URL manipulation

I want to do a little manipulation with URLs.

It is required to add a sub domain in already created URL like shown below

Inputs

String inputURL = "http://www.myhost.com";
String subdomain = "newlocation";

output

String output = "http://www.newlocation.myhost.com";

I was thinking if there is any existing utility class that can do this for me. expert can have someth开发者_如何学Pythoning to say.

Thanks for your help !

Note that "www" is also subdomain. So you are actually appending another subdomain.

    String inputURL = "http://www.myhost.com";
    String subdomain = "newlocation";

    URL url = new URL(inputURL);

    String[] domainParts = url.getHost().split("\\.");
    StringBuilder sb = new StringBuilder();
    for (int i = 0; i < domainParts.length; i ++) {
        if (i == 1) {
            sb.append(subdomain + ".");
        }
        sb.append(domainParts[i] + ".");
    }
    String query = "";
    String port = "";
    if (url.getQuery() != null) {
        query = "?" + url.getQuery();
    }
    if (url.getPort() != -1) {
        port = url.getPort() + "";
    }
    String output = url.getProtocol() + ":" + port + "//" + sb.toString() + "/" + url.getPath() + query;
    System.out.println(output);

It is sufficient to parse only the host part of the URL and use the URI to render.

URL url = new URL(inputURL);
String host = url.getHost().replaceAll("(([.][^.]+){2,2})$", "." + subdomain + "$1");
String newUrl = new URI(url.getProtocol(), host, url.getPath(), url.getQuery(), null).toString();

Perhaps:

String output = inputURL.replaceAll("(http://[^.]+\\.)(.*)", "$1" + subdomain + ".$2");

Look at StringBuffer (Link to the Java API doc) and then you will probably need to use one of the insert() methods