After a user resets a password, I want to force the user to change the password before she gets access to secured content. This is usually done with a servlet filter. But with Spring MVC, you can also use a HandlerInterceptor . According to Spring JavaDoc: HandlerInterceptor is basically similar to a Servlet 2.3 Filter, but in contrast to the latter it just allows custom pre-processing with the option of prohibiting the execution of the handler itself, and custom post-processing. Filters are more powerful, for example they allow for exchanging the request and response objects that are handed down the chain. Note that a filter gets configured in web.xml, a HandlerInterceptor in the application context. As a basic guideline, fine-grained handler-related preprocessing tasks are candidates...

Example code: import javax.xml.ws.BindingProvider; import jav... Wierdly, even though the response context ( ctx ) itself is a Map, you cannot iterate through the keys. This: for (String key: ctx.keySet()) { logger.inf... fails: WARN : InternalError - Handler execution resulted ...

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.*; ...

This is an example that uses tag handler, UI component and renderer together to support a custom taglib. The main purpose is to show how these components play together. The tag renders <ui:param name="extra" value="el interpreted"/> ... as <h3>my:foreach</h3> <ul class="css class" extra... These are the files: The tag handler ( src/main/java/com/example/ForeachTagHandler.java ): package com.example; import java.util.Map; ... The UI component ( src/main/java/com/example/UIForeach.java ): package com.example; import java.io.IOExcep... The renderer ( src/main/java/com/example/ForeachRenderer.java ): package com.example; import java.io.IOExcep... Faces config ( src/main/resources/META-INF/faces-config.xml ): <?xml version="1.0" encoding="UTF-8"?> <faces-c... Taglib config ( src/main/resources/META-INF/foreach.taglib.xml ): <?xml version="1.0" encoding="UTF-8"?> <facelet...

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:...

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...

Syntax highlighted XML schema for JSF 2.0 Application Configuration Resource File ( faces-config.xml ). Almost 3000 lines! <?xml version="1.0" encoding="UTF-8"?> <xsd:sch...

Given a class A : class A { public int doWork(String s, int i... it is OK to call method doWork with both primitive types and the corresponding wrapping object types: new A().doWork("Hello", 1, false); new A().doWo... However, if you find method by parameter types with Java reflection, the types must match exactly, i.e., Class<?> c = Class.forName("A"); // This call f... This is a utility to find methods with compatible parameter types: import java.lang.reflect.*; import java.util.*;... Example usage: Method m = ReflectionUtil.getCompatibleMethod(c, "...

This is a utility to convert a string value to one of the primitive type values. It is useful in Java reflection code where the value comes in as a string (e.g., from XML parsing), and the type of the value cannot be decided until runtime. import java.util.*; import java.lang.reflect.*;... Note: This method can be extended to convert string to more complex types by writing a converter for the destination type. For example, to convert string to date: public class DateConverter { public static ... Usage: Date d = (Date) ConvertUtil.convert("10/12/2010", ...

Firefox and Google chrome has native support for the trim function for a String. IE (as of IE 8.0) does not provide a trim function for String. Using the JavaScript Executor , if you execute: 'abcd '.trim you get: function trim() { [native code] } in Firefox and Google Chrome. But you get nothing in IE. If you try to execute the trim method on a String: 'abcd '.trim() you get this in IE: TypeError: Object doesn't support this property or... In order to have the trim function across all browsers, define this function: if(typeof String.prototype.trim !== 'function') { ... Or, if you use jQuery, you can use $.trim()