java.lang.NumberFormatException
this my code
import java.io.*;
import java.net.*;
import java.*;
class UDPServer
{
publicstaticvoid main(String args[])throws Exception
{
UDPServer t =new UDPServer();
DatagramSocket serverSocket =new DatagramSocket(5551);
while(true)
{
DatagramPacket receivePacket =new DatagramPacket(receiveData, receiveData.length);
serverSocket.receive(receivePacket);
String sentence =new String(receivePacket.getData());
for (i=0;i<sentence.length();i=i+2){
char letter1= sentence.charAt(i);
String u = h.valueOf(letter1);
time = (Integer.parseInt(u));
char letter2= sentence.charAt(i+1)
char letter3= sentence.charAt(i+2);
u2 = h.valueOf(letter2);
//try{
time2 = (Integer.parseInt(u2));
// }catch(NumberFormatException ex){System.err.println("error2");}
time = 1000*(10*time+time2);
i++;
if (letter3==('F')){
System.out.println ("this is F");
//p5.write(240);
try{
Thread.sleep(time);
}
catch (InterruptedException ie){}
//p5.write(0); // To stop after the movement
}
//
elseif (letter3==('B'))
{
System.out.println ("This is B");
//p5.write(160);
try
{
Thread.sleep(time);
}
catch (InterruptedException ie){}
//p5.write(0); // To stop after the movement
}
//--
elseif (letter3==('L'))
{
// p5.write(192);
System.out.println ("This is L");
try
{
Thread.sleep(time);
}
catch (InterruptedException ie){}
//p5.write(0); // To stop after the movement
}
//
elseif (letter3==('R'))
{
// p5.write(48);
System.out.println ("This is R");
try
{
Thread.sleep(time);
}
catch (InterruptedException ie){}
//p5.write(0); // To stop after the movement
}
//-
elseif (letter3==('S'))
{
// p5.write(0);
System.out.println ("This is S");
try
{
Thread.sleep(0);
}
catch (InterruptedException ie){}
}
}
}
}
}
when I send the input "12F" the following client program
import java.io.*;
import java.net.*;
class UDPClient{
publicstaticvoid main(String args[])throws Exception
{
boolean send =true;
BufferedReader inFromUser =new BufferedReader(new InputStreamReader(System.in));
DatagramSocket clientSocket =new DatagramSocket();
InetAddress IPAddress = InetAddress.getByName("coe-347B-Fac");
byte[] sendData =newbyte[1024];
byte[] receiveData =newbyte[1024];
while(send){
System.out.println (" Please Enter String You Want to Send : " );
String sentence = inFromUser.readLine();
sendData = sentence.getBytes();
DatagramPacket sendPacket =
new DatagramPacket(sendData, sendData.length, IPAddress, 5551);
clientSocket.send(sendPacket);
}
clientSocket.close();
}
}
after execution this input it exit and do not take onther input. it give me this output
******************************
this is F
Exception in thread "main" java.lang.NumberFormatException: For input string: "
"
at java.lang.NumberFormatException.forInputString(NumberFormatException.
java:48)
at java.lang.Integer.parseInt(Integer.java:447)
at java.lang.Integer.parseInt(Integer.java:497)
at UDPServer.main(UDPServer.java:51)
***********************************************
So what is the problem?>
