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...

There is no XSLT 2.0 support in the JDK as of 7.0. According to Stackoverflow , there are three Java packages that support XSLT 2.0: Saxon IBM WebSphere XML Feature Pack Oracle XDK There are no known support for XSLT in browsers. According to Wikipedia : XSLT is developed by the World Wide Web Consortium (W3C). The most recent version is XSLT 2.0, which reached W3C recommendation status on 23 January 2007. As of 2010, however, XSLT 1.0 is still widely used, as there are no products that support XSLT 2.0 running in the browser, nor on some important server environments such as LAMP. Expressions like this: format-date(xs:date('1999-12-31'), '[D01] [MNn] ... where format-date is a XSLT 2.0 function and date is a XPath 2.0 constructor...

Experts may disagree but I found it absolutely stunning that JSF EL does not provide an operator for string concatenation. The Java "+" operator is there for the take. Java, which is a strongly typed compiled language, overloads the "+" operator in such a way that any object can be concatenated with a string. But JSF EL, which definitely isn't as strongly typed as Java, restricts the "+" operator to numerical values only! Of course, experts may argue that the "+" operator overloading is a huge design flaw of the Java language. But even so, JSF EL is not the right place to fix it! In some cases, a concatenation operator isn't needed, for example: <ui:repeat var="tab" value="#{tabs}"> <img ... But in case the concatenated...

Facelet taglib schema from JavaServer Faces Spec 2.0: <xsd:schema targetNamespace="http://java.sun.com/x...

JSTL was built for Java Server Pages (JSPs). With the coming of JSF 2.0, facelets, instead of JSP , is the preferred page rendering technology. Facelets exposes a subset of the JSTL Core tag library and the entirety of the JSTL Function tag library. The JSTL tags available in facelets are: c:set c:if c:forEach c:choose c:when c:otherwise c:catch

The String.trim function trims spaces from both ends. There's no built-in function to trim only the right side or left side. To right trim: String trimmed = original.replaceAll("\\s+$", ""); To left trim: String trimmed = original.replaceAll("^\\s+", "");

For Android, there's no entry function like " public static void main() " in Java. The main activity is declared by intent-filter in AndroidManifest.xml : <intent-filter> <action android:name="andro... The category LAUNCHER declaration puts it in the Launcher . The action MAIN means this is the activity to start when the application icon is clicked in the Launcher. In fact, the Android ActivityManager starts the main activity with the intent: { act=android.intent.action.MAIN cat=[android.inte...

It seems that the JDBC standard way to create a BLOB is to call Connection.createBlob . However, this does not work for PostgreSQL (as of version 9.0-801 jdbc4): Exception in thread "main" org.postgresql.util.PSQ... The workaround is to call a PostgreSQL function to create the Blob, then use JDBC to update it: Connection conn = jdbcTemplate.getDataSource().get... Oracle Note: the Oracle way function to create an empty BLOB is EMPTY_BLOB() . stmt.execute ("INSERT INTO my_blob_table VALUES ('...

The tags XML flow control tags are exactly the same as their Core flow control equivalents, except that the test condition with a boolean EL expression is replaced by the select condition with an XPath expression. In the case of the forEach tag, the items attribute is replaced with the select attribute. In a test condition, the XPath expression is evaluated to a boolean value by the rules of the XPath boolean() function, which converts its argument to a boolean as follows: a number is true if and only if it is neither positive or negative zero nor NaN. a node-set is true if and only if it is non-empty. a string is true if and only if its length is non-zero. an object of...

JSTL uses XPath expressions as a concise notation to specify or select parts of an XML document. JSTL provides EL like expressions to access web application data and comes with the core function library of the XPath specification. Accessing Web Application Data XPath Expression Mapping $foo pageContext.findAttribute("foo") $param:foo request.getParameter("foo") $header:foo request.getHeader("foo") $cookie:foo maps to the cookie's value for name foo $initParam:foo application.getInitParameter("foo") $pageScope:foo pageContext.getAttribute("foo", PageContext.PAGE_SCOPE) $requestScope:foo pageContext.getAttribute("foo", PageContext.REQUEST_SCOPE) $sessionScope:foo pageContext.getAttribute("foo", PageContext.SESSION_SCOPE) $applicationScope:foo pageContext.getAttribute("foo", PageContext.APPLICATION_SCOPE) For example, to find the bar element whose x attribute equals the value of the HTTP request parameter named paramName : /foo/bar[@x=$param:paramName] Java Type to XPath Type Mappings XPath Type Java Type java.lang.Boolean boolean java.lang.Number number java.lang.String string Object exported by <x:parse> node-set Please note that JSTL, as of version 1.2,...