Hibernate Annotations is my preferred way to map my entity classes, since they don't require any external file (thus keeping mapping info in your Java files), is fully integrated with all Hibernate mapping capabilities and Hibernate documentation encourages us to use this kind of configuration because it's more efficient.
Annotation driven mapping in Hibernate uses the standard JPA API annotations and introduce some specific extensions to deal with some Hibernate features. You can find a full reference in the official documentation.
Sie wollen die Programmiersprache Java lernen? Dann sind Sie hier genau richtig! Im Java Blog Buch werden nach und nach mehr oder weniger aufeinander aufbauende Lektionen veröffentlicht, so dass am Ende eine Art Buch zur Java Programmierung entsteht. Navigieren Sie sich einfach durch das Kapitelverzeichnis auf der linken Seite oder durchstöbern Sie das Inhaltsverzeichnis!
Gerne dürfen Sie auch interessante Themen vorschlagen, über welche wir dann ggf. bloggen werden.
Aber jetzt wünsche ich Ihnen viel Spaß beim Java lernen!
Ps.: Sollten Sie sich dazu berufen fühlen, einen Beitrag zu diesem Werk zu leisten oder gleich als Autor einzusteigen, so nehmen Sie doch einfach Kontakt zu uns auf.
Hibernate saveOrUpdate trap for web developers and StaleStateException
Summary: Hibernate users should be aware of saveOrUpdate method if they continue to use the same persistent object even if a transaction failed at some point.
Details:
Suppose you have a persistent object bound to your web(like JSF) views. Entered some data (which will lead to a db ConstraintViolationException) and tried to save it (at your DAO service) by using saveOrUpdate method. As we expected, it will throw a ConstraintViolationException and you'll rollback the transaction.
Then, go back to the entry page, correct the wrong field value at the same object, and try to save it again. You'll get a StaleStateException since saveOrUpdate method assigned identifier values automatically to your new object when you attempt to save it first. Later, when the save operation failed, it didn't roll back your object's state to its initial state. The summary of the flow causing this error is as below;
The Java™ programming language made starting a new thread easier than ever before. But freeing your concurrent programs of obscure bugs is a different matter, and Java's programming model might not be the best available. A language called Erlang is getting some good press now in the areas of concurrency, distributed systems, and soft real-time systems.
Citing a need to be able to respond faster to events, and disappointment in the feature set and timeframe for Java 7, the team behind guardian.co.uk is using Scala as an alternative to Java for their new projects. InfoQ spoke to Web Platform Development Team Lead Graham Tackley about their current stack, the reasons behind the move, and the experience of using Scala in large-scale development.
mainly marketing articlle by cofiiunder What if you didn't have to do any of this funny business to get scalability and reliability? What if the JVM had access to a service that you could plug into to make its heap durable, arbitrarily large, and shared with every other JVM in your application tier? Enter Terracotta, network-attached, durable virtual heap for the JVM. In the spirit of full-disclosure, I'm a co-founder of Terracotta and work there as a software developer. Terracotta is an infrastructure service that is deployed as a stand-alone server plus a library that plugs into your existing JVMs and transparently clusters your JVM's heap. Terracotta makes some of your JVM heap shared via a network connection to the Terracotta server so that a bunch of JVMs can all access the shared heap as if it were local heap. You can think of it like a network-attached filesystem, but for your object data; see Figure 1.
We have used Spring Roo in a web project and show how we generated an early prototype and transistioned to early development and then to production code.
The mock-object testing pattern has commonly been used to test an individual unit of code without testing its dependencies. While this pattern works well for interaction-based testing, it can be overkill for state-based testing. Learn how to streamline your unit-testing using stubs and the pseudo-objects testing pattern.
Jersey 1.0 is an open-source, production-ready reference implementation of JAX-RS, the Java API for RESTful Web Services (JSR-311). Jersey makes it easy to create RESTful web services in Java.
In an earlier Tech Tip, Implementing RESTful Web Services in Java, Paul Sandoz and I introduced RESTful Web Services, JAX-RS, and Jersey, and showed how to write RESTful web services in Java that conform to the JAX-RS specification. In this tip you will learn how to configure data in JSON (JavaScript Object Notation) using Jersey 1.0. JSON is a lightweight data-interchange format that is based on the object notation of the JavaScript language. Because of it's simple text format, JSON provides a good alternative to other data interchange formats such as XML and is particularly attractive as a data interchange format for RESTful web services.
In this tip you will build a Jersey-based web application that provides information about printer status. The application returns the information in JSON format. To build the application, you will use the Maven 2 software project management tool. For more information about Maven, see Welcome to Maven and Building Web Applications with Maven 2.
The Brazilian National Healthcare System has been called the largest Enterprise Java application ever built, with over 2M lines of code, and a domain model of 350 classes. The application models all of the domain concepts one could imagine in a country-wi
I just saw this page comparing the performance of several languages on a simple Mandelbrot set generator. His numbers show Java being over twice as slow as C, but then I noticed that he's using an older version of java and only running the test once, whic