Error while deploying a web service whose return type is java.util.Date

Question

Hi
I have written a simple web service which takes in a date input (java.util.Date) and returns the same date back to the client.
public interface Ping extends Remote
* A simple method that pings the server to test the webservice.
* It sends a datetime to the server which returns the datetime.
* @param pingDateRequest A datetime sent to the server
* @returns The original datetime
public Date ping(Date pingDateRequest) throws RemoteException;
The generation of the Web service related files goes smoothly in JDeveloper 10g. The problem arises when I try to deploy this web service on the Oracle 10g (10.0.3) OC4J standalone. it gives me the following error on the OC4J console :
E:\Oracle\oc4j1003\j2ee\home\application-deployments\Sachin-TradingEngineWS-WS\
WebServices\com\sachin\tradeengine\ws\Ping_Tie.java:57: ping(java.util.Date) in com.sachin.tradeengine.ws.Ping cannot be applied to (java.util.Calendar) _result  = ((com.sachin.tradeengine.ws.Ping) getTarget()).ping
(myPing_Type.getDate_1());
^
1 error
04/03/23 17:17:35 Notification ==> Application Deployer for Sachin-TradingEngineWS-WS FAILED: java.lang.InstantiationException: Error compiling :E:\Oracle\oc4j1003\j2ee\home\applications\Sachin-TradingEngineWS-WS\WebServices: Syntax error in source [ 2004-03-23T17:17:35.937GMT+05:30 ]
I read somewhere that the conversion between java to xml datatype and vice versa fails for java.util.Date, so it is better to use java.util.Calendar. When I change the code to return a java.util.Calendar then the JDeveloper prompts me the following failure:
Method Ping: the following parameter types do not have an XML Schema mapping and/or serializer specified : java.util.Calendar.
This forces me to return a String data.
I would appreciate if someone can help me out.
Thanks
Sachin Mathias
Datamatics Ltd.

Answer 1

Hi
I got the web service working with some work around. But I am not sure it this approach would be right and good.
I started altogether afresh. I did the following step :
1. Created an Interface (Ping.java) for use in web Service as follows :
public interface Ping extends Remote{
public java.util.Date ping(java.util.Date pingDateRequest)
throws RemoteException;
2. Implemented the above interface in PingImpl.java as follows :
public class PingImpl implements Ping
public java.util.Date ping(java.util.Date pingDateRequest) throws RemoteException {
System.out.println("PingImpl: ping() return datetime = " + pingDateRequest.toString());
return pingDateRequest;
3. Compiled the above 2 java files.
4. Generated a Stateless Java Web Service with the help of JDeveloper. This time the generation was sucessful.(If I had "java.util.Calendar" in place of "java.util.Date" in the java code of the above mentioned files the web service generation would prompt me for error)
5. After the generation of Web Service, I made modification to the Ping interface and its implementing class. In both the files I replaced "java.util.Date" with "java.util.Calendar". The modified java will look as follows :
Ping.Java
=========
public interface Ping extends Remote{
public java.util.Calendar ping(java.util.Calendar pingDateRequest)
throws RemoteException;
PingImpl.Java
================
public class PingImpl implements Ping
public java.util.Calendar ping(java.util.Calendar pingDateRequest) throws RemoteException {
System.out.println("PingImpl: ping() return datetime = " + pingDateRequest.toString());
return pingDateRequest;
6. Now I recompile both the java files.
7. Withour regenerating the Web Service I deploy the Web Service on OC4j 10.0.3 from JDeveloper. This time the deployment was sucessful.(The Deployment fails if I don't follow the step 5.)
8. Now I generated a Stub from JDeveloper and accessed the stub from a client. It works fine. Here if you see the Stub code it takes java.util.Date as a parameter and returns a java.util.Date. (Mind you I am accepting a java.util.Calendar and returning the same in my Web Service interface. Step 5)
The confusing thing is the Serialization and Deserialization of Data from Client java data to Soap message and Soap message to Server java data.
From Client to SOAP :
java.util.Date to datetime
From SOAP to Server :
datetime to java.util.Calendar
From Server to SOAP :
java.util.Calendar to datetime
From SOAP to Client :
datetime to java.util.Date (I am not able to understand this part of the conversion)
Any help or inputs would be appreciated.
Thanks
Sachin Mathias