this really isnt Java, but it shares similar syntax 


					
		
		
int ledPin = 9;
int val;

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

void loop()
{
  if( Serial.available() )
  {
    val = Serial.read();
    analogWrite( ledPin, val );
  }
}