从URL读取文件时出现问题-权限被拒绝

Question

I was trying to connect to some host like this

                url = new URL(urlString);
                BufferedReader in = new BufferedReader(
                                new InputStreamReader(
                                url.openStream()));

but I always get MalformedException - permission denied, I need to provide username and password ( which I know ) but I don't know how, there is no constructor in URL with those parametere neither setusername/password methods. Where to put username and password ?

Answer 1

I never has such a problem but.... try to give a look at this:

class urllib2.HTTPPasswordMgr Keep a database of (realm, uri) -> (user, password) mappings.

maybe it can help documentation about URLLIB2 at this link:

http://docs.python.org/library/urllib2.html

hope it's going to be helpful

Answer 2

If it's an HTTP authentication, use an URL of the form http://user:password@server:80/path .
If it's an application authentication, submit a POST/GET HTTP request with the details.

Answer 3

I had do this in a previous project. In order to access a protected resource you need to use the Authenticator class.

The username and password go in the variables defined for them towards the end but they do not have to hard coded, you can externalize them using java properties.

Here is an old snippet

// Install the custom authenticator
Authenticator.setDefault(new MyAuthenticator());

// Access the page
try {
    // Create a URL for the desired page
    URL url = new URL("THE URL YOU NEED TO OPEN/ACCESS");

    // Read all the text returned by the server
    BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream()));
    String str;
    while ((str = in.readLine()) != null) {
        // str is one line of text; readLine() strips the newline character(s)
    }
    in.close();
} catch (MalformedURLException e) {
} catch (IOException e) {
}

public class MyAuthenticator extends Authenticator {
    // This method is called when a password-protected URL is accessed
    protected PasswordAuthentication getPasswordAuthentication() {
        // Get information about the request
        String promptString = getRequestingPrompt();
        String hostname = getRequestingHost();
        InetAddress ipaddr = getRequestingSite();
        int port = getRequestingPort();

        // Get the username from the user...
        String username = "myusername";

        // Get the password from the user...
        String password = "mypassword";

        // Return the information
        return new PasswordAuthentication(username, password.toCharArray());
    }
}