Java EE 7 Simplifies Development

Java Platform, Enterprise Edition 7 (Java EE 7)

JSR-342 is the umbrella specification ties together the various subsystems which compose the platform, and provides additional integration support. The Java EE 7 platform added the following new APIs to previous version of the platform:

• Batch Applications for the Java Platform (1.0)
• Java API for WebSocket (1.0)
• Java API for JSON Processing (1.0)
• Concurrency Utilities for Java EE (1.0)

Also the following APIs have also been significantly updated to help simplify building enterprise applications with Java:

• Java Message Service (2.0)
• Contexts and Dependency Injection (1.1)
• Java Persistence API (2.1)
• Java Transaction API (1.2)
  Adds 2 important new features : @Transactional and @TransactionScoped
• Java Server Faces (2.2)
• Java API for RESTful Web Services (2.0)
• Bean Validation (1.1)
• Servlet (3.1)

Java Transaction API (1.2)

The new @Transactional annotation solve this by basically bringing the semantics of those EJB transaction attributes in managed beans without any dependencies on the EJB container. So the @Transactional annotation provides the ability to declaratively control transaction boundaries on managed beans. Under the hood, this capability is provided by a CDI interceptor that handle the necessary transaction plumbings (suspend, resume, commit, …). In a nutshell, @Transactional bring the ease of CMT transactions to various Java EE Components (Servlet, JAX-RS, etc.) without requiring to use EJBs.

The new @TransactionScoped annotation provides the ability to specify a standard CDI scope to define bean instances whose lifecycle is scoped to the currently active JTA transaction. This simple code driven post explain and demonstrate such a behaviour in action.

package com.espalier.javaee7.bean;
 
import java.util.Random;
 
import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import javax.transaction.TransactionScoped;
 
@TransactionScoped
public class TestTransactionalScopeBean 
              implements TestTransactionalScope {
 
  private static final long serialVersionUID = 1L;
  private long value;
 
  @PostConstruct
  private void init() {
    value = System.currentTimeMillis();
    System.out.println("TestTransactionalScopeBean initialized. Value is "
        + value);
  }
 
  @PreDestroy
  private void destroy() {
    System.out.println("TestTransactionalScopeBean destroyed. Value is "
        + value);
  }
 
  @Override
  public long getValue() {
    return value;
  }
}

Example Links

• Cargo Tracker
  Applied domain-driven design blueprints for Java EE
• Wildfly Quickstart
  Quickstarts demonstrate WildFly, Java EE 7 and a few additional technologies.
  They provide small, specific, working examples that can be used as a reference.

Implementation Links

• GlassFish Server Open Source Edition (4.0)
• Wildfly (8.0.0)

Useful Links

• Javadocs for the Java EE 7 API
• Java EE 7 tutorial
• Java EE 7 samples