Java sockets listener server program

/*================================================================= */
import java.net.*;
import java.io.*;
import java.util.*;

public class lslist01 extends Thread{
   protected Socket ls_socket;
   protected InputStream is;
   protected OutputStream os;

   public lslist01(Socket s){ls_socket = s;}

   public static void main(String[] args){

      try{
         ServerSocket ses = new ServerSocket(3457);
         while(true){
            lslist01 ddd = new lslist01(ses.accept());
            ddd.start();
            }
         }
      catch (IOException e){
         System.out.println("lslist01 ERROR accept("+e+")");
         System.exit(1);
         }
      }

   public void run(){
      System.out.println("Thread started " + new Date() );
      try{is = new DataInputStream (ls_socket.getInputStream());
          os = new DataOutputStream(ls_socket.getOutputStream());

         String bom  = ls_get_value_comma(is,"BOM");
         String sid  = ls_get_value_comma(is,"SID=");
         String uid  = ls_get_value_comma(is,"UID=");
         String cust = ls_get_value_comma(is,"CUST=");
         String func = ls_get_value_comma(is,"FUNC=");
         String fid  = ls_get_value_comma(is,"FID=");
         String fi_rec = ls_get_value_rest(is,"DATA=");
         if (!fi_rec.endsWith(",EOM")){
            fi_rec="ERROR Expected(,EOM)";
            System.out.println(fi_rec);
            try{os.write(fi_rec.getBytes());}
            catch (IOException e){System.out.println("lslist01t WNO("+e+")");}
            }
         ls_write_file(fi_rec.substring(0,fi_rec.length()-4)
                ,sid,uid,cust,func,fid);
         try{os.write("OK".getBytes());}
         catch (IOException e){System.out.println("lslist01t WNO("+e+")");}
         try{
            is.close();
            os.close();
            ls_socket.close();
            }
         catch (IOException e){System.out.println("ER close WNO("+e+")");}
         System.out.println("Thread ended");
         }
      catch (IOException e){
         ls_write_log("ERROR Unable to get streams "+e);
         return;
         }
//      try{Thread.currentThread().setPriority(MIN_PRIORITY);}
//      catch(Exception e){System.out.println("ER Prior "+e);}
//      try{Thread.currentThread().sleep(100);}
//      catch(Exception e){System.out.println("ER sleep "+e);}
      }
// =========================================================
   String ls_get_value_rest(InputStream i1,String sss){

      String line = ls_get_rest(i1);
      ls_write_log("Read ("+line+")");

      if (!line.startsWith(sss)){
         String mm="ERROR Expected("+sss+")";
         ls_write_log(mm);
         System.exit(16);
         }
       return line.substring(sss.length());
       }
// =========================================================
   String ls_get_rest(InputStream i2){
      byte b[] = new byte[500004];
      int ct =0;
      int pt =0;

      try{ct = i2.read(b,pt,b.length-pt);
         if (ct < 1) return null;
         pt=ct;
         }
      catch (IOException e){return null;}

      while(b[pt-1] != 0){
         try{ct = i2.read(b,pt,b.length-pt);
            if (ct < 1) return null;
            pt=pt+ct;
            System.out.print("("+ct+")");
            }
         catch (IOException e){return null;}
       }
      return (new String(b, 0, pt-1));
      }
// =========================================================
   String ls_get_value_comma(InputStream i3,String sss){

      byte bb[] = new byte[304];
      int cc =0;
      int pp =0;

      try{cc = i3.read(bb,pp,1);
         if (cc < 1) return null;
         pp=cc;
         }
      catch (IOException e){return null;}

      while(bb[pp-1] != ','){
         try{cc = i3.read(bb,pp,1);
            if (cc < 1) return null;
            pp=pp+cc;
            }
         catch (IOException e){return null;}
         }
      String lll = new String(bb,0, pp-1);

      ls_write_log("Read ("+lll+")");

      if (!lll.startsWith(sss)){
         String mmm="ERROR Expected("+sss+")";
         ls_write_log(mmm);
         System.exit(16);
         }
      return lll.substring(sss.length());
      }
// =========================================================
   void ls_write_log(String s){
      FileWriter          ls_log;
      PrintWriter         flog;

      try{ls_log = new FileWriter("LSLOG.TXT",true);
         flog    = new PrintWriter(ls_log);
         flog.println(s);

         if (!s.startsWith("Read (DATA=")) System.out.println(s);
         else   System.out.println("DATA length("+s.length()+")");

         flog.close();
         }
      catch (IOException e) {
         System.out.println("ERROR log file "+e);
         System.exit(1);}

      }
// =========================================================
   void ls_write_file(String              s_data
                     ,String              s_sid
                     ,String              s_uid
                     ,String              s_cust
                     ,String              s_func
                     ,String              s_fid
                     ){
      FileWriter          ls_file;
      PrintWriter         fo;
      boolean             open_type;

      open_type=s_func.equals("APPEND");

      try{ls_file = new FileWriter("d:/LAIS_DEVT/"
                                  +s_sid  +"_"
                                  +s_uid  +"_"
                                  +s_cust +"_"
                                  +s_fid
                                  ,open_type);

          fo      = new PrintWriter(ls_file);
         }
      catch (IOException e) {
         System.out.println("ERROR file write "+e);
         return;}

      fo.println(s_data);
      fo.close();
      }
// =========================================================
   }


/*================================================================= */