There are many frameworks available for building Java or Groovy-based web applications, with the most popular Groovy options being Grails or Gaelyk for Google App Engine development. Fortunately however, a lot of the functionality required for building simple web applications is built into the Groovy library itself. Groovy Servlets Support for executing arbitrary Groovy ...

Something I have always lamented about OSGi is a lack of simple examples to get up and running quickly. So here is a simple example using Groovy: First, dependencies are easily added via Maven, adding the following to your pom.xml should do it. [code] <dependencies> <dependency> <groupId>org.codehaus.groovy</groupId> <artifactId>groovy-all</artifactId> </dependency> <dependency> <groupId>org.apache.felix</groupId> <artifactId>org.apache.felix.framework</artifactId> <version>4.0.2</version> </dependency> </dependencies> [/code] Then a simple Groovy script to start ...

A simple way to prevent running of multiple instances of your application is to use Socket communication. For example, in Groovy the first thing you would execute is something like this: [code] try { // choose a unique port (!!) new Socket('localhost', 1337) ...

Sometimes we may have more than one implementation and/or instance of a service to which we need to route requests. Routing may be controlled by a number of different factors, such as the request type, request arguments, runtime configuration, etc. An implementation of such routing might look something like this: [java] public interface ...

Typically object caching in Java is managed by the container or framework in use. Occasionally however there is a need to manually cache domain-specific objects, whereby a java.util.Map implementation will not suffice. Using the popular ehcache framework as an example, the following pattern is typically observed: [java] public class SomeClass { private ...