When I run the following code, the applet viewer appears and the serial connection works but when I create this thread in another class and start it applet viewer does not appear but the the serial connection works
package parkingStatus;
import gnu.io.CommPortIdentifier;
import gnu.io.SerialPort;
import gnu.io.SerialPortEvent;
import java.applet.Applet;
import java.awt.Canvas;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Image;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.util.Enumeration;
public class lifeDisplay extends Applet implements Runnable {
SerialPort serialPort;
private static final String PORT_NAMES[] = {"COM20"};
private BufferedReader input;
private OutputStream output = null;
private static final int TIME_OUT = 2000;
private static final int DATA_RATE = 9600;
String ParkingStatus = "";
Image backGround;
public lifeDisplay (){}
public void run() {
repaint();
try {
Thread.sleep(1500);
} catch (InterruptedException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
while (true){
try {
Thread.sleep(1500);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//String ParkingStatus = "";
repaint();
ParkingStatus = initialize("2", "2");//to serial // in the uc 0 = enter, 1 = exit, 2 = life display
System.out.println(ParkingStatus);
System.out.println ("========================");
for (int i = 0; i < 5000; i++){}
}
}
public String initialize(String num1, String num2) {
CommPortIdentifier portId = null;
Enumeration portEnum = CommPortIdentifier.getPortIdentifiers();
while (portEnum.hasMoreElements()) {
CommPortIdentifier currPortId = (CommPortIdentifier) portEnum.nextElement();
for (String portName : PORT_NAMES) {
if (currPortId.getName().equals(portName)) {
portId = currPortId;
break;
}
}
}
if (portId == null) {
System.out.println("Could not find COM port.");
return null;
}
String Status = "";
try {
serialPort = (SerialPort) portId.open(this.getClass().getName(),TIME_OUT);
serialPort.setSerialPortParams(DATA_RATE, SerialPort.DATABITS_8, SerialPort.STOPBITS_1, SerialPort.PARITY_NONE);
input = new BufferedReader(new InputStreamReader(serialPort.getInputStream()));
output = serialPort.getOutputStream();
Thread.sleep(1000);
output.write(num1.getBytes());
Thread.sleep(1000);
System.out.println("Life display of the parking lots");
String convert = "";
int lots;
while (true){
lots = input.read() - '0';
if (lots == 9)
break;
convert = Integer.toString(lots);
Status += convert;
}
serialPort.removeEventListener();
serialPort.close();
//serialPort.addEventListener(this);
//serialPort.notifyOnDataAvailable(true);
} catch (Exception e) {
System.err.println(e.toString());
}
return Status;
}
public synchronized void close() {
if (serialPort != null) {
serialPort.removeEventListener();
serialPort.close();
}
}
public synchronized void serialEvent(SerialPortEvent oEvent) {
if (oEvent.getEventType() == SerialPortEvent.DATA_AVAILABLE) {
try {
String inputLine=input.readLine();
System.out.println(inputLine);
} catch (Exception e) {
System.err.println(e.toString());
}
}
}
///////////////////////applet/////////////////////////////
Thread t;
public void init() {
setSize(480, 600);
System.out.println("in init");
t = new Thread(this);
t.start();
}
/*public void start() {
System.out.println("in start");
Thread t;
t = new Thread(this);
t.start();
}*/
public void paint(Graphics g) {
System.out.println("in paint");
super.paint(g);
backGround = getImage(getCodeBase(), "park.png");
g.drawImage( backGround, 0, 0, (int)getBounds().getWidth(), (int)getBounds().getHeight(), this);
String first = "1111100000";
if (first.charAt(4) == '0')
g.setColor(Color.green); //GREEN
else
g.setColor(Color.red); //red
g.fillRect(345,56,63,50);
g.setColor(Color.black);
g.setFont(new Font("Times", Font.BOLD, 20));
g.drawString("5",370 , 90);
if (first.charAt(3) == '0')
g.setColor(Color.green); //GREEN
else
g.setColor(Color.red); //red
g.fillRect(345,108,63,50);
g.setColor(Color.black);
g.setFont(new Font("Times", Font.BOLD, 20));
g.drawString("4",370 , 140);
if (first.charAt(2) == '0')
g.setColor(Color.green); //GREEN
else
g.setColor(Color.red); //red
g.fillRect(345,160,63,47);
g.setColor(Color.black);
g.setFont(new Font("Times", Font.BOLD, 20));
g.drawString("3",370 , 190);
if (first.charAt(1) == '0')
g.setColor(Color.green); //GREEN
else
g.setColor(Color.red); //red
g.fillRect(345,377,63,50);
g.setColor(Color.black);
g.setFont(new Font("Times", Font.BOLD, 20));
g.drawString("2",370 , 410);
if (first.charAt(0) == '0')
g.setColor(Color.green); //GREEN
else
g.setColor(Color.red); //red
g.fillRect(345,429,63,50);
g.setColor(Color.black);
g.setFont(new Font("Times", Font.BOLD, 20));
g.drawString("1",370 , 460);
if (first.charAt(8) == '0')
g.setColor(Color.green); //GREEN
else
g.setColor(Color.red); //red
g.fillRect(72,440,63,47);
g.setColor(Color.black);
g.setFont(new Font("Times", Font.BOLD, 20));
g.drawString("9",95 , 471);
if (first.charAt(9) == '0')
g.setColor(Color.green); //GREEN
else
g.setColor(Color.red); //red
g.fillRect(72,489,63,42);
g.setColor(Color.black);
g.setFont(new Font("Times", Font.BOLD, 20));
g.drawString("10",88 , 520);
if (first.charAt(7) == '0')
g.setColor(Color.green); //GREEN
else
g.setColor(Color.red); //red
g.fillRect(72,244,63,49);
g.setColor(Color.black);
g.setFont(new Font("Times", Font.BOLD, 20));
g.drawString("8",95 , 276);
if (first.charAt(6) == '0')
g.setColor(Color.green); //GREEN
else
g.setColor(Color.red); //red
g.fillRect(72,196,63,45);
g.setColor(Color.black);
g.setFont(new Font("Times", Font.BOLD, 20));
g.drawString("7",95 , 225);
if (first.charAt(5) == '0')
g.setColor(Color.green); //GREEN
else
g.setColor(Color.red); //red
g.fillRect(72,144,63,49);
g.setColor(Color.black);
g.setFont(new Font("Times", Font.BOLD, 20));
g.drawString("6",95 , 177);
}
}
The way that I am creating and starting this thread in another class is as following
lifeDisplay display = new lifeDisplay ();
Thread parkingLots = new Thread (display);
parkingLots.start();
I am trying to use multithreading
what is the problem?
