Recent Notes
Displaying keyword search results 1 - 10
Created by Fang on April 16, 2012 13:18:40
Last update: April 16, 2012 13:18:40
Simply call pageContext.setAttribute() to export a variable from within a JSP custom tag:
public class MyCustomVarTag extends TagSupport {
...
The availability of the exported variable can be limited in the TLD:
<tag>
<name>setVar</name>
<tag-class...
The availability scopes are:
Value Availability
NESTED Between the start tag and the end tag.
AT_BEGIN From the start tag until the scope of any enclosing tag. If there’s no enclosing tag, then to the end of the page.
AT_END After the end tag until the scope of any enclosing tag. If there’s no enclosing tag, then to the end of the page.
Created by Fang on April 16, 2012 12:58:35
Last update: April 16, 2012 12:58:35
To implement a JSP custom tag with dynamic attributes (for example, to pass-thru arbitrary attributes not handled by the JSP tag):
Set the dynamic-attributes element to true in the TLD:
<tag>
<name>mark</name>
<tag-class>c...
The tag handler must implement javax.servlet.jsp.tagext.DynamicAttributes :
package com.example.jsp;
import java.io.*;
...
Created by Fang on March 30, 2012 15:04:04
Last update: March 30, 2012 15:04:04
Spring MVC 3.1 can send either JSON or HTML response on the same URL, depending on the type of response requested. With this mechanism, a page can be sent when directly requested from a link, but a JSON response can be sent in response to an AJAX request. This is the controller code:
package com.example; import java.util.Map; ... In the above example, JSON response will be sent when the HTTP request contains header "Accept: application/json". HTML response will be sent then the header is "Accept: */*", or "Accept: text/html", or anything else. You can add a limitation that the HTML response does not produce "application/json". But then the question is which response will be sent when the HTTP header is "Accept: */*"? Both methods will...
Created by Dr. Xi on March 13, 2012 08:46:57
Last update: March 13, 2012 08:46:57
This trick sets HTML base to the root context path of the current webapp:
The short version:
<!DOCTYPE html>
<%@ taglib uri="http://java.sun...
The long version:
<!DOCTYPE html>
<%@ taglib uri="http://java.sun...
Created by Fang on February 08, 2012 21:15:00
Last update: February 08, 2012 21:15:00
This was the error message:
[ERROR] sun.security.validator.ValidatorExceptio...
The certificate was actually signed by Verisign, but somehow failed to pass Java cert validation.
To resolve the problem:
Download the cert from the server (with RetrieveSSLCert , for example)
Import the certificate into the keystore:
$ keytool -import -trustcacerts -alias myserver -f...
Define MAVEN_OPTS :
$ export MAVEN_OPTS='-Djavax.net.ssl.trustStore=/h...
The quotes must exist for the value of MAVEN_OPTS , and the path must be absolute ( ~/etc/mavenKeyStore.jks does not work).
Created by Dr. Xi on February 01, 2012 12:55:28
Last update: February 01, 2012 12:55:28
You can define environment variables in the Tomcat context.xml file like this:
<?xml version="1.0" encoding="UTF-8"?>
<Context...
which is equivalent to the following in web.xml :
<env-entry>
<env-entry-name>varName</env-entr...
In Java code, the variable can be looked up like this:
// import javax.naming.Context;
// import javax...
Created by Fang on January 31, 2012 15:40:34
Last update: January 31, 2012 15:41:28
This is a simple Hello World application with Spring 3 MVC. Like the default Apache HTTPd welcome page, it displays " It works! " when successfully deployed. The sole purpose is to show the minimum elements needed to setup Spring 3 MVC.
I use Maven since it's so much easier than downloading the dependencies manually.
Directory layout:
./src
./src/main
./src/main/webapp
./src/...
pom.xml :
<?xml version="1.0" encoding="UTF-8"?>
<project...
WEB-INF/web.xml :
<?xml version="1.0" encoding="UTF-8"?>
<web-app...
WEB-INF/applicationContext.xml (empty, but needed):
<?xml version="1.0" encoding="UTF-8"?>
<beans x...
WEB-INF/spring-servlet.xml :
<?xml version="1.0" encoding="UTF-8"?>
<beans x...
WEB-INF/jsp/home.jsp :
<!DOCTYPE html>
<html>
<head>
<title>H...
Build with:
mvn clean package
The resulting webapp is target/springmvc.war .
Created by Fang on January 31, 2012 13:57:56
Last update: January 31, 2012 15:04:29
These are the minimum steps to configure Spring MVC in web.xml :
Bootstrap Spring MVC by registering ContextLoaderListener :
<listener>
<listener-class>
org.springfra...
Register the DispatcherServlet :
<servlet>
<servlet-name>spring</servlet-name>
...
Add servlet-mapping :
<servlet-mapping>
<servlet-name>spring</servle...
Configure DispatcherServlet with WEB-INF/spring-servlet.xml , which configures WebApplicationContext specific to this servlet.
<?xml version="1.0" encoding="UTF-8"?>
<beans x...
Optionally, use context-param in web.xml to configure the global WebApplicationContext :
<!-- XmlWebApplicationContext is the default, so t...
If you omit this section, you have to create file WEB-INF/applicationContext.xml , even if it's empty.
This is the full web.xml :
<?xml version="1.0" encoding="UTF-8"?>
<web-app...
Created by Fang on January 28, 2012 13:24:09
Last update: January 28, 2012 13:31:22
This is a simple JSP custom tags library with tag body. Just like the JSF counterpart , it splits a string and repeats the body for each word, i.e., with this markup:
<%@ taglib uri="http://custom.tag.com/demo" prefix...
output:
<html>
<body>
<p>Hello Tigger!</p>
<p>H...
With Maven, this is the directory structure:
./src
./src/main
./src/main/resources
./s...
There are three files to write:
pom.xml :
<project xmlns="http://maven.apache.org/POM/4.0.0"...
src/main/java/tagdemo/IterateTag.java :
package tagdemo;
import java.io.IOException...
src/main/resources/META-INF/demotag.tld :
<?xml version="1.0" encoding="UTF-8"?>
<!DO...
Build with:
mvn clean install
To use it as a dependency in other Maven projects:
<dependency>
<groupId>tag-demo</groupId>
...
Created by nogeek on December 30, 2011 13:25:28
Last update: December 30, 2011 13:57:37
By default, tomcat uses an enhanced java.util.logging implementation called JULI, which can be configured at two different levels: Globally, with the ${catalina.base}/conf/logging.properties file. Per web application, with WEB-INF/classes/logging.properties . The configuration file is a normal Java properties file: Logging handlers are specified with the handlers property.
handlers = 1catalina.org.apache.juli.FileHandler, ... The root logger can define its set of handlers using the .handlers property. .handlers = 1catalina.org.apache.juli.FileHandler,... A prefix may be added to handler names. The prefix starts with a digit and ends with a dot ( . ), for example: # 1catalina. is a prefix 1catalina.org.apache.j... System property replacement is performed for property values which contain ${systemPropertyName} . Each handler can have its own specific properties: 3manager.org.apache.juli.FileHandler.level = FINE ... Loggers can define their own...
