The cdl.gateway option generates generic gateway codes.
The cdl.gateway option takes one of the following values as a parameter.
The default configuration is false.
No parameter implies that the parameter is true.
The cdl option generates the following base classes:
In addition to these base classes, the cdl.gateway options-related class shown below are generated.
The cdl.gateway option adds no additional methods to Relaxer objects.
List 18.8.3.1[cdlGateway.rcdl] is a sample RCDL definition, and List 18.8.3.2[cdlGateway.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="cdlGateway.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.gateway option is as follows:
$ relaxer -cdl -cdl.gateway cdl.rcdl
As a result, Relaxer generates 18 files as follows:
List 18.8.3.3[IAccountManager.java] shows
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 18.8.3.4[IAccountManagerService.java] shows
IAccountManagerService which is a Java interface
to be used as an SPI.
import java.rmi.*;
public interface IAccountManagerService extends IAccountManager {
}
To complete this component,
you must develop a service provider.
For this purpose, Relaxer generates a prototype of the service provider.
In the example,
the AccountManagerService shown in
List 18.8.3.5[AccountManagerService.java.AccountManager] is
prototype of the service provider.
AccountManagerService extends
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 write
a findAccount method.
The service provider AccountManagerService
is shown in List 18.8.3.6[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));
}
}
}
Compilation of AccountManagerCommand is as follows.
No special compile options are needed.
$ javac AccountManagerCommand.java
Execution of AccountManagerCommand is shown here:
$ java AccountManagerCommand -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 -findAccount followed by a12345 means
invoking a findAccount method
with a parameter a12345.
As a result, the command outputs an XML document produced by the service provider.