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Created by Fang on November 08, 2011 20:55:00    Last update: November 21, 2011 18:19:44
In the simple taglib example , I used a tag handler class to implement a taglib. This is an example to implement a taglib with a UI component. The purpose is to use a custom tag to split a string and print each part in a separate paragraph, i.e., print <p>john</p> <p>steve</p> <p>mike</p> with custom tag <my:foreach> : <my:foreach var="who" value="john steve mike"> ... These are the files: pom.xml <project xmlns="http://maven.apache.org/POM/4.0.0"... src/main/java/com/example/UIForeash.java : package com.example; import java.io.IOExcep... src/main/resources/META-INF/faces-config.xml : <?xml version="1.0" encoding="UTF-8"?> <faces-c... src/main/resources/META-INF/foreach.taglib.xml : <?xml version="1.0" encoding="UTF-8"?> <facelet... How to use: Put the JAR file generated by the above project in the WEB-INF/lib folder of the web app. If the web app is a Maven project, just add the taglib project as a dependency:...
Created by Dr. Xi on June 22, 2011 09:42:35    Last update: June 22, 2011 11:39:40
Demo code for CSV parsing with Skife CSV . Java code: import java.io.*; import java.util.*; import... Test with a simple CSV file: psmith01,CLASS2B,Peter Smith 1,YEAR2,1,N,ADVANCED,... The parser worked correctly: Line 1 has 11 values: |psmith01| |CLASS2B|... Test with a more complicated CSV file: "psmith01 abc", "CLASS2B " , " Peter... Result: Line 1 has 4 values: |psmith01 abc| | CLAS... The parser worked correctly. But notice that it counts the spaces outside of the quotes significant, and doing so consistently. One more test for spaces: "Smith, Jack" , "210-345-8888" "Smith, Jack"... Result: Line 1 has 2 values: | Smith, Jack | | 210... Add a new line in item two: "One", "Two ", "Three" Result: Line 1 has 2 values: |One| | Two| L...
Created by freyo on May 23, 2011 14:30:18    Last update: May 23, 2011 14:31:08
There are two distinct ways to process XPath: with namespace and without namespace. The code is different depending on whether the parser is namespace aware. Code without namespace: import java.io.*; import javax.xml.parsers.*; ... code with namespace: import java.io.*; import java.util.Iterator; ... XML without namespace: <?xml version="1.0" encoding="UTF-8" standalone="n... XML with namespace: <?xml version="1.0" encoding="UTF-8" standalone="n... The same XPath expression works for both XML files when the parser is not namespace aware. When the parser is namespace aware, you have to adjust the XPath accordingly depending on whether the XML has namespace declarations: " /test-license/licensee/name/text() " works for the XML file without namespace, while " /p:test-license/p:licensee/p:name/text() " works for the XML file with namespace.
Created by Dr. Xi on October 26, 2010 16:07:40    Last update: October 26, 2010 16:07:40
This is a more generic version, which can be expanded to accommodate additional file signatures. import java.io.*; import java.util.*; pu...
Created by Fang on August 17, 2010 19:27:32    Last update: August 17, 2010 19:27:32
Get the length of a collection The length function returns the size of a collection. It can be applied to any object supported by the JSTL core tag <c:forEach> , namely: Arrays Implementation of java.util.Collection Implementation of java.util.Iterator Implementation of java.util.Enumeration Implementation of java.util.Map String When used on String , it returns the number of characters in the string. Test it Make these additions to the expanded test application : Create a new Java class LengthFunction : package jstl.demo.handler; import java.... Create a new JSP ( lengthfunction.jsp ) under webapp : <%@ taglib uri="http://java.sun.com/jsp/jstl/c... Compile and package the WAR with: mvn package Deploy the WAR to a servlet container of your choice (for example, Tomcat or JBoss). Test the page with this URL...
Created by Dr. Xi on July 21, 2010 22:14:53    Last update: July 21, 2010 22:14:53
This is a Java program to test XPATH expressions with namespace option. It's been tested with JDK1.6. import java.io.FileInputStream; import java.uti... Following Getting Started with XML Security , these are the test files: Without namespace (patient.xml). <PatientRecord> <Name>John Doe</Nam... With namespace (patient_ns.xml). <med:PatientRecord xmlns:med="http://www.medic... Test results: C:\>java XPathExample patient.xml /PatientRecord/V...
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......
Created by Dr. Xi on November 19, 2008 00:22:27    Last update: January 07, 2010 23:00:36
There is a open source project named [ini4j] for processing Windows .ini configuration files. However, I found it an overkill for my purposes. So here is my simple implementation of a .ini parser. It mimics the standard java.util.Properties class with enhancements to get and set properties by section name. There are only a few simple rules: Leading and trailing spaces are trimmed from section names, property names and property values. Section names are enclosed between [ and ] . Properties following a section header belong to that section Properties defined before the appearance of any section headers are considered global properties and should be set and get with no section names. You can use either equal sign ( = ) or colon ( : )...