Node.js + MongoDB – Performing CRUD Operations


In this post we will look at how we can implement CRUD operations using Node.js and MongoDB as the database. CRUD stands for Create Read Update Delete. The programming language we would use for this is Javascript based Node.js (Read : Introduction to Node.js) framework and MongoDB as the NoSQL database. And this example is going to […]

JAX-RS : RESTful Webservice using JAX-RS 2.0


In this tutorial I am going to explain how to develop restful web services in java using the opensource JAX-RS 2.0 APIs. Also explains how to write JAX-RS 2.0 client API for invoking the JAX-RS 2.0 web services. In my previous post I wrote about using JAXB to marshall and unmarshal XML data and in that […]

Getting Started with JAXB


There are quite a few APIs out there for processing XML in Java like DOM Parser, SAX Parser, SAX parser to name a few. But there are scenarios and requirements where we have our data in Java beans and we want that data to be transformed into XML or we have some data in XML […]

Binary Search Tree Traversal Implemented in Java


Most of the students fresh out of their engineering studies or those who are still studying will have the concept of Binary Search Trees fresh in their minds. But with most of the people who have been out of college for many years now will kind of be having a not so clear idea of […]

Bean Validation in Java EE 7 – Creating Custom Constraints and Validations


In my previous post I showed how one can make use of the default constraints provided by the Bean Validation API in validatng the model data. Bean Validation API allows the developers to define their own constraints by creating a new annotation and writing the validator which is used to validate the value. In this […]

Bean Validation 1.1 in Java EE 7 – Using Default Constraints


Bean Validation 1.1 (JSR 349) is integrated as part of Java EE 7. The new features of Bean Validation 1.1 are as follows: Applying constraints on method parameters and return values. This can be used in creating a pre and post condition contract. Constraints can be applied to constructors. New API to obtain metadata of […]

Creating Managed Threads Using ManagedThreadFactory in Java EE 7 – Part 3


So far we have seen: In Part-1: Creating ManagedExecutorService to submit a single task or a list of tasks where each task would be an implementation of either Callable or Runnable interface. In Part-2: Creating ManagedScheduledExecutorService for scheduling tasks to run at a later time or to schedule repeating tasks. In this post, which will […]

ManagedScheduledExecutorService for Implementing Concurrency Utilities in Java EE 7 – Part 2


In my previous post you saw how to use the concurrency utilities in Java EE 7 by using the ManagedExecutorService. In this post we will have a look at a variant of this i.e the ManagedScheduledExecutorService. ManagedScheduledExecutorService is used to schedule tasks to be executed in future by specifying the delay in terms of SECONDS, […]

ManagedExecutorService for Implementing Concurrency Utilities in Java EE 7 – Part 1


Prior to Java EE 7 one could make use of the concurrency utilities present in java.util.concurrent package or the java.lang.Thread or java.lang.Runnable. But it was not considered a best practice, not a standard and not safe for the application. This was because the Java EE web and EJB containers instantiate objects using container-managed thread pools […]

Parsing a vCard file to generate a CSV file with the required data


Off late I have been juggling between a Nokia Symbian phone and an Android phone. The issue which I was facing while I juggled between the phones is the availability of contacts across both the devices. My Android phone had all the contacts which I wanted to be transferred to the Symbian phone as well. […]