HttpURLConnection reading response content on 403

问题:

This question already has an answer here:

• Read error response body in Java 6 answers

When I fetch data from an URL with a 403 response

is = conn.getInputStream();

It throws an IOException and I can't get the response data.

But when I use firefox and access that url directly, The ResponseCode is still 403, but I can get the html content

回答1:

The HttpURLConnection.getErrorStream method will return an InputStream which can be used to retrieve data from error conditions (such as a 404), according to the javadocs.

回答2:

Usage example of HttpURLConnection :

String response = null;
try {
    URL url = new URL("http://google.com/pagedoesnotexist");
    HttpURLConnection connection = (HttpURLConnection) url.openConnection();

    // Hack to force HttpURLConnection to run the request
    // Otherwise getErrorStream always returns null
    connection.getResponseCode();
    InputStream stream = connection.getErrorStream();
    if (stream == null) {
        stream = connection.getInputStream();
    }
    // This is a try with resources, Java 7+ only
    // If you use Java 6 or less, use a finally block instead
    try (Scanner scanner = new Scanner(stream)) {
        scanner.useDelimiter("\\Z");
        response = scanner.next();
    }
} catch (MalformedURLException e) {
    // Replace this with your exception handling
    e.printStackTrace();
} catch (IOException e) {
    // Replace this with your exception handling
    e.printStackTrace();
}

回答3:

try something like this:

try {
    String text = "url";
    URL url = new URL(text);
    URLConnection conn = url.openConnection();
    // fake request coming from browser
    conn.setRequestProperty("User-Agent", "Mozilla/5.0 (Windows; U; Windows NT 6.1; en-GB;     rv:1.9.2.13) Gecko/20101203 Firefox/3.6.13 (.NET CLR 3.5.30729)");
    BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream(), "UTF-8"));
    String f = in.readLine();
    in.close();
    System.out.println(f);
} catch (Exception e) {
    e.printStackTrace();
}

回答4:

try this:

BufferedReader reader = new BufferedReader(new InputStreamReader(con.getResponseCode() / 100 == 2 ? con.getInputStream() : con.getErrorStream()));

source https://stackoverflow.com/a/30712213/505623

回答5:

I got the same error even after adding agent string. Finally after a days investigation figured out the issue. It is really weired if the url scheme start with "HTTPS" it results in error 403. It should be in lowercase ("https"). So make sure you call "url.toLowercase()" before opening the connection