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Created by Dr. Xi on April 20, 2011 21:44:15    Last update: May 02, 2011 20:56:58
The String.format() method provides versatile formatting capabilities. This tutorial tries to present these capabilities in a accessible manner. The format string A format string can contain zero, one, or more format specifiers . The general form of a format specifier is: %[argument_index$] [flags] [width] [.precision]co... where things in square brackets are optional, and conversion is a character indicating the conversion to be applied to the corresponding variable value. The only required characters in the format specifier is the percent sign % and the conversion character. A simple example: public static void simpleFormat() { System.out... The Argument index The argument index is specified by a number, terminated by the dollar sign $ . The same argument may be repeated multiple times in a format string. Unindexed...
Created by jinx on April 25, 2011 12:43:40    Last update: April 25, 2011 12:43:40
Use the PHP function method_exists to check if the class or object has a certain method. It returns TRUE if the method exists (even when the value of the property is NULL), FALSE if the method does not exist. Example: <?php class A { var $p = 'A property'; ... Outputs: Class A has method f1: bool(true) Object $a has... Also note that C++-like method overloading does not exist in PHP. Thus there's no ambiguity about which version of the method exists, i.e., with no argument, with one argument... etc. The following code generates Fatal error: <?php class A { var $p = 'A property'; ...
Created by James on June 30, 2010 20:14:28    Last update: July 03, 2010 18:41:12
The HTML page <!DOCTYPE html> <html> <head> <title>jQu... Client Side Code // called before upload submit function sta... Server Side Code Using Apache Commons FileUpload as example. Upload code (responds to fileUpload.do ): final HttpSession session = httpServletRequest... Progress code (responds to uploadProgress.do ): HttpSession session = httpServletRequest.getSe...
Created by Fang on April 03, 2010 20:21:15    Last update: April 04, 2010 03:30:22
The tags <c:out> The <c:out> tag evaluates an expression and outputs the result on the page. The syntax is: <c:out value="value" [escapeXml="{true|false}"] ... where escapeXml defaults to true and default defaults to empty string "". <c:out value="${expr}" escapeXml="false"/> is equivalent to ${expr} . If a variable is set in multiple scopes, the lower scope wins. In the following example code, attribute1 is set in request, session, and application scopes; attribute2 is set in session and application scopes; attribute3 is set in the application scope. The results are: <c:out value="${attribute1}"/> : Attribute1 request scope <c:out value="${attribute2}"/> : Attribute2 session scope <c:out value="${attribute3}"/> : Attribute3 application scope To access values in higher scopes, you have to specify the scope explicitly, like this: <c:out value="${sessionScope.attribute1}"/> : Attribute1 session...
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......