Connect the
enterprise with the JCA, Part 2
Tutorial Details:
Connect the enterprise with the JCA, Part 2
Connect the enterprise with the JCA, Part 2
By: By Dirk Reinshagen
Build your own J2EE Connector Architecture adapter
n " Connect the Enterprise with the JCA, Part 1 ," I introduced JCA (J2EE Connector Architecture), explained how it compares to EAI (enterprise application integration) products, and offered details on JCA interfaces.
JCA, an important new Java standard addressing enterprise integration, provides a framework, much like JDBC (Java Database Connectivity), to read and write data to different enterprise systems such as SAP, PeopleSoft, or Siebel. Reflecting its importance, the latest releases of most J2EE (Java 2 Platform, Enterprise Edition) application servers support JCA.
Read the whole series on the JCA:
Part 1. A look at the J2EE Connector Architecture
Part 2. Build your own J2EE Connector Architecture adapter
In this article, the second of two, I demonstrate how to implement a JCA adapter -- a set of classes with which a J2EE application server targets a particular enterprise system. A JCA adapter functions similarly to how a JDBC driver connects to databases. However, because developing a full-featured JCA adapter is a complex task, I can only scratch the surface in this article. Nevertheless, by the end, you will understand a basic JCA adapter's construction, and grasp the effort required to build your own.
To accomplish those goals, I first describe the sample adapter's capabilities, as well as how to deploy and run it. I then introduce the implementation classes, followed by what occurs when the adapter executes in the container. Finally, I discuss the lessons learned from creating the sample adapter.
Note: To download the myjca.rar source code that accompanies this article, see Resources .
What the sample JCA adapter implementation does (and doesn't) contain
First, it's important to frame the sample-adapter discussion by describing its functionality. This article's sample adapter doesn't actually hook up to an enterprise system; it merely implements the interfaces required to deploy the adapter and look up a connection.
Moreover, the sample adapter implements only those classes required for the JCA specification's connection management section. Further, most of the adapter's method implementations contain print statements that let you see the method calls' order, without hooking up a debugger. The sample adapter does not, however, address transaction and security contacts.
This article's sample adapter does not use the CCI (Common Client Interface) interfaces. It strictly demonstrates the classes necessary to connect to an enterprise system.
What you need to deploy the sample adapter
To use the adapter (or any JCA adapter for that matter), you need a J2EE application server with JCA 1.0 specification support. I used BEA's WebLogic 6.1 server to test the sample adapter; however, other application servers should work.
To deploy the sample adapter with BEA's WebLogic 6.1, you must:
Navigate to the connector tree in the Administration Console
Click on the "Install new connector" link
Navigate to the myjca.rar file, then upload it
In a later section, you'll find instructions on how to compile and build myjca.rar .
The sample class files
Next, let's delve into the Java classes required to implement the sample JCA adapter. The adapter includes two class categories:
Managed classes: The application server calls managed classes to perform the connection management. They're needed only if the application server is managing the connection (via a connection pool), a likely situation.
Physical connection classes: These required classes, which the aforementioned managed classes may call, establish the connection to the EIS (enterprise information systems).
MyManagedConnectionFactory
With the MyManagedConnectionFactory class, which implements the ManagedConnectionFacytory interface, you create the MyConnectionFactory and MyManagedConnection classes. The MyManagedConnectionFactory class acts as the main entry point for the application server to call into the adapter:
package myjca;
import java.io.PrintWriter;
import java.io.Serializable;
import java.sql.DriverManager;
import java.util.Iterator;
import java.util.Set;
import javax.resource.ResourceException;
import javax.resource.spi.*;
import javax.security.auth.Subject;
public class MyManagedConnectionFactory
implements ManagedConnectionFactory, Serializable
{
public MyManagedConnectionFactory() {
System.out.println("In MyManagedConnectionFactory.constructor");
}
public Object createConnectionFactory(ConnectionManager cxManager) throws ResourceException {
System.out.println("In MyManagedConnectionFactory.createConnectionFactory,1");
return new MyDataSource(this, cxManager);
}
public Object createConnectionFactory() throws ResourceException {
System.out.println("In MyManagedConnectionFactory.createManagedFactory,2");
return new MyDataSource(this, null);
}
public ManagedConnection createManagedConnection(Subject subject, ConnectionRequestInfo info) {
System.out.println("In MyManagedConnectionFactory.createManagedConnection");
return new MyManagedConnection(this, "test");
}
public ManagedConnection matchManagedConnections(Set connectionSet, Subject subject, ConnectionRequestInfo info)
throws ResourceException
{
System.out.println("In MyManagedConnectionFactory.matchManagedConnections");
return null;
}
public void setLogWriter(PrintWriter out) throws ResourceException {
System.out.println("In MyManagedConnectionFactory.setLogWriter");
}
public PrintWriter getLogWriter() throws ResourceException {
System.out.println("In MyManagedConnectionFactory.getLogWriter");
return DriverManager.getLogWriter();
}
public boolean equals(Object obj) {
if(obj == null)
return false;
if(obj instanceof MyManagedConnectionFactory)
{
int hash1 = ((MyManagedConnectionFactory)obj).hashCode();
int hash2 = hashCode();
return hash1 == hash2;
}
else
{
return false;
}
}
public int hashCode()
{
return 1;
}
}
MyManagedConnection
The MyManagedConnection class implements the ManagedConnection interface. MyManagedConnection encapsulates the adapter's physical connection, in this case the MyConnection class:
package myjca;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.*;
import javax.resource.NotSupportedException;
import javax.resource.ResourceException;
import javax.resource.spi.*;
import javax.security.auth.Subject;
import javax.transaction.xa.XAResource;
public class MyManagedConnection
implements ManagedConnection
{
private MyConnectionEventListener myListener;
private String user;
private ManagedConnectionFactory mcf;
private PrintWriter logWriter;
private boolean destroyed;
private Set connectionSet;
MyManagedConnection(ManagedConnectionFactory mcf, String user)
{
System.out.println("In MyManagedConnection");
this.mcf = mcf;
this.user = user;
connectionSet = new HashSet();
myListener = new MyConnectionEventListener(this);
}
private void throwResourceException(SQLException ex)
throws ResourceException
{
ResourceException re = new ResourceException("SQLException: " +
ex.getMessage());
re.setLinkedException(ex);
throw re;
}
public Object getConnection(Subject subject, ConnectionRequestInfo
connectionRequestInfo)
throws ResourceException
{
System.out.println("In MyManagedConnection.getConnection");
MyConnection myCon = new MyConnection(this);
addMyConnection(myCon);
return myCon;
}
public void destroy()
{
System.out.println("In MyManagedConnection.destroy");
destroyed = true;
}
public void cleanup()
{
System.out.println("In MyManagedConnection.cleanup");
}
public void associateConnection(Object connection)
{
System.out.println("In MyManagedConnection.associateConnection");
}
public void addConnectionEventListener(ConnectionEventListener listener)
{
System.out.println("In MyManagedConnection.addConnectionEventListener");
myListener.addConnectorListener(listener);
}
public void removeConnectionEventListener(ConnectionEventListener listener)
{
System.out.println("In MyManagedConnection.removeConnectionEventListener");
myListener.removeConnectorListener(listener);
}
public XAResource getXAResource()
throws ResourceException
{
System.out.println("In MyManagedConnection.getXAResource");
return null;
}
public LocalTransaction getLocalTransaction()
{
System.out.println("In MyManagedConnection.getLocalTransaction");
return null;
}
public ManagedConnectionMetaData getMetaData()
throws ResourceException
{
System.out.println("In MyManagedConnection.getMetaData");
return new MyConnectionMetaData(this);
}
public void setLogWriter(PrintWriter out)
throws ResourceException
{
System.out.println("In MyManagedConnection.setLogWriter");
logWriter = out;
}
public PrintWriter getLogWriter()
throws ResourceException
{
System.out.println("In MyManagedConnection.getLogWriter");
return logWriter;
}
Connection getMyConnection()
throws ResourceException
{
System.out.println("In MyManagedConnection.getMyConnection");
return null;
}
boolean isDestroyed()
{
System.out.println("In MyManagedConnection.isDestroyed");
return destroyed;
}
String getUserName()
{
System.out.println("In MyManagedConnection.getUserName");
return user;
}
void sendEvent(int eventType, Exception ex)
{
System.out.println("In MyManagedConnection.sendEvent,1");
myListener.sendEvent(eventType, ex, null);
}
void sendEvent(int eventType, Exception ex, Object connectionHandle)
{
System.out.println("In MyManagedConnection.sendEvent,2 ");
myListener.sendEvent(eventType, ex, connectionHandle);
}
void removeMyConnection(MyConnection myCon)
{
System.out.println("In MyManagedConnection.removeMyConnection");
connectionSet.remove(myCon);
}
void addMyConnection(MyConnection myCon)
{
System.out.println("In MyManagedConnection.addMyConnection");
conn
Read
Tutorial at: Click here to view the tutorial
Rate Tutorial: Connect the
enterprise with the JCA, Part 2
View Tutorial: Connect the
enterprise with the JCA, Part 2
Related
Tutorials:
 The state of Java middleware, Part II: Enterprise JavaBeans - JavaWorld - April
1999
The state of Java middleware, Part II: Enterprise JavaBeans - JavaWorld - April
1999
|
JNDI overview,
Part 3: Advanced JNDI - JavaWorld March
2000
JNDI overview,
Part 3: Advanced JNDI - JavaWorld March
2000
|
JNDI overview,
Part 2: An
introduction to directory services - JavaWorld February
2000
JNDI overview,
Part 2: An
introduction to directory services - JavaWorld February
2000
|
J2EE clustering,
Part 1 - JavaWorld February 2001
J2EE clustering,
Part 1 - JavaWorld February 2001
|
XML messaging, Part
3
XML messaging, Part
3
|
Connect the
enterprise with the JCA, Part 1
Connect the
enterprise with the JCA, Part 1
|
To EJB, or not to
EJB?
To EJB, or not to
EJB?
|
Connect the
enterprise with the JCA, Part 2
Connect the
enterprise with the JCA, Part 2
|
Create your own type 3 JDBC driver, Part 1
Create your own type 3 JDBC driver, Part 1
|
Rumble in the
jungle: J2EE versus .Net, Part
1
Rumble in the
jungle: J2EE versus .Net, Part
1
|
Comparison between the two major JDO architectures
Comparison between the two major JDO architectures
|
Business process
automation
made easy with
Java, Part 1
Business process
automation
made easy with
Java, Part 1
|
Should you go
with JMS?
Should you go
with JMS?
|
Servlet 2.4:
What's in store
Servlet 2.4:
What's in store
|
Good
introduction
Good
introduction
|
Finally, getting hands in !
Finally, getting hands in !
|
Using a JMS Provider with MDBs via the J2EE Connector Architecture
Using a JMS Provider with MDBs via the J2EE Connector Architecture
In this article I will provide a brief introduction to MDB and the J2EE Connector Architecture (JCA), examining how MDBs can be deployed with the JCA 1.5 resource adapter to use a JMS pro
|
Developing Your First EJBs, Part 2
the authors walked through what you need to do to develop your first entity bean. This week concludes this series with a look at how to develop a session bean, building on the examples presented in part one.
|
Oracle answers on Linux
The world's business software giant offers answers to the 10 most frequently asked questions about Linux.
|
What is Persistence Framework?
What is Persistence Framework?
What is Persistence Framework?
A persistence framework moves the program data in its most natural form (in memory objects) to and from a permanent data store the database. The persistence framework manages the
|
|
|
|
