Create Your Own Annotation For EJB : Annotation « EJB3 « Java Tutorial

1. Java Tutorial
2. EJB3
3. Annotation

File: EmployeeBean.java

import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.transaction.SystemException;
import javax.transaction.TransactionManager;

@Stateless
public class EmployeeBean implements EmployeeServiceLocal, EmployeeServiceRemote {
  @PersistenceContext(unitName="EmployeeService") private EntityManager manager;
  
  @JndiInjected("java:/TransactionManager")
  TransactionManager tm;
  public void doAction(){
    try {
      System.out.println("Is there a transaction: " + (tm.getTransaction() != null));
    } catch (SystemException e) {
      e.printStackTrace();
    }
    Customer cust = new Customer();

    cust.setLastName("Bond");
    cust.setSsn(1L);
    manager.persist(cust);
    
    System.out.println("Saved");
    
    cust = manager.find(Customer.class,1L);
    System.out.println(cust.getLastName());
    
    cust.setLastName("new name");
    
    manager.persist(cust);
    
    cust = manager.find(Customer.class,1L);
    System.out.println(cust.getLastName());
    
    manager.remove(cust);
    
    
    
  }
}

File: EmployeeServiceLocal.java

import javax.ejb.Local;
import javax.jws.WebParam;

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


}

File: EmployeeServiceRemote.java

import javax.ejb.Remote;


@Remote
public interface EmployeeServiceRemote {
  public void doAction();
}

File: JndiInjected.java

import java.lang.annotation.*;

@Target({ElementType.METHOD, ElementType.FIELD})
@Retention(RetentionPolicy.RUNTIME)
public @interface JndiInjected {
   String value();
}

File: JndiInjector.java

import java.lang.reflect.Field;
import java.lang.reflect.Method;

import javax.annotation.PostConstruct;
import javax.ejb.EJBException;
import javax.interceptor.InvocationContext;
import javax.naming.InitialContext;

public class JndiInjector {

  @PostConstruct
  public void jndiInject(InvocationContext invocation) {
    Object target = invocation.getTarget();
    Field[] fields = target.getClass().getDeclaredFields();
    Method[] methods = target.getClass().getDeclaredMethods();

    try {
      InitialContext ctx = new InitialContext();
      for (Method method : methods) {
        JndiInjected inject = method.getAnnotation(JndiInjected.class);
        if (inject != null) {
          Object obj = ctx.lookup(inject.value());
          method.setAccessible(true);
          method.invoke(target, obj);
        }
      }
      for (Field field : fields) {
        JndiInjected inject = field.getAnnotation(JndiInjected.class);
        if (inject != null) {
          Object obj = ctx.lookup(inject.value());
          field.setAccessible(true);
          field.set(target, obj);
        }
      }
      invocation.proceed();
    } catch (Exception ex) {
      throw new EJBException("Failed to execute @JndiInjected", ex);
    }
  }
}

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();
    


  }

}

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: Customer.java

import javax.persistence.Entity;
import javax.persistence.EntityListeners;
import javax.persistence.Id;
import javax.persistence.PostRemove;

@Entity
public class Customer implements java.io.Serializable {
  private String firstName;

  private String lastName;
  @Id
  private long ssn;

  public String getFirstName() {
    return firstName;
  }

  public void setFirstName(String firstName) {
    this.firstName = firstName;
  }


  public String getLastName() {
    return lastName;
  }

  public void setLastName(String lastName) {
    this.lastName = lastName;
  }


  public long getSsn() {
    return ssn;
  }

  public void setSsn(long ssn) {
    this.ssn = ssn;
  }

}

27.17.Annotation
	27.17.1.	Create Your Own Annotation For EJB