The N+1 problem is a common issue when working with ORM solutions. It happens when you set the fetchType for some @OneToMany relation to lazy, in order to load the child entities only when the Set/List is accessed. Let’s assume we have a Customer entity with two relations: a set of orders and a set of addresses for each customer. ...

Using an ORM to abstract from your specific database and to let it create and issue all the SQL statements you would have to write by hand yourself seems handy. This is what made ORM solutions popular. But it also comes with a downside: As the ORM does a lot of work for you, you lose to some degree control ...

When you design a new API you have to take a lot of decisions. These decisions are based on a number of design principles. Joshua Bloch has summarized some of them in his presentation “How to Design a Good API and Why it Matters”. The main principles he mentions are:             Easy to learn Easy ...

JSON (JavaScript Object Notation) is a compact text file format that can be used to store and transfer data. It has become very popular over the years as it is very simple to read and parse. Beyond that each JSON construct should be valid JavaScript and it should be possible to evaluate it using JavaScript’s eval() function. The latter has ...

One year has passed by since the Java EE 7 specification has been published. Now that Wildfly 8 Final has been released, it is time to take a closer look at the new features. One thing which was missing since the beginning of the Java EE days is the ability to work with fully-fledged Java EE threads. Java EE 6 ...

Dependency injection is a great technology for the organization of class dependencies. All class instances you need in your current class are provided at runtime from the DI container. But what about your configuration? Of course, you can create a “Configuration” class and inject this class everywhere you need it and get the necessary value(s) from it. But CDI lets ...

Sometimes there is the need to intercept certain method calls in order to execute your own logic everytime the intercepted method is called. If you are not within in Java EE’s CDI world and don’t want to use AOP frameworks like aspectj, you have a simple and similar effective alternative. Since version 1.5 the JDK comes with the class java.lang.reflect.Proxy ...

A common requirement for enterprise applications is to have all JSF pages protected behind a login page. Sometimes you even want to have protected areas inside the application that are only accessible by users that own a specific role. The Java EE standards come with all the means you need to implement a web application that is protected by some security ...

The upcoming version of JBoss Application Server will no longer use Tomcat as integrated webserver, but will replace it with undertow. The architecture of undertow is based on handlers that can be added dynamically via a Builder API to the server. This approach is similar to the way of constructing a webserver in Node.js. It allows developers to embed the ...