Devops for Growth

In Java 7, resource cleanup was automated by means of the try-with-resources block. In practice, this new syntax allows you to declare resources that are part of the try block. You define the resources ahead of time and the runtime automatically closes those resources (if they are not already closed) after the execution of the try block.

A resource can be any object that implements the interface java.lang.AutoCloseable.

Although the try-with-resources block can have a finally or catch block, it is not mandatory.

Cet article a pour objectif de présenter les Design Patterns du "Gang of Four" avec des exemples concis appliqués à Java.
Chaque Design Pattern est présenté avec son diagramme de classes, ses objectifs, les motivations pour l'utiliser, les responsabilités des classes le constituant, puis une implémentation simple.

Table of Contents

1. Java Preferences API
2. Exercise: Using the API
2.1. Create program
2.2. Validate
3. About this website
3.1. Donate to support free tutorials
3.2. Questions and discussion
3.3. License for this tutorial and its code
4. Links and Literature
4.1. vogella Resources

Je suis régulièrement amené à recevoir des candidats de tous niveaux afin de procéder à une évaluation technique et une de mes questions fétiches concerne `equals` et `hashCode`. Tout développeur se doit évidemment d'être parfaitement affûté sur ce sujet on ne peut plus basique. Pourtant, la réalité montre que la majorité des réponses sont au mieux incomplètes et bien souvent totalement fausses.

Oracle is targeting a Java 9 GA release date of September 2016. The schedule follows Oracle’s plans to release a new major version every two years, although contrasting to previous releases the currently proposed deadline might be at risk for some slippage.

Java 8 has a new feature called Default Methods. It is now possible to add method bodies into interfaces!

These issues are discussed in context on this page and are also listed in this section of Hibernate Guidelines.

No communication with the database should occur outside of a database transaction. Doing so will probably result in synchronization issues. Transactions should also not encompass user think time. Details are of how it's done is discussed in the Defining Transaction Bounds section of this page.
createQuery() can easily be passed a tainted SQL or HQL string, dialect is irrelevant. The proper way to construct a sql string hibernate style is to use Query and SQLQuery's setParameter(), setString(), setXXX() methods for named parameter and placeholder binding. Just like prepared statements. Details are discussed in the Creating Queries section of this page.
Persisting tainted objects is stored xss. Since stored XSS is generally hard to find with static tools, it is best to sanitize all data going in rather than waiting for it to show up on a jsp somewhere. Details of these functions are discussed in the Persisting Tainted Data section of this page.
An application should rollback and discard Session instance on error. So if the Session throws an exception, the catch block should have rollback() and finally should call Session.close(). This applies to any SQLException. Pretty cut and dry, see Example1 above.
You may not mix and match JDBC-style parameters ("?") and named parameters (:namedparam) in the same query.
Person aPerson = (Person) session
.createQuery("select :somenamedparameter from ? where x = :someothernamedparameter");
Transaction.setTimeout(int) should be called to ensure that misbehaving transactions do not tie up resources in definitely.
Session sess = factory.openSession();
try {
//set transaction timeout to 3 seconds
sess.getTransaction().setTimeout(3);
sess.getTransaction().begin();
// do some work
...

Ce tutoriel a pour but de présenter la sérialisation XML en Java. Il commence par les bases et continue sur les fonctionnalités plus complexes qui vous permettront une maîtrise totale de ce mécanisme.

Table of Contents

1. Overview
1.1. Logging
1.2. Logging in Java
1.3. Create a logger
1.4. Level
1.5. Handler
1.6. Formatter
1.7. Log Manager
1.8. Best Practices
2. Example
2.1. Create the logger
2.2. Use the logger
3. About this website
3.1. Donate to support free tutorials
3.2. Questions and discussion
3.3. License for this tutorial and its code
4. Links and Literature