Send data to arduino from PC in java over Serial (RXTXlib)

Projects Interfacing w/ Software on the Computer
12

use Tools + Auto Format.
The Serial.write() statement goes AFTER the }.

Definitely serial.write should be after the " } " it's a typo when editing the post. and thank you for the auto format tip I like it :wink:
I think there are a problem with the unsigned and signed bytes.
Now I tried with a very simple arduino program :

char byteRead;
int led = 13 ;
void setup() {
  Serial.begin(9600);
  pinMode(led, OUTPUT);     

}

void loop() {
  if (Serial.available()) {

    byteRead = Serial.read();
    Serial.write(byteRead);
  }

}

and a simpler java code

public static void main(String[] args) throws IOException, PortInUseException, NoSuchPortException, InterruptedException{
        SerialPortHandler serial = new SerialPortHandler();
        serial.connect("COM2");
        Thread.sleep(3000);
		OutputStream serialOut = serial.getSerialOutputStream();
        InputStream serialIn=serial.getSerialInputStream();
        String s = "1";
        byte[] b=new byte[] {0,0,0,0} ;
        serialOut.write(s.getBytes());
        serialOut.flush();
        Thread.sleep(1000);
        serialIn.read(b);
        System.out.print("Reçu ");
    	for (int j = 0; j < b.length; j++) {
			System.out.print(b[j]+ " ");
		}
    	System.out.println();
    	b[0]=0 ;
    	b[1]=0;
    	b[2]=0;
    	b[3]=0;
    	
        serial.disconnect();
    }
}

I keep receiving the same result -32 0 0 0 0 with any caracter that I send.
All my arduino codes work fine on the serial monitor.

serialIn.read(b);

serialIn.read(b) reads data from the SerialInputStream and put them in b which is a byte array.
I tried so many codes until now and I also having the same output : -32 which is 224 in decimal.
Can anyone help me check if my data types are correct ?