Java: HttpURLConnection 模拟登录方法 (带cookie 的Post/Get)_20160908_七侠镇莫尛貝

// http://blog.csdn.net/woxueliuyun/article/details/43267365package tool class MyHttpUrlConn {    public static String cookieVal=""    public static void Get(String url_get,String str_param_url,String charset,String cookie) throws IOException  {        // 拼凑get请求的URL字串，使用URLEncoder.encode对特殊和不可见字符进行编码        //    String getURL = GET_URL + "?username="  + URLEncoder.encode("fat man", "utf-8");        String getURL = url_get + "?" + str_param_url        URL getUrl = new URL(getURL);        // 根据拼凑的URL，打开连接，URL.openConnection函数会根据URL的类型，        // 返回不同的URLConnection子类的对象，这里URL是一个http，因此实际返回的是HttpURLConnection        HttpURLConnection connection = (HttpURLConnection) getUrl                .openConnection();        if (cookie != null) {            //发送cookie信息上去，以表明自己的身份，否则会被认为没有权限            println("set cookieVal = [" + cookie + "]")            connection.setRequestProperty("Cookie", cookie);        }        // 进行连接，但是实际上get request要在下一句的connection.getInputStream()函数中才会真正发到        // 服务器        connection.connect();        // 取得输入流，并使用Reader读取        BufferedReader reader = new BufferedReader(new InputStreamReader(                connection.getInputStream(),charset));        System.out.println("Contents of get request:");        String lines;        while ((lines = reader.readLine()) != null)  {             System.out.println(lines);        }        println(" ")        reader.close();        // 断开连接        connection.disconnect();    }    public static String Post(String url_post,String str_param_body,String charset,boolean b_flag,String cookies) throws IOException  {        // Post请求的url，与get不同的是不需要带参数        URL postUrl = new URL(url_post);        // 打开连接        HttpURLConnection connection = (HttpURLConnection) postUrl                .openConnection();        // Output to the connection. Default is        // false, set to true because post        // method must write something to the        // connection        // 设置是否向connection输出，因为这个是post请求，参数要放在        // http正文内，因此需要设为true        if("" != cookies){            connection.setRequestProperty("Cookie", cookies);        }        connection.setDoOutput(true);        // Read from the connection. Default is true.        connection.setDoInput(true);        // Set the post method. Default is GET        connection.setRequestMethod("POST");        // Post cannot use caches        // Post 请求不能使用缓存        connection.setUseCaches(false);        // This method takes effects to        // every instances of this class.        // URLConnection.setFollowRedirects是static函数，作用于所有的URLConnection对象。        // connection.setFollowRedirects(true);        // This methods only        // takes effacts to this        // instance.        // URLConnection.setInstanceFollowRedirects是成员函数，仅作用于当前函数        connection.setInstanceFollowRedirects(b_flag);        // Set the content type to urlencoded,        // because we will write        // some URL-encoded content to the        // connection. Settings above must be set before connect!        // 配置本次连接的Content-type，配置为application/x-www-form-urlencoded的        // 意思是正文是urlencoded编码过的form参数，下面我们可以看到我们对正文内容使用URLEncoder.encode        // 进行编码        connection.setRequestProperty("Content-Type",                "application/x-www-form-urlencoded");        // 连接，从postUrl.openConnection()至此的配置必须要在connect之前完成，        // 要注意的是connection.getOutputStream会隐含的进行connect。        connection.connect();        DataOutputStream out = new DataOutputStream(connection                .getOutputStream());        // The URL-encoded contend        // 正文，正文内容其实跟get的URL中'?'后的参数字符串一致        //    String content = "userName=" + URLEncoder.encode("console", "utf-8");        //    content = content + "&password=" + URLEncoder.encode("12345678", "utf-8");        println("http param body = [" + str_param_body + "]")        // DataOutputStream.writeBytes将字符串中的16位的unicode字符以8位的字符形式写道流里面        out.writeBytes(str_param_body);        out.flush();        // 取得cookie，相当于记录了身份，供下次访问时使用        //    cookieVal = connection.getHeaderField("Set-Cookie").split(";")[0]        cookieVal = connection.getHeaderField("Set-Cookie")        println("get cookieVal = [" + cookieVal  + "]")        out.close(); // flush and close        BufferedReader reader = new BufferedReader(new InputStreamReader(                connection.getInputStream(),charset));        String line;        System.out.println("Contents of post request:");        while ((line = reader.readLine()) != null)  {            System.out.println(line);        }        println(" ")        reader.close();        connection.disconnect();        return cookieVal    }}

用法：

String cookie_login = MyHttpUrlConn.Post(URL_LOGIN,"userName=admin&password=12345678","utf-8",false,"");

MyHttpUrlConn.Post(URL_POST_SAVE,"name=mxb&yearsold=6","utf-8",false,cookie_login);MyHttpUrlConn.Get(URL_GET_VIEW,"name=mxb&yearsold=6","utf-8",cookie_login);

说明：

向URL_POST_SAVE Post数据时，要带上URL_LOGIN时生成的cookie，否则无法save数据。

同理Get也是。