Parse file name from URL before downloading the file

In android you can use the guessFileName() method:

URLUtil.guessFileName(url, null, null)

Alternatively, a simplistic solution in Java could be:

String fileName = url.substring(url.lastIndexOf('/') + 1);

(Assuming your url is in the format: http://xxxxxxxxxxxxx/filename.ext)

UPDATE March 23, 2018

This question is getting lots of hits and someone commented my 'simple' solution does not work with certain urls so I felt the need to improve the answer.

In case you want to handle more complex url pattern, I provided a sample solution below. It gets pretty complex quite quickly and I'm pretty sure there are some odd cases my solution still can't handle but nevertheless here it goes:

public static String getFileNameFromURL(String url) {    if (url == null) {        return "";    }    try {        URL resource = new URL(url);        String host = resource.getHost();        if (host.length() > 0 && url.endsWith(host)) {            // handle ...example.com            return "";        }    }    catch(MalformedURLException e) {        return "";      }    int startIndex = url.lastIndexOf('/') + 1;    int length = url.length();    // find end index for ?    int lastQMPos = url.lastIndexOf('?');    if (lastQMPos == -1) {        lastQMPos = length;     }    // find end index for #    int lastHashPos = url.lastIndexOf('#');    if (lastHashPos == -1) {        lastHashPos = length;       }    // calculate the end index    int endIndex = Math.min(lastQMPos, lastHashPos);    return url.substring(startIndex, endIndex);}

This method can handle these type of input:

Input: "null" Output: ""Input: "" Output: ""Input: "file:///home/user/test.html" Output: "test.html"Input: "file:///home/user/test.html?id=902" Output: "test.html"Input: "file:///home/user/test.html#footer" Output: "test.html"Input: "http://example.com" Output: ""Input: "http://www.example.com" Output: ""Input: "http://www.example.txt" Output: ""Input: "http://example.com/" Output: ""Input: "http://example.com/a/b/c/test.html" Output: "test.html"Input: "http://example.com/a/b/c/test.html?param=value" Output: "test.html"Input: "http://example.com/a/b/c/test.html#anchor" Output: "test.html"Input: "http://example.com/a/b/c/test.html#anchor?param=value" Output: "test.html"

You can find the whole source code here: https://ideone.com/uFWxTL

Try to use URLUtil.guessFileName(url, null, null) for example. I think this is the best Android way.

More info here: https://developer.android.com/reference/android/webkit/URLUtil.html#guessFileName(java.lang.String, java.lang.String, java.lang.String)

Keep it simple :

/** * This function will take an URL as input and return the file name. * <p>Examples :</p> * <ul> * <li>http://example.com/a/b/c/test.txt -> test.txt</li> * <li>http://example.com/ -> an empty string </li> * <li>http://example.com/test.txt?param=value -> test.txt</li> * <li>http://example.com/test.txt#anchor -> test.txt</li> * </ul> *  * @param url The input URL * @return The URL file name */public static String getFileNameFromUrl(URL url) {    String urlString = url.getFile();    return urlString.substring(urlString.lastIndexOf('/') + 1).split("\\?")[0].split("#")[0];}