由于想测试性能，想模拟多个用户同时登陆系统进行访问，于是写了一个例子。

代码如下：

URL url = null;

HttpURLConnection httpurlconnection = null;

try {

url = new URL("http://www.****.com");

httpurlconnection = (HttpURLConnection) url.openConnection();

httpurlconnection.setRequestProperty("User-Agent", "Internet Explorer");

httpurlconnection.setRequestProperty("Host", "www.baidu.com");

httpurlconnection.connect();

String cookie0 = httpurlconnection.getHeaderField("Set-Cookie");

/**

* write out the cookie

*/

System.out.println(cookie0);

System.out.println(cookie0.split(";")[0]);

httpurlconnection.disconnect();

//http://www.360itsm.com/desktop;

url = new URL("http://www.****.com/desktop;"+cookie0.split(";")[0]);

String strPost = "j_username=****&j_password=****";

httpurlconnection = (HttpURLConnection) url.openConnection();

HttpURLConnection.setFollowRedirects(true);

httpurlconnection.setInstanceFollowRedirects(true);

httpurlconnection.setDoOutput(true); // 需要向服务器写数据

httpurlconnection.setDoInput(true); //

httpurlconnection.setUseCaches(false); // 获得服务器最新的信息

httpurlconnection.setAllowUserInteraction(false);

httpurlconnection.setRequestMethod("POST");

httpurlconnection

.addRequestProperty(

"Accept",

"image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, application/x-shockwave-flash, application/msword, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/x-silverlight, */*");

httpurlconnection

.setRequestProperty("Referer",

"http://www.360itsm.com");

httpurlconnection.setRequestProperty("Accept-Language", "zh-cn");

httpurlconnection.setRequestProperty("Content-Type",

"application/x-www-form-urlencoded");

httpurlconnection.setRequestProperty("Accept-Encoding",

"gzip, deflate");

httpurlconnection

.setRequestProperty(

"User-Agent",

"Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; Foxy/1; .NET CLR 2.0.50727; MEGAUPLOAD 1.0)");

httpurlconnection.setRequestProperty("Host", "****.com");

httpurlconnection.setRequestProperty("Content-Length", strPost

.length()

+ "");

httpurlconnection.setRequestProperty("Connection", "Keep-Alive");

httpurlconnection.setRequestProperty("Cache-Control", "no-cache");

httpurlconnection.setRequestProperty("Cookie", cookie0);

httpurlconnection.connect();

httpurlconnection.getOutputStream().write(strPost.getBytes());

httpurlconnection.getOutputStream().flush();

httpurlconnection.getOutputStream().close();

int code = httpurlconnection.getResponseCode();

System.out.println("code   " + code);

String cookie1 = httpurlconnection.getHeaderField("Set-Cookie");

System.out.print(cookie0 + "; " + cookie1);

byte[] bytes = new byte[10240];

httpurlconnection.getInputStream().read(bytes);

System.out.println(new String(bytes,"GBK"));

httpurlconnection.disconnect();