Recent Notes
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Created by Fang on April 04, 2010 04:12:14
Last update: July 21, 2010 14:52:58
The tags <c:if> The <c:if> tag may be used with or without body content:
<!-- Without body content, used to export vari... In my opinion, the version without body content is pretty much useless (the <c:set> tag is a lot more meaningful for this purpose). If body content exists, it is inserted into the page if the testCondition is true . Optional attributes var and scope may be specified. If var is specified, a variable whose name is the value of var is exported to the associated scope ( pageScope if no scope is specified). The type of the exported variable is Boolean and its value is the value of the testCondition . <c:choose>, <c:when>, <c:otherwise> These tags imitate the Java control structure if...else...
Created by Fang on April 02, 2010 21:45:47
Last update: July 17, 2010 02:55:06
This is built upon the simple test application for JSTL , which contained a single servlet and a single JSP page. If I want to use it to test all available JSTL tags, the servlet and JSP page would be too complicated. Instead, I want to group the JSTL tags into separate JSP pages and display each group based on the requested URL. For example, if the URL ends with /CoreBasic , I'll display a page that contains the basic core tags; if the URL ends with /I18N , I'll display a page that contains the internationalization tags (e.g., <fmt:message> ). Furthermore, I want to delegate the handling of each group of tags to separate Java classes. This is the application I'll use for the...
Created by voodoo on July 12, 2010 18:44:06
Last update: July 12, 2010 18:44:06
Use the \d command to show information about a table:
postgres=# \d patchtype
Table ...
Created by voodoo on July 12, 2010 18:37:14
Last update: July 12, 2010 18:37:14
Use the \d command to list tables, sequences, etc.:
postgres=# \d
List of relations
...
Created by James on June 30, 2010 20:14:28
Last update: July 03, 2010 18:41:12
The HTML page
<!DOCTYPE html>
<html>
<head>
<title>jQu...
Client Side Code
// called before upload submit
function sta...
Server Side Code
Using Apache Commons FileUpload as example.
Upload code (responds to fileUpload.do ):
final HttpSession session = httpServletRequest...
Progress code (responds to uploadProgress.do ):
HttpSession session = httpServletRequest.getSe...
Created by Dr. Xi on June 20, 2010 14:35:17
Last update: June 20, 2010 14:35:17
This XML signature validator comes from the Apache XML Security project. It validates the signature according to the core validation processing rules .
It does not verify that the key used to generate the signature is a trusted key. You can override the KeySelector class to make sure that the signing key is from a trusted store.
import javax.xml.crypto.*;
import javax.xml.cry...
Created by Dr. Xi on June 19, 2010 04:34:01
Last update: June 19, 2010 04:39:13
Java SE 6 contains built-in utilities to generate XML signatures. This is an example that generates XML signatures using a Java keystore. It has options to generate signature for the whole document, for an element with a specific ID, or for elements matched by an XPATH expression.
The XML document used to test is taken from Getting Started with XML Security :
<?xml version="1.0"?>
<PatientRecord>
...
This is the Java code:
import java.io.FileInputStream;
import java.io....
However, it looks like the XPATH transform is not working. The digest generated with XPATH filter is exactly the same as that without it (i.e., the whole document)!
Another reference:
Programming With the Java XML Digital Signature API
Created by Dr. Xi on June 11, 2010 23:11:59
Last update: June 11, 2010 23:14:02
Given a simple XML file like this:
<?xml version="1.0"?> <root id="1"> ... Calling Document.getElementById returns null (surprisingly!): import java.io.*; import org.w3c.dom.*; impo... In fact the JavaDoc says something along the lines that getElementById returns the Element that has an ID attribute with the given value. An attribute with the name "ID" or "id" is not of type ID unless it is so defined. How is an attribute defined as an ID attribute ? With a DTD or schema. If you are not validating the XML, then the API is useless. So, what to do if you want to find an element for which the attribute named "id" has a given value? Several options were offered in GetElementById Pitfalls . One of them is to...
Created by nogeek on April 25, 2010 05:09:14
Last update: April 25, 2010 05:10:46
Oracle Web Cache version used:
Oracle Application Server Web Cache 10.1.2.3.0
...
The test page is a simple Struts action sending a URL redirect:
public ActionForward execute(ActionMapping map...
Web Cache setup
Origin server
Host Name Port
oas.host 7777
Site
Host Name Port URL Path Prefix
webcache.host 80
Test results
Request directly to the OC4J (Oracle Application Server):
C:\work\testAppWebApp2>curl --dump-header - http:/...
Request to Oracle Web Cache:
C:\work\testAppWebApp2>curl --dump-header - http:/...
Notice that Oracle Web Cache correctly translated the host name in the header and HTML page. However, the port number remained that of the Oracle App Server.
Created by Fang on April 01, 2010 22:24:58
Last update: April 02, 2010 02:49:38
In this note I'll show you how to create and package a JSP custom tag. The purpose of this tag is to display a random splash image for a home page, among a set of images. We should be able to add or delete candidate splash images from the WAR archive without the need to change the JSP. This is the intended use of the tag:
<%@ taglib uri="http://custom.tag.com/demo" prefix... In the above example you provide a set of images named splash*.png (e.g., splash1.png, spalsh2.png, ...), and the tag will pick a random one to display when the JSP is rendered. Let's get started. I'll use Maven for this purpose. Create the standard Maven directory structure ./pom.xml ./src ./src/main ./src/main/jav... pom.xml <project xmlns="http://maven.apache.org/POM/4.0.0"... SplashTag.java package tagdemo; import java.util.ArrayList......
