LibsDisguises/src/me/libraryaddict/disguise/utilities/UpdateChecker.java

package me.libraryaddict.disguise.utilities;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.regex.Pattern;

public class UpdateChecker {
    private String latestVersion;

    private boolean checkHigher(String currentVersion, String newVersion) {
        String current = toReadable(currentVersion);
        String newVers = toReadable(newVersion);
        return current.compareTo(newVers) < 0;
    }

    public void checkUpdate(String currentVersion) {
        String version = getSpigotVersion();
        if (version != null) {
            if (checkHigher(currentVersion, version)) {
                latestVersion = version;
            }
        }
    }

    public String getLatestVersion() {
        return latestVersion;
    }

    /**
     * Asks spigot for the version
     */
    private String getSpigotVersion() {
        try {
            HttpURLConnection con = (HttpURLConnection) new URL("http://www.spigotmc.org/api/general.php").openConnection();
            con.setDoOutput(true);
            con.setRequestMethod("POST");
            con.getOutputStream().write(
                    ("key=98BE0FE67F88AB82B4C197FAF1DC3B69206EFDCC4D3B80FC83A00037510B99B4&resource=81").getBytes("UTF-8"));
            String version = new BufferedReader(new InputStreamReader(con.getInputStream())).readLine();
            if (version.length() <= 7) {
                return version;
            }
        } catch (Exception ex) {
            System.out.print("[LibsDisguises] Failed to check for a update on spigot. Now checking bukkit..");
        }
        return null;
    }

    private String toReadable(String version) {
        String[] split = Pattern.compile(".", Pattern.LITERAL).split(version.replace("v", ""));
        version = "";
        for (String s : split)
            version += String.format("%4s", s);
        return version;
    }
}