Reader Writer java with a limited number of readers

Question

I am a Master Student and I have to write code for the classic reader writer problem with a limited number of readers at a time. I have to write in Java using multithreading. But without semaphore. Only using monitors and the keyword synchronized. I have already get some code that working. But I have to change it to limit to 3 readers at a time. And I dont know how...

My code is below There is no priority to readers or writer but I don't want any staravation too. But at first step I just want to play with sleeping to let my writer access the journal. Thanks (I have to do this in the next hours)

class Journal {
public static final int PAUSE = 5;
private int nbReaders ;
private boolean Reading,Writing ; 
public Journal () {nbReaders = 0 ;Reading = false ;Writing = false ;}

public synchronized int demandeReading () {
    while (Writing == true)           
           try{ wait(); } catch(InterruptedException e) {}

    if (++nbReaders == 1)
        Reading = true ;
    return nbReaders ;
}
public synchronized int finReading () {
    if (--nbReaders == 0)
        Reading = false ;
    notifyAll(); 
    return nbReaders ;
}
public synchronized void demandeWriting () {
    while ( Reading == true || Writing == true )
        try{ wait () ; }catch(InterruptedException e) {}
    Writing = true ;
}
public synchronized void finWriting() { Writing = false ; notifyAll () ; }

public static void travaille(){
    int tpsPause = (int) ( PAUSE * Math.random () ) ;
    try {  Thread.sleep ( tpsPause * 100 ) ; }  catch(InterruptedException e) {}
}
}
class Reader extends Thread {
private int nbReadings = 5;
private Journal journal ;
public Reader ( Journal j ) {        journal = j ;    }
public void run () {
    int nbReaders ;
    while ( nbReadings > 0 ) {
        nbReaders = journal.demandeReading () ;
        System.out.println( Thread.currentThread().getName() +  " lit ... " +nbReaders + " Reading en cours" ) ;
        Journal.travaille () ;
        nbReaders = journal.finReading () ;
        nbReadings -- ;
        System.out.println( Thread.currentThread().getName() + " ne lit plus ..." +nbReaders + " Readings en cours" ) ;
    }
}
}
class Writer extends Thread {
private int nbWritings = 2;
private Journal journal;
public Writer(Journal j) {journal = j;}

public void run() {
    while (nbWritings > 0) {
        journal.demandeWriting();
        System.out.println(Thread.currentThread().getName() + " ecrit ...");
        Journal.travaille();
        journal.finWriting();
        nbWritings--;
    }
}
}
class ReadersWriterCours {
static Journal journal = new Journal ( ) ; 
public static void main ( String [] args ) {
    Writer tabW [] = new Writer [ 5 ] ;
    Reader tabR [] = new Reader [ 5 ] ;
    for (int i = 0 ; i < 5 ; i ++ ) {
        tabW[ i ] = new Writer ( journal ) ;
        tabR[ i ] = new Reader ( journal ) ;
        tabW [ i ].start () ;
        tabR [ i ].start () ;
    }
}
}