Create simple EJB component, exposed it as a webservice using oracle JDeveloper

Here are a simple steps where you create a enterprise component using EJB3.0 and exposing the same as a webservice using JDeveloper.

Creating a simple enterprise java bean (JPA entity/application)

1. Create new Application or a Project

• From the File menu, select New->General->Applications
• Enter the application name as AdharServiceApplication
• Select Generic Application in the Application template list and click Finish

2. Create a new DB connection

• From the File menu, select New->General->Connections->Database connections
• Provide the connection details (connection name, connection type, schema user name and password, host details, service details ) and click Finish
• In the Application Navigator, you can expand the Connections and Database nodes in the Application Resources panel to see the database objects

3. Create the Persistence objects ( JPA Entity)

 

• Launch the Create Entities from tables wizard (File->New->Business Tier->EJB->Entities from tables)
  • step1 : select the EJB version 3.0
  • step2 : no need to create a new persistence unit, simply click next
  • step3 : select online database connections
  • step4 : select the connection which you created above
  • step5 : Query the POCADHAR table and shuttle it to the selected list
  • click Finish

This creates the Pocadhar class

• every entity object should have a primary key. Identify the instance variable and the accessor methods (getter & setter) and annotate it as @Id
• you will find this class annotated with @Entity

There is also a persistence.xml created under the META-INF folder, this defines the JTA persistence level details to the container. 

• No need of any changes in this XML.  

4. Create the Java service Session facade 

• Select the persistence.xml and launch the create Java service Facade wizard (File->New->Business Tier->EJB->Java Service Facade)
• give the facade name as AdharJavaServiceFacade
• Tick the check box on 'Generate a main() method' and then click finish
• Open this newly created class AdharJavaServiceFacade and put the following code into the main method

final AdharJavaServiceFacade adharJavaServiceFacade = new AdharJavaServiceFacade();       

Pocadhar newAdhar = new Pocadhar(); // create a new instance to persist            newAdhar.setFirstname("Tupperware");

        newAdhar.setLastname("Plastic");

        newAdhar.setAddress1("DLF");

        newAdhar.setCity("Hyderabad");

        newAdhar.setCountry("India");

         

// You can create a dbtrigger to generate the values fo the primary key uniqueid, if not then you need to provide a value in the below call to persist a new row
//System.out.println("before call to persist ");

        adharJavaServiceFacade.persistPocadhar(newAdhar);

        //System.out.println("after the call to persist ");

        // the below lists all the rows from the POCADHAR database table

        List<Pocadhar> pocAdharList = adharJavaServiceFacade.getPocadharFindAll();

          for (Pocadhar adhar : pocAdharList) {

           System.out.println("First name : " +adhar.getFirstname() + ". LastName : " + adhar.getLastname() + ". UniqueId : " + adhar.getUniqeid()+ ".");

          }
 

5. Run the AdharJavaServiceFacade.java from the Application Navigator. You should see the newly created adhar instance details in the database and as well as a list of all the rows displayed in the log window.

Creating the Webservice

Select the AdharJavaServiceFacade.java from the application navigator window and right click select Create Webservice, this launches the webservice wizard

Message Format :

tick check box on SOAP 1.1 Binding

Message format : Document / Wrapped

Methods :Select the methods you want to expose as webservices

leave the rest as defaults and click Finish.

Note : you can view the wsdl generated by selecting 'Show WSDL for webservice annotations' on right click of AdharJavaServiceFacade.java

You can test this webservice either as an application or in a WLS container

Deploy the Webservice to a WLS

 

NOTE : There is a trivial problem while using the JAX-WS to marshall objects with no-arg default constructor.

Resolving java.sql.Timestamp does not have a no-arg default constructor

Problem : Usually JAXB expects a default constructor for the objects which it needs marshalling (object to XML).

You face problems when you use java.sql.Timestamp, java.sql.Date etc., object which does not have a no-arg constructor.

Solution : create the following adapter classes and info classes and build again. This should work.

1. Create a Timestamp adapter class

package project1.adapters;

import java.sql.Timestamp;

import java.util.Date;

import javax.xml.bind.annotation.adapters.XmlAdapter;

public class TimestampAdapter extends XmlAdapter<Date, Timestamp> {
public Date marshal(Timestamp v) {
return new Date(v.getTime());
}
public Timestamp unmarshal(Date v) {
return new Timestamp(v.getTime());
}
}

2. create a package-info.java at your project1 level.

@XmlJavaTypeAdapters(
@XmlJavaTypeAdapter(value=TimestampAdapter.class,type=Timestamp.class))
package project1;

import java.sql.Timestamp;

import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;
import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapters;

import project1.adapters.TimestampAdapter;

Deploying the Webservice

deploying to the integrated server or to any application server through JDeveloper IDE

• Start the IntegratedWebLogicApplication server from the Application Server Navigator
• Select the top level application/project name in the Application Navigator and right click
• Select Deploy->Webservices..., this opens up the deployment wizard
• Deployment Action : Deploy to Application server
• Select Server : Select the application server (IntegratedWebLogicServer)
• Weblogic Options : leave the defaults and click Next
• Summary section : View and click the Finish

You can test this webservice from

1. Application server Navigator window
2. The weblogic server console
3. test the server as an application within the Jdeveloper IDE
4. configure the wsdl generated through SOAPUI tool 

You can edit the AdharJavaServiceFacade.java to add more functionality.
Say, you want to search for a ahdar details using the FIRSTNAME and get the related adhar records. Simply adding the below code to the AdharJavaServiceFacade.java and rebuild and re-deploy will make the service available.

    public List<Pocadhar> findAdharByFirstNames(String firstName) {
        final EntityManager em = getEntityManager();
        return em.createQuery("select o from Pocadhar o WHERE o.firstname like :fname")
            .setParameter("fname", firstName)
            .getResultList();
    }

Database table used for this POC:

DESC POCADHAR

Name Null Type

------------------------------ --------

UNIQEID NUMBER

FIRSTNAME VARCHAR2(50)

LASTNAME VARCHAR2(50)

RELATIONNAME VARCHAR2(50)

RELATIONTYPE VARCHAR2(10)

ADDRESS1 VARCHAR2(50)

ADDRESS2 VARCHAR2(50)

WARD VARCHAR2(50)

CITY VARCHAR2(50)

STATE VARCHAR2(50)

COUNTRY VARCHAR2(50)

PINCODE VARCHAR2(8)

The following steps explains you how to create a DB Sequence and attach the same to the uniqueID.
1. create a db sequence object with the name ADHAR_UNIQUE

CREATE SEQUENCE ADHAR_UNIQUE INCREMENT BY 1 MAXVALUE 9999999999999999999999999999 MINVALUE 10020 CACHE 20;

2. From the database navigator window, select the POCADHAR table and right click, select Trigger->Create(PK from Sequence)... and enter the details for Trigger Name, Sequenc Name as ADHAR_UNIQUE, Column name as UNIQEID and apply.

Hope, this is a very simple process using the JDeveloper in creating a EJB component and there after exposing it as a webservice.

Thanks,
Hari