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:...

From the Java Language Specification : Because some type information is erased during compilation, not all types are available at run time. Types that are completely available at run time are known as reifiable types . A type is reifiable if and only if one of the following holds: It refers to a non-generic type declaration. It is a parameterized type in which all type arguments are unbounded wildcards. It is a raw type. It is a primitive type. It is an array type whose component type is reifiable. For example: int is a reifiable type (primitive type) List is a reifiable type (raw type) List<?> is a reifiable type (parameterized type with unbound wildcards) List<String> is not a reifiable type (generic type) Class<?> is...

This is a simple doclet that prints all public methods and their parameter names and types. Code import com.sun.javadoc.*; public class List... Compile javac -cp $JAVA_HOME/lib/tools.jar:. ListMethodsDo... Use javadoc -doclet ListMethodsDoclet -sourcepath /pat...

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", ...

For Java arrays, the class name is [ followed by an encoded name of the element class. The number of [ characters represents the number of dimensions of the array. The class name encoding is following: Element Type Encoding boolean Z byte B char C class or interface L classname; double D float F int I long J short S Example: public class ClassNameEncoding { public sta...

There are two ways to get the Class object for primitive types: Type name followed by .class : Class intClass = int.class TYPE field for the corresponding wrapper class: Class doubleClass = Double.TYPE; Class.forName() does not work for primitive types. But it works for primitive arrays: Class c1 = int[].class; Class c2 = Class.forNam...

Java reflection with Apache beanutils example. import org.apache.commons.beanutils.MethodUtils; ...

The PHP function strval returns the string value of a variable. It does the same thing as casting a variable to string, or automatic conversion where string is expected. Conversion rules: Type String Value Boolean TRUE '1' Boolean FALSE '' (empty string) integer of float string representing the number Array The string 'Array' Object Result of __toString() if defined, error otherwise Resource 'Resource id #n' , where n is a number assigned to the resource. NULL '' (empty string) Example: <?php set_error_handler(function($errno, $errst... Results: bool(true) --------------------- strval: '1'...

List of functions testing variable type: Function Description is_bool Finds out whether a variable is a boolean is_double Alias of is_float() is_float Finds whether the type of a variable is float is_int Find whether the type of a variable is integer is_integer Alias of is_int() is_long Alias of is_int() is_null Finds whether a variable is NULL is_numeric Finds whether a variable is a number or a numeric string is_object Finds whether a variable is an object is_real Alias of is_float() is_scalar Finds whether a variable is a scalar is_string Find whether the type of a variable is string Test code: <?php class A { } $a = ar... Output: var_dump: int(1) ------------------------- i...