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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 March 05, 2012 20:32:37
Last update: March 05, 2012 20:32:37
In this simple example, I create a simple validating bean and create a JUnit test to test the validation.
The bean ( src/main/java/com/example/Person.java ):
package com.example;
import javax.validatio...
The test ( src/test/java/com/example/TestPerson.java ):
package com.example;
import java.util.Set;
...
Run the test:
mvn clean test
You'll notice that one test passed and the other failed.
The tests require that a person must have a name and the name cannot be empty, so @NotNull is not the right rule to use here. To make sure that the name is not empty, we need to use @Pattern . But since a null String matches any pattern, @NotNull is also needed:
package com.example;
import javax.validatio...
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 21, 2011 13:49:11
Last update: November 21, 2011 13:49:11
In the test for the simple taglib example , I used a literal string for the name attribute:
<my:hello name="Jack"/> What happens if the name attribute contains EL expresson? For example: <my:hello name="#{param['name']}"/> If EL works, the tag should take the value of the " name " request parameter and print it out. But the tag as implemented in the simple taglib example prints the literal string: Hello #{param['name']}! I am FaceletTag. In order to make a tag to recognize EL, we have to use TagAttribute.getValue(FaceletContext ctx) instead of TagAttribute.getValue() . The latter returns the literal value of the attribute. The HelloTagHandler should be changed to: package com.example; import java.io.IOExcep... Rebuild the taglib and test with a URL like this: http://localhost:8080/facelet-test/?name=Jack The tag will print:...
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 Fang on October 31, 2011 21:10:10
Last update: October 31, 2011 21:13:10
In this example I'll add a parameter to a facelets template. The example contains three tabs, each tab points to a different page. The tab control is shared among all pages, therefore, it is put in the template.
Starting from the simple facelet example , make these additions:
Create a new template WEB-INF/templates/tabs.xhtml :
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Stric...
Add a page for the about tab ( about.xhtml ):
<?xml version="1.0" encoding="UTF-8"?>
<ui:comp...
Add a page for the news tab ( news.xhtml ):
<?xml version="1.0" encoding="UTF-8"?>
<ui:comp...
Add a page for the partner tab ( partner.xhtml ):
<?xml version="1.0" encoding="UTF-8"?>
<ui:comp...
Build and re-deploy the application. Launch the browser and load page http://localhost:8080/facelet-demo/about.jsf .
This is a screenshot:
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 freyo on May 09, 2011 14:15:01
Last update: May 09, 2011 14:17:22
In short, use the PackageManager class to get the PackageInfo :
PackageInfo pkgInfo = getPackageManager().getP...
To build an APK, make these changes to the greetings app :
Change the layout to ( res/layout/main.xml ):
<?xml version="1.0" encoding="utf-8"?>
<LinearL...
Change the string values ( res/values/strings.xml ):
<?xml version="1.0" encoding="utf-8"?>
<resourc...
Update AndroidManifest.xml :
<?xml version="1.0" encoding="utf-8"?>
<manifes...
Create a new Java class src/com/android/appinfo/GetAppVersion.java :
package com.android.appinfo;
import android...
Edit build.xml , change project name to "AppInfo":
<?xml version="1.0" encoding="UTF-8"?>
<project...
Install to emulator:
ant install
Screenshot:
Created by James on March 29, 2010 03:11:38
Last update: January 11, 2011 20:19:39
This is an age old problem. Since it comes up time and time again, I'm writing this down for future reference. Let's start with a two-column layout generated by the 2 Column Layout Generator :
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Trans... It renders like this: The left column is shorter than the right column. How to make the left and right column the same height? Adding height: 100% to the style sheet of the left column doesn't cut it. There are several hacks, none of them are straightforward: In search of the One True Layout Faux Columns Creating Liquid Layouts with Negative Margins In short, there's no instruction in CSS that tells a DIV that its height should be 100% of that of the...