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Created by Fang on March 30, 2012 10:07:25    Last update: March 08, 2013 13:41:57
After a user resets a password, I want to force the user to change the password before she gets access to secured content. This is usually done with a servlet filter. But with Spring MVC, you can also use a HandlerInterceptor . According to Spring JavaDoc: HandlerInterceptor is basically similar to a Servlet 2.3 Filter, but in contrast to the latter it just allows custom pre-processing with the option of prohibiting the execution of the handler itself, and custom post-processing. Filters are more powerful, for example they allow for exchanging the request and response objects that are handed down the chain. Note that a filter gets configured in web.xml, a HandlerInterceptor in the application context. As a basic guideline, fine-grained handler-related preprocessing tasks are candidates...
Created by Fang on November 21, 2011 15:57:49    Last update: November 22, 2011 09:51:26
The improved custom taglib works with existing facelet ui taglibs. For example: <ui:param name="theName" value="John"/> <my:hel... produces the expected output. However, a problem exists with the ui:repeat tag: <h3>With ui:repeat</h3> <ui:repeat var="theName... When tested with a URL like: http://localhost:8080/facelet-demo/?name=Zack&name... the raw EL prints out the correct names, but my custom tag substitutes empty string for theName2 ! In theory, the response is rendered in the Render Response phase, way after the Apply Request Values phase, actual values should be available to EL. The answer to this anomaly turned out to be very deep ! Yes, right there in the code! I would consider this a bug in facelets implementation, but the JSF spec did not tell what the expected behavior should be. In my custom...
Created by Fang on November 10, 2011 09:26:12    Last update: November 10, 2011 09:26:12
Syntax highlighted XML schema for JSF 2.0 Application Configuration Resource File ( faces-config.xml ). Almost 3000 lines! <?xml version="1.0" encoding="UTF-8"?> <xsd:sch...
Created by Fang on September 07, 2009 20:44:15    Last update: November 03, 2011 14:43:19
Step 1: Repackage a web app as EAR A Java EE application is a multimodule Maven project. At the very least you'll need to package a WAR and an EAR. To get started, I'll simply re-package the simple webapp as an EAR. Create a directory named javaee-app Copy the webapp from here to javaee-app . Rename struts1app to webapp . Create pom.xml under javaee-app : <project> <modelVersion>4.0.0</modelVersion>... Create a directory named ear under javaee-app . Create pom.xml under ear : <project> <modelVersion>4.0.0</modelVersion>... Modify pom.xml in the webapp directory so that it looks like this: <project> <modelVersion>4.0.0</modelVersion> ... Build with " mvn package " in the javaee-app directory. You can see that ear-1.0.ear is successfully generated in javaee-app/ear/target . Maven successfully resolves dependencies between the sub-projects....
Created by alfa on June 02, 2011 15:26:37    Last update: June 02, 2011 15:26:37
While doing some Java reflection code, I noticed the method Class.isSynthetic() , which the JavaDoc says returns " true if and only if this class is a synthetic class as defined by the Java Language Specification". However, there's no definition of "synthetic class" in the JLS ! The only thing that I can find that remotely resembles a definition is in the JVM spec , where it defines the synthetic attribute : "The Synthetic attribute is a fixed-length attribute in the attributes table of ClassFile (§4.1), field_info (§4.5), and method_info (§4.6) structures. A class member that does not appear in the source code must be marked using a Synthetic attribute." By this definition, a default constructor, which does not appear in the source code, should...
Created by alfa on May 24, 2011 14:51:29    Last update: May 24, 2011 14:51:29
The following code generates warning "warning: [unchecked] unchecked call to getMethod" when compiled: Class c = Class.forName("MyClass"); Method m = ... This is because the method getMethod is parameterized , while the variable c is not parameterized. There are two ways to eliminate this warning: Make c parameterized: Class<?> c = Class.forName("MyClass"); Meth... Suppress the warning with annotation: Class c = Class.forName("MyClass"); @SuppressWa...
Created by voodoo on July 11, 2009 15:14:55    Last update: July 29, 2010 22:45:48
cURL is a command line tool for transferring files with URL syntax. The main purpose and use for cURL is to automate unattended file transfers or sequences of operations. It's really easy to see HTTP headers with curl: C:\>curl --head http://www.google.com HTTP/1.0 ... or, headers and page together (dump headers to stdout): $ curl --dump-header - http://www.google.com HTTP/... Download openssl from openssl.org: curl http://www.openssl.org/source/openssl-0.9.6m.... C:\>curl --help Usage: curl [options...] <url> ...
Created by James on June 30, 2010 19:04:45    Last update: July 03, 2010 21:24:33
Technically, file upload cannot be handled by Ajax, because XMLHttpRequest (XHR) does not handle file inputs. All techniques not using Flash rely on an invisible iframe as the upload form submit target. JavaScript then grabs the response content from the iframe and present it, giving the same illusion as Ajax. webtoolkit AIM The technique by webtoolkit is very simple. It involves 3 simple steps: include the AIM script, implement the start/finish JavaScript functions, and add an onsubmit handler to the normal file upload form. The hooked up form looks like: <head> <script type="text/javascript" src="webt... The AIM script is also quite simple: /** * * AJAX IFRAME METHOD (AIM) * http... The above code only supports HTML responses. In order to support JSON responses, the above...