java 发送GET和POST请求

//发送GET请求

public static String sendGet(String url, String param) {
  String result = "";
  BufferedReader in = null;
  try {
   String urlNameString = url + "?" + param;
   URL realUrl = new URL(urlNameString);
   URLConnection connection = realUrl.openConnection();
   connection.setRequestProperty("accept", "*/*");
   connection.setRequestProperty("connection", "Keep-Alive");
   connection.setRequestProperty("user-agent",
     "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");

    //有安全过滤时，需要带上当前的会话IP才能访问
   String sessionId = ContextUtil.getProperty().getProperty(
     "JSESSIONID");
   connection.setRequestProperty("Cookie", "JSESSIONID=" + sessionId);
   connection.connect();
   Map map = connection.getHeaderFields();
   logger.info("自动打印" + urlNameString);
   in = new BufferedReader(new InputStreamReader(
     connection.getInputStream()));
   String line = "";
   while ((line = in.readLine()) != null) {
    result = result + line;
   }
   logger.info("自动打印" + result);
  } catch (Exception e) {
   logger.error("发送GET请求出现异常！" + ContextUtil.getTrace(e));
  } finally {
   try {
    if (in != null)
     in.close();
   } catch (Exception e2) {
    logger.error("发送GET请求出现异常！" + ContextUtil.getTrace(e2));
   }
  }
  return result;
 }

//发送POST请求

 public static String sendPost(String url, String param) {
  PrintWriter out = null;
  BufferedReader in = null;
  String result = "";
  try {
   URL realUrl = new URL(url);
   URLConnection conn = realUrl.openConnection();
   conn.setRequestProperty("accept", "*/*");
   conn.setRequestProperty("connection", "Keep-Alive");
   conn.setRequestProperty("user-agent",
     "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
   conn.setDoOutput(true);
   conn.setDoInput(true);
   out = new PrintWriter(conn.getOutputStream());
   out.print(param);
   out.flush();
   in = new BufferedReader(
     new InputStreamReader(conn.getInputStream()));
   String line = "";
   while ((line = in.readLine()) != null) {
    result = result + line;
   }
   logger.info("自动打印" + result);
  } catch (Exception e) {
   logger.info("发送 POST 请求出现异常！" + ContextUtil.getTrace(e));
  } finally {
   try {
    if (out != null) {
     out.close();
    }
    if (in != null)
     in.close();
   } catch (IOException ex) {
    logger.error("发送 POST 请求出现异常！" + ContextUtil.getTrace(ex));
   }
  }
  return result;
 }