Control an Arduino with Java

I am looking to turn an LED on and off with a Java program. I did the project in C# in roughly 5 minutes, but it seems to be somewhat more challenging in Java. I had the Arduino wait for a 1 or 0 to be written to the COM port and would change the LED based on that. The code I am using for the Arduino is as follows.

int LedPin = 13;
char data;

void setup()
{
    Serial.begin(9600);
    pinMode( LedPin , OUTPUT );
}

void loop()
{
    data = Serial.read();
    if (Serial.available() > 0)
    {
        if(data == '1' )
        {
            digitalWrite(LedPin,HIGH);
        }
        else if(data == '0' )
        {
            digitalWrite(LedPin,LOW);
        }
    }
    else
        if (Serial.available()<0)
        {
            digitalWrite(LedPin,HIGH);
            delay(500);
            digitalWrite(LedPin,LOW);
            delay(500);
        }
}

How would I do this with a Java application?