Question

I am trying to login to a website using java.net in Google App Engine for Java.
The login id and password are stored in variables ‘loginid’ and ‘password’ respectively.

The code that I have created is given below:

public Integer login()
{

    String param1="", param2="", query="";
    String charset = "UTF-8";
    String loginurl = "https://website.com/login";
    try {
        param1 = URLEncoder.encode(loginid, "UTF-8");
        param2 = URLEncoder.encode(password, "UTF-8");
        query = String.format("username=%s&password=%s", 
                 URLEncoder.encode(param1, charset), 
                 URLEncoder.encode(param2, charset));
    } catch (UnsupportedEncodingException ex) {
        // ...
    }
    try {
        URL url = new URL(loginurl + "?" + query);
        BufferedReader reader = new BufferedReader(new InputStreamReader(url.openStream()));
        String line="";
        String resp="";
        while ((line = reader.readLine()) != null) {
        resp=resp + line;
        }
         actionmessage=" Response-" + resp;              
            return(1);   
    }

    catch (Exception e) {
        // ...

    }
  }

I want to know more about a couple of things with ref to above code.

1. I am sure that I have entered correct ID and password, but still I am getting login failure. What is wrong with the above code?

2. How do I check if a submission as made by above code is successful or if there is an error? If there is an error, how do I get the error stream?

Answer 1

It was an error on my part- I encoded the 2 parameters passed to input url, twice!! So the site where I was authenticating, received a garbled value for user id and password!