basic bukkit crash detector

import org.bukkit.Bukkit;
import org.bukkit.craftbukkit.v1_6_R3.CraftServer;

import java.io.File;

public class CrashDetection {
    private File crashReportDirectory = null;
    private int startSize;
    private boolean active;

    public CrashDetection() {
        CraftServer server = (CraftServer) Bukkit.getServer();
        if (server != null) {
            File worldFolder = server.getWorldContainer();
            if (worldFolder != null) {
                File serverFolder = worldFolder.getParentFile();
                if (serverFolder != null) {
                    this.crashReportDirectory = new File(serverFolder, "crash-reports");
                    if (!this.crashReportDirectory.exists()) {
                        this.crashReportDirectory.mkdir();
                    }

                    this.active = true;
                }
            }
        }

        if (this.active) {
            this.startSize = getCrashReportsCount();
        }
        else {
            this.startSize = -1;
        }
    }

    public File getCrashReportDirectory() {
        return this.crashReportDirectory;
    }

    public int getCrashReportsCount() {
        String[] filePaths = this.crashReportDirectory.list();
        if (filePaths == null || filePaths.length == 0) {
            return 0;
        }

        int size = 0;
        for (int i = 0, len = filePaths.length; i < len; i++) {
            if (filePaths[i].endsWith("-server.txt")) {
                size++;
            }
        }

        return size;
    }

    public boolean hasDirectoryContentsChanged() {
        if (!this.active) {
            return false;
        }

        int sizeNow = getCrashReportsCount();
        if (sizeNow < this.startSize) {
            this.startSize = sizeNow;
        }

        return sizeNow != this.startSize;
    }

    public boolean hasCrashed() {
        return hasDirectoryContentsChanged();
    }
}