TwoThreads.java

package ro.demostene.tests;

public class TwoThreads{

    public static void main(String[] args) {
        DeadLock dl = new DeadLock();
        Thread tr = new ThreadRead(dl, "TH1");
        Thread tw = new ThreadWrite(dl, "TH2");
        tr.start();
        tw.start();

    }
}
class ThreadRead extends Thread {
    DeadLock dl;
    ThreadRead(DeadLock dl, String name){
        super(name);
        this.dl=dl;
    }
    @Override
    public void run() {
        dl.lenght();
    }
}
class ThreadWrite extends Thread {
    DeadLock dl;
    ThreadWrite(DeadLock dl, String name){
        super(name);
        this.dl=dl;
    }
    @Override
    public void run() {
        dl.print();
    }
}

DeadLock.java

package ro.demostene.tests;

public class DeadLock {

    private StringBuffer strBuf1 = new StringBuffer();
    private StringBuffer strBuf2= new StringBuffer();

    public void lenght() {
        synchronized (strBuf1) {
            try {
                Thread.sleep(200);
                } catch (InterruptedException e) {
                e.printStackTrace();
            }
            synchronized (strBuf2) {
                System.out.println(strBuf1.length() + strBuf2.length());
            }
        }
    }

    public void print() {
        synchronized (strBuf2) {
            try {
                Thread.sleep(200);
                } catch (InterruptedException e) {
                e.printStackTrace();
            }
            synchronized (strBuf1) {
                System.out.println(strBuf1.toString() + strBuf2);
            }
        }
    }

System.out.println(Boolean.valueOf("demostene.ro"));
System.out.println(Boolean.valueOf("tRuE"));
System.out.println(Boolean.valueOf(null));

Raspuns:
Afiseaza false, true, false.
Explicatie:
Metoda valueOf are urmatoarea semnatura:

public static Boolean valueOf (String s)

Valoarea returnata este true daca argumentul nu este null si este egal, ignorand literele mari, cu “true”. Altfel returneaza false.

“Programming as an intellectual activity is the only art form that allows you to create interactive art. You can create projects that other people can play with, and you can talk to them indirectly. No other art form is quite this interactive. Movies flow to the audience in one direction. Paintings do not move. Code goes both ways.”

(Mai mult  aici)

 setProjection(Projections.sum(("amount * direction")))

auntci va fi aruncata o exceptie

org.hibernate.QueryException: could not resolve property: amount * direction ....". 

Solutia este urmatoarea:

Criteria criteria = currentSession().createCriteria(Transaction.class)
.add(Restrictions.ne("user.userId", userId))
.add(Restrictions.ge("transactionDate", dateCreated))
.setProjection(Projections.sqlProjection
("sum(cast(amount as signed)* direction) as amntDir",
new String[] {"amntDir"} ,
new Type[] {Hibernate.DOUBLE})
);

     end;
    end;
   end;
  end;
 end.

Programarea in 1990
     }
    }
   }
  }
 }

Programarea in 2000

     </div>
    </div>
   </div>
  </div>
 </div>

Avem date :  

int a=5, b=10;

Metoda 1

a=a+b; b=a-b; a=a-b;

Metoda 2

a = a ^ b; b = a ^ b; a = a ^ b;