Static field should be accessed in a static way

Question

I am getting the following warning message: static field should be accessed in a static way. What does it mean?
thanks.

Answer 1

Below is the code. I'm getting the "warning" in the Waiter class on the statement: this.r = r;
public class Threads {
     public Threads() {
          super();
          System.out.println("==> Threads.constructor");
     public static void main(String args[]){
          System.out.println("==> main");
          Threads t = new Threads();
          Rendezvous r = new Rendezvous();
          Waiter w1 = new Waiter(r);w1.start();
          Waiter w2 = new Waiter(r);w2.start();
          Waiter w3 = new Waiter(r);w3.start();
          new Waiter(r).start();
          new Waiter(r).start();
          new Waiter(r).start();
          new Waiter(r).start();
          Waiter w4 = new Waiter(r);w4.start();
          Waiter w5 = new Waiter(r);w5.start();
          Waiter w6 = new Waiter(r);w6.start();
          System.out.println("==> main done");
     static class Rendezvous{
          private static int ri = -1;
          public synchronized void doWait(Waiter w){  
               System.out.println("==> doWait - sNum="+w.serialNum+",tries="+w.numTries+" name="+Thread.currentThread().getName());
               while (w.numTries < 5){
                    notifyAll();
                    w.numTries++;
                    System.out.println("==> before wait()- sNum="+w.serialNum+",tries="+w.numTries);
                    try {wait();} catch (InterruptedException e){}
                    System.out.println("==> after wait() - sNum="+w.serialNum+",tries="+w.numTries);
               } //end-while
          } //end-doWait()
          public void doNotify(){
               notify();
     } //end-Rendezvous-class
     static class Waiter extends Thread{
          private static int counter = 1000;
          private static Rendezvous r;
          public int serialNum;
          public int numTries = 0;
          public Waiter(Rendezvous r){
               this.r = r;
               serialNum = counter++;
               System.out.println("==> Waiter.counstructor:sNnum="+serialNum+" name="+Thread.currentThread().getName());
          public void run(){
               System.out.println("==> Waiter.run():" + serialNum+" name="+Thread.currentThread().getName());
               r.doWait(this);