How to share an array among members of a package

Question

I need to share the value of h among members of a package. The values for Byte h are generated by button events in the other program in the package [ sample below ]. That is transformed into ASCII code, h, which ideally should go through SerialWriter and out the serial port.
private void menuButtonActionPerformed(java.awt.event.ActionEvent evt) {                                          
        Charset asciiCharset = Charset.forName("US-ASCII");
     CharsetDecoder decoder = asciiCharset.newDecoder();
     byte h[] = {33, 48, 48, 66, 77, 69, 78, 85, 13}; //brings menu up
     ByteBuffer asciiBytes = ByteBuffer.wrap(h);
     CharBuffer hChars = null;
     try {
          hChars = decoder.decode(asciiBytes);
     } catch (CharacterCodingException e) {
          System.err.println("Error decoding");
          System.exit(-1);
          System.out.println(hChars);
    }                                          Predictably, when trying to run the main member of the package -- listed below -- h is not transferred, hence not instantiated, and I get a Null Pointer Exception. How can I transfer the value of h so that is seen by the "connect" method below? thanks
package desktopapplication1;
import org.jdesktop.application.Application;
import org.jdesktop.application.SingleFrameApplication;
import java.nio.*;
import java.nio.channels.*;
import java.nio.ByteBuffer.*;
import java.nio.charset.*;
import java.lang.String.*;
import java.io.*;
import java.util.*;
import gnu.io.*;
import java.nio.*;
import java.nio.channels.*;
import java.nio.ByteBuffer.*;
import java.nio.charset.*;
import gnu.io.CommPort;
import gnu.io.CommPortIdentifier;
import gnu.io.SerialPort;
* The main class of the application.
public class DesktopApplication1 extends SingleFrameApplication {
        String defaultPort = "/dev/ttyS0";
     * At startup create and show the main frame of the application.
    @Override protected void startup() {
        show(new DesktopApplication1View(this));
     * This method is to initialize the specified window by injecting resources.
     * Windows shown in our application come fully initialized from the GUI
     * builder, so this additional configuration is not needed.
    @Override protected void configureWindow(java.awt.Window root) {
     * A convenient static getter for the application instance.
     * @return the instance of DesktopApplication1
    public static DesktopApplication1 getApplication() {
        return Application.getInstance(DesktopApplication1.class);
    public void connect ( String portName ) throws Exception {
     String defaultPort = "/dev/ttyS0";
        Byte h;
        CommPortIdentifier portIdentifier = CommPortIdentifier.getPortIdentifier(portName);
        if ( portIdentifier.isCurrentlyOwned() )
            System.out.println("Error: Port is currently in use");
        else
            CommPort commPort = portIdentifier.open(this.getClass().getName(),200);
            if ( commPort instanceof SerialPort )
                SerialPort serialPort = (SerialPort) commPort;
                serialPort.setSerialPortParams(4800,SerialPort.DATABITS_8,SerialPort.STOPBITS_1,SerialPort.PARITY_NONE);
                InputStream in = serialPort.getInputStream();
                OutputStream out = serialPort.getOutputStream();
                (new Thread(new SerialReader(in))).start();
                (new Thread(new SerialWriter(out))).start();
          out.write(h);
          out.flush();
            else
                System.out.println("Error: Only serial ports are addressable by this application.");
     public static class SerialReader implements Runnable
        InputStream in;
        public SerialReader ( InputStream in )
            this.in = in;
        public void run ()
            byte[] buffer = new byte[1024];
            int len = -1;
            try
                while ( ( len = this.in.read(buffer)) > -1 )
                    System.out.print(new String(buffer,0,len));
            catch ( IOException e )
                e.printStackTrace();
    public static class SerialWriter implements Runnable {
        OutputStream out;
        SerialPort     serialPort;
        public SerialWriter ( OutputStream out )
            this.out = out;
        public void run ()
            try
                int c = 0;
                while ( ( c = System.in.read()) > -1 )
                    this.out.write(c);
            catch ( IOException e )
                e.printStackTrace();
         try {
                 Thread.sleep(2000);  // Be sure data is xferred before closing
              } catch (Exception e) {}
              serialPort.close();
              System.exit(1);
     * Main method launching the application.
    public static void main(String[] args) {
        launch(DesktopApplication1.class, args);
      try
            (new DesktopApplication1()).connect("/dev/ttyS0");
        catch ( Exception e )
            e.printStackTrace();
}

Answer 1

Make h global, and make an getH method in that class. And then make an instance of the class containing the getH() method, and call it from the connect() method.
private byte h[] = {33, 48, 48, 66, 77, 69, 78, 85, 13};
public byte[] getH() {
     return h;
private void menuButtonActionPerformed(java.awt.event.ActionEvent evt) {                                          
        Charset asciiCharset = Charset.forName("US-ASCII");
     CharsetDecoder decoder = asciiCharset.newDecoder();
      //brings menu up
     ByteBuffer asciiBytes = ByteBuffer.wrap(h);
     CharBuffer hChars = null;
     try {
          hChars = decoder.decode(asciiBytes);
     } catch (CharacterCodingException e) {
          System.err.println("Error decoding");
          System.exit(-1);
          System.out.println(hChars);
    }