Ejb? ?? ? ????? ?? ????? ?? Enterprise Java Bean ?? ??? ?????. ?? ??????? ???? ???? ?????. ??? ??? ???? ? ?????? ????? ?? ??, ??? ??, ??? ???? ??, ???? ?? ? ? ???? ?????. EJB? ??? ????? ?? ??? ???? Java ????? ??? ??? ???? ?????? ????????? ?????-?? ??? ?????. ?? ejb? ? ????? ????? ?? ???? Java Bean ??? ?? ? ???????? ??? ??? ?????? ??? ??? ????.

?? ????? ?? ?? ??

? ??, ????? ??, ????? ??? ?

??:

Java ??????? EJB ??? ?? ??? ??? ????.

import javax.ejb.*;
import java packages;
class classname
{
Main? method()
{
-----Some programming logics----
}
}

? ??? ejb ???? ???? ??????? ???? ?? ?? ?????.

Java Works?? EJB? ??? ??????

• EJB?? Java Bean ???? ejb ??? ?? ? ? ??? ??? ???? ?? ???? ??? ?? ??? ?? ??? ???? ? ??? ???. EJB? ??? ?? ??? ??? JNDI? ?? ??? ?????. (java ?? ?? ???? ?????). jndi ??? ??? ? ??? ejb, ??? ?? ? JMS ??? ???? ?? ???? ??? ???? ? ???? ???? ??????. ???? jndi ???? ?? ?? ??? ??? ??? ?? ??? ??? ??? ?? ?? ????? ???.
• EJB? Java Bean?? ?????. ???? ? ?? ??? ????. 1. Session Bean? 2.Message Driven BeansSession Bean???. ?? ?? ?????-?? ?? ??? ?????. ?? ????? ??? ?? ????? ??? ?? ??????? ???? ??? ??????. ?? ??? ?? ?? ??? Bean? ???? ? ???? ???? ?????? ?????. Session Bean? ? ?? ??? ????. 1. Stateless, 2.Stateful ? 3.Singleton.Stateless Bean ?????? ??? ??? Bean? ??? ? ? ?????? ?? ??? ???? ??? ? ?????? ??? ??? ?? ????. ?? ?? ??. ? ?? ??? ?? ?????? ?????.
• ?? ?? Bean? ??? ????? ??? ? ????. ?????? ??? ???? ??? ??? ???? ?????. Singelton Bean?? ?? ??????? ?? ???? ?? ?? ???? ??? ????. ? Bean? ?? ?? ?????? ??? ??????. ? Bean? ?????? ????? ???? Stateful Bean? ?? ? ?? ??? ? ?? ??? ????.
• Message Driven Beans(MDB)? JMS ??? ???? ????? ???? ??? ???? ???? Bean ????? ??? ??? ???? ?? JMS ???? ?????. ???? ?? ????? ?? onMessage() ???? ???? MDB ?? ???? ????? ??? ??? jndi ???? ???? ???? ??? ? ????. onMessage() ???? ???? MDB? ?? ????? ?? ????? ???. ??? ????? ????? ???? ??? ???? ?? ??????.

Java?? EJB? ???? ?

??? ??? ?????.

?? #1

?????:

package JPAEJB;
import java.util.List;
import javax.ejb.Remote;
@Remote
public interface CustomerInterface {
void addBooks(String name);
List getBooks();
}

??:

import java.util.ArrayList;
import java.util.List;
import javax.ejb.Stateless;
import JPAEJB.CustomerInterface;
@Stateless
public class CustomerClass implements CustomerInterface {
List<String>books;
public CustomerClass() {
books = new ArrayList<String>();
}
public void addBooks(String name) {
books.add(name);
}
public List<String> getBooks() {
return books;
}
}

?? ?????:

import JPAEJB.CustomerInterface;
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.List;
import java.util.Properties;
import javax.naming.InitialContext;
import javax.naming.NamingException;
public class CustomerInterfaceImplem {
BufferedReader brConsoleReader = null;
Properties p;
InitialContext c;
{
p = new Properties();
try {
p.load(new FileInputStream("jndi.properties"));
} catch (IOException ex) {
ex.printStackTrace();
}
try {
c = new InitialContext(p);
} catch (NamingException ex) {
ex.printStackTrace();
}
brConsoleReader =
new BufferedReader(new InputStreamReader(System.in));
}
public static void main(String[] args) {
CustomerInterfaceImplem cust = new CustomerInterfaceImplem();
cust.testStatelessEjb();
}
private void show() {
System.out.println("Welcome to my domain");
System.out.print("Options \n1. Add the Books\n2. Exit \nEnter your Choice: ");
}
private void StatelessEjb() {
try {
intc = 1;
CustomerInterface cust =
(CustomerInterface)ctx.lookup("CustomerInterface/remote");
while (c != 2) {
String books;
show();
String str = brConsoleReader.readLine();
c = Integer.parseInt(str);
if (c == 1) {
books = brConsoleReader.readLine();
cust.addBooks(books);
}elseif (c == 2) {
break;
}
}
List<String>books1 = cust.getBooks();
System.out.println(books1.size());
for (inti = 0; i<books1.size(); ++i) {
System.out.println((i+1)+". " + books1.get(i));
}
CustomerInterface cust1 =
(CustomerInterface)ctx.lookup("cust/remote");
List<String>books2 = cust.getBooks();
System.out.println(books2.size());
for (inti = 0; i<books2.size(); ++i) {
System.out.println((i+1)+". " + books2.get(i));
}
} catch (Exception e) {
System.out.println(e.getMessage());
e.printStackTrace();
} finally {
try {
if(brConsoleReader !=null) {
brConsoleReader.close();
}
} catch (IOException ex) {
System.out.println(ex.getMessage());
}
}
}
}

?? ??:

?? #2

? ???? EJB:

package JPAEJB;
import java.util.List;
import Customers.CustomerInterfaceImplem;
public class Ejbclients{
public static void main(String[] args) {
for(CustomerInterface cust:getBooks()) {
System.out.println(cust.getBooks());
}
}
private static List
<CustomerInterface> getBooks() {
CustomerInterfaceImplem s =
new CustomerInterfaceImplem();
CustomerInterface c =
s.getCustomerInterfacePort();
return c.getBooks();
}
}

?? #3

EJB ??:

import javax.ejb.*
@Stateless
@DeclareRoles({"customer""books"})
public class CustSecurity implements CustomerInterface {
@RolesAllowed({"books"})
public void delete(CustomerInterface cust) {
System.out.println("customer delete the books");
}
@PermitAll
public void showBooks(CustomerInterface cust) {
System.out.println("customer viewed the books");
}
@DenyAll
public void deleteAll() {
System.out.println("customer delete all the books in libraries");
}
}

?? XML:

<?xml version="1.0"encoding="UTF-8"?>
<!DOCTYPE sun-ejb-jar PUBLIC "-//Sun Microsystems, Inc.//DTD Application Server 9.0 EJB 3.0//EN""http://www.sun.com/software/appserver/dtds/sun-ejb-jar_3_0-0.dtd">
<ejb-jar>
<security-role-mapping>
<role-name>customer</role-name>
<group-name>customer-groups</group-name>
</security-role-mapping>
<security-role-mapping>
<role-name>Books</role-name>
<group-name>Books-group</group-name>
</security-role-mapping>
<enterprise-beans/>
</ejb-jar>

??: ? ? ?? ?? ??? ???? ejb ? ?? ?? ?? ??? ??? ?? ??? ?????. ??? ??? ???? jndi(java naming ???? ?????)? ???? ?? ?? ? ?????. ??? ?? ? ???? ? ?? ??? ?? ??? ????? ?? ??? ??????.

??

????? EJB? ???? ?? ?????? ??? ????? ??? ???. ?? ???? ?? ?????? ??? ? ?? ???? ???? ??? ??? ? ?????. ?? ??? ??? ????? ?????.

? ??? ??? EJB? ?? ?????. ??? ??? PHP ??? ????? ?? ?? ??? ?????!