This manual uses several conventions to highlight certain words and phrases and draw attention to specific pieces of information.
In PDF and paper editions, this manual uses typefaces drawn from the Liberation Fonts set. The Liberation Fonts set is also used in HTML editions if the set is installed on your system. If not, alternative but equivalent typefaces are displayed. Note: Red Hat Enterprise Linux 5 and later includes the Liberation Fonts set by default.
Four typographic conventions are used to call attention to specific words and phrases. These conventions, and the circumstances they apply to, are as follows.
Mono-spaced Bold
Used to highlight system input, including shell commands, file names and paths. Also used to highlight key caps and key-combinations. For example:
To see the contents of the file
my_next_bestselling_novel
in your current working directory, enter thecat my_next_bestselling_novel
command at the shell prompt and press Enter to execute the command.
The above includes a file name, a shell command and a key cap, all presented in Mono-spaced Bold and all distinguishable thanks to context.
Key-combinations can be distinguished from key caps by the hyphen connecting each part of a key-combination. For example:
Press Enter to execute the command.
Press Ctrl+Alt+F1 to switch to the first virtual terminal. Press Ctrl+Alt+F7 to return to your X-Windows session.
The first sentence highlights the particular key cap to press. The second highlights two sets of three key caps, each set pressed simultaneously.
If source code is discussed, class names, methods, functions, variable names and returned values mentioned within a paragraph will be presented as above, in Mono-spaced Bold
. For example:
File-related classes include
filesystem
for file systems,file
for files, anddir
for directories. Each class has its own associated set of permissions.
Proportional Bold
This denotes words or phrases encountered on a system, including application names; dialogue box text; labelled buttons; check-box and radio button labels; menu titles and sub-menu titles. For example:
Choose Mouse Preferences. In the Buttons tab, click the Left-handed mouse check box and click to switch the primary mouse button from the left to the right (making the mouse suitable for use in the left hand).
from the main menu bar to launchTo insert a special character into a gedit file, choose from the main menu bar. Next, choose from the Character Map menu bar, type the name of the character in the Search field and click . The character you sought will be highlighted in the Character Table. Double-click this highlighted character to place it in the Text to copy field and then click the button. Now switch back to your document and choose from the gedit menu bar.
The above text includes application names; system-wide menu names and items; application-specific menu names; and buttons and text found within a GUI interface, all presented in Proportional Bold and all distinguishable by context.
Note the
shorthand used to indicate traversal through a menu and its sub-menus. This is to avoid the difficult-to-follow 'Select from the sub-menu in the menu of the main menu bar' approach.
or Mono-spaced Bold Italic
Proportional Bold Italic
Whether Mono-spaced Bold or Proportional Bold, the addition of Italics indicates replaceable or variable text. Italics denotes text you do not input literally or displayed text that changes depending on circumstance. For example:
To connect to a remote machine using ssh, type
ssh
at a shell prompt. If the remote machine isusername
@domain.name
example.com
and your username on that machine is john, typessh john@example.com
.The
mount -o remount
command remounts the named file system. For example, to remount thefile-system
/home
file system, the command ismount -o remount /home
.To see the version of a currently installed package, use the
rpm -q
command. It will return a result as follows:package
.
package-version-release
Note the words in bold italics above username, domain.name, file-system, package, version and release. Each word is a placeholder, either for text you enter when issuing a command or for text displayed by the system.
Aside from standard usage for presenting the title of a work, italics denotes the first use of a new and important term. For example:
When the Apache HTTP Server accepts requests, it dispatches child processes or threads to handle them. This group of child processes or threads is known as a server-pool. Under Apache HTTP Server 2.0, the responsibility for creating and maintaining these server-pools has been abstracted to a group of modules called Multi-Processing Modules (MPMs). Unlike other modules, only one module from the MPM group can be loaded by the Apache HTTP Server.
Two, commonly multi-line, data types are set off visually from the surrounding text.
Output sent to a terminal is set in Mono-spaced Roman
and presented thus:
books Desktop documentation drafts mss photos stuff svn books_tests Desktop1 downloads images notes scripts svgs
Source-code listings are also set in Mono-spaced Roman
but are presented and highlighted as follows:
package org.jboss.book.jca.ex1;
import javax.naming.InitialContext;
public class ExClient
{
public static void main(String args[])
throws Exception
{
InitialContext iniCtx = new InitialContext();
Object ref = iniCtx.lookup("EchoBean");
EchoHome home = (EchoHome) ref;
Echo echo = home.create();
System.out.println("Created Echo");
System.out.println("Echo.echo('Hello') = " + echo.echo("Hello"));
}
}
Finally, we use three visual styles to draw attention to information that might otherwise be overlooked.
A note is a tip or shortcut or alternative approach to the task at hand. Ignoring a note should have no negative consequences, but you might miss out on a trick that makes your life easier.
Important boxes detail things that are easily missed: configuration changes that only apply to the current session, or services that need restarting before an update will apply. Ignoring Important boxes won't cause data loss but may cause irritation and frustration.
A Warning should not be ignored. Ignoring warnings will most likely cause data loss.
If you find a typographical error in this manual, or if you have thought of a way to make this manual better, we would love to hear from you! Please submit a report in the the Issue Tracker, against the product JBoss Communications JAIN SLEE HTTP Servlet Resource Adaptor, or contact the authors.
When submitting a bug report, be sure to mention the manual's identifier: JAIN_SLEE_HttpServlet_RA_User_Guide
If you have a suggestion for improving the documentation, try to be as specific as possible when describing it. If you have found an error, please include the section number and some of the surrounding text so we can find it easily.
An HTTP Servlet is used to extend the capabilities of servers that host applications access via a request-response programming model. Although servlets can respond to any type of request, they are commonly used to extend the applications hosted by web servers. The aim of the HTTP Servlet Resource Adaptor is to provide the ease of same request-response programming model in SLEE environment. HTTP Servlet Resource Adaptor is not an replacement for HTTP Servlets but is suppose to work in close proximity with Servlet to gain the smooth integration between web application hosted in Web Server and application developed using Service Building Block hosted in the SLEE container.
The Resource Adaptor Type is the interface which defines the contract between the RA implementations, the SLEE container, and the Applications running in it.
The name of the RA Type is HttpServletResourceAdaptorType
, its vendor is org.mobicents
and its version is 1.0
.
The Resource Adaptor Type defines two activity objects, the types net.java.slee.resource.http.HttpServletRequestActivity
and net.java.slee.resource.http.HttpSessionActivity
.
The HttpServletRequestActivity
represents a specific incoming request. It is created by the Resource Adaptor when processing the incoming event, unless the request is received with an HttpSession
. The activity ending is done by the Resource Adaptor once the related request event is unreferenced inside the SLEE Container. The activity object interface is defined as follows:
package net.java.slee.resource.http;
public interface HttpServletRequestActivity {
/**
* Method to fetch the Request ID for this request.
*
* @return
*/
public Object getRequestID();
}
getRequestID()
method:Retrieves the Request's ID.
The HttpSessionActivity
represents an HttpSession
. It is created on demand by an SBB, through the RA SBB Interface, and ends on timeout, managed by the underlying HTTP Servlet framework, or by an SBB, invoking the invalidate()
on the related HttpSession
Object. The activity object interface is defined as follows:
package net.java.slee.resource.http;
public interface HttpSessionActivity {
public String getSessionId();
}
getSessionId()
method:Retrieves the Session's ID.
The Events fired by HTTP Servlet Resource Adaptor represent an incoming HTTP Request, and for each HTTP Request a different event type is used for each activity type. The table below lists the Resource Adaptor Type event types.
Table 2.1. Events fired on the HttpServletRequestActivity:
Name | Vendor | Version | Event Class | Description |
---|---|---|---|---|
net.java. slee.resource. http.events. incoming.request. HEAD | net.java.slee | 1.0 | net.java. slee.resource. http.events. HttpServletRequestEvent | An incoming HEAD HTTP request. |
net.java. slee.resource. http.events. incoming.request. GET | net.java.slee | 1.0 | net.java. slee.resource. http.events. HttpServletRequestEvent | An incoming GET HTTP request. |
net.java. slee.resource. http.events. incoming.request. POST | net.java.slee | 1.0 | net.java. slee.resource. http.events. HttpServletRequestEvent | An incoming POST HTTP request. |
net.java. slee.resource. http.events. incoming.request. PUT | net.java.slee | 1.0 | net.java. slee.resource. http.events. HttpServletRequestEvent | An incoming PUT HTTP request. |
net.java. slee.resource. http.events. incoming.request. DELETE | net.java.slee | 1.0 | net.java. slee.resource. http.events. HttpServletRequestEvent | An incoming DELETE HTTP request. |
net.java. slee.resource. http.events. incoming.request. OPTIONS | net.java.slee | 1.0 | net.java. slee.resource. http.events. HttpServletRequestEvent | An incoming OPTIONS HTTP request. |
net.java. slee.resource. http.events. incoming.request. TRACE | net.java.slee | 1.0 | net.java. slee.resource. http.events. HttpServletRequestEvent | An incoming TRACE HTTP request. |
Spaces where introduced in Name
and Event Class
column values, to correctly render the table. Please remove them when using copy/paste.
Table 2.2. Events fired on the HttpSessionActivity:
Name | Vendor | Version | Event Class | Description |
---|---|---|---|---|
net.java. slee.resource. http.events. incoming.session. HEAD | net.java.slee | 1.0 | net.java. slee.resource. http.events. HttpServletRequestEvent | An incoming HEAD HTTP request. |
net.java. slee.resource. http.events. incoming.session. GET | net.java.slee | 1.0 | net.java. slee.resource. http.events. HttpServletRequestEvent | An incoming GET HTTP request. |
net.java. slee.resource. http.events. incoming.session. POST | net.java.slee | 1.0 | net.java. slee.resource. http.events. HttpServletRequestEvent | An incoming POST HTTP request. |
net.java. slee.resource. http.events. incoming.session. PUT | net.java. slee | 1.0 | net.java. slee.resource. http.events. HttpServletRequestEvent | An incoming PUT HTTP request. |
net.java. slee.resource. http.events. incoming.session. DELETE | net.java.slee | 1.0 | net.java. slee.resource. http.events. HttpServletRequestEvent | An incoming DELETE HTTP request. |
net.java. slee.resource. http.events. incoming.session. OPTIONS | net.java.slee | 1.0 | net.java. slee.resource. http.events. HttpServletRequestEvent | An incoming OPTIONS HTTP request. |
net.java. slee.resource. http.events. incoming.session. TRACE | net.java.slee | 1.0 | net.java. slee.resource. http.events. HttpServletRequestEvent | An incoming TRACE HTTP request. |
Spaces where introduced in Name
and Event Class
column values, to correctly render the table. Please remove them when using copy/paste.
All event types use the same type net.java.slee.resource.http.events.HttpServletRequestEvent
. It's interface is as follows:
package net.java.slee.resource.http.events;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public interface HttpServletRequestEvent {
public HttpServletRequest getRequest();
public HttpServletResponse getResponse();
public String getId();
}
getRequest()
method:Retrieves the HttpServletRequest which is associated with the event.
getResponse()
method:Retrieves the HttpServletResponse which is associated with the request, which can be used to reply to the incoming request.
getId()
method:Retrieves unique event ID.
The Resource Adaptor's Activity Context Interface Factory is of type net.java.slee.resource.http.HttpServletRaActivityContextInterfaceFactory
, it allows the SBB to retrieve the ActivityContextInterface
related with an existing Resource Adaptor activity object. The interface is defined as follows:
package net.java.slee.resource.http;
import javax.slee.ActivityContextInterface;
import javax.slee.FactoryException;
import javax.slee.UnrecognizedActivityException;
public interface HttpServletRaActivityContextInterfaceFactory {
public ActivityContextInterface getActivityContextInterface(
HttpSessionActivity activity) throws NullPointerException,
UnrecognizedActivityException, FactoryException;
public ActivityContextInterface getActivityContextInterface(
HttpServletRequestActivity activity) throws NullPointerException,
UnrecognizedActivityException, FactoryException;
}
The HTTP Servlet Resource Adaptor interface, of type net.java.slee.resource.http.HttpServletRaSbbInterface
, which an SBB uses to create HtppSessionActivity instances, is defined as follows:
package net.java.slee.resource.http;
import javax.servlet.http.HttpSession;
import javax.slee.SLEEException;
import javax.slee.resource.ActivityAlreadyExistsException;
import javax.slee.resource.StartActivityException;
public interface HttpServletRaSbbInterface {
public HttpSessionActivity getHttpSessionActivity(HttpSession httpSession)
throws NullPointerException, IllegalArgumentException, IllegalStateException,
ActivityAlreadyExistsException, StartActivityException,
SLEEException;
}
getHttpSessionActivity(HttpSession)
method:Retrieves an HttpSessionActivity
for the specified HttpSession
. If the activity does not exist a new one is created.
The HTTP Servlet
does imposes some restrictions on the usage of the
HTTP Servlet
API java objects:
getAttribute(String)
method of the
HttpSession
object, retrieved from a request:
The
_ENTRY_POINT
attribute is reserved for internal usage, if such parameter value
is
used a SecurityException is thrown.
getValue(String)
method of the
HttpSession
object, retrieved from a request:
The
_ENTRY_POINT
attribute is reserved for internal usage, if such parameter value
is
used a SecurityException is thrown.
putValue(String,Object)
method of the
HttpSession
object, retrieved from a request:
The
_ENTRY_POINT
attribute is reserved for internal usage, if such value is used on
the first parameter a SecurityException is thrown.
removeAttribute(String)
method of the
HttpSession
object, retrieved from a request:
The
_ENTRY_POINT
attribute is reserved for internal usage, if such parameter value
is
used a SecurityException is thrown.
removeValue(String)
method of the
HttpSession
object, retrieved from a request:
The
_ENTRY_POINT
attribute is reserved for internal usage, if such parameter value
is
used a SecurityException is thrown.
setAttribute(String,Object)
method of the
HttpSession
object, retrieved from a request:
The
_ENTRY_POINT
attribute is reserved for internal usage, if such value is used on
the first parameter a SecurityException is thrown.
The following code examples shows how to use the Resource Adaptor Type for common functionalities
The following code examples the handling of an HTTP GET request:
public void onGet(HttpServletRequestEvent event,
ActivityContextInterface aci) {
// detach from HttpServletRequestActivity
aci.detach(sbbContext.getSbbLocalObject());
HttpServletResponse response = event.getResponse();
try {
PrintWriter w = response.getWriter();
w.print("onGet OK! Served by SBB = " + getSbbId());
w.flush();
response.flushBuffer();
log
.info("HttpServletRAExampleSbb: GET Request received and OK! response sent.");
} catch (Exception e) {
log.error(e);
}
}
The following code examples the handling of an HTTP PUT request, and the creation of an HttpSessionActivity:
public void onPut(HttpServletRequestEvent event,
ActivityContextInterface aci) {
SbbLocalObject sbbLocalObject = sbbContext.getSbbLocalObject();
// detach from HttpServletRequestActivity
aci.detach(sbbLocalObject);
try {
// here we will setup a session activity before sending the response back
if (httpServletRaSbbInterface == null) {
Context myEnv = (Context) new InitialContext().lookup("java:comp/env");
httpServletRaSbbInterface = (HttpServletRaSbbInterface) myEnv.lookup(
"slee/resources/mobicents/httpservlet/sbbrainterface");
httpServletRaActivityContextInterfaceFactory =
(HttpServletRaActivityContextInterfaceFactory) myEnv.lookup(
"slee/resources/mobicents/httpservlet/acifactory");
}
HttpSession httpSession = event.getRequest().getSession();
HttpSessionActivity httpSessionActivity = httpServletRaSbbInterface
.getHttpSessionActivity(httpSession);
ActivityContextInterface httpSessionActivityContextInterface =
httpServletRaActivityContextInterfaceFactory
.getActivityContextInterface(httpSessionActivity);
httpSessionActivityContextInterface.attach(sbbLocalObject);
HttpServletResponse response = event.getResponse();
PrintWriter w = response.getWriter();
w.print("onPut OK! Served by SBB = " + getSbbId());
w.flush();
response.flushBuffer();
log.info("HttpServletRAExampleSbb: PUT Request received and OK! response sent.");
} catch (Exception e) {
log.error(e);
}
}
This chapter documents the HTTP Servlet Resource Adaptor Implementation details, such as the configuration properties, the default Resource Adaptor entities, and the JAIN SLEE 1.1 Tracers and Alarms used.
The name of the RA is HttpServletResourceAdaptor
, its vendor is org.mobicents
and its version is 1.0
.
The Resource Adaptor supports configuration only at Resource Adaptor Entity creation time, the following table enumerates the configuration properties:
Table 3.1. Resource Adaptor's Configuration Properties
Property Name | Description | Property Type | Default Value |
---|---|---|---|
name | the servlet name which the RA entity should use | java.lang.String | mobicents |
JAIN SLEE 1.1 Specification requires values set for properties without a default value, which means the configuration for those properties are mandatory, otherwise the Resource Adaptor Entity creation will fail!
There is a single Resource Adaptor Entity created when deploying the Resource Adaptor, named HttpServletRA
.
The HttpServletRA
entity is also bound to Resource Adaptor Link Name HttpServletRA
, to use it in an Sbb add the following XML to its descriptor:
<resource-adaptor-type-binding>
<resource-adaptor-type-ref>
<resource-adaptor-type-name>
HttpServletResourceAdaptorType
</resource-adaptor-type-name>
<resource-adaptor-type-vendor>
org.mobicents
</resource-adaptor-type-vendor>
<resource-adaptor-type-version>
1.0
</resource-adaptor-type-version>
</resource-adaptor-type-ref>
<activity-context-interface-factory-name>
slee/resources/mobicents/httpservlet/acifactory
</activity-context-interface-factory-name>
<resource-adaptor-entity-binding>
<resource-adaptor-object-name>
slee/resources/mobicents/httpservlet/sbbrainterface
</resource-adaptor-object-name>
<resource-adaptor-entity-link>
HttpServletRA
</resource-adaptor-entity-link>
</resource-adaptor-entity-binding>
</resource-adaptor-type-binding>
Each Resource Adaptor Entity uses a single JAIN SLEE 1.1 Tracer, named HttpServletResourceAdaptor
. The related Log4j Logger category, which can be used to change the Tracer level from Log4j configuration, is javax.slee.RAEntityNotification[entity=HttpServletRA]
Ensure that the following requirements have been met before continuing with the install.
The RA hardware requirements don't differ from the underlying JBoss Communications JAIN SLEE requirements, refer to its documentation for further information.
Downloading the source code
Subversion is used to manage its source code. Instructions for using Subversion, including install, can be found at http://svnbook.red-bean.com
Use SVN to checkout a specific release source, the base URL is ?, then add the specific release version, lets consider 2.4.0.FINAL.
[usr]$ svn co ?/2.4.0.FINAL slee-ra-http-servlet-2.4.0.FINAL
Building the source code
Maven 2.0.9 (or higher) is used to build the release. Instructions for using Maven2, including install, can be found at http://maven.apache.org
Use Maven to build the deployable unit binary.
[usr]$ cd slee-ra-http-servlet-2.4.0.FINAL [usr]$ mvn install
Once the process finishes you should have the deployable-unit
jar file in the target
directory, if JBoss Communications JAIN SLEE is installed and environment variable JBOSS_HOME is pointing to its underlying JBoss Enterprise Application Platform directory, then the deployable unit jar will also be deployed in the container.
Similar process as for Section 4.2.1, “Release Source Code Building”, the only change is the SVN source code URL, which is NOT AVAILABLE.
To install the Resource Adaptor simply execute provided ant script build.xml
default target:
[usr]$ ant
The script will copy the RA deployable unit jar to the default
JBoss Communications JAIN SLEE server profile deploy directory, to deploy to another server profile use the argument -Dnode=
.
To uninstall the Resource Adaptor simply execute provided ant script build.xml
undeploy
target:
[usr]$ ant undeploy
The script will delete the RA deployable unit jar from the default
JBoss Communications JAIN SLEE server profile deploy directory, to undeploy from another server profile use the argument -Dnode=
.
The HTTP Servlet Resource Adaptor is not cluster aware, which means there is no failover process for a cluster node's requests being handled once the node fails.
Revision History | |||
---|---|---|---|
Revision 1.0 | Tue Dec 30 2009 | ||
|