LogThread.java

   1 import java.util.*;
   2 import java.io.*;
   3
   4 /**
   5  * LogThread &ndash;
   6  */
   7 public class LogThread extends Thread {
   8
   9     // local fields
  10     private final Node node;
  11     private final String logFileName;
  12     private boolean keepLogging = true;
  13     private final int SLEEPTIME = 50;
  14     private FileWriter file = null;
  15     private BufferedWriter out = null;
  16     private long startTime;
  17
  18     /**
  19      * Constructs a new object of the LogThread class.
  20      * This class writes out lap times of packets that
  21      * circle the ring of UDP/TCP nodes.
  22      */
  23     public LogThread(Node node) {
  24         this.node = node;
  25         this.logFileName = "laptimes.log";
  26         try {
  27             this.file = new FileWriter(logFileName);
  28             this.out = new BufferedWriter(file);
  29         }
  30         catch (IOException e) {
  31             System.out.println(e);
  32         }
  33     }
  34
  35     public void end() {
  36         this.keepLogging = false;
  37     }
  38
  39     /**
  40      * Sets the startTime fields of this Node.
  41      * The startTime field is used by the logging
  42      * Node's LogThread to calculate average lap times.
  43      *
  44      * @param long The startTime of the Node.
  45      */
  46     public void setStartTime(long startTime) {
  47         this.startTime = startTime;
  48     }
  49
  50     public void log() {
  51         try {
  52             out.write("Average time for a packet to circle the ring: " +
  53                       (System.nanoTime() -
  54                        startTime)/(double)node.getSentPackets() +
  55                       " ms\n");
  56         }
  57         catch (IOException e) {
  58             System.out.println(e);
  59         }
  60     }
  61
  62     public void run() {
  63         while (keepLogging) {
  64             try {
  65                 out.write("Average time for a packet to circle the ring: " +
  66 (System.nanoTime() - startTime)/(double)node.getSentPackets() + " ms\n");
  67             }
  68             catch (IOException e) {
  69                 System.out.println(e);
  70             }
  71             try {
  72                 // sleep for a bit before writing
  73                 // the next average lap time (so not
  74                 // to fill the log file too much)
  75                 this.sleep(SLEEPTIME);
  76             }
  77             catch (InterruptedException e) {
  78                 System.out.println(e);
  79             }
  80         }
  81         try {
  82             out.close();
  83         }
  84         catch (IOException e) {
  85             System.out.println(e);
  86         }
  87     }
  88 }