Stateful EJB objects and stateless EJB objects

One, define stateful beans and stateless beans

Stateful Bean:

@Stateful @remotepublic class Statefulejbbean implements statefulejb{private int state; @Overridepublic void Compute (int i) {state=state+i;} @Overridepublic int GetResult () {return state;}}

Stateless Bean:

@Stateless @remotepublic class Statelessejbbean implements STATELESSEJB {private int state; @Overridepublic void Compute ( int i) {state = state + i;} @Overridepublic int GetResult () {return state;}}

two, client test and results

1, test the stateful EJB object:

public class Statefulejbclient {public static void main (string[] args) throws Exception {InitialContext context=new Initia Lcontext ();//First session STATEFULEJB ejb1= (STATEFULEJB) context.lookup ("Statefulejbbean/remote"); System.out.println (Ejb1.getresult ()); Ejb1.compute (1); System.out.println (Ejb1.getresult ()); Ejb1.compute (1); System.out.println (Ejb1.getresult ()); Ejb1.compute (1); System.out.println (Ejb1.getresult ()); Ejb1.compute (1); System.out.println (Ejb1.getresult ()); Ejb1.compute (1); System.out.println (Ejb1.getresult ()); System.out.println ("First session end---------");//second session STATEFULEJB ejb2= (STATEFULEJB) context.lookup ("statefulejbbean/ Remote "); System.out.println (Ejb2.getresult ()); Ejb2.compute (1); System.out.println (Ejb2.getresult ()); Ejb2.compute (1); System.out.println (Ejb2.getresult ()); Ejb2.compute (1); System.out.println (Ejb2.getresult ()); Ejb2.compute (1); System.out.println (Ejb2.getresult ()); Ejb2.compute (1); System.out.println (Ejb2.getresult ()); System.out.println ("Second session end---------");}}

Results:

2, test the stateless EJB object:

public class Statelessejbclient {public static void main (string[] args) throws Namingexception {InitialContext Context=ne W InitialContext ();//First session STATELESSEJB ejb1= (STATELESSEJB) context.lookup ("Statelessejbbean/remote"); System.out.println (Ejb1.getresult ()); Ejb1.compute (1); System.out.println (Ejb1.getresult ()); Ejb1.compute (1); System.out.println (Ejb1.getresult ()); Ejb1.compute (1); System.out.println (Ejb1.getresult ()); Ejb1.compute (1); System.out.println (Ejb1.getresult ()); Ejb1.compute (1); System.out.println (Ejb1.getresult ()); System.out.println ("First session end---------");//second session STATELESSEJB ejb2= (STATELESSEJB) context.lookup ("statelessejbbean/ Remote "); System.out.println (Ejb2.getresult ()); Ejb2.compute (1); System.out.println (Ejb2.getresult ()); Ejb2.compute (1); System.out.println (Ejb2.getresult ()); Ejb2.compute (1); System.out.println (Ejb2.getresult ()); Ejb2.compute (1); System.out.println (Ejb2.getresult ()); Ejb2.compute (1); System.out.println (Ejb2.getresult ()); System.out.println ("The second session ends---------");//Determine if each object found is the sameSystem.out.println (EJB1==EJB2);//false}} 

Results:

Third, the results contrast

Through multiple executions, it is found that for stateful EJB objects, each object obtained through a lookup is a new object, whereas for stateless EJB objects, each Find object has a singleton effect, and executes the method of testing the stateless EJB object multiple times. You will find that the server looks like it is always working on an object.

Stateful EJB objects and stateless EJB objects