Problem interfacing with Java

I followed the Interfacing with Java tutorial Arduino Playground - Java, but ran into some problems on testing. Currently my Arduino program works fine when I try with manual inputs.

Segment of C Code on Arduino:

...

char line[20];
int line_pos = 0;
char action[10];
unsigned long duration;
boolean data_ready = false;

void setup()
{
  Serial.begin(9600);
  delay(1500);
  Serial.println("Ready!");
}

void loop()
{
    char state;
    if(Serial.available()>0)
    {
        delay(20);
        state = Serial.read();
        
        if(state == '!')
        {
          data_ready = true;
          line[line_pos] = state;
          line_pos = 0;
        }
        else
        {
          line[line_pos] = state;
          line_pos = line_pos + 1;
        }
        
        if(data_ready == true)
        {
            split(line);
            Serial.print(action);
            delay(20);
            Serial.print("!");
            delay(20);
            Serial.print(duration);
            delay(20);
            Serial.print("!");
            
            Serial.println("Data has been split");

            if(strcmp(action, "left") == 0)
            {
                Serial.println("Received left");
            }
            else if(strcmp(action, "right") == 0)
            {
                Serial.println("Received rightt");
            }
            else if(strcmp(action, "straight") == 0)
            {
                Serial.println("Received straight");
            }
            
            memset(line, 0, 20);
            data_ready = false;
        }
    }
}  

void split(char input[20])
{
    char *param, *ptr;
    
    param = strtok_r(input, "#", &ptr);
    strncpy(action, param, sizeof(action));
    action[sizeof(action)-1] = '\0';
    
    param = strtok_r(NULL, "!", &ptr);
    duration = strtoul(param, &param, 10);
}

...

When I input "left#123!" I get the following output in the COM which is what I expected. No problems here:

Ready!
left!123!Data has been split
Received left

Now here's my Java code:

import java.io.InputStream;
import java.io.OutputStream;
import gnu.io.CommPortIdentifier; 
import gnu.io.SerialPort;
import gnu.io.SerialPortEvent; 
import gnu.io.SerialPortEventListener; 
import java.util.Enumeration;

public class SerialTest implements SerialPortEventListener {
	SerialPort serialPort;
        /** The port we're normally going to use. */
	private static final String PORT_NAMES[] = { 
			"/dev/tty.usbserial-A9007UX1", // Mac OS X
			"/dev/ttyUSB0", // Linux
			"COM3", // Windows
			};
	/** Buffered input stream from the port */
	private InputStream input;
	/** The output stream to the port */
	private OutputStream output;
	/** Milliseconds to block while waiting for port open */
	private static final int TIME_OUT = 2000;
	/** Default bits per second for COM port. */
	private static final int DATA_RATE = 9600;

	private String display = "";
	
	public void initialize() {
		CommPortIdentifier portId = null;
		Enumeration portEnum = CommPortIdentifier.getPortIdentifiers();

		// iterate through, looking for the port
		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;
		}

		try {
			// open serial port, and use class name for the appName.
			serialPort = (SerialPort) portId.open(this.getClass().getName(),
					TIME_OUT);

			// set port parameters
			serialPort.setSerialPortParams(DATA_RATE,
					SerialPort.DATABITS_8,
					SerialPort.STOPBITS_1,
					SerialPort.PARITY_NONE);

			// open the streams
			input = serialPort.getInputStream();
			output = serialPort.getOutputStream();

			// add event listeners
			serialPort.addEventListener(this);
			serialPort.notifyOnDataAvailable(true);
		} catch (Exception e) {
			System.err.println(e.toString());
		}
	}

	/**
	 * This should be called when you stop using the port.
	 * This will prevent port locking on platforms like Linux.
	 */
	public synchronized void close() {
		if (serialPort != null) {
			serialPort.removeEventListener();
			serialPort.close();
		}
	}

	/**
	 * Handle an event on the serial port. Read the data and print it.
	 */
	public synchronized void serialEvent(SerialPortEvent oEvent) {
		if (oEvent.getEventType() == SerialPortEvent.DATA_AVAILABLE) {
			try {
				int available = input.available();
				byte chunk[] = new byte[available];
				input.read(chunk, 0, available);

				System.out.println(display);
				
				display += (new String(chunk)).trim();
				if(display.contains("!"))
				{
					display = display.substring(0, display.indexOf("!"));
					
					if(display.equals("Ready"))
					{
						String reply = "left#123!";
						byte reply_byte[] = new byte[reply.length()];
						reply_byte = reply.getBytes("UTF-16LE");
						output.write(reply_byte);
					}
					
					display = "";
				}
				
			} catch (Exception e) {
				System.err.println(e.toString());
			}
		}
		// Ignore all the other eventTypes, but you should consider the other ones.
	}

	public static void main(String[] args) throws Exception {
		SerialTest main = new SerialTest();
		main.initialize();
		System.out.println("Started");
	}
}

Here's what Java code prints out in console:

Rea
l
0
Data
Datahas
Datahasbee
Datahasbeen sp
Datahasbeen split

The serial input doesn't seem to be read fluidly, but in repeating parts. Can anybody help me diagnose the problem and give me a solution?