通过HttpURLConnection获取SESSIONID

package test; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.io.OutputStream; import java.net.HttpURLConnection; import java.net.MalformedURLException; import java.net.URL; import java.util.List; import java.util.Map; public class HttpTest { private HttpURLConnection hc = null; private static final String oneUrlString = "http://xxx.jsp"; private static final String twoUrlString = "http://xxx.action"; public String getSessionId() { String sessionId = ""; try { URL url = new URL(oneUrlString); hc = (HttpURLConnection) url.openConnection();//默认的用GET提交 hc.setDoOutput(true); hc.connect(); Map map = hc.getHeaderFields(); //得到Cookie的所有内容，包括SESSIONID，在进行下次提交的时候 直接把这个Cookie的值设到头里头就行了 //淡然只得到SESSIONID也很简单的 ，但是有时候Set-Cookie的值有几个的 List<String> list = (List) map.get("Set-Cookie"); if(list.size() == 0||list == null) { return null; } StringBuilder builder = new StringBuilder(); for(String str : list) { sessionId = builder.append(str).toString(); } hc.disconnect(); } catch (MalformedURLException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } return sessionId; } public String getResponseContext(String parameters) { String responseContext = ""; try { URL url = new URL(twoUrlString); hc = (HttpURLConnection) url.openConnection();//使用POST提交 hc.addRequestProperty("Cookie", getSessionId()); hc.setDoOutput(true); hc.connect(); OutputStream out = hc.getOutputStream(); //参数是a=""&b=""这样拼接的一个串 out.flush(); out.close(); out.write(parameters.getBytes(),0,parameters.getBytes().length); InputStream in = hc.getInputStream(); InputStreamReader reader = new InputStreamReader(in,"gb2312"); BufferedReader read = new BufferedReader(reader); StringBuilder builder = new StringBuilder(); String str = ""; while((str = read.readLine()) != null) { builder = builder.append(str); } read.close(); reader.close(); in.close(); hc.disconnect(); responseContext = builder.toString(); } catch (MalformedURLException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } return responseContext; } }