1 /*
 2         urlString:访问的地址
 3         nameValuePair:一个文件 包含登陆名密码
 4     */
 5     private static String doPost(String urlString, Map<Object, Object> nameValuePairs) throws IOException {
 6         //发送请求
 7         URL url=new URL(urlString);        
 8         URLConnection connection=url.openConnection();
 9         connection.setDoInput(true);
10         connection.setDoOutput(true);
11         connection.setRequestProperty("Host","eol.siit.edu.cn:85");
12         connection.setRequestProperty("Connection","keep-alive");
13         connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");    
14         connection.connect();
15         //connection.setRequestProperty("Content-Length", "52");            
16             try(PrintWriter out=new PrintWriter(connection.getOutputStream())){
17                 boolean first=true;
18                 for(Map.Entry<Object, Object> pair:nameValuePairs.entrySet()){
19                     if(first)first=false;
20                     else{ 
21                         out.print("&");
22                     }
23                     
24                     String name=pair.getKey().toString();
25                     String value=pair.getValue().toString();
26                     
27                     out.print(name);
28                     out.print('=');
29                     out.print(value);
30                 }    
31             }    
32         //获取请求成功后的JSESSIONID
33         String repex="\\;";
34         Pattern pattern=Pattern.compile(repex,Pattern.CASE_INSENSITIVE);
35         Map<String, List<String>> map=connection.getHeaderFields();
36         for(Map.Entry<String, List<String>> air:map.entrySet()){    
37             System.out.println(air.getKey()+":"+air.getValue().toString());
38             String s=":"+air.getKey();
39             System.out.println(s);
40             if(s.equals(":Set-Cookie")){                
41                 s=air.getValue().toString();
42                 Matcher matcher=pattern.matcher(s);
43                 matcher.find();
44                 int stat=matcher.start();
45                 int end=matcher.end();
46                 String match=s.substring(1,end-1);
47                 JSESSIONID=match;
48             }
49         }
50         //接受返回的信息
51         StringBuilder response=new StringBuilder();
52         try(Scanner in=new Scanner(connection.getInputStream())){
53             while(in.hasNextLine()){
54                 response.append(in.nextLine());
55                 response.append("\n");
56             }            
57         }catch (IOException e) {
58             // TODO: handle exception
59             if(!(connection instanceof HttpURLConnection)){
60                 InputStream err=((HttpURLConnection)connection).getErrorStream();
61                 if(err==null)throw e;
62                 Scanner in=new Scanner(err);
63                 response.append(in.nextLine());
64                 response.append("\n");
65             }
66         }
67         return response.toString();
68     }