Notes by Fang
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Created by Fang on April 16, 2012 13:32:10
Last update: April 16, 2012 13:32:10
There are two steps to create a custom function for JSP:
Declare the function in the TLD:
<?xml version="1.0" encoding="UTF-8" ?>
<taglib...
Implement the function (must be static):
package com.example;
public class UrlTransl...
To use the function:
<%@ taglib uri="http://www.example.com/jsp/tags" p...
Created by Fang on March 30, 2012 15:12:14
Last update: March 30, 2012 15:12:14
I tested this on Spring MVC 3.1.
<?xml version="1.0" encoding="UTF-8"?>
<beans x...
Created by Fang on March 30, 2012 10:07:25
Last update: March 30, 2012 10:09:08
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 20:11:56
Last update: March 05, 2012 20:11:56
This is a bare bones Maven project to get started with Java JSR 303 bean validation.
Directory structure:
./pom.xml
./src
./src/main
./src/main/jav...
pom.xml :
<project xmlns="http://maven.apache.org/POM/4.0.0"...
which includes dependencies on JUnit, Java bean validation API and the Hibernate validator reference implementation.
Created by Fang on February 23, 2012 14:25:57
Last update: March 01, 2012 13:53:59
Some example snippets for Spring message configuration and usage.
To configure a message source in Spring context (basename=messages):
<bean id="messageSource"
class="org.springf...
Locale change interceptor can also be setup with:
<?xml version="1.0" encoding="UTF-8"?>
<beans x...
The messages file should be named messages.properties (or messages_en.properties , etc.) and located on CLASSPATH , for example: WEB-INF/classes .
To use a message resource in JSP:
<%@ taglib prefix="spring" uri="http://www.springf...
Created by Fang on February 21, 2012 20:54:23
Last update: February 21, 2012 20:57:57
Tomcat gzip compression filter can be turned on with " compression=on " in server.xml :
<Connector port="8080" protocol="HTTP/1.1"
...
The default compressed MIME types are: text/html,text/xml,text/plain .
It would be nice to add other types:
<Connector
port="8080"
protocol="HTT...
Created by Fang on February 21, 2012 20:33:58
Last update: February 21, 2012 20:33:58
You can customize Tomcat error page with error code:
<error-page>
<error-code>404</error-code>
...
or Java exception type:
<error-page>
<exception-type>java.lang.Throwab...
Either error-code or exception-type is required, but not both. There's no way to aggregate error codes, such as:
<!-- This does not work! -->
<error-page>
...
Customizing error pages is about the only way to suppress the default stack trace in Tomcat in case of an unhandled exception.
Created by Fang on February 17, 2012 14:35:25
Last update: February 17, 2012 14:36:25
Javadoc for javax.validation.Validation gives three ways to bootstrap JSR303 validation:
Build default validator factory:
ValidatorFactory factory = Validation.buildDefault...
The logic for buildDefaultValidatorFactory is:
if XML configuration ( META-INF/validation.xml ) defines a provider, use it.
if XML configuration does not exist or does not define a provider, use the first provider returned by ValidationProviderResolver .
Use custom ValidationProviderResolver :
Configuration<?> configuration = Validation
...
Ask for a specific provider by class:
EXAMPLEConfiguration configuration = Validation
...
Created by Fang on February 10, 2012 16:17:13
Last update: February 10, 2012 16:17:13
The annotation @org.hibernate.annotations.Type overrides the default hibernate mapping type used for a column. This can usually be omitted since Hibernate normaly infers the correct type to use.
But @Type is required in ambiguous scenarios such as a java.util.Date attribute, which can map to SQL DATE , TIME or TIMESTAMP . You use the @Type("timestamp") annotation to tell Hibernate that a timestamp converter should be used, which identifies an instance of org.hibernate.type.TimestampType .
@Type can also be used to identify custom type converters, which can be defined with @TypeDef at the class level:
@TypeDefs(
{
@TypeDef(
na...
or with an xml file:
<?xml version="1.0"?>
<!DOCTYPE hibernate-mappi...
Created by Fang on January 10, 2010 00:19:30
Last update: January 31, 2012 16:28:42
Maven is a powerful yet complex tool. When I started learning Maven, the first obstacle was, of course, its complexity. The second, was the lack of documentation that can get me off the ground quickly. This tutorial is an attempt to create a pragmatic guide that aims to get you familiar with Maven in the quickest way possible. The main theme is to get you on some hands on experience to start out and lead you through the creation of a simple Java EE project as quickly as possible. Instead of trying to give you a good read, I try to get you on the journey right away. The topics are roughly ordered by the logical sequence but you can jump around in any way...
