Compact Error Logger

ErrorLogger.java

import org.apache.commons.lang.exception.ExceptionUtils;
import org.bukkit.Bukkit;
import org.bukkit.Server;
import org.bukkit.plugin.Plugin;
import org.bukkit.plugin.PluginDescriptionFile;
import org.bukkit.plugin.PluginLogger;

import java.io.*;
import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.logging.Level;
import java.util.logging.LogRecord;

import static java.lang.System.getProperty;

/**
 * Custom logger to save errors.
 *
 * @author Icyene
 */

public class ErrorLogger extends PluginLogger {

    static ArrayList<Pair<String, ArrayList<String>>> registered = new ArrayList<Pair<String, ArrayList<String>>>();

    public ErrorLogger(Plugin context) {
        super(context);
        register("NULL", "NULL", "NULL", "NULL");
    }

    public ErrorLogger(final Plugin context, final String name, final String pack, final String tracker) {
        super(context);
        String endl = "";
        StringBuilder temp = new StringBuilder();
        for (int i = 0; i < name.length(); ++i)
            temp.append('=');
        endl = endl + temp.toString();
        register(name, pack, tracker, endl);

    }

    private void register(final String name, final String pack, final String tracker, final String endl) {

        //This line is horrendously hard to read. It works, though.
        registered.add(
                new Pair<String, ArrayList<String>>(name,
                        new ArrayList<String>() {
                            {
                                add(pack);
                                add(tracker);
                                add(endl);
                            }
                        }
                )
        );
    }

    @Override
    public void log(LogRecord logRecord) {
        if (!generateErrorLog(logRecord))
            super.log(logRecord);
    }

    private boolean generateErrorLog(LogRecord record) {
        Server server = Bukkit.getServer();
        Throwable thrown;
        if ((thrown = record.getThrown()) == null)
            return false;
        String ERROR = ExceptionUtils.getStackTrace(thrown), NAME = "", TICKETS = "", PACKAGE = "", ENDL = "";
        Plugin PLUGIN = null;

        for (Pair par : registered) {
            ArrayList<String> data = (ArrayList) par.RIGHT;
            if (ERROR.contains((PACKAGE = data.get(0)))) { //If the ERROR contains the package

                NAME = (String) par.LEFT;
                PLUGIN = Bukkit.getPluginManager().getPlugin(NAME);
                TICKETS = data.get(1);
                ENDL = data.get(2);

            }
        }

        if (!ERROR.contains(NAME + " has encountered an error!") && !ERROR.contains(this.getClass().getName()))  //Check if its not our own
            return false;
        PluginDescriptionFile pdf = PLUGIN.getDescription();
        StringBuilder err = new StringBuilder();
        boolean disable = false;
        err.append("\n=============" + NAME + " has encountered an error!=============");
        err.append("\nStacktrace:\n" + ERROR);
        err.append("\n" + NAME + " version: " + pdf.getVersion());
        err.append("\nBukkit message: " + record.getMessage());
        err.append("\nPlugins loaded: " + Arrays.asList(server.getPluginManager().getPlugins()));
        err.append("\nCraftBukkit version: " + server.getBukkitVersion());
        err.append("\nJava version: " + getProperty("java.version"));
        err.append("\nOS info: " + getProperty("os.arch") + " " + getProperty("os.name") + ", " + getProperty("os.version"));
        err.append("\nPlease report this error to the " + NAME + " ticket tracker (" + TICKETS + ")!");
        ERROR = ERROR.toLowerCase();
        if (ERROR.contains("nullpointerexception") || ERROR.contains("stackoverflowexception")) {
            err.append("\nA critical error has been thrown. " + NAME + " has been disabled to prevent further damage.");
            disable = true;
        } else {
            err.append("\nError was minor; " + NAME + " will continue operating.");
        }
        String name = NAME + "_" + md5(err).substring(0, 6) + ".error.log"; //Name is PLUGIN_NAME with first 6 chars of md5 appended
        File root = new File(PLUGIN.getDataFolder(), "errors");
        if (!root.exists())
            root.mkdir();
        File dump = new File(root.getAbsoluteFile(), name);

        if (!dump.exists()) {
            try {
                dump.createNewFile();
                BufferedWriter writer = new BufferedWriter(new FileWriter(dump));
                writer.write((err.toString() + ENDL).substring(1)); //Remove the extra /n
                writer.close();
                err.append("\nThis has been saved to the file ./" + PLUGIN.getName() + "/errors/" + name);
            } catch (Exception e) {
                System.err.println("Ehm, errors occured while displaying an error >.< Stacktrace:\n");
                e.printStackTrace();
            }
        }
        err.append(ENDL);
        System.err.println(err);

        if (disable)
            Bukkit.getServer().getPluginManager().disablePlugin(PLUGIN);
        return true;
    }

    public void initErrorHandler() {
        Thread.setDefaultUncaughtExceptionHandler(new Thread.UncaughtExceptionHandler() {
            @Override
            public void uncaughtException(Thread thread, Throwable throwable) {
                LogRecord o_u_screwd = new LogRecord(Level.SEVERE, "Uhoh");
                o_u_screwd.setThrown(throwable);
                generateErrorLog(o_u_screwd);
            }
        });
    }

    private String md5(StringBuilder builder) {
        String hash = "";
        try {
            MessageDigest m = MessageDigest.getInstance("MD5");
            m.reset();
            m.update(builder.toString().getBytes());
            hash = new BigInteger(1, m.digest()).toString(16);
            while (hash.length() < 32) {
                hash = 0 + hash;
            }
        } catch (NoSuchAlgorithmException e) {
        }
        return hash;
    }
}