Tukukkk

I have a input String as:

String text = "Some content which contains link as <A HREF="/relative-path/fruit.cgi?param1=abc&param2=xyz">URL Label</A> and some text after it";

I want to convert this text to:

Some content which contains link as http://www.google.com/relative-path/fruit.cgi?param1=abc&param2=xyz&myParam=pqr (URL Label) and some text after it

So here:

1) I want to replace the link tag with plain link. If the tag contains label then it should go in braces after the URL.

2) If the URL is relative, I want to prefix the base URL (http://www.google.com).

3) I want to append a parameter to the URL. (&myParam=pqr)

I am having issues retrieving the tag with URL and label, and replacing it.

I wrote something like:

public static void main(String args) {

    String text = "String text = "Some content which contains link as <A HREF="/relative-path/fruit.cgi?param1=abc&param2=xyz">URL Label</A> and some text after it";";

    text = text.replaceAll("&lt;", "<");

    text = text.replaceAll("&gt;", ">");

    text = text.replaceAll("&amp;", "&");



    // this is not working

    Pattern p = Pattern.compile("href="(.*?)"");

    Matcher m = p.matcher(text);

    String url = null;

    if (m.find()) {

        url = m.group(1);



    }

}



// helper method to append new query params once I have the url

public static URI appendQueryParams(String uriToUpdate, String queryParamsToAppend) throws URISyntaxException {

    URI oldUri = new URI(uriToUpdate);

    String newQueryParams = oldUri.getQuery();

    if (newQueryParams == null) {

        newQueryParams = queryParamsToAppend;

    } else {

        newQueryParams += "&" + queryParamsToAppend;  

    }

    URI newUri = new URI(oldUri.getScheme(), oldUri.getAuthority(),

            oldUri.getPath(), newQueryParams, oldUri.getFragment());

    return newUri;

}

Edit1:

Pattern p = Pattern.compile("HREF="(.*?)"");

This works. But then I want it to be capitalization agnostic. Href, HRef, href, hrEF, etc. all should work.

Also, how do I handle if my text has several URLs.

Edit2:

Some progress.

Pattern p = Pattern.compile("href="(.*?)"");

Matcher m = p.matcher(text);

String url = null;

while (m.find()) {

  url = m.group(1);

  System.out.println(url);

}

This handles the case of multiple URLs.

Last pending issue is, how do I get hold of the label and replace the href tags in original text with URL and label.

Edit3:

By multiple URL cases, I mean there are multiple url present in given text.

String text = "Some content which contains link as <A HREF="/relative-path/fruit.cgi?param1=abc&param2=xyz">URL Label</A> and some text after it and another link <A HREF="/relative-path/vegetables.cgi?param1=abc&param2=xyz">URL2 Label</A> and some more text";



Pattern p = Pattern.compile("href="(.*?)"", Pattern.CASE_INSENSITIVE);

Matcher m = p.matcher(text);

String url = null;

while (m.find()) {

 url = m.group(1); // this variable should contain the link URL

 url = appendBaseURI(url);

 url = appendQueryParams(url, "license=ABCXYZ");

 System.out.println(url);

}

public static void main(String args) {

    String text = "Some content which contains link as <A HREF="/relative-path/fruit.cgi?param1=abc&param2=xyz">URL Label</A> and some text after it and another link <A HREF="/relative-path/vegetables.cgi?param1=abc&param2=xyz">URL2 Label</A> and some more text";

    text = StringEscapeUtils.unescapeHtml4(text);

    Pattern p = Pattern.compile("<a href="(.*?)">(.*?)</a>", Pattern.CASE_INSENSITIVE);

    Matcher m = p.matcher(text);

    while (m.find()) {

        text = text.replace(m.group(0), cleanUrlPart(m.group(1), m.group(2)));

    }

    System.out.println(text);

}



private static String cleanUrlPart(String url, String label) {

    if (!url.startsWith("http") && !url.startsWith("www")) {

        if (url.startsWith("/")) {

            url = "http://www.google.com" + url;

        } else {

            url = "http://www.google.com/" + url;

        }

    }

    url = appendQueryParams(url, "myParam=pqr").toString();

    if (label != null && !label.isEmpty()) url += " (" + label + ")";

    return url;

}

Output

Some content which contains link as http://www.google.com/relative-path/fruit.cgi?param1=abc&param2=xyz&myParam=pqr (URL Label) and some text after it and another link http://www.google.com/relative-path/vegetables.cgi?param1=abc&param2=xyz&myParam=pqr (URL2 Label) and some more text

You can use apache commons text StringEscapeUtils to decode the html entities and then replaceAll, i.e.:

import org.apache.commons.text.StringEscapeUtils;



String text = "Some content which contains link as <A HREF="/relative-path/fruit.cgi?param1=abc&param2=xyz">URL Label</A> and some text after it";

String output = StringEscapeUtils.unescapeHtml4(text).replaceAll("([^<]+).+"(.*?)">(.*?)<[^>]+>(.*)", "$1https://google.com$2&your_param ($3)$4");

System.out.print(output);

// Some content which contains link as https://google.com/relative-path/fruit.cgi?param1=abc&param2=xyz&your_param (URL Label) and some text after it

Demos:

1. jdoodle


2. 
   Regex Explanation

// this is not working

Because your regex is case-sensitive.

Try:-

Pattern p = Pattern.compile("href="(.*?)"", Pattern.CASE_INSENSITIVE);

Edit1:

To get the label, use Pattern.compile("(?<=>).*?(?=</a>)", Pattern.CASE_INSENSITIVE) and m.group(0).

Edit2:

To replace the tag (including label) with your final string, use:-

text.replaceAll("(?i)<a href="(.*?)</a>", "new substring here")

Almost there:

public static void main(String args) throws URISyntaxException {

        String text = "Some content which contains link as <A HREF="/relative-path/fruit.cgi?param1=abc&param2=xyz">URL Label</A> and some text after it and another link <A HREF="/relative-path/vegetables.cgi?param1=abc&param2=xyz">URL2 Label</A> and some more text";

        text = StringEscapeUtils.unescapeHtml4(text);

        System.out.println(text);

        System.out.println("**************************************");

        Pattern patternTag = Pattern.compile("<a([^>]+)>(.+?)</a>", Pattern.CASE_INSENSITIVE);

        Pattern patternLink = Pattern.compile("href="(.*?)"", Pattern.CASE_INSENSITIVE);

        Matcher matcherTag = patternTag.matcher(text);



        while (matcherTag.find()) {

            String href = matcherTag.group(1); // href

            String linkText = matcherTag.group(2); // link text

            System.out.println("Href: " + href);

            System.out.println("Label: " + linkText);

            Matcher matcherLink = patternLink.matcher(href);

            String finalText = null;

            while (matcherLink.find()) {

                String link = matcherLink.group(1);

                System.out.println("Link: " + link);

                finalText = getFinalText(link, linkText);

                break;

            }

            System.out.println("***************************************");

            // replacing logic goes here

        }

        System.out.println(text);

    }



    public static String getFinalText(String link, String label) throws URISyntaxException {

        link = appendBaseURI(link);

        link = appendQueryParams(link, "myParam=ABCXYZ");

        return link + " (" + label + ")";

    }



    public static String appendQueryParams(String uriToUpdate, String queryParamsToAppend) throws URISyntaxException {

        URI oldUri = new URI(uriToUpdate);

        String newQueryParams = oldUri.getQuery();

        if (newQueryParams == null) {

            newQueryParams = queryParamsToAppend;

        } else {

            newQueryParams += "&" + queryParamsToAppend;  

        }

        URI newUri = new URI(oldUri.getScheme(), oldUri.getAuthority(),

                oldUri.getPath(), newQueryParams, oldUri.getFragment());

        return newUri.toString();

    }



    public static String appendBaseURI(String url) {

        String baseURI = "http://www.google.com/";

        if (url.startsWith("/")) {

            url = url.substring(1, url.length());

        }

        if (url.startsWith(baseURI)) {

            return url;

        } else {

            return baseURI + url;

        }

    }