<<Interface>> EntityBean (from ejb) EJBHome. <<Interface>> CountHome. (from entity) create() findbyprimarykey() <<Interface>> EJBObject.

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Count BMP Entity EJB Count BMP Entity EJB EJBHome (from ejb) EntityBean (from ejb) CountClient main() CountHome create() findbyprimarykey() EJBObject (from ejb) Count getcurrentsum() setcurrentsum()

1 Count BMP Entity EJB Count BMP Entity EJB EJBHome (from ejb) EntityBean (from ejb) CountClient main() CountHome create() findbyprimarykey() EJBObject (from ejb) Count getcurrentsum() setcurrentsum() increment() CountBmpEJBBean countername : String currentsum : int CountBmpEJB() ejbactivate() ejbpassivate() setentitycontext() unsetentitycontext() ejbload() ejbstore() ejbremove() ejbcreate() ejbpostcreate() ejbfindbyprimarykey() beanexists() Copyright , Dan Harkey. All rights reserved. Page 1-2

2 Count BMP Entity EJB Interaction Diagram Client : CountClient JNDI : InitialContext EJB Home : CountHome EJB Object : Count EJB : CountBmpEJBBean Database 1: new() 2: lookup(jndihomename) 3: new() 4: create(countername, initialsum) 5: new() 6: setsessioncontext(sessioncontext) 7: ejbcreate(countername, initialsum) 10: new() 8: Search 9: insert 11: ejbpostcreate(countername,initialsum) 12: increment() 13: ejbload() 14: select 15: increment() 16: ejbstore() 17: update Count BMP Entity: EJB Class (1 of 12) // CountBMPBean.java import java.util.properties; import java.sql.*; import javax.naming.*; import javax.ejb.*; import javax.sql.*; public class CountBmpEJBBean implements EntityBean public String countername; public int currentsum; private EntityContext entitycontext; private Connection connection = null; private DataSource ds = null ; private String countdb = "java:comp/env/jdbc/countdb"; Copyright , Dan Harkey. All rights reserved. Page 3-4

3 Count BMP Entity: EJB Class (2 of 12) // no arg contructor public CountBmpEJBBean() countername = null; currentsum = 0; public void ejbactivate() countername = (String)entityContext.getPrimaryKey(); public void ejbpassivate() Count BMP Entity: EJB Class (3 of 12) public void setentitycontext(entitycontext ctx) entitycontext = ctx; try javax.naming.context context = (javax.naming.context) new javax.naming.initialcontext(); ds = (javax.sql.datasource)context.lookup(countdb); catch (Exception e) System.out.println("Error looking up " + countdb + " " + e.getmessage()); throw new EJBException("Error looking up " + countdb + " " + e.getmessage()); public void unsetentitycontext() entitycontext = null; ds = null; Copyright , Dan Harkey. All rights reserved. Page 5-6

4 Count BMP Entity: EJB Class (4 of 12) public void ejbload() try connection = ds.getconnection(); "SELECT \"currentsum\" FROM \"CountEJBTable\" + " WHERE \"countername\" =?"); ps.setstring(1, countername); ResultSet rs = ps.executequery(); rs.next(); currentsum = rs.getint(1); ps.close(); catch (Exception e) System.out.println("Error loading state for " throw new EJBException("Error loading state for " finally try connection.close(); catch (Exception e) throw new EJBException(e); Count BMP Entity: EJB Class (5 of 12) public void ejbstore() try connection = ds.getconnection(); "UPDATE \"CountEJBTable\" SET \"currentsum\" =? " + "WHERE \"countername\" =?"); ps.setint(1, currentsum); ps.setstring(2, countername); ps.executeupdate(); ps.close(); catch (Exception e) System.out.println("Error storing state for " throw new EJBException("Error storing state for " finally try connection.close(); catch (Exception e) throw new EJBException(e); Copyright , Dan Harkey. All rights reserved. Page 7-8

5 Count BMP Entity: EJB Class (6 of 12) public void ejbremove ( ) throws RemoveException try connection = ds.getconnection(); "DELETE FROM \"CountEJBTable\" WHERE \"countername\" =?"); ps.setstring(1, countername); int resultcount = ps.executeupdate(); ps.close(); catch (Exception e) System.out.println("Error removing bean " throw new EJBException("Error removing bean " finally try connection.close(); catch (Exception e) throw new EJBException(e); Count BMP Entity: EJB Class (7 of 12) public String ejbcreate( String name, int initialsum) throws CreateException // Set the initial data on the instance countername = name; currentsum = initialsum; try connection = ds.getconnection(); if (beanexists(countername)) throw new DuplicateKeyException( "Bean " + countername + " already exists."); Copyright , Dan Harkey. All rights reserved. Page 9-10

6 Count BMP Entity: EJB Class (8 of 12) "INSERT INTO \"CountEJBTable\" (\"countername\", " + " \"currentsum\") values (?,?)"); ps.setstring(1, countername); ps.setint(2, currentsum); ps.executeupdate(); ps.close(); catch (Exception e) System.out.println("Error creating " throw new EJBException("Error creating " finally try connection.close(); catch (Exception e) throw new EJBException(e); return countername; Count BMP Entity: EJB Class (9 of 12) public void ejbpostcreate(string name, int initialsum) throws CreateException public String ejbfindbyprimarykey(string primarykey ) throws FinderException countername = primarykey; try connection = ds.getconnection(); if (beanexists(countername)) return primarykey; throw new FinderException("Error finding " + countername); catch (Exception e) Copyright , Dan Harkey. All rights reserved. Page 11-12

7 Count BMP Entity: EJB Class (10 of 12) catch (Exception e) System.out.println("Error finding " throw new EJBException("Error finding " finally try connection.close(); catch (Exception e) throw new EJBException(e); Count BMP Entity: EJB Class (11 of 12) // private methods private boolean beanexists(string key) throws SQLException "SELECT \"currentsum\" FROM \"CountEJBTable\" " + " WHERE \"countername\" =?"); ps.setstring(1, countername); ResultSet rs = ps.executequery(); if (!rs.next() ) ps.close(); return false; else ps.close(); return true; Copyright , Dan Harkey. All rights reserved. Page 13-14

8 Count BMP Entity: EJB Class (12 of 12) // Business Methods // get sum public int getcurrentsum() return currentsum; // set sum public void setcurrentsum(int val) currentsum = val; public int increment ( ) currentsum++; return currentsum; Count BMP Entity: Deployment Descriptor (1 of 4) <?xml version="1.0" encoding="utf-8"?> <!DOCTYPE ejb-jar PUBLIC '-//Sun Microsystems, Inc.//DTD Enterprise JavaBeans 1.1//EN' ' <ejb-jar> <description>no description</description> <display-name>ejb1</display-name> <enterprise-beans> <entity> <description>no description</description> <display-name>countbmp</display-name> <home>count.entity.counthome</home> <remote>count.entity.count</remote> <ejb-class>count.entity.countbmpejb</ejb-class> <persistence-type>bean</persistence-type> <prim-key-class>java.lang.string</prim-key-class> <reentrant>false</reentrant> <resource-ref> <description>a description for ResourceRefName</description> <res-ref-name>jdbc/countdb</res-ref-name> <res-type>javax.sql.datasource</res-type> <res-auth>container</res-auth> </resource-ref> </entity> Copyright , Dan Harkey. All rights reserved. Page 15-16

9 Count BMP Entity: Deployment Descriptor (2 of 4) </enterprise-beans> <assembly-descriptor> <method-intf>home</method-intf> <method-name>remove</method-name> <method-params> <method-param>java.lang.object</method-param> </method-params> </method> <method-intf>remote</method-intf> <method-name>getcurrentsum</method-name> <method-params /> </method> <method-intf>remote</method-intf> <method-name>setcurrentsum</method-name> Count BMP Entity: Deployment Descriptor (3 of 4) <method-params> <method-param>int</method-param> </method-params> </method> <method-intf>remote</method-intf> <method-name>remove</method-name> <method-params /> </method> <method-intf>remote</method-intf> <method-name>increment</method-name> <method-params /> </method> Copyright , Dan Harkey. All rights reserved. Page 17-18

10 Count BMP Entity: Deployment Descriptor (4 of 4) <method-intf>home</method-intf> <method-name>remove</method-name> <method-params> <method-param>javax.ejb.handle</method-param> </method-params> </method> <method-intf>home</method-intf> <method-name>create</method-name> <method-params> <method-param>java.lang.string</method-param> <method-param>int</method-param> </method-params> </method> </assembly-descriptor> </ejb-jar> Count BMP Entity Application Deployment Descriptor <?xml version="1.0" encoding="utf-8"?> <!DOCTYPE application PUBLIC '-//Sun Microsystems, Inc.//DTD J2EE Application 1.2//EN' ' <application> <display-name>countbmp</display-name> <description>application description</description> <module> <ejb>ejb-jar52913.jar</ejb> </module> </application> Copyright , Dan Harkey. All rights reserved. Page 19-20

11 Count BMP Entity J2EE Specific Deployment Descriptor <?xml version="1.0" encoding="utf-8"?> <j2ee-ri-specific-information> <server-name></server-name> <rolemapping /> <enterprise-beans> <ejb> <jndi-name>mycountbmp</jndi-name> <resource-ref> <res-ref-name>jdbc/countdb</res-ref-name> <jndi-name>jdbc/cloudscape</jndi-name> </resource-ref> <cmp> <table-create-sql></table-create-sql> <table-remove-sql></table-remove-sql> <create-table-deploy>true</create-table-deploy> <delete-table-undeploy>true</delete-table-undeploy> </cmp> </ejb> </enterprise-beans> </j2ee-ri-specific-information> Count BMP Entity: An Alternative Implementation that Reuses the CMP Entity Class EJBHome (from ejb) EntityBean (from ejb) CountHome create() findbyprimarykey() CountCmpEJB currentsum : int countername : String CMP Entity CountClient main() EJBObject (from ejb) Count getcurrentsum() setcurrentsum() increment() CountBmp1EJB CountBmp1EJB() ejbactivate() ejbpassivate() setentitycontext() unsetentitycontext() ejbload() ejbstore() ejbremove() ejbcreate() ejbpostcreate() ejbfindbyprimarykey() beanexists() Copyright , Dan Harkey. All rights reserved. Page 21-22

12 Count BMP Entity EJB as CMP Extension: Code Snippet (1 of 3) public class CountBmp1EJB extends CountCmpEJB private Connection connection = null; private DataSource ds = null ; private String countdb = "java:comp/env/jdbc/countdb";... Count BMP Entity EJB as CMP Extension: Code Snippet (2 of 3) public void ejbload() try connection = ds.getconnection(); "SELECT \"currentsum\" FROM \"CountBeanTable\" " + "WHERE \"countername\" =?"); ps.setstring(1, countername); ResultSet rs = ps.executequery(); rs.next(); currentsum = rs.getint(1); ps.close(); super.ejbload(); catch (Exception e) throw new EJBException("Error loading state for " finally try connection.close(); catch (Exception e) throw new EJBException(e); Copyright , Dan Harkey. All rights reserved. Page 23-24

13 Count BMP Entity EJB as CMP Extension: Code Snippet (3 of 3) public void ejbstore() try super.ejbstore(); connection = ds.getconnection(); "UPDATE \"CountBeanTable\" SET \"currentsum\" =?" + " WHERE \"countername\" =?"); ps.setint(1, currentsum); ps.setstring(2, countername); ps.executeupdate(); ps.close(); catch (Exception e) throw new EJBException("Error storing state for " finally try connection.close(); catch (Exception e) throw new EJBException(e); Copyright , Dan Harkey. All rights reserved. Page 25-26

Enterprise JavaBeans. Session EJBs

Enterprise JavaBeans. Session EJBs Enterprise JavaBeans Dan Harkey Client/Server Computing Program Director San Jose State University dharkey@email.sjsu.edu www.corbajava.engr.sjsu.edu Session EJBs Implement business logic that runs on