CODEWITHSUNDEEP
javastringjspsubstring
AKS
AKS

Reputation: 17326

How to extract / restructure a string value

I have the following possible values in a variable: URL, in JAVA/JSP.

URL="http://a.b.com/Something?IDToken1=AppUser1"
URL="http://a.b.com/Something?IDToken1=AppUser1&variable1=value1"
URL="http://a.b.com/Something?IDToken1=AppUser1variable1=value1&variable2=value2"

URL="http://a.b.com/Something?variable1=value1&IDToken1=AppUser1"
URL="http://a.b.com/Something?variable1=value1&IDToken1=AppUser1&variable2=value2"

I'm trying to find what code can I write (one-liner or 2-5 lines) using string or related functions that can give me a variable called: "user=AppUser1" and reConstructedURL=whatever value is the above link (except after removing IDToken1=AppUser1 from it if IDToken1 is the only parameter passed to the URL) otherwise, keep "?" character and all other parameters (+ exclude first & character as well i.e. no & character/value in reConstructedURL variable as the end character). I tried substring and index of functions but I couldn't get it to work.

For ex:

reConstructedURL="http://a.b.com/Something"

if URL was:
URL="http://a.b.com/Something?IDToken1=AppUser1" 


reConstructedURL="http://a.b.com/Something?variable1=value1"

if URL was:
URL="http://a.b.com/Something?IDToken1=AppUser1&variable1=value1"




reConstructedURL="http://a.b.com/Something?variable1=value1&variable2=value2"

if URL was:
URL="http://a.b.com/Something?IDToken1=AppUser1&variable1=value1&variable2=value2"




reConstructedURL="http://a.b.com/Something?variable1=value1"

if URL was:
URL="http://a.b.com/Something?variable1=value1&IDToken1=AppUser1"




reConstructedURL="http://a.b.com/Something?variable1=value1&variable2=value2"

if URL was:
URL="http://a.b.com/Something?variable1=value1&IDToken1=AppUser1&variable2=value2"

THIS is what I have tried so far.

   public final String USER_VAR = "IDToken1";
   public String[] extractNewURL(String currentGoToURL)
   {
       String[] userAndRetURL = new String[2];
       //Sample incoming
       //http://a.b.com/Something?IDToken1=Apptester2
       //http://a.b.com/Something?IDToken1=Apptester2&variable2=100
       //http://a.b.com/Something?variable1=Giga&IDToken1=Apptester2&variable2=100
       try
       {
           String extractedUsername = "";
           String[] stringArray = currentGoToURL.split(USER_VAR+"=");
           String usernamePlusPlus = stringArray[1];
           //Go up to the &
           int firstAmp = usernamePlusPlus.indexOf('&');
           if(firstAmp != -1)
           {
               extractedUsername = usernamePlusPlus.substring(0, firstAmp);
           }
           else
           {
               extractedUsername = usernamePlusPlus;
           }
           userAndRetURL[0] = extractedUsername;

           //2nd part to reconstruct the URL
           if(!"".equals(extractedUsername))
           {
               //TODO this needs to be smarter to pass along extra params
               String[] splitURL = currentGoToURL.split("\\?");
               String beginningURL = splitURL[0];
               //System.err.println("BEG:"+beginningURL);
               userAndRetURL[1] = beginningURL;
           }
           else
           {
               userAndRetURL[1] = currentGoToURL;
           }

       } catch (Exception e) {
           //Ends up in catalina.out
           System.err.println("EXCEPTION OCCURRED IN LOGIN.JSP:  "+e.toString());
           e.printStackTrace();
       }

       return userAndRetURL;
   }
        %>
            <%
        boolean weHaveUser = false;
        String userNameCarryFwd = "DummyUser";
        //App_USERNAME info is present in Headers
        userNameCarryFwd = response.getHeader("App_USERNAME");
        if (userNameCarryFwd == null)
        {
            userNameCarryFwd = request.getParameter("App_USERNAME");
            if(userNameCarryFwd == null) 
            {
                userNameCarryFwd = request.getParameter("IDToken1");
                if(userNameCarryFwd == null) 
                {
                    //This is crazy but we are passing it on the URL to get around header not fwding
                    String somethingToParse = request.getParameter("goto");
                    String[] uAndURL = extractNewURL(somethingToParse);
                    userNameCarryFwd = uAndURL[0];
                    String nonEncoded = uAndURL[1];
                    //This will be after reconstructive surgery
                    gotoURL = viewBean.getEncodedInputValue(nonEncoded);

                    if(userNameCarryFwd == null) 
                        userNameCarryFwd = "";
                }
            }
        }
        weHaveUser = (userNameCarryFwd == null || userNameCarryFwd.length() < 1) ? false : true;

I think the best way to get it logically is: 1. From the current Go To URL string, if I can just strip out IDToken=< value > part out and make sure the resultant "redirected URL" string's end character is not ending with - either a ? or & i.e. remove ? or & if that's the last character and after stripping the above variable=value part, if ?& or && consecutive characters exists, then replace it with ? or & character, that would do it.

Upvotes: 0

Views: 236

Answers (1)

Harun Raseed
Harun Raseed

Reputation: 26

below code can help you.

public class URLResonstruction {


    public static String reconstructURL(String url) {
        int beginTknInx = url.indexOf("IDToken1");

        // If there is no IDToken
        if (beginTknInx < 0)
            return url;

        // If IDToken is only query parameter or IDToken is at end
        int endTknInx = url.substring(beginTknInx).indexOf("&");
        if (endTknInx < 0)
            return url.substring(0, beginTknInx - 1);

        // If IDToken is at beginning or in middle
        String part1 = url.substring(0, beginTknInx);
        String part2 = url.substring(beginTknInx + endTknInx);
        return part1 + part2.substring(1, part2.length());
    }
}

Upvotes: 1

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