Java/EJB3/Context

Context Injection

File: AnotherBean.java
import javax.ejb.Stateless;
@Stateless
public class AnotherBean implements AnotherBeanLocal {
  public void doAnother(){
    System.out.println("from another bean");
  }
}

File: AnotherBeanLocal.java

public interface AnotherBeanLocal {
  public void doAnother();
}

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: EmployeeBean.java
import javax.annotation.Resource;
import javax.ejb.EJB;
import javax.ejb.SessionContext;
import javax.ejb.Stateless;
@Stateless
@EJB(name = "audit", beanInterface = AnotherBeanLocal.class)
public class EmployeeBean implements EmployeeServiceLocal, EmployeeServiceRemote {
  @Resource SessionContext context;
  public EmployeeBean() {
  }
  public void doAction() {
    System.out.println("doAction");
    AnotherBeanLocal a = (AnotherBeanLocal) context.lookup("audit");;
    a.doAnother();
  }
}

File: EmployeeServiceLocal.java
import java.util.Map;
import javax.ejb.Local;

@Local
public interface EmployeeServiceLocal {
  public void doAction();
}

File: EmployeeServiceRemote.java

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 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.doAction();
  }
}

Explicityly Set Context with JNDI

File: HelloServiceBean.java

import javax.ejb.Stateless;
@Stateless
public class HelloServiceBean implements HelloServiceLocal, HelloServiceRemote {
    public String sayHello(String name) {
        return "Hello1, "  + name;
    }
}
    

File: HelloServiceLocal.java

import javax.ejb.Local;
@Local
public interface HelloServiceLocal {
    public String sayHello(String name);
}

File: HelloServiceRemote.java


import javax.ejb.Remote;
@Remote
public interface HelloServiceRemote{
    public String sayHello(String name);
}

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.*;
import javax.naming.*;

public class Main{
   public static void main(String[] a) throws Exception{
    /* get a initial context. By default the settings in the file
     * jndi.properties are used.
     * You can explicitly set up properties instead of using the file.
     * 
    
    Properties properties = new Properties();
    properties.put("java.naming.factory.initial","org.jnp.interfaces.NamingContextFactory");
    properties.put("java.naming.factory.url.pkgs","=org.jboss.naming:org.jnp.interfaces");
    properties.put("java.naming.provider.url","localhost:1099");
     */   
        String name = "jexp";
        HelloServiceRemote service = null;
        
        //Context compEnv = (Context) new InitialContext().lookup("java:comp/env");
        
        //service = (HelloService)new InitialContext().lookup("java:comp/env/ejb/HelloService");
        service = (HelloServiceRemote)new InitialContext().lookup("HelloServiceBean/remote");
        System.out.println(service.sayHello(name));
 
   }
}

Initialize javax.naming.InitialContext with System.getProperties

public class InitContext {
  public static void main(String args[]) throws Exception {
    javax.naming.Context ctx = new javax.naming.InitialContext(System.getProperties());
    System.err.println("Success!");
  }
}

Use Context To Lookup Another Ejb

File: AnotherBean.java
import javax.ejb.Stateless;
@Stateless
public class AnotherBean implements AnotherBeanLocal {
  public void doAnother(){
    System.out.println("from another bean");
  }
}

File: AnotherBeanLocal.java

public interface AnotherBeanLocal {
  public void doAnother();
}

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: EmployeeBean.java
import javax.ejb.EJB;
import javax.ejb.EJBException;
import javax.ejb.Stateless;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
@Stateless
@EJB(name = "audit", beanInterface = AnotherBeanLocal.class)
public class EmployeeBean implements EmployeeServiceLocal, EmployeeServiceRemote {
  public EmployeeBean() {
  }
  public void doAction() {
    System.out.println("doAction");
    try {
      Context ctx = new InitialContext();
      AnotherBeanLocal a = (AnotherBeanLocal) ctx.lookup("java:comp/env/audit");
      a.doAnother();
    } catch (NamingException e) {
      throw new EJBException(e);
    }
  }
}

File: EmployeeServiceLocal.java
import java.util.Map;
import javax.ejb.Local;

@Local
public interface EmployeeServiceLocal {
  public void doAction();
}

File: EmployeeServiceRemote.java

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 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.doAction();
  }
}