Recent Notes
Displaying keyword search results 1 - 10
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 Dr. Xi on August 15, 2012 12:05:39
Last update: August 15, 2012 12:05:39
Use OpenSSL's s_client command to fetch a page manually:
$ openssl s_client -connect localhost:443 -state -...
Sample session for Google:
$ openssl s_client -connect www.google.com:443 -st...
Resource: SSL/TLS Strong Encryption: FAQ
Created by Fang on March 30, 2012 12:15:49
Last update: March 30, 2012 12:15:49
1. mvc:default-servlet-handler Configures a handler for serving static resources by forwarding to the Servlet container's default Servlet. Use of this handler allows using a "/" mapping with the DispatcherServlet while still utilizing the Servlet container to serve static resources. HandlerMapping: org.springframework.web.servlet.handler.SimpleUrlHandlerMapping Handler: org.springframework.web.servlet.handler.SimpleUrlHandlerMapping Attribute Description default-servlet-name The name of the default Servlet to forward to for static resource requests. The handler will try to auto-detect the container's default Servlet at startup time using a list of known names. If the default Servlet cannot be detected because of using an unknown container or because it has been manually configured, the servlet name must be set explicitly. 2. mvc:view-controller Defines a simple Controller that selects a view to render the response. HandlerMapping: org.springframework.web.servlet.handler.SimpleUrlHandlerMapping Handler: org.springframework.web.servlet.mvc.ParameterizableViewController Attribute Description...
Created by Fang on March 06, 2012 14:38:52
Last update: March 06, 2012 15:56:45
This may or may not be useful, but I did the research so here's the code.
import org.springframework.beans.factory.annotatio...
Created by Dr. Xi on February 06, 2012 12:14:11
Last update: February 07, 2012 15:39:35
Oracle sqlplus command line tools does not support command line editing out-of-the-box. But on Linux there's a handy utility that enables command line editing with any command line tool: rlwrap - readline wrapper.
Install rlwrap:
$ sudo apt-get install rlwrap
Create a keywords file .sql.dict (optional, but convenient):
false null true
access add as asc begin by chec...
It would be nice to add the tables names also.
Create an alias for sqlplus (put it in .bashrc ):
alias sqlplus='rlwrap -f $HOME/.sql.dict sqlplus'
Created by Fang on December 06, 2011 19:03:25
Last update: December 07, 2011 08:54:11
Our custom tag, as implemented in the previous note , is broken when a template is used.
Create a template file ( home-template.xhtml ):
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Stric...
and a test page that uses it ( home.xhtml ):
<?xml version="1.0" encoding="UTF-8"?>
<ui:comp...
Then request the page with URL: http://localhost:8080/facelet-demo/home.jsf?name=Jack .
You'll find that our hello tag works inside ui:repeat but fails to get the value defined by ui:param ! What's the problem? Our hello tag implementation evaluated the EL with the wrong EL context!
This is the corrected implementation:
package com.example;
import java.io.IOExcep...
Created by Fang on November 22, 2011 10:40:16
Last update: November 22, 2011 10:40:16
This is an example that uses tag handler, UI component and renderer together to support a custom taglib. The main purpose is to show how these components play together.
The tag renders
<ui:param name="extra" value="el interpreted"/>
...
as
<h3>my:foreach</h3>
<ul class="css class" extra...
These are the files:
The tag handler ( src/main/java/com/example/ForeachTagHandler.java ):
package com.example;
import java.util.Map;
...
The UI component ( src/main/java/com/example/UIForeach.java ):
package com.example;
import java.io.IOExcep...
The renderer ( src/main/java/com/example/ForeachRenderer.java ):
package com.example;
import java.io.IOExcep...
Faces config ( src/main/resources/META-INF/faces-config.xml ):
<?xml version="1.0" encoding="UTF-8"?>
<faces-c...
Taglib config ( src/main/resources/META-INF/foreach.taglib.xml ):
<?xml version="1.0" encoding="UTF-8"?>
<facelet...
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 20:33:46
Last update: November 10, 2011 20:33:46
The stack trace is like this:
java.lang.IllegalArgumentException: Component prop...
You get this error because you are using the class attribute with a JSF UI component, for which the class attribute cannot be altered. Of course you meant CSS class, not Java class! You can use the styleClass attribute instead of the class attribute. The styleClass attribute becomes the class attribute when the component is rendered.
If you can add a tag handler to the UI component, you can alias class to styleClass , which will allow you to use the class attribute on the UI component:
import javax.faces.view.facelets.*;
pub...
