gistfile1.java

import java.io.File;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import java.util.logging.Logger;

public class MergeV2 {

    private static final Logger log = Logger.getLogger(MergeV2.class.getName());
    private static final File ROOT_FOLDER = new File(System.getProperty("user.home") + (System.getProperty("os.name").contains("Windows") ? "/AppData/Roaming/X-Chat 2/xchatlogs" : "/.xchat2/xchatlogs"));
    private static final HashMap<String, File[]> files = new HashMap<String, File[]>();

    public static void main(String... args) {
        if (ROOT_FOLDER.exists()) {
            for (final File f : ROOT_FOLDER.listFiles()) {
                if (f.isDirectory() && f.getName().contains("System")) { //mandatory check
                    for (final File sub : f.listFiles()) {
                        String channelName = sub.getName().split("#")[1].replaceAll(".log", "");
                        log.info("Channel found: #" + channelName);
                        if (files.containsKey(channelName)) {
                            final ArrayList<File> temp = new ArrayList<File>();
                            for (File t : files.get(channelName)) {
                                temp.add(t);
                            }
                            temp.add(sub);
                            files.put(channelName, (File[]) temp.toArray());
                        } else {
                            files.put(channelName, new File[]{sub});
                        }
                    }
                }
            }
        } else {
            log.info("No log folder detected.");
        }
        for (Map.Entry<String, File[]> es : files.entrySet()) {
            StringBuilder sb = new StringBuilder();
            for (File f : es.getValue()) {
                sb.append(f.getName() + " ");
            }
            log.info("Channel: #" + es.getKey() + ", files: " + sb.toString());
        }
    }
}