EJB-JAR - Marco Ronchetti
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Marco Ronchetti - [email protected] “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento J0 1 EJB: the details “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Marco Ronchetti - [email protected] Actors: Component Interface: Same role as in RMI Component Implementation: Same role as in RMI Home Interface: Implemented by the server, plays the role of a factory class for the component JNDI service: Plays the same role as the register in RMI J0 2 “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Marco Ronchetti - [email protected] The logical architecture App server (container) Machine NamingService Client HomeInterface Pool Trovami la Home interface Trova Dammi una istanza Metodo() J0 3 Directory Machine Client Machine Crea o recupera una istanza Istanza Marco Ronchetti - [email protected] “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento J0 4 Session Beans -) stateless -) stateful “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Marco Ronchetti - [email protected] Stateful Example J0 5 Stateless Example: Euro Converter “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Marco Ronchetti - [email protected] Stateful Example – suggested hierarchy J0 6 App server src client deploy src xHome.java x.java xBean.java xHome.class x.class xBean.class META-INF ejb-jar.xml client.java xHome.class x.class “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Stateless example – The Component (Remote) Interface Marco Ronchetti - [email protected] package statelessDemo; J0 7 import java.rmi.*; import javax.ejb.*; public interface Converter extends EJBObject { public double convert(int lire); } “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Marco Ronchetti - [email protected] Stateless example – The Home Interface J0 8 package statelessDemo; import java.rmi.*; import javax.ejb.*; public interface ConverterHome extends EJBHome { public Converter create() throws RemoteException, CreateException; } “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Marco Ronchetti - [email protected] Stateless example – The bean J0 9 package statelessDemo; import java.rmi.*; import javax.ejb.*; public class ConverterBean implements SessionBean { private SessionContext sessionContext; public void ejbCreate() {} public void ejbRemove() {} public void ejbActivate() {} public void ejbPassivate() {} public void setSessionContext(SessionContext sessionContext) { this.sessionContext = sessionContext; } private static double ratio=1936.27; public double convert(int lire) { return lire/ratio; } } “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Stateless example – The descriptor Marco Ronchetti - [email protected] <?xml version="1.0" encoding="UTF-8"?> J0 10 <!DOCTYPE ejb-jar PUBLIC "-//Sun Microsystems, Inc.//DTD Enterprise JavaBeans 1.1//EN" "http://java.sun.com/j2ee/dtds/ejb-jar_1_1.dtd"> <ejb-jar> <description>A simple demo of a stateless Bean</description> <display-name>An Euro Converter Bean</display-name> <enterprise-beans> <session> <description>A converter from Lire to Euro</description> <ejb-name>EuroConverter</ejb-name> <home>statelessDemo.ConverterHome</home> <remote>statelessDemo.Converter</remote> <ejb-class>statelessDemo.ConverterBean</ejb-class> <session-type>Stateless</session-type> <transaction-type>Container</transaction-type> </session> </enterprise-beans> “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Marco Ronchetti - [email protected] Stateless example – The descriptor J0 11 <assembly-descriptor> <container-transaction> <method> <ejb-name>EuroConverter</ejb-name> <method-name>*</method-name> </method> <trans-attribute>Required</trans-attribute> </container-transaction> </assembly-descriptor> <ejb-client-jar /> </ejb-jar> “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Marco Ronchetti - [email protected] structure of the jar file J0 12 In this directory, run jar cvf converter.jar * META-INF ejb-jar.xml statelessDemo this directory(ies) reflect the package hierarchy ConverterBean.class ConverterHome.class Converter.class Watch out! Packages often make life complex. (it’s easy to make mistakes) Try first without packages. “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Marco Ronchetti - [email protected] Compile the sources, generate jar file J0 13 cls javac move javac move javac move Converter.java Converter.class statelessDemo\ ConverterHome.java ConverterHome.class statelessDemo\ ConverterBean.java ConverterBean.class statelessDemo\ cd ..\deployment del *.jar del statelessDemo\*.class move ..\src\statelessDemo\* statelessDemo\ jar cvf Converter.jar * cd ..\src “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Marco Ronchetti - [email protected] Start the container J0 14 We assume you installed the j2ee sdk distribution provided by Sun in some %J2EE_HOME% directory. 1) Run %J2EE_HOME%/bin/j2ee.bat 2) Run %J2EE_HOME%/bin/deploytool.bat “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Start the container Marco Ronchetti - [email protected] FileNew Application… J0 15 FileAdd to Application… EJB-JAR (scegliere converter.jar) “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Marco Ronchetti - [email protected] View the properties J0 16 “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Start deployment Marco Ronchetti - [email protected] ToolsDeploy J0 17 Check this box Crea ConverterApp.ear “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Marco Ronchetti - [email protected] Start deployment J0 18 Choose a JNDI name “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Marco Ronchetti - [email protected] Start deployment J0 19 Crea ConverterAppClient.jar “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Marco Ronchetti - [email protected] Stateless example – The client J0 20 import javax.ejb.*; import javax.naming.InitialContext; public class ConverterClient { public ConverterClient() { } Get naming context public static void main(String[] args) { and object reference try { InitialContext ctx=new InitialContext(); JNDI name Object objref=ctx.lookup("L2EConverter"); statelessDemo.ConverterHome home = Cast to correct type (statelessDemo.ConverterHome) javax.rmi.PortableRemoteObject.narrow( objref,statelessDemo.ConverterHome.class); statelessDemo.Converter bean=home.create(); Get a bean instance from container “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Marco Ronchetti - [email protected] Stateless example – The client J0 21 int lire=100000; Do your business System.out.println(lire+" Lire = "+ bean.convert(lire)+" Euro"); } catch (javax.naming.NamingException ex) { System.out.println("NamingException: "+ex); } catch (ClassCastException cc) { System.out.println(" ClassCastException : "+cc);} catch (javax.ejb.CreateException ce) { System.out.println("CreateException: "+ce); } catch (java.rmi.RemoteException re) { System.out.println("RemoteException: "+re); } } } “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Marco Ronchetti - [email protected] Compile the client J0 22 Questa è la directory che contiene i sorgenti del client cls cd client\statelessDemo\ copy ..\server\deployment\statelessDemo\Converter.class . copy ..\server\deployment\statelessDemo\ConverterHome.class . cd .. javac ConverterClient.java “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Marco Ronchetti - [email protected] Stateless example – execution J0 23 java -classpath .;%J2EEHOME%\lib\j2ee.jar;…\ConverterAppClient.jar -Dorg.omg.CORBA.ORBInitialHost=localhost ConverterClient 100000 Lire = 51.64568990894865 Euro “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Marco Ronchetti - [email protected] Stateful Example J0 24 Stateful Example: Dollar Converter “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Marco Ronchetti - [email protected] Stateful example – The Component (Remote) Interface import java.rmi.*; import javax.ejb.*; public interface DollarConverter extends EJBObject { public double convertInEuro(double dollar) throws java.rmi.RemoteException; public double convertInDollar(double euro) throws java.rmi.RemoteException; public void setRate(double euro_dollar_ratio) throws java.rmi.RemoteException; } J0 25 “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Marco Ronchetti - [email protected] Stateful example – The Home Interface J0 26 import java.rmi.*; import javax.ejb.*; public interface DollarConverterHome extends EJBHome { public DollarConverter create() throws RemoteException, CreateException; } “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Marco Ronchetti - [email protected] Stateful example – The bean J0 27 import java.rmi.*; import javax.ejb.*; public class DollarConverterBean implements SessionBean { private SessionContext sessionContext; public void ejbCreate() {} public void ejbRemove() {} public void ejbActivate() {} public void ejbPassivate() {} public void setSessionContext(SessionContext sessionContext) { this.sessionContext = sessionContext; } “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Stateful example – The bean Marco Ronchetti - [email protected] private double euro_dollar_ratio=1; J0 28 public double convertInEuro(double dollar) throws java.rmi.RemoteException{ return dollar/euro_dollar_ratio; } public double convertInDollar(double euro) throws java.rmi.RemoteException{ return euro*euro_dollar_ratio; } public void setRate(double euro_dollar_ratio) throws java.rmi.RemoteException{ this.euro_dollar_ratio=euro_dollar_ratio; } } “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Stateful example – The descriptor Marco Ronchetti - [email protected] <?xml version="1.0" encoding="UTF-8"?> J0 29 <!DOCTYPE ejb-jar PUBLIC "-//Sun Microsystems, Inc.//DTD Enterprise JavaBeans 1.1//EN" "http://java.sun.com/j2ee/dtds/ejb-jar_1_1.dtd"> <ejb-jar> <description>A simple demo of a stateful Bean</description> <display-name>An Euro to Dollar Converter Bean</display-name> <enterprise-beans> <session> <description>A converter from Euro to Dollar</description> <ejb-name>DollarConverter</ejb-name> <home>DollarConverterHome</home> <remote>DollarConverter</remote> <ejb-class>DollarConverterBean</ejb-class> <session-type>Stateful</session-type> <transaction-type>Container</transaction-type> </session> </enterprise-beans> “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Marco Ronchetti - [email protected] Stateful example – The descriptor J0 30 <assembly-descriptor> <container-transaction> <method> <ejb-name>DollarConverter</ejb-name> <method-name>*</method-name> </method> <trans-attribute>Required</trans-attribute> </container-transaction> </assembly-descriptor> <ejb-client-jar /> </ejb-jar> “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Marco Ronchetti - [email protected] Stateful example – The client J0 31 import javax.ejb.*; import javax.naming.InitialContext; import javax.rmi.PortableRemoteObject; public class ConverterClient { public ConverterClient() {} public static void main(String[] args) { Object objref=null; DollarConverterHome home=null; Get naming context DollarConverter bean=null; and object reference try { InitialContext ctx=new InitialContext(); objref=ctx.lookup("EDC"); Cast to correct type JNDI name home =(DollarConverterHome)PortableRemoteObject.narrow( objref,DollarConverterHome.class); bean=home.create(); Get a bean instance from container “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Stateful example – The client Marco Ronchetti - [email protected] bean.setRate(0.978); double euro=1000; System.out.println(euro+" Euro = " +bean.convertInDollar(euro)+" Dollar"); double dollar=1000; System.out.println(dollar+" Dollar = " +bean.convertInEuro(dollar)+" Euro"); } catch (Exception e) { e.printStackTrace(); } } } J0 32 Do your business “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Marco Ronchetti - [email protected] Stateful example – execution J0 33 java -classpath .;%J2EEHOME%\lib\j2ee.jar;…\DollarConverterAppClient.jar -Dorg.omg.CORBA.ORBInitialHost=localhost ConverterClient 1000.0 Euro = 978.0 Dollar 1000.0 Dollar = 1022.4948875255624 Euro “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Marco Ronchetti - [email protected] Session Beans Lifecycle: client’s view J0 34 Start Does not exist Is not referenced Crash, Timeout Exists Is not referenced Client releases reference home.create() Client obtains handle Client releases reference Client invokes method (NoSuchObject Exception) Does not exist Is referenced object.remove(), home.remove(), Crash, timeout Exists Is referenced Client invokes method “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Marco Ronchetti - [email protected] Stateless session Beans Lifecycle J0 35 Client invokes method (NoSuchObject Exception) Does not exist Client invokes create() Container executes: 1) newInstance() 2) setSessionContext(sc) 3) ejbCreate() Client invokes remove() Container executes: ejbRemoved() Exists In the pool Client invokes method “Basi di Dati Web e Distribuite” – Laurea Specialistica in Informatica – Università di Trento Stateful session Beans Lifecycle Marco Ronchetti - [email protected] Client invokes create() Container executes: 1) newInstance() 2) setSessionContext(sc) 3) ejbCreate() J0 36 Does not exist Client invokes remove(), or timeout is reached Container executes: ejbRemoved() ejbPassivate() Client invokes non TX method Exists, method ready in the pool Client invokes TX method AfterBegin() Client invokes commit beforeCompletion() afterCompletion(true) Client invokes TX method Passive ejbActivate() Exists, method ready in TX Client invokes rollback afterCompletion(false)
