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An Example explaining on how @Required annotation from Spring Framework works. Provides sample on how to use @Required and expected exception if beans are not properly configured like BeanInitializationException or Property is required for bean.

The aim of this paper is a brief introduction to MDA technology and a summary / comparison to the approachments to MDA of AndroMDA and Acceleo, intending to be a practical and understandable summary Introduction Model-driven architecture (MDA) is a software design approach for the development of software systems. It provides a set of guidelines for the structuring of specifications, which are expressed as models. It was launched by the Object Management Group (OMG) in 2001 The Model-Driven Architecture approach defines system functionality using a platform-independent model (PIM) using an appropriate domain-specific language (DSL). One of the main aims of the MDA is to separate design from architecture. As the concepts and technologies used to realize designs and the concepts and technologies used to realize architectures have changed at their own pace, decoupling them allows system developers to choose from the best and most fitting in both domains. The design addresses the functional (use case) requirements while architecture provides the infrastructure through which non-functional requirements like scalability, reliability and performance are realized. MDA envisages that the platform independent model (PIM), which represents a conceptual design realizing the functional requirements, will survive changes in realization technologies and software architectures.

There are many approaches available to scale PostgreSQL beyond running on a single server. An outline of the terminology and basic technologies involved is at High Availability and Load Balancing. There is a presentation covering some of these solutions. There is no one-size fits all replication software. You have to understand your requirements and how various approaches fit into that. For example, here are two extremes in the replication problem space: You have a few servers connected to a local network you want to always keep current for failover and load-balancing purposes. Here you would be considering solutions that are synchronous, eager, and therefore conflict-free. Your users take a local copy of the database with them on laptops when they leave the office, make changes while they are away, and need to merge those with the main database when they return. Here you'd want an asynchronous, lazy replication approach, and will be forced to consider how to handle conflicts in cases where the same record has been modified both on the master server and on a local copy. These are both database replication problems, but the best way to solve them is very different. And as you can see from these examples, replication has a lot of specific terminology that you'll have to understand to figure out what class of solution makes sense for your requirements. A great source for this background is in the Postgres-R Terms and Definitions for Database Replication. The main theoretical topic it doesn't mention is how to resolve conflict resolution in lazy replication cases like the laptop situation, which involves voting and similar schemes.

Caching is the most important performance optimization technique. There are many things that can be cached in persistence, objects, data, database connections, database statements, query results, meta-data, relationships, to name a few. Caching in object persistence normally refers to the caching of objects or their data. Caching also influences object identity, that is that if you read an object, then read the same object again you should get the identical object back (same reference). JPA 1.0 does not define a shared object cache, JPA providers can support a shared object cache or not, however most do. Caching in JPA is required with-in a transaction or within an extended persistence context to preserve object identity, but JPA does not require that caching be supported across transactions or persistence contexts. JPA 2.0 defines the concept of a shared cache. The @Cacheable annotation or cacheable XML attribute can be used to enable or disable caching on a class.

"The PHP/Java Bridge is an implementation of a streaming, XML-based network protocol, which can be used to connect a native script engine, for example PHP, Scheme or Python, with a Java virtual machine. It is up to 50 times faster than local RPC via SOAP, requires less resources on the web-server side. It is faster and more reliable than direct communication via the Java Native Interface, and it requires no additional components to invoke Java procedures from PHP or PHP procedures from Java. "

"Community Dashboard Framework (CDF) is a project that allows you to create friendly, powerful, fully featured dashboards on top of the Pentaho BI server. Former Pentaho dashboards had several drawbacks from a developer's point of view. The developing process was awkward, it required know-how of web technologies and programming languages, and basically it was time-consuming. CDF emerged as a need for a framework that overcame all those difficulties. The final result is a powerful framework featuring the following: . It is based on Open Source technologies. . It separates logic (JavaScript) of the presentation (HTML, CSS) . It features a life cycle with components interacting with each other . It uses AJAX . It is extensible, which gives the users a high level of customization: . Advanced users can extend the library of components. . They also can insert their own snippets of JavaScript and jQuery code. CDF can be used: . As part of a Pentaho solution. This is the most common scenario. . In a standalone mode as an alternative to the Pentaho User Console . Integrated with Portlets, PHP applications, intranet portals and even desktop applications. "

" OT/J: extreme modularity Whenever modularity gets tricky, OT/J provides just one more dimension for your architecture. With OT/J there's no excuse for any architectural workarounds. OT/J: extreme reuse With OT/J any existing piece of Java code is reusable. Existing components can be adapted to specific needs in full adherence to your projects requirements and without compromising a crisp modular architecture. The fabric for quality software OT/J is the fabric from which high quality software can be produced: flexible, durable, elegant. OT/J in the Wiki"

Google provides a scalable application hosting environment called Google App Engine (GAE). One of the many benefits of GAE is that hosting small scale applications is 100% free. Google starts charging for hosting when your application resource requirements start to grow.

Papyrus is aiming at providing an integrated and user-consumable environment for editing any kind of EMF model and particularly supporting UML and related modeling languages such as SysML and MARTE. Papyrus provides diagram editors for EMF-based modeling languages amongst them UML 2 and SysML and the glue required for integrating these editors (GMF-based or not) with other MBD and MDSD tools. Papyrus also offers a very advanced support of UML profiles that enables users to define editors for DSLs based on the UML 2 standard. The main feature of Papyrus regarding this latter point is a set of very powerful customization mechanisms which can be leveraged to create user-defined Papyrus perspectives and give it the same look and feel as a "pure" DSL editor.

"Businesses involve a lot of functions and in any company, large or small, dedicated departments handle the functions assigned to them. This compartmentalization ensures that experts in the respective domain handle things efficiently. But as the company grows there arises a situation when too much time and resources are wasted when each of the departments carry out functions that are redundant. For example, it is too expensive when both the purchase team and the warehouse management team maintain the same list of products but each in their own format. That may be a tiny part of how Enterprise Resource Planning (ERP) can help you avoid redundancies to run an efficient business. Based on the size of the company and requirements, ERP packages are available from a few thousand to millions of dollars. Today we'll check out how to set up Openbravo, a modern and professionally backed open source ERP that is cost effective to acquire, operate and upgrade."

Sample of using Hibernate Annotations by reducing XML configuration files thus making it simpler to define required metadata directly into our Java code. When using annotations, we no longer need the additional mapping file (*.hbm.xml). The metadata for the ORM is specified in the individual classes.

"sbt is a simple build tool for Scala projects that aims to do the basics well. It requires Java 1.5 or later. "

UNICASE is a CASE-Tool integrating models from the different development acitivities, such as requirements, use cases, UML models, schedules, bug and feature models into a unified model. This unified model is highly traceable by design. The UNICASE client allows to view and edit these models in a textual, tabular and diagram visualization. The models are stored and versioned on a server comparable to svn but customized for models. Client and server are easily extensible to support integrating new models into the unified model. UNICASE is based on the Eclipse platform including EMF and GMF. It can also be used as a framework to build modeling applications that reuse its repository and visualization capabilities. The project is open-source and released under the Eclipse Public License v 1.0 (EPL). It builds on our experience from the Sysiphus project in building a CASE tool.

Provide mechanisms for integrating Java security providers into Eclipse: Applications that need to implement security related functionality require cryptographic services upon which to build. Java provides the Java Cryptography Architecture (JCA) as a mechanism for installing implementations of several interfaces used for cryptography, including MessageDigest, Signature, KeyStore, Certstore, and more. In a typical Java application, these implementations reside in the extensions directory of the JRE. In a dynamic Eclipse application, the appropriate packaging mechanism is in Eclipse plug-ins. The goal is to allow JCA to be used in an Eclipse environment while maintaining the programming model of the JCA subsystem. A related goal is to expose the configuration of the JCA system via an Eclipse-based user interface, allowing authorized users to inspect and modify the Security object.

"At this point, the only source of useful overview documentation for the Common Navigator are the excellent tutorials at Michael Elder's (the author of the CN) blog. Soon I hope to get some of this transferred into the Eclipse Plugin Developer's Guide. RCP applications can quickly and easily use the CN to show the resources in the workspace. This assumes that your RCP application uses resources (which is another discussion). The CN can also be used for non-resource RCP applications, in that case, these instructions don't apply, as the objects treated by the CN have to be created directly by the RCP application. If you are planning to use the CN in an RCP application that uses resources, there are 3 (2 of which are completely undocumented) things you must do:"

Knowledge Discovery Metamodel (KDM) is publicly available specification from the Object Management Group (OMG). KDM is a common intermediate representation for existing software systems and their operating environments, that defines common metadata required for deep semantic integration of Application Lifecycle Management tools. KDM was designed as the OMG's foundation for software modernization, IT portfolio management and software assurance. KDM uses OMG's Meta-Object Facility to define an XMI interchange format between tools that work with existing software as well as an abstract interface (API) for the next-generation assurance and modernization tools. KDM standardizes existing approaches to knowledge discovery in software engineering artifacts, also known as software mining.

"A hub for integrating your enterprise with the rich information available on the Web, the WSO2 Mashup Server leverages popular Web 2.0 formats and protocols into your service platform. Combining simple yet rich mashups with reusability, security, reliability, and governance, the WSO2 Mashup Server includes features for connecting Web Services to humans through Web pages, gadgets, feeds, instant messages, email and more. The WSO2 Mashup Server offers: Go Cloud-Native WSO2 Mashups as a Service gives you instant self-service provisioning, multi-tenancy and has built-in monitoring and metering capabilities. Increase productivity Reduce cost Gain more control Avoid vendor lock-in The ideal platform for defining composite services for user interfaces and mobile applications. A simple way to deploy services developed in JavaScript. Access to REST and WS-* web services, feeds, and scraped web pages with data scripted together quickly using common Web developer skills, the result being a new service, or a web page, gadget, email or instant message. The ability to secure hosted Mashups. Support for both recurring and longer-running tasks and service lifecycles. Monitoring, configuration of security and quality of service settings such as throttling. With no up-front license agreements or subscription fees, getting started with the WSO2 Mashup Server requires less developer effort, ensuring faster ROI."

"The Open Services for Lifecycle Collaboration (OSLC) is an open (creative commons) REST based service specification aimed at improving/simplifying Application Lifecycle Management (ALM) system integration. A number of aspects of ALM integration are covered by OSLC ranging from Requirements Management to Automation(Build/Deploy). The OSLC Change Management (CM) spec outlines a standard for creating, modifying, and querying for change requests (tasks) from OSLC based service providers. A goal of the Mylyn project is to implement a client for OSLC-CM (see [1]). Additionally, support for both OSLC Automation and OSLC SCM are part of the Mylyn restructuring proposal: http://www.eclipse.org/project-slides/mylyn-restructuring-review.html Once these plans have solidified, we can begin to fill out the roadmaps for each specification. "

The Java Content Repository (JCR) standard, which is based on the Java Specification Requests JSR170 (version 1.0) and JSR 283 (version 2.0), provides a Java-centric object-oriented storage API specifically targeted at content management scenarios. The JCR is not a content management system or a full-fledged content management system API, but rather a content repository API. A content repository provides a common API for all content-driven applications and CMS components, which require access to the content. It provides methods to read, write, and query content. The primary motivation of the JCR standard is to provide a standard and vendor-neutral programmatic interface for content repositories, allowing applications of multiple vendors to interact efficiently.

"Contributed and administered by ICEsoft Technologies Inc., ICEpdf.org is a place where enterprise Java developers can learn, share, and contribute information and ideas to a growing community of ICEpdf developers. ICEpdf is an open source Java PDF engine that can render, convert, or extract PDF content within any Java application or on a Web server. ICEpdf.org provides a range of development and support resources to benefit all ICEpdf developers. Source code and application reference implementations are available for download here. Numerous reference implementations and examples are available to enable rapid learning and successful use of the product. The reference implementations are commercial quality implementations that can be deployed as-is, customized to meet specific requirements, or used as learning aids on how to use various features. Visit the ICEpdf demos page to see ICEpdf in action and to evaluate the capabilities of ICEpdf as a Java PDF viewer or deployed as servlet a headless server engine. Remember that ICEpdf is completely customizable and and can be completely embedded in your Java application. We invite you to join the ICEpdf community and to participate in the user forums. The resources available here and on the ICEpdf forums will get you up and developing that much quicker. "