I have Written a Chat client and a Chat Server and evrything works really god. But I have the problem that if I starts the server or the client the Java Process in the Taskmanager needs 50% of my Cpu power and I have two cpu's with 2,66 ghz and I have no idea why.
I would be very happy if someone could help me with this Problem. And Sory for my bad english I am German.

This is the Code for the Client.

String input;
String pinput;
String output;
String poutput [];
String client;
String clientsplit [];
String clientsplit2 [];
String ipp [];
int ippnr;
int stopper;
int delete;
int i;
int clientNr;
import processing.net.*;
Client myClient;

void setup(){
 size(800, 250);
 background(0);
 textFont(createFont("SanSerif", 16));
 myClient = new Client(this, "5.134.169.118", 5204);
 input = "";
 output = "";
 delay(200);
 poutput = new String [500];
 ipp = new String [500];
 ippnr = 1;
 stopper = 1;
 poutput [1] = "";
 delete = 0;
 client = "";
 while(clientNr == 0){
   if (myClient.available() > 0){
     delay(200);
     clientNr = myClient.read();
     delay(200);
     myClient.clear();
   }
   for(int b = 0; b < clientNr; b++){
     client += ",";  
   }
   clientsplit = split(client, ',');
   client = "±";
   client += clientsplit.length;

 }

}

void draw(){
 background(0);
 information_holen();
 text(input, 30, 50);
 text(output, 30, 100);
 text(hour(), 30, 200);
 text(minute(), 70, 200);
 text(second(), 110, 200);

}

void keyPressed(){
 if( key == ENTER ){
   if(output.equals("exit") == true){
     shut_down();
   }
   output += client;
   myClient.write(output);
   output = "";
   delete = 0;
 }
 if( key == 'a' || key == 'A' || key == 'b' || key == 'B' || key == 'c' || key == 'C' || key == 'D' || key == 'd' || key == 'e' || key == 'E' || key == 'f' || key == 'F' || key == 'g' || key == 'G' || key == 'h' || key == 'H' || key == 'i' || key == 'I' || key == 'j' || key == 'J' || key == 'K' || key == 'k' || key == 'l' || key == 'L' || key == 'm' || key == 'M' || key == 'n' || key == 'N' || key == 'O' || key == 'o' || key == 'p' || key == 'P' || key == 'q' || key == 'Q' || key == 'r' || key == 'R' || key == 's' || key == 'S' || key == 't' || key == 'T' || key == 'u' || key == 'U' || key == 'V' || key == 'v' || key == 'w' || key == 'W' || key == 'x' || key == 'X' || key == 'y' || key == 'Y' || key == 'z' || key == 'Z' || key == 'ö' || key == 'Ö' || key == 'ä' || key == 'Ä' || key == 'ü' || key == 'Ü' || key == '1' || key == '2' || key == '3' || key == '4' || key == '5' || key == '6' || key == '7' || key == '8' || key == '9' || key == '0' || key == '^' || key == '°' || key == '!' || key == '"' || key == '§' || key == '$' || key == '%' || key == '&' || key == '/' || key == '(' || key == ')' || key == '=' || key == '?' || key == '´' || key == '²' || key == '³' || key == '{' || key == '[' || key == ']' || key == '}' || key == '\\' || key == '\'' || key == '´' || key == '+' || key == '*' || key == '~' || key == '#' || key == '\'' || key == '-' || key == '_' || key == '.' || key == ':' || key == ',' || key == ';' || key == 'µ' || key == '€' || key == '@' || key == '|' || key == '<' || key == '>' || key == ' ' || key == 'ß' || key == '`'){
   delete++;
   poutput [delete] = output;
   output += key;
 }
 if( key == BACKSPACE || key == DELETE){
   output = poutput [delete];
   if(delete >= 2){
     delete = delete - 1;
   }
 }
 if( key == CODED){
 if( keyCode == UP){
   if( ippnr >=2){
 ippnr = (ippnr-1);
 input = ipp [ippnr];
   }
 }
 if( keyCode == DOWN){
   if( ippnr <= (stopper-2)){
 ippnr++;
 input = ipp [ippnr];
   }
 }
 }

}



void information_holen(){
 if (myClient.available() != 0) {
   println("hallo");
   pinput = input;
   input = myClient.readString();
   myClient.clear();
   clientsplit2 = split(input, '±');
   input = clientsplit2[0];

   if(clientsplit2.length == 2){


     int l2 = client.length();
     char l22;
     String l2s = "";
     int b = 1;

     for(int g = 0; g < (l2-1); g++){

       l22 = client.charAt(b);
       println(client.charAt(b));
       l2s += l22;
       b++;

     }

     if(clientsplit2[1].equals(l2s) == true){
       input = pinput;
     }
   }
   ipp [stopper] = input;
   ippnr++;
   stopper++;
 }
}
void shut_down(){
 delay(1000);
 myClient.stop();
 exit();
}

Processing will attempt to run the draw() method at 60fps and the code in your draw method looks quite demanding. You can find out the framerate of your application with
Code:

println(framerate); 

inside the draw() method

You might try changing the framerate to something lower e.g. in setup()
Code:

frameRate(10);