java - My Five Philosophers are all eating at the same time, why? -

this class philosopher

public class filosofo implements runnable{      public string nome = null;     public static bacchetta[] bacchette = new bacchetta[5]; //this whould resource     public bacchetta bacchettadx; //right resource     public bacchetta bacchettasx; //left resource     public static int indice = 0;      public int x[] = {};     public int y[] = {};      public jbutton filosofo = new jbutton();  //button associated philos.      public filosofo(string nome, int sx, int dx){         indice++;         for(int = 0; i<5; i++){             bacchette[i] = new bacchetta();         }         this.nome = nome;         this.bacchettasx = bacchette[sx];         this.bacchettadx = bacchette[dx];      }      @override     public synchronized void  run() {         random r = new random();         int random;          while(true){             random = (int) r.nextint(100);             pensa(5000);             random = (int) r.nextint(100);             mangia(5000);          }     }       //the method mangia means phil. eating, has both chopsticks     public synchronized void mangia(int tempo){          do{         if(!bacchettasx.isoccupied){             bacchettasx.isoccupied = true;             bacchettasx.setchioccupa(this.nome);         }         if(!bacchettadx.isoccupied){             bacchettadx.isoccupied = true;             bacchettadx.setchioccupa(this.nome);         }         }while(bacchettasx.getchioccupa().compareto(this.nome) != 0 && bacchettadx.getchioccupa().compareto(this.nome) != 0);          this.filosofo.setbackground(color.green);         try {             sleep(1000);         } catch (interruptedexception ex) {             logger.getlogger(filosofo.class.getname()).log(level.severe, null, ex);         }         system.out.println("\t\t\t" + this.nome + " sta mangiando");         int = 0;         /*for(long = 0; i<1000000000; i++){             a++;         }*/            bacchettasx.isoccupied = false;         bacchettadx.isoccupied = false;         bacchettasx.setchioccupa(null);         bacchettadx.setchioccupa(null);          system.out.println("\t\t\t\t\t\t" + this.nome + " ha finito di mangiare");         this.filosofo.setbackground(color.blue);      }     //the method pensa means philosopher no longer eating     public void pensa(int tempo){         system.out.println(this.nome + " sta ponderando");         try {             sleep(tempo);         } catch (interruptedexception ex) {             logger.getlogger(filosofo.class.getname()).log(level.severe, null, ex);         }      }  } 

it's supposed print out in terminal what's doing what, problem should eat 1 one or in best scenario maximum 2 philosophers. however, eat together. synchronization not doing it's supposed doing. problem?

your code block

for(int = 0; i<5; i++){     bacchette[i] = new bacchetta(); } 

initializes static array each time create new philosopher, end different bachettasx , bachettadx. initialize once in static code block outside of constructor.

static {   for(int = 0; i<5; i++){     bacchette[i] = new bacchetta();   } }