[JAVA] HEX from File

import java.io.FileInputStream;

import java.io.IOException;

import java.nio.file.Files;

import java.nio.file.Paths;

import org.apache.commons.codec.binary.Hex;

public class HexFileUtil {

    public static void main(String[] args) {

        String filePath = "path/to/your/file.txt";

        try {

            // Example 1: Read and convert hex string to byte array

            String hexString = Files.readString(Paths.get(filePath)).trim();

            byte[] byteArray = hexStringToByteArray(hexString);

            System.out.println("Byte array from hex string: " + java.util.Arrays.toString(byteArray));

            // Example 2: Read file as bytes and convert to hex string

            byte[] fileBytes = Files.readAllBytes(Paths.get(filePath));

            String hexStringFromFile = byteArrayToHexString(fileBytes);

            System.out.println("Hex string from file bytes: " + hexStringFromFile);

             // Example 3: Read file as bytes and convert to hex string using Apache Commons Codec

             byte[] fileBytes2 = Files.readAllBytes(Paths.get(filePath));

             String hexStringFromBytes = Hex.encodeHexString(fileBytes2);

             System.out.println("Hex string from file bytes using Apache Commons Codec: " + hexStringFromBytes);

            // Example 4: Read file and print it in hex representation using FileInputStream

            printHexStream(new FileInputStream(filePath), 16);

        } catch (IOException e) {

            System.err.println("Error reading file: " + e.getMessage());

        }

    }

    public static void printHexStream(final FileInputStream inputStream, final int numberOfColumns) throws IOException{

         long streamPtr=0;

         while (inputStream.available() > 0) {

             final long col = streamPtr++ % numberOfColumns;

             System.out.printf("%02x ",inputStream.read());

             if (col == (numberOfColumns-1)) {

                 System.out.printf("\n");

             }

         }

    }

    public static byte[] hexStringToByteArray(String hexString) {

        int len = hexString.length();

        byte[] data = new byte[len / 2];

        for (int i = 0; i < len; i += 2) {

            data[i / 2] = (byte) ((Character.digit(hexString.charAt(i), 16) << 4)

                                 + Character.digit(hexString.charAt(i + 1), 16));

        }

        return data;

    }

    public static String byteArrayToHexString(byte[] bytes) {

        StringBuilder sb = new StringBuilder();

        for (byte b : bytes) {

            sb.append(String.format("%02x", b));

        }

        return sb.toString();

    }

}

[JAVA] PRINT DATA

import java.awt.*;

import java.awt.print.*;

public class PrintExample implements Printable {

    public int print(Graphics graphics, PageFormat pageFormat, int pageIndex) throws PrinterException {

        if (pageIndex > 0) {

            return NO_SUCH_PAGE;

        }

        Graphics2D g2d = (Graphics2D) graphics;

        g2d.drawString("Hello, Printer!", 100, 100);

        return PAGE_EXISTS;

    }

    public static void main(String[] args) {

        PrinterJob printerJob = PrinterJob.getPrinterJob();

        PrintService[] services = PrinterJob.lookupPrintServices();

        if (services.length > 0) {

            try {

                printerJob.setPrintService(services[0]);

                printerJob.setPrintable(new PrintExample());

                if (printerJob.printDialog()) {

                    printerJob.print();

                }

            } catch (PrinterException e) {

                e.printStackTrace();

            }

        } else {

            System.out.println("No printers found.");

        }

    }

}

[JAVA] SPEEDTEST NETWORK

long download1 = net.getBytesRecv();

long timestamp1 = net.getTimeStamp();

Thread.sleep(2000); //Sleep for a bit longer, 2s should cover almost every possible problem

net.updateNetworkStats(); //Updating network stats

long download2 = net.getBytesRecv();

long timestamp2 = net.getTimeStamp();

System.out.println("prova " + (download2 - download1)/(timestamp2 - timestamp1));

//Do the correct calculations

[JAVA] SERVER CLIENT NETWORK

// Server.java

import java.io.*;

import java.net.*;

public class Server {

    public static void main(String[] args) throws IOException {

        ServerSocket serverSocket = new ServerSocket(12345);

        Socket clientSocket = serverSocket.accept();

        PrintWriter out = new PrintWriter(clientSocket.getOutputStream(), true);

        BufferedReader in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));

        String inputLine;

        while ((inputLine = in.readLine()) != null) {

            System.out.println("Received: " + inputLine);

            out.println("Server received: " + inputLine);

        }

    }

}

// Client.java

import java.io.*;

import java.net.*;

public class Client {

    public static void main(String[] args) throws IOException {

        Socket socket = new Socket("localhost", 12345);

        PrintWriter out = new PrintWriter(socket.getOutputStream(), true);

        BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));

        out.println("Hello from client");

        System.out.println("Server response: " + in.readLine());

    }

}

[JAVA] FILL COLOUR from MOUSE

import javax.swing.*;

import java.awt.*;

import java.awt.event.*;

public class ColorFromMouse extends JPanel {

    private Color selectedColor = Color.BLACK;

    private int regionWidth = 50; // Example region width

    public ColorFromMouse() {

        addMouseListener(new MouseAdapter() {

            @Override

            public void mouseClicked(MouseEvent e) {

                int x = e.getX();

                int region = x / regionWidth;

                // Example mapping of regions to colors

                switch (region) {

                    case 0: selectedColor = Color.RED; break;

                    case 1: selectedColor = Color.GREEN; break;

                    case 2: selectedColor = Color.BLUE; break;

                    default: selectedColor = Color.BLACK;

                }

                repaint(); // Trigger redraw with the new color

            }

        });

    }

    @Override

    protected void paintComponent(Graphics g) {

        super.paintComponent(g);

        g.setColor(selectedColor);

        g.fillRect(50, 50, 100, 100); // Example filled rectangle

    }

    public static void main(String[] args) {

        JFrame frame = new JFrame("Color From Mouse");

        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        frame.add(new ColorFromMouse());

        frame.setSize(300, 300);

        frame.setVisible(true);

    }

}

[JAVA] DOWNLOAD DATA FROM PROCESS

import java.io.BufferedOutputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.URL;

import javax.swing.JFrame;
import javax.swing.JProgressBar;
import javax.swing.SwingUtilities;
import javax.swing.WindowConstants;

public class Progressbar {

    public static void main(String[] args) {

        final JProgressBar jProgressBar = new JProgressBar();
        jProgressBar.setMaximum(100000);
        JFrame frame = new JFrame();
        frame.setContentPane(jProgressBar);
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        frame.setSize(300, 70);
        frame.setVisible(true);

        Runnable updatethread = new Runnable() {
            public void run() {
                try {

                    URL url = new URL("http://downloads.sourceforge.net/project/bitcoin/Bitcoin/blockchain/bitcoin_blockchain_170000.zip");
                    HttpURLConnection httpConnection = (HttpURLConnection) (url.openConnection());
                    long completeFileSize = httpConnection.getContentLength();

                    java.io.BufferedInputStream in = new java.io.BufferedInputStream(httpConnection.getInputStream());
                    java.io.FileOutputStream fos = new java.io.FileOutputStream(
                            "package.zip");
                    java.io.BufferedOutputStream bout = new BufferedOutputStream(
                            fos, 1024);
                    byte[] data = new byte[1024];
                    long downloadedFileSize = 0;
                    int x = 0;
                    while ((x = in.read(data, 0, 1024)) >= 0) {
                        downloadedFileSize += x;

                        // calculate progress
                        final int currentProgress = (int) ((((double)downloadedFileSize) / ((double)completeFileSize)) * 100000d);

                        // update progress bar
                        SwingUtilities.invokeLater(new Runnable() {

                            @Override
                            public void run() {
                                jProgressBar.setValue(currentProgress);
                            }
                        });

                        bout.write(data, 0, x);
                    }
                    bout.close();
                    in.close();
                } catch (FileNotFoundException e) {
                } catch (IOException e) {
                }
            }
        };
        new Thread(updatethread).

        start();
    }

}

[JAVA] PROCESS BAR

public class ProgressBar {

    public static void main(String[] args) throws InterruptedException {

        int total = 100;

        for (int i = 0; i <= total; i++) {

            String bar = generateProgressBar(i, total);

            System.out.print("\r" + bar + " " + i + "%");

            Thread.sleep(50);

        }

        System.out.println();

    }

    private static String generateProgressBar(int current, int total) {

        int progressBarLength = 30;

        int filledLength = (int) (progressBarLength * ((double) current / total));

        StringBuilder sb = new StringBuilder("[");

        for (int i = 0; i < progressBarLength; i++) {

            if (i < filledLength) {

                sb.append("=");

            } else {

                sb.append(" ");

            }

        }

        sb.append("]");

        return sb.toString();

    }

}