Detect when a new post is made on @beardog108's blog (https://chaoswebs.net/blog/).

ChaosWebs.java

import java.util.*;
import java.util.regex.Pattern;
import java.net.*;
import java.io.*;

public class ChaosWebs {
    public static double time = 6 * 60 * 60 * 1000;
    public static String filename = ".last_post.txt";
    
    public static void main(String[] args) {
        if(args.length != 0)
            try {
                double time = Double.parseDouble(args[0]) * 60 * 60 * 1000;
            } catch(Exception e) {
                System.out.println("java ChaosWebs <hours>");
                System.exit(0);
            }
        
        Timer t = new Timer();
        t.schedule(new TimerTask() {
            @Override
            public void run() {
                try {
                    boolean exists = new File(filename).exists();
                    
                    String top = getPosts().get(0);
                    String contents = decode(read());
                    write(encode("" + top));
                    
                    if(!contents.equals(top) && exists) {
                        // Put whatever code you want to run when a new post is detected here!
                        
                        System.out.println(top);
                        alert("chaoswebs.net Blog Update", "New post on https://chaoswebs.net/blog/ titled \"" + top + "\".");
                    }
                } catch(Exception e) {
                    e.printStackTrace();
                }
            }
        }, 0, (long) time);
    }
    
    public static String encode(String text) throws Exception { // encode post title so malicious code isn't written to the file.
        return Arrays.toString(text.getBytes("UTF-8"));
    }
    
    
    public static String decode(String text) throws Exception {
        if(text.length() == 0)
            return "";
        
        List<Byte> bytes = new ArrayList<>();
        for(String s : text.substring(1, text.length() -1).split(Pattern.quote(", ")))
            bytes.add((byte)Integer.parseInt(s));
        
        byte[] asdf = new byte[bytes.size()];
        int i = 0;
        for(byte b : bytes) {
            asdf[i] = b;
            i++;
        }
        
        return new String(asdf);
    }
    
    public static List<String> getPosts() throws Exception {
        List<String> list = new ArrayList<>();
        String html = getText("https://chaoswebs.net/blog/");
        
        int i = 0;
        for(String s : html.split(Pattern.quote("<h2 class=\"post-title\">            "))) {
            if(i != 0)
                list.add(s.split(Pattern.quote("        </h2>"))[0]);
            i++;
        }
        
        return list;
    }
    
    public static String read() throws Exception {
        if(!new File(filename).exists()) {
            try {new File(filename).createNewFile();} catch(Exception e) {e.printStackTrace();}
            return "";
        }
        
        BufferedReader br = new BufferedReader(new FileReader(filename));
        try {
            StringBuilder sb = new StringBuilder();
            String line = br.readLine();

            while (line != null) {
                sb.append(line);
                line = br.readLine();
            }
            return sb.toString();
        } finally {
            br.close();
        }
    }
    
    public static void write(String text) {
        try{
            PrintWriter writer = new PrintWriter(filename, "UTF-8");
            writer.println(text);
            writer.close();
        } catch (IOException e) {
           e.printStackTrace();
        }
    }
    
    public static void alert(String title, String text) {
        javax.swing.JOptionPane.showMessageDialog(null, text, title, javax.swing.JOptionPane.WARNING_MESSAGE);
    }
    
    public static String getText(String url) throws Exception {
        BufferedReader in = new BufferedReader(new InputStreamReader(new URL(url).openConnection().getInputStream()));

        StringBuilder response = new StringBuilder();
        String inputLine;

        while ((inputLine = in.readLine()) != null) 
            response.append(inputLine);

        in.close();

        return response.toString();
    }
}