Sticking with Container managed concurrency. Changing the explicit lock type from WRITE to READ

MySingletonBean.java

import java.util.Date;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.ejb.ConcurrencyManagement;
import javax.ejb.ConcurrencyManagementType;
import javax.ejb.Lock;
import javax.ejb.LockType;
import javax.ejb.Singleton;
import javax.ejb.Startup;
 
@Singleton
@Startup
@ConcurrencyManagement(ConcurrencyManagementType.CONTAINER)
public class MySingletonBean {
 
    @Lock(LockType.READ)
    public void act() {
        System.out.println("Entered MySingletonBean/act() on " + new Date().toString() + " . Singleton instance " + this.hashCode() + " Thread : " + Thread.currentThread().getName());
        try {
            Thread.sleep(2000);
        } catch (InterruptedException ex) {
            Logger.getLogger(MyStatefulBean.class.getName()).log(Level.SEVERE, null, ex);
        }
 
        System.out.println("Exit MySingletonBean/act() on " + new Date().toString() + " . Singleton instance " + this.hashCode() + " Thread : " + Thread.currentThread().getName());
 
    }
}