create new url protocol to load spring configuration resource from the relative path R

i had a problem with spring framework, as you know while we are defining dependency over the xml documents, it becomes less changeable unless you know about my recent post about ext-util namespace handler and if you know any other alternatives.

before digging inside the problem better i clarify my context -

i have been working with one of my projects, where i have a several configurations which suppose to be different in different deployment environment, for example - to make my service avail, user has to define his database, his content index directory, server port, ip address and few more.

all these configurations were kept within the spring bean declaration scope. though few of them were moved to the properties file through ext-util namespace handler.

previously to make those configuration changeable i kept those files under WEB-INF/classes so it overrides the default bundled resource.

but still it wasn’t user friendly, since my user has to change one xml document to add more index services also he has to edit different configurations from java properties file.

again when i started bundling jetty with my whole application i found it is tricker to keep those xml outside of application, since i don’t wanna make my user confused with lot of xml files. and i have to keep few xml out of  my classpath context, so spring has to load my configuration from my “config/index-configuration/” directory.

though by default spring can do it over “file:///absolute/path/to/file.xml” since spring is using java URL class to locate this resource.  but in my case i can’t put any aboslute path.
so i found a simple way out there to support relative path reference.

previously i had the following xml document -

within spring container i was getting problem with managing multi level configuration.
for example while i am developing i got a specific filesystem path, database configuration and so on.
this configuration are mostly get changed while i an deploying them on the test or production environment.

this type of scenario is common on most of the projects. managing different scoped configuration is one of the bothering stuff. so i was always thinking some simpler way with in spring container.

so i wrote “ext-util” namespace handler, which is locating property from multi scoped resource.
lets give you a more details use case -

in my test environment i have a property “index.directory=/Users/…/index”
in my test server i use “index.directory=/var/index”
in my production server i use “index.directory=/nfs/index”

here i have a bean which need this property.

< bean id="fsDirectory" class="org.springmodules.lucene.index.support.FSDirectoryFactoryBean" >
< property name="location" value="file:////Users/nhmtanveerhossainkhanhasan/java-tmp/index" / >
< /bean>

you can see the hardcoded configuration. which is not easy to manage.
thats why here my “ext-util” goes with the simplest solution -

< ext-util:resource id="directoryResource" from-property="index.directory" scope="test" / >
< bean id="fsDirectory" class="org.springmodules.lucene.index.support.FSDirectoryFactoryBean" >
< property name="location" ref="directoryResource" / >
< /bean>

now my property resource is locating from “test” scope.

you might think, this “scope=’test’” is again hardcoded stuff, so i also support the following value -
scope=”sys:env”, now you have to define “-Denv=test” while you running your application, and spring bean will find the right property.

so what ever you put over your spring are no longer hardcoded as long as you locate them through “ext-util” which is stands for “extended utility”.

here is my attached source code - (i just extracted them from my on going project, thats why no build script or prebuilt package or maven artifact is bundled)

how to use -
include the source file with in your project
keep “META-INF” while you building your jar or keep them inside your classpath.
change your spring configuration -

xmlns:xsi=”http://www.w3.org/2001/XMLSchema-instance”
xmlns:lang=”http://www.springframework.org/schema/lang”
xmlns:aop=”http://www.springframework.org/schema/aop”
xmlns:ext-util=”http://dev.somewherein.net/schema/ext-util”
xsi:schemaLocation=”http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
http://www.springframework.org/schema/lang http://www.springframework.org/schema/lang/spring-lang-2.0.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd
http://dev.somewherein.net/schema/ext-util http://dev.somewherein.net/resources/schemas/ext-util-0.1.xsd“/>
basic properties of ext-util -

1. from-property - which property you are looking for.

2. or-default - define default value if no property is found from default scope (system properties) this value is returned.

3. scope - define scope name, by default whatever you set except “sys:” prefixed string, will search for “classpath:”. also you can use “sys:abc” where abc is located from system properties.

4. path-prefix - you can define scope properties path prefix, this prefix can be “file:///, classpath:”. this value also can be prefixed by “sys:abc” where abc is located from system properties.

[download source code]
[download missing xsd file]

best wishes,

JETTY RUNNER version 0.2 R

those who doesn’t know about JETTY RUNNER:
JETTY RUNNER is a standalone swing based application which is used to bundle java ee based application along with jetty container. it comes with simple web app configuration xml file and global properties manager through a simple properties file.

actually i have been using this project for my own development solution, so i belief this project will become a great strengthen feature gradually.

JETTY RUNNER is now running on max OSX, i have removed system try support in new tag v-0.2, soon i will release *.dmg package for mac osx. here are few screen snaps -

figure - 1: server console main window

figure - 2: global properties editor

change logs -
1. removed system tray support
2. removed default jmx configuration
3. added “start.sh” to launch JETTY RUNNER on *nix based platform where ruby script is installed.
here are few screen snaps, which i have taken from the newly added ruby script! -

figure - 3: newly added jetty runner on ruby

figure - 4: newly added jetty runner implementation in ruby

this script really great , at least i like it

Performance issue with tomcat 5.x.x series R

one of our escenic colleagues (Simen L. Haagenrud) just noticed a bottleneck with tomcat 5.x.x series containers. so we had a details digging to let find the reason.

as he mentioned it was because of recurring invocation of “getAttribute”, and tomcat 5.x.x series is using synchornization block inside “getAttribute” method, where lock is kept on “attributes” variable.
so i had a quick look on the source code of the 3 recent series -

1. 5.0.28
http://svn.apache.org/repos/asf/tomcat/container/tags/tc5.0.x/TOMCAT_5_0_28/catalina/src/share/org/apache/catalina/core/ApplicationContext.java

2. 5.5.24 (the last version from 5.5.x series)
http://svn.apache.org/repos/asf/tomcat/container/tags/tc5.5.x/TOMCAT_5_5_24/catalina/src/share/org/apache/catalina/core/ApplicationContext.java

3. 6.0.x (trunk)
http://svn.apache.org/repos/asf/tomcat/tc6.0.x/trunk/java/org/apache/catalina/core/ApplicationContext.java

so the code says 6.0.x series came with the fixes, the fix is the replacement of HashMap with ConcurrentHashMap.

in his case, recurring invocation of “getAttribute” was nearly reduced 50% server request handling capability.
best wishes,

Open Search Servlet - build open search configuration on the fly R

Here is open search specification - http://www.opensearch.org/Specifications/OpenSearch/1.1

Let’s enable your browser to detect your search engine automatically; using open search servlet you can generate open search configuration file on the fly.

Download information is here -

Binary library

Source maven project

Binary war file (includes example usages)

Usages:

1. Copy “open-search-x.jar” file on your WEB-INF/lib/ directory
2. Edit web.xml file.
3. add these entries -

< servlet >
    < servlet-name >openSearch< /servlet-name >
    < servlet-class >com.we4tech.openSearch.servlet.OpenSearchServlet< /servlet-class >
    < !-- URL matching pattern -- >
    < init-param >
      < param-name >url-match< /param-name >
      < param-value >.*/(.+).osd< /param-value >
      < !--< param-value >.*/search/(.+)< /param-value >-- >
    < /init-param >
    < !-- map open search configuration with url -- >
    < init-param >
      < param-name >open-search< /param-name >
      < param-value >open-search.properties< /param-value >
    < /init-param >
    < init-param >
      < param-name >somewherein-blog< /param-name >
      < param-value >somewherein-blog.properties< /param-value >
    < /init-param >
  < /servlet >

  < servlet-mapping >
    < servlet-name >openSearch< /servlet-name >
    < !--< url-pattern >/search/*< /url-pattern >-- >
    < url-pattern >*.osd< /url-pattern >
  < /servlet-mapping >

4. Now place configuration properties file with in your WEB-INF/classes/
5. for example: “open-search.properties”

# Default open-search. properties
shortName=colorful moment.
description=somewhere in blog
contact=hasan@somewherein.net

url.1=text/html,get,http://www.somewherein.net/blog/index.php?s={searchTerms}&submit=
image.1=16,16,image/x-icon,http://www.searchmash.com/favicon.ico

6. Congratulations you have completed all steps

Sample usages on your web site can be found here –

http://www.opensearch.org/Specifications/OpenSearch/1.1#Autodiscovery_in_HTML.2FXHTML

Best wishes,

Remind me: servlet, Jsp performance tuning note R

hi,
here is a great collection on servlet jsp performance related stuffs.
http://www.javaperformancetuning.com/tips/j2ee_srvlt.shtml

best wishes,

struts rewrite, link rewrites url with “;jsessionid=” session id. R

hi,
on my server i found some strange problem. it was actually related with < html:rewrite page=""/ > tag. the problem was with the url rewriting, which was performed by struts tag library. struts tag library was creating an invalid URL.
for example i wrote the following code:
< img src="< html:rewrite page="${urlPrefix}"/>my-image.gif” />

as i have only wrapped “${urlPrefix}” with in html:rewrite tag. so struts tag library wrote the following output.

< img src="/mycontext/gfx/;jsessionid=825A15A08BE76581B356D6225B1A9265my-image.gif" mce_src="/mycontext/gfx/;jsessionid=825A15A08BE76581B356D6225B1A9265my-image.gif" />

which is totally a wrong url.

so how i resolved it?
very simple just fixing my weired code. now it looks like the following -
< img src="< html:rewrite page="${urlPrefix}my-image.gif"/>” />

the generated output looks like -
< img src="/mycontext/gfx/my-image.gif;jsessionid=825A15A08BE76581B356D6225B1A9265" mce_src="/mycontext/gfx/my-image.gif;jsessionid=825A15A08BE76581B356D6225B1A9265" />

here is a regex which may help you to find out the error tags:
“< (html):rewrite\s+page="(.+)"\s*/ >(.+)”

yeap it is working now

A RESTful url using Stripes. R

RESTful url may contain the content type with in the url string. For example: http://host/action/xml/bookmark. Here “xml” is content type, this content type can be changed to “text, json” or etc…

So following urls are valid too. http://host/action/text/bookmark, http://host/action/json/bookmark etc…

these days I am playing with “Stripes” web framework a lot. Those who didn’t get in touch with “Stripes” have a look on the following URL - http://stripes.mc4j.org, hope you will enjoy it.

stripes has fantastic flexibility, it enables a lot of customization. Now my tutorial will demonstrate how you can enable this url pattern, where your single “ActionBean” will be invoked on the following url patterns:

http://host/action/xml/bookmark, http://host/action/text/bookmark, http://host/action/json/bookmark etc…

My target audience:
Who has already been introduced with Stripes or those who are interested on stripes framework.

Routing plan:
Request Dispatch
[visitor] —  > http://host/action/xml/bookmark — > [web server] — > [Stripe servlet] — > [Custom Action resolver] — > [remove user defined content type “xml” and retrieve action bean]

Response Dispatch
[clean url (after removing content type)] — > http://host/action/bookmark — > [BookmarkActionBean] — > [Resolution] — > <  hello world/  >

Pre requisite:
Stripes servlet is configured and web context is up and running.

ActionBean code:
*  create an ActionBean, for example “BookmarkActionBean”

<  CODE  >

@UrlBinding(”/action/bookmark”)

public class BookmarkAction implements ActionBean {

    private final Log LOG = LogFactory.getLog(getClass());

    private ActionBeanContext mActionBeanContext;

    private String mContentType = “text/xml”;

    public void setContext(ActionBeanContext actionBeanContext) {

        mActionBeanContext = actionBeanContext;

        // retrieve user requested content type constant for example “text,json, xml”

        // convert consts to mime type “text, text/xml, application/JSON”

        mContentType = URLHelper.getMimeType(URLHelper.getContentType(getContext().getRequest().getPathInfo()));

    }

    public ActionBeanContext getContext() {

        return mActionBeanContext;

    }

    @DefaultHandler

    public Resolution save() {

        if (LOG.isDebugEnabled())

            LOG.debug( “storing bookmark object on the data store, ” +

                       “response content type is requested - ” + mContentType );

        return new StreamingResolution( mContentType, new StringReader(”< test/ >“) );

    }

}

<  /CODE  >

Description:
Here i have set our action on “/action/bookmark” url, but our user requested url pattern is “/action/< contentTypeConstants >/actionBean”

Look on the “setContext” method, I have added an extra line

mContentType = URLHelper.getMimeType(URLHelper.getContentType(getContext().getRequest().getPathInfo()));

now have a look on the URLHelper class.

public static String getContentType( String pRequestedUrl ) {

        String contentType = CACHED_URL_CONTENT_TYPE.get(pRequestedUrl);

        if (contentType == null) {

            contentType = DEFAULT_CONTENT_TYPE;

            Perl5Util util = new Perl5Util();

            if (util.match( REGEX_ACTION_CONTENT_TYPE, pRequestedUrl ))

                contentType = util.group(1)+”";

            CACHED_URL_CONTENT_TYPE.put( pRequestedUrl, contentType );

        }

        return contentType;

    }

This method is responsible to retrieve user requested content type constants.
for example “text, xml, json”

public static String getMimeType( String pContentType ) {

        // convert content type to MIME Type

        if (pContentType.equalsIgnoreCase(CONTENT_TYPE_CONST_XML))

            pContentType = CONTENT_TYPE_XML;

        else if (pContentType.equalsIgnoreCase(CONTENT_TYPE_CONST_JSON))

            pContentType = CONTENT_TYPE_JSON;

        return pContentType;

    }

This method is also converting constant to MIME content type.
For example “xml –> text/xml”

Now return to my base action bean. I have added the following method, which is defined as default handler.

@DefaultHandler
public Resolution save() {

        ….

        return new StreamingResolution( mContentType, new StringReader(”< test/ >“) );

    }

Here “mContentType” is repopulate when “setContext” is invoked.

ActionResolver code:
This is my action resolver.

public class NBookmarkSystemActionResolver extends NameBasedActionResolver {

     // ………   

    @Override

    public ActionBean getActionBean(ActionBeanContext pActionBeanContext, String pRequestedUrl) throws StripesServletException {

        String cleanUrl = URLHelper.getCleanUrl(pRequestedUrl);

        if (LOG.isDebugEnabled())

            LOG.debug( “user requested url - ” + pRequestedUrl + ” clean url - ” + cleanUrl);

        return super.getActionBean(actionBeanContext, cleanUrl);

    }

}

Now let’s have a look on “getCleanUrl” method.

public static String getCleanUrl( String pRequestedUrl ) {

        return pRequestedUrl.replaceAll(”/”+getContentType(pRequestedUrl),”");

    }

Custom ActionResolver configuration:

< filter  >

        < display-name  >Stripes Filter< /display-name  >

        < filter-name >StripesFilter< /filter-name >

        < filter-class >net.sourceforge.stripes.controller.StripesFilter< /filter-class >

        <� init-param >

            <� param-name >ActionResolver.UrlFilters<� /param-name >

            <� param-value >/WEB-INF/classes/<� /param-value >

        <� /init-param >

        <� init-param >

            < param-name >ActionResolver.PackageFilters< /param-name >

            < param-value >com.we4tech.nBookmarkSystem.service.webService/*< /param-value >

        < /init-param >

        < init-param >

            < param-name >ActionResolver.Class< /param-name >

            < param-value >com.we4tech.nBookmarkSystem.configuration.NBookmarkSystemActionResolver< /param-value >

        < /init-param >

    < /filter >

That’s all for today,

Hope you will enjoy stripes. Best of luck…

Nice Stripes web framework R

hi,
at least i could manage some time to write about Stripes (http://stripes.mc4j.org/)

stripes is a web framework, it has very few dependencies, configuration over convention is highly adopted on Stripes.

you don’t need to bother about any separate XML file or properties file, it is as simple as web.xml servlet configuration. just put your all configuration over

more over it has default convention centric url discovery… for example “HelloAction”.. this action can be accessed over “http:///Hello.htm” or whatever u map on url mapping.

very flexible system. it has very simple work flow management, (who already familiar with JSF navigation or Spring web flow will be interested on its work flow)

by default it has multi action on each class, and you can override the url or any settings over @annotation. which is the most powerful feature over stripes.

web form validation is one of the nice and simple approaches over stripes. i am really loving it..
you can apply validation rule over @annotation. here is few example.. hope it will give you clean understanding.

@ValidateNestedProperties({
@ValidateNestedProperties({
@Validate( field = “accountName”, required = true, on = {”register”}),
@Validate( field = “password”, required = true, minlength = 6, on = {”register”})})
private User user;

@Validate( expression = “user.password == this”, on = “register”, required = true)
private String confirmPassword;

it has support over spring container, so spring developer won’t get you out…

best wishes…
http://hasan.we4tech.com

Wow, new configuration option on Spring 2.0 R

hi today i found an interesting stuff..

Rod talked about new configuration option in spring (actually you can add as an addon) Define bean using Java code Wow!!!.. i was looking for this stuff for a long while… sometimes it is really meaningful to me…

here is code example for rod blog: