CORBA.UNKNOWN Exception on method call

Hi,

here comes the code...

// HomeIF

public interface PricingHome extends EJBHome {

// defines method for creating pricing-bean

public Pricing create() throws RemoteException, CreateException;

}

//RemoteIF

public interface Pricing extends EJBObject

{

/** Returns all the available product codes */

public String[] getProductCodes() throws RemoteException;

}

//Bean itself

public class PricingImpl implements SessionBean{

/** The session context */

private SessionContext context;

/** The database connection*/

private Connection conn;

/** constructor */

public PricingImpl() {

}

/** Called by the EJB container to set this session's context */

public void setSessionContext(SessionContext aContext) {

context = aContext;

}

/** Called by the EJB container when a client calls the create() method in

the home interface */

public void ejbCreate() throws CreateException {

try {

// Allocate a database connection

conn = getConnection();

}

catch (Exception exc) {

throw new CreateException("Unable to access database: "+exc.toString());

}

}

/** Called by the EJB container for putting bean to sleep). */

public void ejbPassivate() throws EJBException {

try {

// Shut down the current database connection

conn.close();

conn = null;

}

catch (Exception exc) {

throw new EJBException("Unable to close database connection: "+

exc.toString());

}

}

/** Called by the EJB container to wake this session bean up */

public void ejbActivate() throws EJBException {

try {

// When the bean wakes back, connect DB again

conn = getConnection();

}

catch (Exception exc) {

throw new EJBException("Unable to access database: "+exc.toString());

}

}

/** Called by the EJB container to tell this session bean that it has been

removed*/

public void ejbRemove() throws EJBException {

try {

// Shut down the current database connection

conn.close();

conn = null;

}

catch (Exception exc) {

throw new EJBException("Unable to close database connection: "+

exc.toString());

}

}

/** Returns a list of the available product codes */

public String[] getProductCodes() throws EJBException {

Statement s = null;

try {

s = conn.createStatement();

ResultSet results = s.executeQuery(

"select product_code from price");

Vector v = new Vector();

// Copy the results into a temporary vector

while (results.next()){

v.addElement(results.getString("product_code"));

}

// Copy the vector into a string array

String[] productCodes;

v.copyInto(productCodes);

return productCodes;

}

catch (Exception e){

throw new EJBException("Unable to get product codes: "+

e.toString());

}

finally {

// Close down the statement in a finally block to guarantee that it gets

// closed, whether an exception occurred or not

try{

s.close();

}

catch (Exception ignore) {

}

}

}

protected Connection getConnection()

throws SQLException, NamingException {

// Get a reference to the naming service

InitialContext context = new InitialContext();

// Get the data source for the pricing database

DataSource ds = (DataSource) context.lookup(

"java:comp/env/jdbc/testDB");

// Ask the data source to allocate a database connection

return ds.getConnection();

}

}

//Client

public class TestPricing

{

public static void main(String[] args)

{

try

{

/** Creates a JNDI naming context for location objects */

Context context = new InitialContext();

/** Asks the context to locate an object named "Pricing" and expects the

object to implement the PricingHome interface */

PricingHome home = (PricingHome)

PortableRemoteObject.narrow(context.lookup("Pricing"),

PricingHome.class);

/** Asks the Home interface to create a new session bean */

Pricing session = (Pricing) home.create();

/** Get a list of valid product codes */

String[] codes = session.getProductCodes();

for (int i=0; i < codes.length; i++)

{

System.out.println(codes+": "+

session.getPrice(codes));

}

/** Destroy this session */

session.remove();

}

catch (Exception exc)

{

exc.printStackTrace();

}

}

}

Thanks for having a look at it,

regards

Anke

ankeVolkhardta at 2007-7-8 >

Hi Anke

When setting up an InitialContext from a client you need to provide it with some information, not just use the no arg constructor. It tends to be app server dependent so you'll have to experiment / look for examples. But will be of the form:

Properties prop = new Properties();

prop.put(Context.INITIAL_CONTEXT_FACTORY,"name of app servers's factory class");

prop.put(Context.PROVIDER_URL,"localhost:7001");

Context ctx = new InitialContext(prop);

Good luck.

gseela at 2007-7-8 >

Hi again,

I'm using the J2EE server, which is included in the j2sdkee installation from sun. But I think I will try the same with BEA weblogic, maybe it works better...

The narrow() uses the JNDI-name. I deployed my bean as 'Pricing'. I did the same before with the other beans and it worked.

I'm using the book J2EE Developer's Guide by Mark Wutka.

I don't have an ejb-jar.xml... hmmmmm - should I?

There is an application.xml:

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE application PUBLIC '-//Sun Microsystems, Inc.//DTD J2EE Application 1.3//EN' 'http://java.sun.com/dtd/application_1_3.dtd'>

<application>

<display-name>HelloWorld</display-name>

<description>Application description</description>

<module>

<ejb>ejb-jar-ic.jar</ejb>

</module>

<module>

<ejb>ejb-jar-ic3.jar</ejb>

</module>

</application>

and a sun-j2ee-ri.xml:

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE j2ee-ri-specific-information PUBLIC '-//Sun Microsystems Inc.//DTD J2EE Reference Implementation 1.3//EN' 'http://localhost:8000/sun-j2ee-ri_1_3.dtd'>

<j2ee-ri-specific-information>

<server-name></server-name>

<rolemapping />

<enterprise-beans>

<module-name>ejb-jar-ic.jar</module-name>

<unique-id>0</unique-id>

<ejb>

<ejb-name>Pricing</ejb-name>

<jndi-name>Pricing</jndi-name>

<ior-security-config>

<transport-config>

<integrity>supported</integrity>

<confidentiality>supported</confidentiality>

<establish-trust-in-target>supported</establish-trust-in-target>

<establish-trust-in-client>supported</establish-trust-in-client>

</transport-config>

<as-context>

<auth-method>username_password</auth-method>

<realm>default</realm>

<required>false</required>

</as-context>

<sas-context>

<caller-propagation>supported</caller-propagation>

</sas-context>

</ior-security-config>

<resource-ref>

<res-ref-name>jdbc/testDB</res-ref-name>

<jndi-name>jdbc/Cloudscape</jndi-name>

</resource-ref>

<gen-classes />

</ejb>

</enterprise-beans>

<enterprise-beans>

<module-name>ejb-jar-ic3.jar</module-name>

<unique-id>0</unique-id>

<ejb>

<ejb-name>StatelessHello</ejb-name>

<jndi-name>StatelessHello</jndi-name>

<ior-security-config>

<transport-config>

<integrity>supported</integrity>

<confidentiality>supported</confidentiality>

<establish-trust-in-target>supported</establish-trust-in-target>

<establish-trust-in-client>supported</establish-trust-in-client>

</transport-config>

<as-context>

<auth-method>username_password</auth-method>

<realm>default</realm>

<required>false</required>

</as-context>

<sas-context>

<caller-propagation>supported</caller-propagation>

</sas-context>

</ior-security-config>

<gen-classes />

</ejb>

</enterprise-beans>

</j2ee-ri-specific-information>

ankeVolkhardta at 2007-7-8 >

I finally found the ejb-jar.xml.

I just looked for it in the wrong .jar-file.

I'm already using the deploytool and it works fine for the other programs. But this one really drives me crazy.

I started playing with the deploytool. I changed the settings for the bean, it's now a stateful bean (though in the example it should be stateless).

Now I get

SQL Exception. Connection refused to host: XXX

when trying to initialise the DB connection.

CU and thanks a lot

Anke

ankeVolkhardta at 2007-7-8 >