[Deque]

Hello HC,

this code snippet checks a given URL for redirects. I.e. if there is someone providing a shortened link with services like TinyURL can check the real URL here without visiting the site.

Code:

import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Scanner;

public class RedirectLocationScanner {

    public static void main(final String[] args) throws IOException {
        
        String urlStr = null;

        if (!(args.length == 1)) {
            Scanner scan = new Scanner(System.in);
            System.out.println("URL?");
            urlStr = scan.nextLine();
            scan.close();
        } else {
            urlStr = args[0];
        }
        
        if(!urlStr.startsWith("http://")){
            urlStr = "http://" + urlStr;
        }
        
        URL url = new URL(urlStr);
        HttpURLConnection.setFollowRedirects(false);
        String redirectLoc = url.openConnection().getHeaderField("Location");
        
        if(redirectLoc == null){
            System.out.println("No redirect.");
        } else {
            System.out.println("real URL: " + redirectLoc);
        }
    }
}

__________________________________________________________________

This code is an updated version, that also scans for target links in ad link services like adfly, adfoc and linkbucks.

Code:

package scanner;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.util.Scanner;

public class LinkScanner {

    private static final String[] adServiceStrings = { "adf.ly", "adfoc.us",
            "any.gs", "tinylinks.co", "linkbucks.com", "yyv.co", "miniurls.co",
            "qqc.co", "whackyvidz.com", "ultrafiles.net", "dyo.gs",
            "megaline.co", "uberpicz.com", "linkgalleries.net", "qvvo.com",
            "urlbeat.net", "seriousfiles.com", "zxxo.net", "ugalleries.net",
            "picturesetc.net" };

    private static final String USAGE = "java -jar scanner.jar <URL>";

    public static void main(String[] args) {
        try {
            if (args.length == 1) {
                System.out.println("Target URL: ");
                scanAndPrint(args[0]);
            } else if (args.length == 0) {
                Scanner scan = new Scanner(System.in);
                System.out.println("URL?");
                String url = scan.nextLine();
                scanAndPrint(url);
            } else {
                System.out.println(USAGE);
            }
        } catch (IOException e) {
            System.err.println(e.getMessage());
        }
    }

    private static void scanAndPrint(String string) throws IOException {
        System.out.println("Scanning ...");
        String target = new LinkScanner().scan(string);
        if (target != null) {
            System.out.println("Target URL: ");
            System.out.println(target);
        } else {
            System.err.println("No target URL found");
        }
    }

    public String scan(String urlStr) throws IOException {
        if (!urlStr.startsWith("http://")) {
            urlStr = "http://" + urlStr;
        }
        URL url = new URL(urlStr);
        HttpURLConnection.setFollowRedirects(false);

        if (isAdServiceLink(urlStr)) {
            return handleAdLink(url);
        } else {
            return handleRedirect(url);
        }

    }

    private boolean isAdServiceLink(String urlStr) {
        for (String str : adServiceStrings) {
            if (urlStr.contains(str)) {
                return true;
            }
        }
        return false;
    }

    private String handleRedirect(URL url) throws IOException {
        return url.openConnection().getHeaderField("Location");
    }

    private String handleAdLink(URL url) throws IOException {
        URLConnection urlc = url.openConnection();
        urlc.addRequestProperty("user-agent", "Firefox");
        BufferedReader in = null;
        try {
            in = new BufferedReader(
                    new InputStreamReader(urlc.getInputStream()));
            String line;
            while ((line = in.readLine()) != null) {
                if (line.contains("var zzz =")) {
                    return extractADFlyURL(line);
                }
                if (line.contains("var click_url =")
                        && !line.contains("//var click_url =")) {
                    return extractADFocURL(line);
                }
                if (line.contains("Lbjs.TargetUrl =")) {
                    return extractLinkBucksURL(line);
                }
            }
            throw new IOException("Unable to find target URL in link");
        } finally {
            if (in != null) {
                in.close();
            }
        }
    }

    private String extractLinkBucksURL(String line) {
        String go = line.split("'")[1];
        return go;
    }

    private String extractADFocURL(String line) throws IOException {
        String go = line.split("\"")[1];
        return go;
    }

    private String extractADFlyURL(String line) throws IOException {
        String go = line.split("'")[1];
        String redirect = handleRedirect(new URL("http://adf.ly" + go));
        if (redirect == null) {
            return go;
        }
        return redirect;
    }
}

[H4R0015K]

will this work on every type of short links?

[Deque]

Edit: They have to use redirects. Something like adf.ly doesn't work. Maybe I will provide a solution for this too.

[H4R0015K]

nice code worked for me!

will wait for your solution for adf.ly links.

[Deque]

Here it is:

Code:

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.util.Scanner;

public class RedirectLocationScanner {

    public static void main(final String[] args) throws IOException {

        String urlStr = getURLStr(args);

        if (!urlStr.startsWith("http://")) {
            urlStr = "http://" + urlStr;
        }

        URL url = new URL(urlStr);
        HttpURLConnection.setFollowRedirects(false);

        if (urlStr.contains("adf.ly")) {
            handleAdfLyLink(url);
        } else {
            handleRedirect(url);
        }
    }

    private static String getURLStr(final String[] args) {
        String urlStr;
        if (!(args.length == 1)) {
            Scanner scan = new Scanner(System.in);
            System.out.println("URL?");
            urlStr = scan.nextLine();
            scan.close();
        } else {
            urlStr = args[0];
        }
        return urlStr;
    }

    private static void handleRedirect(URL url) throws IOException {
        String redirectLoc = url.openConnection().getHeaderField("Location");
        if (redirectLoc == null) {
            System.out.println("No redirect.");
        } else {
            System.out.println("real URL: " + redirectLoc);
        }
    }

    private static void handleAdfLyLink(URL url) throws IOException {
        URLConnection urlc = url.openConnection();
        urlc.addRequestProperty("user-agent", "Firefox");
        try (BufferedReader in = new BufferedReader(new InputStreamReader(
                urlc.getInputStream()))) {
            String line;
            boolean foundURL = false;
            while ((line = in.readLine()) != null) {
                if (line.contains("var url =")) {
                    extractAndPrintURL(line);
                    foundURL = true;
                    break;
                }
            }
            if (!foundURL) {
                System.err.println("Unable to find URL in adf.ly link");
            }
        }
    }

    private static void extractAndPrintURL(String line)
            throws IOException {
        String go = line.split("'")[1];
        handleRedirect(new URL("http://adf.ly" + go));
    }
}

Example:

URL?
http://adf.ly/5XR
real URL: http://www.google.com

[H4R0015K]

Here it is:

Code:

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.util.Scanner;

public class RedirectLocationScanner {

    public static void main(final String[] args) throws IOException {

        String urlStr = getURLStr(args);

        if (!urlStr.startsWith("http://")) {
            urlStr = "http://" + urlStr;
        }

        URL url = new URL(urlStr);
        HttpURLConnection.setFollowRedirects(false);

        if (urlStr.contains("adf.ly")) {
            handleAdfLyLink(url);
        } else {
            handleRedirect(url);
        }
    }

    private static String getURLStr(final String[] args) {
        String urlStr;
        if (!(args.length == 1)) {
            Scanner scan = new Scanner(System.in);
            System.out.println("URL?");
            urlStr = scan.nextLine();
            scan.close();
        } else {
            urlStr = args[0];
        }
        return urlStr;
    }

    private static void handleRedirect(URL url) throws IOException {
        String redirectLoc = url.openConnection().getHeaderField("Location");
        if (redirectLoc == null) {
            System.out.println("No redirect.");
        } else {
            System.out.println("real URL: " + redirectLoc);
        }
    }

    private static void handleAdfLyLink(URL url) throws IOException {
        URLConnection urlc = url.openConnection();
        urlc.addRequestProperty("user-agent", "Firefox");
        try (BufferedReader in = new BufferedReader(new InputStreamReader(
                urlc.getInputStream()))) {
            String line;
            boolean foundURL = false;
            while ((line = in.readLine()) != null) {
                if (line.contains("var url =")) {
                    extractAndPrintURL(line);
                    foundURL = true;
                    break;
                }
            }
            if (!foundURL) {
                System.err.println("Unable to find URL in adf.ly link");
            }
        }
    }

    private static void extractAndPrintURL(String line)
            throws IOException {
        String go = line.split("'")[1];
        handleRedirect(new URL("http://adf.ly" + go));
    }
}

Example:

URL?
http://adf.ly/5XR
real URL: http://www.google.com

this time got some errors!

Code:

RedirectLocationScanner.java:54: '{' expected
        try (BufferedReader in = new BufferedReader(new InputStreamReader(
           ^
RedirectLocationScanner.java:54: ')' expected
        try (BufferedReader in = new BufferedReader(new InputStreamReader(
                           ^
RedirectLocationScanner.java:55: ';' expected
                urlc.getInputStream()))) {
                                       ^
RedirectLocationScanner.java:54: 'try' without 'catch' or 'finally'
        try (BufferedReader in = new BufferedReader(new InputStreamReader(
        ^
RedirectLocationScanner.java:71: illegal start of expression
    private static void extractAndPrintURL(String line)
    ^
RedirectLocationScanner.java:71: illegal start of expression
    private static void extractAndPrintURL(String line)
            ^
RedirectLocationScanner.java:71: ';' expected
    private static void extractAndPrintURL(String line)
                  ^
RedirectLocationScanner.java:71: ')' expected
    private static void extractAndPrintURL(String line)
                                                 ^
RedirectLocationScanner.java:71: illegal start of expression
    private static void extractAndPrintURL(String line)
                                                      ^
RedirectLocationScanner.java:71: ';' expected
    private static void extractAndPrintURL(String line)
                                                       ^
RedirectLocationScanner.java:72: not a statement
            throws IOException {
                   ^
RedirectLocationScanner.java:72: ';' expected
            throws IOException {
                              ^
RedirectLocationScanner.java:76: reached end of file while parsing
}
^
13 errors

[Deque]

You have a Java version < 1.7.
1.7 introduced try-with-resources statements which I used here.

This code should work in 1.6:

Code:

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.util.Scanner;

public class RedirectLocationScanner {

    public static void main(final String[] args) throws IOException {

        String urlStr = getURLStr(args);

        if (!urlStr.startsWith("http://")) {
            urlStr = "http://" + urlStr;
        }

        URL url = new URL(urlStr);
        HttpURLConnection.setFollowRedirects(false);

        if (urlStr.contains("adf.ly")) {
            handleAdfLyLink(url);
        } else {
            handleRedirect(url);
        }
    }

    private static String getURLStr(final String[] args) {
        String urlStr;
        if (!(args.length == 1)) {
            Scanner scan = new Scanner(System.in);
            System.out.println("URL?");
            urlStr = scan.nextLine();
            scan.close();
        } else {
            urlStr = args[0];
        }
        return urlStr;
    }

    private static void handleRedirect(URL url) throws IOException {
        String redirectLoc = url.openConnection().getHeaderField("Location");
        if (redirectLoc == null) {
            System.out.println("No redirect.");
        } else {
            System.out.println("real URL: " + redirectLoc);
        }
    }

    private static void handleAdfLyLink(URL url) throws IOException {
        URLConnection urlc = url.openConnection();
        urlc.addRequestProperty("user-agent", "Firefox");
        BufferedReader in = null;
        try {
            in = new BufferedReader(
                    new InputStreamReader(urlc.getInputStream()));
            String line;
            boolean foundURL = false;
            while ((line = in.readLine()) != null) {
                if (line.contains("var url =")) {
                    extractAndPrintURL(line);
                    foundURL = true;
                    break;
                }
            }
            if (!foundURL) {
                System.err.println("Unable to find URL in adf.ly link");
            }
        } finally {
            if (in != null) {
                in.close();
            }
        }
    }

    private static void extractAndPrintURL(String line) throws IOException {
        String go = line.split("'")[1];
        handleRedirect(new URL("http://adf.ly" + go));
    }
}

[H4R0015K]

yup my java version is 1.6.now its working!

[Zakne]

How to use this codes? D::

[Deque]

How to use this codes? D::

Use this: http://www.multiupload.nl/CRC1KW6Y0R
It is the same, but a runnable jar with a GUI.