Problem with xbee-api written in Java

Hi Heverybody,
I’ve a problem when try to send AT command to XBee PRO Serie 1.

My code is this:

try{
String SerialPortID = “/dev/ttyAMA0”; System.setProperty(“gnu.io.rxtx.SerialPorts”, SerialPortID);
XBee xbee = new XBee(new XBeeConfiguration().withStartupChecks(false));
xbee.open(“/dev/ttyAMA0”, 9600);
XBeeResponse response = xbee.sendSynchronous(new AtCommand(“AP”, 2));
}catch (Exception e)
{
log.info("exception: " + e.getMessage());
}

I am not able to receive response.
Log is this:

Sending request to XBee: apiId=AT_COMMAND (0x08),frameId=1,command=AP,value=0x02
computed checksum is base10=99,base16=0x63,base2=01100011
Packet: 0x7e 0x00 0x05 0x08 0x01 0x41 0x50 0x02 0x63
pre-escape packet size is 9, post-escape packet size is 9
Sending packet to XBee 0x7e,0x00,0x05,0x08,0x01,0x41,0x50,0x02,0x63
exception: null
Packet parser thread was interrupted.
This occurs when close() is called
InputStreamThread is exiting

Can Anyone help me?
Thanks a lot!
Kind regards!!