输出该数据。   
             if (requestData != null) {   
                 DataOutputStream dos = new DataOutputStream(con.getOutputStream());                                

                 dos.write(requestData);                                                                            

                 dos.flush();                                                                                       

                 dos.close();                                                                                       

             }                                                                                                      

             int length = con.getContentLength();   
             // 如果回复消息长度不为-1，读取该消息。   
             if (length != -1) {   
                 DataInputStream dis = new DataInputStream(con.getInputStream());  
                 responseData = new byte[length];   
                 dis.readFully(responseData);        
                 dis.close();                                                                                       

             }                                                                                                      

         } catch (Exception e) {   
             throw e;   
         } finally {   
             if (con != null) {   
                 con.disconnect();                                                                                  

                 con = null;   
             }                                                                                                      

         }                                                                                                          

         return responseData;   
     }                                                                                                              

                                                                                                  
     /**  
      * 以POST方式向指定地址提交表单<br>                                                                            

      *                                                                                                             

      * @param urlString                                                                                            

      * @param formProperties                                                                                       

      * @return 返回数据包                                                                                          

      * @throws Exception                                                                                           

      */                                                                                                            

     public static byte[] requestPostForm(String urlString,Properties formProperties) throws Exception {  
         Properties requestProperties = new Properties();   
         requestProperties.setProperty(CONTENT_TYPE,"application/x-www-form-urlencoded");  
         return requestPostForm(urlString, formProperties, requestProperties);   
     }                                                                                                              

                                                                                                  
     /**  
      * 以POST方式向指定地址提交表单<br>                                                                            

      * @param urlString                                                                                            

      * @param formProperties                                                                                       

      * @param requestProperties                                                                                    

      * @return 返回数据包                                                                                          

      * @throws Exception                                                                                           

      */                                                                                                            

     public static byte[] requestPostForm(String urlString,Properties formProperties, Properties requestProperties)

throws Exception {   
         StringBuilder sb = new StringBuilder();   
         if ((formProperties != null) && (formProperties.size() > 0)) {   
             for (Map.Entry<Object, Object> entry : formProperties.entrySet()) {  
                 String key = String.valueOf(entry.getKey());                                                       

                 String value = String.valueOf(entry.getValue());                                                   

                 sb.append(key);                                                                                    

                 sb.append("=");   
                 sb.append(encode(value));                                                                          

                 sb.append("&");   
             }                                                                                                      

         }                                                                                                          

         String str = sb.toString();                                                                                

         str = str.substring(0, (str.length() - 1)); // 截掉末尾字符&   
         return requestPost(urlString, str.getBytes(CHARACTER_ENCODING),requestProperties);                         

     }                                                                                                              

                                                                                                                           

                                                                                                  
     /**  
      * url解码                                                                                                     

      * @param str                                                                                                  

      * @return 解码后的字符串,当异常时返回原始字符串。                                                             

      */                                                                                                            

     public static String decode(String url) {   
         try {   
             return URLDecoder.decode(url, CHARACTER_ENCODING);   
         } catch (UnsupportedEncodingException ex) {   
             return url;   
         }                                                                                                    
     }                                                                                                              

                                                                                                                           

                                                                                                  
     /**  
      * url编码                                                                                                     

      * @param str                                                                                                  

      * @return 编码后的字符串,当异常时返回原始字符串。                                                             

      */                                                                                                            

     public static String encode(String url) {   
         try {   
             return URLEncoder.encode(url, CHARACTER_ENCODING);   
         } catch (UnsupportedEncodingException ex) {   
             return url;   
         }                                                                                                    
     }                             
}