jboss - djVoo: Look it up, take your notes, and define your own

Table of Contents [show]

Keywords

Axis, C3P0, JMX, Java application server

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[JH]

A famous Java application server

1 A Hello World example with Jboss and Eclipse

Install Eclipse and jboss
Install jboss Eclipse IDE
In eclipse create a new project by selecting new->Project->Web project->dynamic web project, say the project name is demo. The project should have a demo\src directory for source files, a demo\WebContent directory for jsp and html files.
Right click project name demo, select properties->packaging configurations. Select Standar-War.war. You need to manually add the items you want in the package. You need to fill out Prefix field: if it's .jsp page, then leave it blank; if it's .class file, use WEB-INF\classes. There is also an include and an exclude field: use **\*.class if you want to include all .class files.
Add a few jsp file and a few servlet
Right click project name demo, then choose Run Packaging. A demo.war file will be generated in the directory you specified when you setup the "Packaging configurations"
Copy the .war file to you jboss server. Put it under $JBOSS_HOME/server/deploy/
The content you created can be accessed by http://www.yourdomainname.com/demo

2 Jboss Admin Interface

visit http://localhost:8080/jmx-console/

3 Deploying datasources

Follow the following steps to deploy a data source in Jboss:

Create a data source xml file login-ds.xml

<?xml version="1.0" encoding="UTF-8"?>
<datasources>
  <local-tx-datasource>
    <jndi-name>login</jndi-name>
    <connection-url>jdbc:postgresql://localhost:5432/login</connection-url>
    <driver-class>org.postgresql.Driver</driver-class>
    <user-name>yourusername</user-name>
    <password>yourpassword</password>
    <metadata>
      <type-mapping>PostgreSQL 7.2</type-mapping>
    </metadata>
  </local-tx-datasource>
</datasources>

Copy this file over to $JBOSS_HOME/server/default/deploy/, JBoss will automatically deploy this datasource file.
Use JNDI naming and directory package to lookup this datasource and use it.

Trouble shooting: if you see this error:

org.jboss.util.NestedSQLException: Could not create connection; 
- nested throwable: (org.jboss.resource.JBossResourceException: Failed to register driver for: org.postgresql.Driver; 
- nested throwable: (java.lang.ClassNotFoundException: org.postgresql.Driver)); 
- nested throwable: (org.jboss.resource.JBossResourceException: Could not create connection; 
- nested throwable: (org.jboss.resource.JBossResourceException: Failed to register driver for: org.postgresql.Driver; 
- nested throwable: (java.lang.ClassNotFoundException: org.postgresql.Driver)))

Check if you have the correct version of database driver, or do you have the correct version? Here is a list jdbc drivers for postgresql.

4 Jboss Web Service

Jboss support SOAP-based web service. Note that starting from Version 4, Apache Axis is not supported by Jboss.

4.1 Jboss vs Axis

Before version 4, Jboss uses a modified version of Axis as web service engine. After version 4, Jboss developed its own ws engine because of the following: [JBOSS].

Portable web service endpoints and clients that do not need to have a dependency on a propriatary stack
Secure your investment and learn a standard rather than a propriatary solution
Achieve good interoperability by beeing BasicProfile-1.0 compliant
Take advantage of test coverage that comes with Sun's Compatibility Test Suite (>2300 WS tests)
Good integration with the overall JBoss architecture i.e. hot deployment/redeployment, management interface
Our support offering covers our own stack and the JBossWS team is dedicated full time to improve that constantly.

4.2 JbossWS vs. Jboss.NET

JBossWS is the J2EE-1.4 compatible web service implemenation in JBoss. It is installed in the all and default configuration. This implementaion will be developed further and replaced JBoss.NET. (http://www.jboss.org/index.html?module=bb&op=viewtopic&t=65248)

5 Setting SQL Server data source

<?xml version="1.0" encoding="UTF-8"?>
<datasources>
  <local-tx-datasource>
    <jndi-name>msuhr</jndi-name>
    <connection-url>jdbc:microsoft:sqlserver://hostname:1433;DatabaseName=test</connection-url>
    <driver-class>com.microsoft.jdbc.sqlserver.SQLServerDriver</driver-class>
    <user-name>username</user-name>
    <password>secret</password>
  </local-tx-datasource>
</datasources>

Note that when you used Microsoft SQL Server database with Microsoft JDBC driver, remeber to include all three .jar files: msbase.jar mssqlserver.jar msutil.jar, if you miss one of them, you'll get this error:

org.jboss.util.NestedSQLException: Could not create connection; 
- nested throwable: (org.jboss.resource.JBossResourceException: Failed to register driver for: com.microsoft.jdbc.sqlserver.SQLServerDriver; 
- nested throwable: (java.lang.ClassNotFoundExcepti

6 Setting up connection pool

http://pipin.tmd.ns.ac.yu/extra/java2/libs/JBoss/ch03s09.html

7 Configuring JBoss with C3P0

Refer to C3P0.

8 A console is not available

Restart your jboss server would usually get back your console.

9 Create your own jboss service

Jboss uses JMX to manage services, for example, ConnectionBindingService, etc. The Jboss API allows us to create our own services. The following shows how to create a simple query service. [J]

9.1 Create the management interface

package com.foo.mbeans;

import org.jboss.system.ServiceMBean;
public interface BarServiceMBean extends ServiceMBean {
	   // Configure getters and setters for the message attribute
	   public String getMessage();
	   public void setMessage(String message);
	   public String getAbc();
	   public void setAbc(String abc);
	   // The print message operation
	   void printMessage();
}

9.2 Service implementation

package edu.msu.egr.decs.config.mbeans;
import org.jboss.system.ServiceMBeanSupport;
public class BarService extends ServiceMBeanSupport implements BarServiceMBean {

	//	 Our message attribute
	private String message = "Sorry no message today";
	private String abc = "";

	//The printMessage operation
	public void printMessage()
	{
		log.info(message);
	}

	//The lifecycle
	protected void startService() throws Exception
	{
		log.info("Starting BarServoce");
	}

	protected void stopService() throws Exception
	{
		log.info("Stopping BarService");
	}

	
	//Getters and Setters
	public String getMessage(){
		return message;
	}

	public void setMessage(String message)
	{ 
		this.message = message;
	}

	public String getAbc() {
		return abc;
	}

	public void setAbc(String abc) {
		this.abc = abc;
	}
}

9.3 Create service descriptor

Note that each attribute in this xml file must have a corresponding pair of getter and setter in the MBean interface file and the java implementation file. People often use service name to name this file, e.g., this one could be named "barservice.xml".

<?xml version="1.0" encoding="UTF-8"?>
<server>
  <mbean code="com.foo.mbeans.BarService" name="foo.com:service=BarService">
    <attribute name="Message">Hello World</attribute>
    <attribute name="abc">haha, here we are</attribute>
  </mbean> 
</server>

9.4 Compile

Compile the Java files and put them into a jar file: barservice.jar.

9.5 Deploy service

First, put a copy of barservice.jar into your jboss deployment directory (which is usually $JBOSSDIR/server/default/deploy), then, put a copy of barservice.jar into your jboss lib directory (which is usually $JBOSSDIR/server/default/lib), then put a copy of barservice.xml into the deployment directory.

9.6 Incomplete deployment?

If you can redeploy the service by updating barservice.xml (without restarting jboss), but you see "incomplete deployment" error when restarting jboss, check to make sure that you have a copy of barservice.jar in the jboss lib directory.

A HelloWorld

Comments

References

[J] http://wiki.jboss.org/wiki/Wiki.jsp?page=ExampleHelloWorldService
[JBOSS] http://www.jboss.org/index.html?module=bb&op=viewtopic&p=3889456#3889456
[JH] http://www.jboss.com