读者写者问题之写者优先（java）

读者写者问题之写者优先（java）(1)

/*
 * Created on 2005-1-9
 *
 * TODO To change the template for this generated file go to
 * Window - Preferences - Java - Code Style - Code Templates
 */

/**
 * @author Michelangelo
 *
 * TODO To change the template for this generated type comment go to
 * Window - Preferences - Java - Code Style - Code Templates
 */
public class Database {

 /**
  *
  */
 private static final int  NAP_TIME=5;
 private int readerCount;
 private int writerCount;
 private boolean dbReading;
 private boolean dbWriting;
 public Database() {
  super();
  readerCount=0;
  writerCount=0;
  dbReading=false;
  dbWriting=false;
  // TODO Auto-generated constrUCtor stub
 }
   
 public static void napping(){
  int sleepTime=(int)(NAP_TIME * Math.random());
  try{
   Thread.sleep(sleepTime*1000);
  }
  catch(Exception e){
   e.printStackTrace();
  }
 }
 public synchronized int startRead(){
  while(writerCount>0){
   try{
    System.out.println("reader is waiting");
    wait();
   }
   catch(Exception e){
    System.out.println(e.toString());
    e.printStackTrace();
   }
  }
  ++readerCount;
  if(readerCount==1){
  dbReading=true;