HTTPClient实现免登陆请求（带cookie请求）

背景：

使用httpclient请求某登录型网站，模拟一个操作，一般步骤一个httpclient模式登录-》httpclient模拟操作；

此时发现，每次操作都需要进行一次登录，极其浪费时间，是否可以通过某一方式进行一次登录多次操作，这里提供一种方式，带cookie登录。

登录获取cookie：

    public string loginmodel(string username, string password) {
        string jsessionid = null;
        httppost httppost = new httppost(url);//httppost
        try {
            list<namevaluepair> para = new arraylist<namevaluepair>();
            para.add(new basicnamevaluepair("password", password));
            para.add(new basicnamevaluepair("username", username));//构造表单
            httppost.setheader(
                    "user-agent",
                    "mozilla/5.0 (windows nt 6.3; win64; x64) applewebkit/537.36 (khtml, like gecko) chrome/41.0.2272.118 safari/537.36");
            httppost.setentity(new urlencodedformentity(para, "utf-8"));//设置请求体
            basiccookiestore cookiestore = new basiccookiestore();//建立一个cookiestore
            closeablehttpclient httpclient = httpclients.custom().setdefaultcookiestore(cookiestore).build();//建立带cookie的httpclient
            int statuts_codes = httpclient.execute(httppost).getstatusline().getstatuscode();//发送请求，发送成功后cookie将存在于cookiestore中
            if (statuts_codes == httpstatus.sc_ok) {//请求成功
                list<cookie> cookies = cookiestore.getcookies();//遍历获取需要的值
                for (int i = 0; i < cookies.size(); i++) {//获取jsessionid
                    if (cookies.get(i).getname().equals("id")) {
                        jsessionid = cookies.get(i).getvalue();
                    }
                }
                cookiemap.put("jsessionid", jsessionid);
               
            } else {//请求失败
               
            }
        } catch (unsupportedencodingexception ex) {
            
        } catch (ioexception ex) {
            
        } finally {
            httppost.releaseconnection();//释放资源
        }
        return cookiemap.get("jsessionid");
    }

创建带有cookie的httpclient

 public closeablehttpclient gethttpclients(string username, string password) {
        basiccookiestore cookiestore = new basiccookiestore();
        httpclientbuilder httpclientbuilder = httpclientbuilder.create();
        string jsessionid = loginmodel(username, password);
        basicclientcookie cookie = new basicclientcookie("jsessionid", jsessionid);
        cookie.setversion(0);
        string domain = constant.hook_url.substring(0, constant.hook_url.indexof(":"));
        if (constant.hook_url.startswith("http://")) {
            domain = constant.hook_url.substring(constant.hook_url.lastindexof("/") + 1, constant.hook_url.lastindexof(":"));
        }
        cookie.setdomain(domain);
        cookie.setpath(constant.hook_fw);
        cookiestore.addcookie(cookie);
        //带有cookie的httpclient
        return httpclientbuilder.setdefaultcookiestore(cookiestore).build();
    }

使用：

public void usecookiehttpclient() {

        closeablehttpclient httpclient = gethttpclients(user, pass);
        httppost httppost = new httppost(url2);
        list<namevaluepair> para = new arraylist<>();//表单
        para.add("键", "值");
        httppost.setentity(new urlencodedformentity(para, "utf-8"));
        httppost.setentity(new urlencodedformentity(para, "utf-8"));
        closeablehttpresponse res = httpclient.execute(httppost);
        int statuts_codes = res.getstatusline().getstatuscode();
        if (statuts_codes == httpstatus.sc_ok) {//请求成功
            string result = entityutils.tostring(res.getentity(), "utf-8");//返回值
        }

    }