Java/EJB3/Timer

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EJB Tutorial from JBoss: timer

   <source lang="java">

File: ExampleTimer.java /* 

* JBoss, Home of Professional Open Source.
* Copyright 2006, Red Hat Middleware LLC, and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/

package org.jboss.tutorial.timer.bean;

public interface ExampleTimer { 

  void scheduleTimer(long milliseconds);

}

File: ExampleTimerBean.java /* 

* JBoss, Home of Professional Open Source.
* Copyright 2006, Red Hat Middleware LLC, and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/

package org.jboss.tutorial.timer.bean; import java.util.Date; import javax.annotation.Resource; import javax.ejb.Remote; import javax.ejb.SessionContext; import javax.ejb.Stateless; import javax.ejb.Timeout; import javax.ejb.Timer; @Stateless @Remote(ExampleTimer.class) public class ExampleTimerBean implements ExampleTimer { 

  private @Resource SessionContext ctx;
  public void scheduleTimer(long milliseconds)
  {
     ctx.getTimerService().createTimer(new Date(new Date().getTime() + milliseconds), "Hello World");
  }
  @Timeout
  public void timeoutHandler(Timer timer)
  {
     System.out.println("---------------------");
     System.out.println("* Received Timer event: " + timer.getInfo());
     System.out.println("---------------------");
     timer.cancel();
  }

}

File: Client.java /* 

* JBoss, Home of Professional Open Source.
* Copyright 2006, Red Hat Middleware LLC, and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/

package org.jboss.tutorial.timer.client; import org.jboss.tutorial.timer.bean.ExampleTimer; import javax.naming.InitialContext;

public class Client { 

  public static void main(String[] args) throws Exception
  {
     InitialContext ctx = new InitialContext();
     ExampleTimer timer = (ExampleTimer) ctx.lookup("ExampleTimerBean/remote");
     timer.scheduleTimer(5000);
  }

} 


      </source>



Timer Service And Timeout Method

   <source lang="java">

File: EmployeeBean.java import javax.annotation.Resource; import javax.ejb.SessionContext; import javax.ejb.Stateless; import javax.ejb.Timeout; import javax.ejb.Timer; import javax.ejb.TimerService; @Stateless public class EmployeeBean implements EmployeeServiceLocal, EmployeeServiceRemote { 

 @Resource
 private SessionContext ctx;
 public EmployeeBean() {
 }
 public Long addBid(String userId, Long itemId, Double bidPrice) {
   System.out.println("Bid for " + itemId + " received with price" + bidPrice);
   TimerService timerService = ctx.getTimerService();
   Timer timer = timerService.createTimer(123, 86400000, null);
   return 0L;
 }
 @Timeout
 public void handleTimeout(Timer timer) {
   System.out.println(" handleTimeout called.");
   // Put here the code for cleaning the database of day limit orders that have
   // not been executed.
 }

}

File: EmployeeServiceLocal.java

import javax.ejb.Local; import javax.jws.WebParam; @Local public interface EmployeeServiceLocal { 

 public Long addBid(String userId,Long itemId,Double bidPrice);

}

File: EmployeeServiceRemote.java import javax.ejb.Remote;

@Remote public interface EmployeeServiceRemote { 

 public Long addBid(String userId,Long itemId,Double bidPrice);

}

File: Employee.java

import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.Id; import javax.persistence.PostRemove; @Entity public class Employee implements java.io.Serializable { 

 private int id;
 private String firstName;
 private String lastName;
 @Id
 @GeneratedValue
 public int getId() {
   return id;
 }

 @PostRemove
 public void postRemove()
 {
    System.out.println("@PostRemove");
 }
 public void setId(int id) {
   this.id = id;
 }
 public String getFirstName() {
   return firstName;
 }
 public void setFirstName(String first) {
   this.firstName = first;
 }
 public String getLastName() {
   return lastName;
 }
 public void setLastName(String last) {
   this.lastName = last;
 }

}

File: Main.java import javax.ejb.EJB; import javax.naming.InitialContext;

public class Main { 

 public static void main(String[] a) throws Exception {
   EmployeeServiceRemote service = null;
   // Context compEnv = (Context) new InitialContext().lookup("java:comp/env");
   // service = (HelloService)new
   // InitialContext().lookup("java:comp/env/ejb/HelloService");
   service = (EmployeeServiceRemote) new InitialContext().lookup("EmployeeBean/remote");

   service.addBid("userId",1L,0.1);
   

 }

}

File: jndi.properties java.naming.factory.initial=org.jnp.interfaces.NamingContextFactory java.naming.factory.url.pkgs=org.jboss.naming:org.jnp.interfaces java.naming.provider.url=localhost:1099 


      </source>



Use Timer Service

   <source lang="java">

File: Employee.java import javax.persistence.Entity; import javax.persistence.EntityListeners; import javax.persistence.GeneratedValue; import javax.persistence.Id; import javax.persistence.PostRemove; @Entity public class Employee implements java.io.Serializable { 

 private int id;
 private String firstName;
 private String lastName;
 @Id
 @GeneratedValue
 public int getId() {
   return id;
 }

 @PostRemove
 public void postRemove()
 {
    System.out.println("@PostRemove");
 }
 public void setId(int id) {
   this.id = id;
 }
 public String getFirstName() {
   return firstName;
 }
 public void setFirstName(String first) {
   this.firstName = first;
 }
 public String getLastName() {
   return lastName;
 }
 public void setLastName(String last) {
   this.lastName = last;
 }

}

File: EmployeeService.java import java.util.Date; import javax.annotation.Resource; import javax.ejb.Stateless; import javax.ejb.Timeout; @Stateless public class EmployeeService implements EmployeeServiceLocal, EmployeeServiceRemote { 

 @Resource
 javax.ejb.TimerService timerService;
 public EmployeeService() {
 }
 public void doAction() {
   String item = "item 1";
   for (Object obj : timerService.getTimers()) {
     javax.ejb.Timer timer = (javax.ejb.Timer) obj;
     String scheduled = (String) timer.getInfo();
     if (scheduled.equals(item)) {
       timer.cancel();
     }
   }
   timerService.createTimer(new Date(System.currentTimeMillis() + 1000), item);
 }

 @Timeout
 public void maintenance(javax.ejb.Timer timer) {
   System.out.println("TIMEOUT METHOD CALLED");
   String scheduled = (String) timer.getInfo();
   System.out.println(scheduled);
 }

}

File: EmployeeServiceLocal.java

import java.util.Collection; import javax.ejb.Local; @Local public interface EmployeeServiceLocal { 

   public void doAction();

}

File: EmployeeServiceRemote.java


import java.util.Collection; import javax.ejb.Remote; @Remote public interface EmployeeServiceRemote{ 

 public void doAction();

}

File: jndi.properties java.naming.factory.initial=org.jnp.interfaces.NamingContextFactory java.naming.factory.url.pkgs=org.jboss.naming:org.jnp.interfaces java.naming.provider.url=localhost:1099

File: Main.java import java.util.Date; import javax.naming.InitialContext;

public class Main { 

 public static void main(String[] a) throws Exception {
   EmployeeServiceRemote service = null;
   // Context compEnv = (Context) new InitialContext().lookup("java:comp/env");
   // service = (HelloService)new InitialContext().lookup("java:comp/env/ejb/HelloService");
   service = (EmployeeServiceRemote) new InitialContext().lookup("EmployeeService/remote");
   
   



   service.doAction();
 }

} 


      </source>
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