Generate a WS from Spring Service

[Frank Hamilton]

Hello,
I have developed one web app make with Spring and JPA. I want to create a Web Service from one Spring Service of the app, but I not sure if this is possible .

Here is the basic code:

The persistence context:

import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import org.springframework.transaction.annotation.Transactional;

@Transactional
public class BaseServiceImpl {
    protected EntityManager em;
    
    @PersistenceContext
    public void setEntityManager(EntityManager em) {
        this.em = em;
    }

    protected EntityManager getEntityManager() {
        return em;
    }
}

The Spring Service Interface:

import com.pmg.ligatenis.modelos.Edicion;

public interface EdicionService {
	public void save(Edicion edicion);
	public Edicion find(Integer id);
	public void remove(Integer id);
}

The implementation:

public class EdicionServiceImpl extends BaseServiceImpl implements EdicionService{
	
	public void save(Edicion edicion) {
		if (edicion.getId()!=null)
			getEntityManager().merge(edicion);
		else
			getEntityManager().persist(edicion);
	}
	public Edicion find(Integer id) {
		return getEntityManager().find(Edicion.class, id);
	}
	public void remove(Integer id) {
		getEntityManager().remove(getEntityManager().find(Edicion.class, id));
	}
}

The persistence entity:

@Entity(name="edicion")
public class Edicion {
	@Id
	@GeneratedValue(strategy=GenerationType.IDENTITY)
	private Integer id;
	private String nombre;
	private String descripcion;
	private Date fechainicio;
	
	public Edicion() {
		// TODO Auto-generated constructor stub
	}
	public Edicion(Integer id, String nombre, String descripcion,Date fechainicio) {
		super();
		this.id = id;
		this.nombre = nombre;
		this.descripcion = descripcion;
		this.fechainicio=fechainicio;
	}

I try to make the *.aar file with eclipse axis2 plugin but when I try to request any service I get a NullPointerException maybe because getEntityManager return null.
The *.aar file contains all necessary lib.

This is the error in catalina.out:

[ERROR] Exception occurred while trying to invoke service method find
java.lang.reflect.InvocationTargetException
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at org.apache.axis2.rpc.receivers.RPCUtil.invokeServiceClass(RPCUtil.java:212)
	at org.apache.axis2.rpc.receivers.RPCMessageReceiver.invokeBusinessLogic(RPCMessageReceiver.java:117)
	at org.apache.axis2.receivers.AbstractInOutMessageReceiver.invokeBusinessLogic(AbstractInOutMessageReceiver.java:40)
	at org.apache.axis2.receivers.AbstractMessageReceiver.receive(AbstractMessageReceiver.java:114)
	at org.apache.axis2.engine.AxisEngine.receive(AxisEngine.java:181)
	at org.apache.axis2.transport.http.util.RESTUtil.invokeAxisEngine(RESTUtil.java:144)
	at org.apache.axis2.transport.http.util.RESTUtil.processURLRequest(RESTUtil.java:139)
	at org.apache.axis2.transport.http.AxisServlet$RestRequestProcessor.processURLRequest(AxisServlet.java:837)
	at org.apache.axis2.transport.http.AxisServlet.doGet(AxisServlet.java:273)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
	at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
	at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602)
	at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
	at java.lang.Thread.run(Thread.java:662)
Caused by: java.lang.NullPointerException
	at com.pmg.ligatenis.servicios.edicion.EdicionServiceImpl.find(EdicionServiceImpl.java:15)
	... 27 more

Can someone help me with this. What is the error? Can I generate the Web Service from this code with eclipse axis2 plugin?
Or maybe need I used Spring "ServletEndpointSupport" ?

Any idea or any web reference.
TIA.