The cdl.iiop option generates a component based on
RMI over IIOP transport.
Relaxer calls this type of component an "IIOP component".
IIOP component is a simillar RMI component.
However, IIOP component has strong advantage against RMI component.
IIOP component can be used by various type of progurams
such as C++, Smalltalk, even COBOL via CORBA ORB.
The cdl.iiop option takes one of the following values as a parameter:
The default configuration is false.
No parameter implies the parameter is set to true.
The cdl option generates base classes as follows:
In addition to these base classes, the cdl.iiop option's related classes are generated as shown below.
The IIOPINTERFACE
and the IIOPINTERFACEServer are important for programmars.
The IIOPINTERFACE is a JavaBeans
that acts as a front end against a application program.
Because of this, the IIOPINTERFACE implements
the API interface IINTERFACE.
Application programs uses the IIOPINTERFACE immdiately.
The IIOPINTERFACEServer is an IIOP server.
This object is executed as an IIOP server.
The INTERFACERemote,
the INTERFACEClientProxy,
The INTERFACEClient are used internally.
The IINTERFACERemote is a Java interface
to be used as an IIOP interface.
For this purpose, the IINTERFACERemote extends
the java.rmi.Remote.
The INTERFACEClientProxy is a client side proxy object.
The IIOPINTERFACEClient is a another
client side proxy object.
The cdl.iiop option adds no additional methods to Relaxer objects.
List 18.4.3.1[cdlIiop.rcdl] is a sample RCDL definition, and List 18.4.3.2[cdlIiop.rng] is a sample RELAX NG schema used by the RCDL definition.
<component xmlns="http://www.relaxer.org/xmlns/cdl"
namespace="http://example.com/account"
name="backOffice">
<interface namespace="http://example.com/account" name="accountManager">
<grammar namespace="http://example.com/account" location="cdlIiop.rng"/>
<operation name="findAccount">
<in name="accountNo" type="token"/>
<out label="account"/>
</operation>
</interface>
</component>
<grammar xmlns="http://relaxng.org/ns/structure/1.0"
datatypeLibrary="http://www.w3.org/2001/XMLSchema-datatypes">
<start>
<ref name="account"/>
</start>
<define name="account">
<element name="account">
<attribute name="accountNo">
<data type="token"/>
</attribute>
<element name="balance">
<data type="int"/>
</element>
<element name="owner">
<data type="token"/>
</element>
<ref name="address"/>
<zeroOrMore>
<ref name="phone"/>
</zeroOrMore>
</element>
</define>
<define name="address">
<element name="address">
<attribute name="zip">
<data type="token"/>
</attribute>
<text/>
</element>
</define>
<define name="phone">
<element name="phone">
<attribute name="area">
<data type="token"/>
</attribute>
<data type="token"/>
</element>
</define>
</grammar>
Execution of Relaxer with the cdl.iiop option is as follows. The cdl option must be used together with cdl.iiop.
$ relaxer -cdl -cdl.iiop cdlIiop.rcdl
As a result, Relaxer generates 22 files:
List 18.4.3.3[IAccountManager.java] is the IAccountManager
which is a Java interface to be used as an API.
import java.rmi.*;
public interface IAccountManager extends Remote {
/**
* Application interface of the operation findAccount.
*
* @param accountNo
* @exception RemoteException
* @return Account
*/
Account findAccount(String accountNo) throws RemoteException;
}
List 18.4.3.4[IAccountManagerService.java] is
the IAccountManagerService which is a Java interface
to be used as an SPI.
import java.rmi.*;
public interface IAccountManagerService extends IAccountManager {
}
To complete this process,
you must develop a service provider.
For this purpose, Relaxer generates a prototype of the service provider.
In the example,
the AccountManagerService, shown as
List 18.4.3.5[AccountManagerService.java.AccountManager], is the
prototype of the service provider.
The AccountManagerService extends
the AbstractAccountManagerService
which is the abstract base class for the service provider.
Therefore, the AccountManagerService implicitly implements
the SPI IAccountManagerService.
import java.rmi.RemoteException;
public class AccountManagerService extends AbstractAccountManagerService {
/**
* Implementation of a operation findAccount.
*
* @param accountNo
* @exception RemoteException
* @return Account
*/
public Account findAccount(String accountNo) throws RemoteException {
throw (new UnsupportedOperationException());
}
}
Copy the file "AccountManagerService.java" and then write
a findAccount method.
The service provider AccountManagerService
is shown in List 18.4.3.6[AccountManagerService.java].
import java.rmi.RemoteException;
import java.io.IOException;
import javax.xml.parsers.ParserConfigurationException;
import org.xml.sax.SAXException;
public class AccountManagerService extends AbstractAccountManagerService {
/**
* Implementation of a operation findAccount.
*
* @param accountNo
* @exception RemoteException
* @return Account
*/
public Account findAccount(String accountNo) throws RemoteException {
try {
Account account = new Account();
account.setAccountNo(accountNo);
account.setBalance(10000);
account.setOwner("XML Taro");
account.setAddress(
new Address("<address zip='123'>Yokohama</address>")
);
Phone phone1 = new Phone();
phone1.setArea("123");
phone1.setContent("456-7890");
account.addPhone(phone1);
Phone phone2 = new Phone("<phone area='090'>123-4567</phone>");
account.addPhone(phone2);
return (account);
} catch (IOException e) {
throw (new RemoteException(e.getMessage(), e));
} catch (SAXException e) {
throw (new RemoteException(e.getMessage(), e));
} catch (ParserConfigurationException e) {
throw (new RemoteException(e.getMessage(), e));
}
}
}
You must compile both client-side and server-side programs.
The client-side program is AccountManagerCommand and
the server-side program is IIOPAccountManagerServer.
Compilation of AccountManagerCommand and
the IIOPAccountManagerServer are shown below.
No special compile options are needed.
$ javac AccountManagerCommand.java $ javac IIOPAccountManagerServer.java
Next, you must execute the rmic with -iiop option
to generate RMI over IIOP stub code.
In the example, the RMI over IIOP server
IIOPAccountManagerServer is
specified as a parameter.
$ rmic -iiop IIOPAccountManagerServer &
There are three steps to execute the IIOP component.
First, prepare the CORBA's COS Naming server tnameserv. In this case, port number 1050 is specified using an ORBInitialPort option.
$ tnameserv -ORBInitialPort 1050 &
Second, start the IIOP server of the IIOP component as follows.
In the example, a COS Nameing name accountManager is bound
with the IIOP server IIOPAccountManagerServer.
The Java properties java.naming.factory.initial and
java.naming.provider.url are also specified.
java.naming.factory.initial is an initial context provider name of JNDI.
In the example, com.sun.jndi.cosnaming.CNCtxFactory,
Sun's COS Naming implementation, is specified.
java.naming.provider.url is an initial value for the context provider.
In the example, iiop://localhost:1050 is specified.
This means that a hostname of an initial COS naming server is localhost and
a port number of it is 1050.
$ java \
-Djava.naming.factory.initial=com.sun.jndi.cosnaming.CNCtxFactory \
-Djava.naming.provider.url=iiop://localhost:1050 \
IIOPAccountManagerServer accountManager &
Finally, execute the client command AccountManagerCommand.
Java properties java.naming.factory.initial and
java.naming.provider.url are also specified.
$ java \
-Djava.naming.factory.initial=com.sun.jndi.cosnaming.CNCtxFactory \
-Djava.naming.provider.url=iiop://localhost:1050 \
AccountManagerCommand --iiop accountManager -findAccount \
a12345
<account accountNo="a12345"><balance>10000</balance><owner>XML \
Taro</owner><address zip="123">Yokohama</address><phone \
area="123">456-7890</phone><phone \
area="090">123-4567</phone></account>
The --iiop option specifies the use of RMI over IIOP
to access the target component.
The accountManager
parameter which follows --iiop is the COS name
for the target RMI over IIOP component.
The -findAccount option followed by a12345
means that you are invoking a findAccount method
with the parameter a12345.
As a result, the command outputs an XML document which is sent back from the component via CORBA's IIOP transport.