Devops for Growth

Java Exception Structure Is More Informative Than You Think

Java Exceptions have a structure that is pretty informative and can tell the developer a set of important things (if the developer uses this structure properly). So, here, you can see the basic structure:

The main parent that can catch all possible situations is Throwable which has 2 children: Error and Exception.   

Java Error

Java Error case stands for abnormal situations. Once an Error appears application will be likely shut down.

Java Exception

Java Exceptions, unlike Error, have a chance to recover an application from a problem and try to keep the application up. Exceptions also split into 2 groups:

Exceptions are represented by Runtime and Not Runtime exceptions, also known as checked exceptions. This classification is pretty similar to Error Exceptions but, in that division, the Checked exception is more optimistic in terms of recovery.

Checked and Unchecked Exceptions

In Java, there are 2 types of exceptions. Checked exceptions force developers to create handler exceptions or rethrown them. If a checked exception is rethrown, then the java function has to declare it in its signature. Unchecked exception unline checked doesn't require any handling. Such design meant that unchecked exceptions can't be handled and are doomed to be thrown up to the top parent.  

Exception Handling in Java

There are two ways to process exceptions thrown: Handle it inside the current method or just rethrow it. There is no better way to do it; you might have one parent handler or handle it somehow, e.g. make retry logic.  

Good, Bad, Ugly

After the introduction, we can split all exceptions into 3 groups: Checked, Runtime, and Error. The main idea is that each of them would be thrown into different situations. The most optimistical is a Checked exception. The Runtime would belong to a situation with a small chance of recovery. And, the most pessimistic is Error.  

Properties in the Application Life Cycle

The following figure illustrates how a typical application might manage its configuration data with a Properties object over the course of its execution.

« Si vous téléchargez Java, vous obtenez tout et vous devez vous assurer que vous installez uniquement les composants auxquels vous avez droit et vous devez supprimer ceux que vous n'utilisez pas », ajoute un autre expert en conformité. Il estime que « l’usage général » dont parle Oracle est vaguement défini, ce qui serait source de beaucoup de différends. « Dès le moment où vous, en tant qu'organisation, livrez quelque chose où Java est distribué aux utilisateurs finals (quelque chose que de plus en plus d'entreprises font en distribuant des applications à travers lesquelles les clients peuvent obtenir des produits et des services), ce n'est pas un usage général … et Oracle veut se faire de l'argent à partir de cela », dit-il.

D’après Guarente, ce n’est pas le seul problème. Le fait est que beaucoup de gens « ne sont pas au courant. Ils pensent que Java est gratuit - parce que c'est open source, donc ils peuvent l'utiliser.