spring-framework/spring-framework-reference/src/new-in-3.xml

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<chapter id="new-in-3">
  <title>What's new in Spring 3.0?</title>

  <para>If you have been using the Spring Framework for some time, you will be
  aware that Spring has undergone two major revisions: Spring 2.0, released in
  October 2006, and Spring 2.5, released in November 2007. It is now time for
  a third overhaul resulting in Spring 3.0.</para>

  <sidebar id="new-in-3-intro-java">
    <title>Java SE and Java EE Support</title>

    <para>The Spring Framework is now based on Java 5 and Java 6 is fully
    supported.</para>

    <para>Furthermore, Spring is compatible with J2EE 1.4 and Java EE 5, while
    at the same time introducing some early support for Java EE 6.</para>
  </sidebar>

  <section id="new-in-3-intro">
    <title>Java 5</title>

    <para>The entire framework code has been revised to take advantage of Java
    5 features like generics, varargs and other language improvements. We have
    done our best to still keep the code backwards compatible. We now have
    consistent use of generic Collections and Maps, consistent use of
    generified FactoryBeans, and also consistent resolution of bridge methods
    in the Spring AOP API. Generified ApplicationListeners automatically
    receive specific event types only. All callback interfaces such as
    TransactionCallback and HibernateCallback declare a generic result value
    now. Overall, the Spring core codebase is now freshly revised and
    optimized for Java 5.</para>

    <para>Spring's TaskExecutor abstraction has been updated for close
    integration with Java 5's java.util.concurrent facilities. We provide
    first-class support for Callables and Futures now, as well as
    ExecutorService adapters, ThreadFactory integration, etc. This has been
    aligned with JSR-236 (Concurrency Utilities for Java EE 6) as far as
    possible. Furthermore, we provide support for asynchronous method
    invocations through the use of the new @Async annotation (or EJB 3.1's
    @Asynchronous annotation).</para>
  </section>

  <section id="new-in-3-improved-docs">
    <title>Improved documentation</title>

    <sidebar id="new-in-3-intro-work-in-progress">
      <title>Note:</title>

      <para>The current documentation is a <emphasis>*** WORK IN PROGRESS
      ***</emphasis> and is currently being re-written to reflect all the
      changes in the framework and from now relying on Java 5 features.</para>
    </sidebar>

    <para>The Spring reference documentation has also substantially been
    updated to reflect all of the changes and new features for Spring 3.0.
    While every effort has been made to ensure that there are no errors in
    this documentation, some errors may nevertheless have crept in. If you do
    spot any typos or even more serious errors, and you can spare a few cycles
    during lunch, please do bring the error to the attention of the Spring
    team by <ulink url="http://jira.springframework.org/">raising an
    issue</ulink>.</para>
  </section>

  <section id="new-in-3-modules-build">
    <title>New module organization and build system</title>

    <para>The framework modules have been revised and are now managed
    separately with one source-tree per module jar:</para>

    <itemizedlist>
      <listitem>
        <para>org.springframework.aop</para>
      </listitem>

      <listitem>
        <para>org.springframework.beans</para>
      </listitem>

      <listitem>
        <para>org.springframework.context</para>
      </listitem>

      <listitem>
        <para>org.springframework.context.support</para>
      </listitem>

      <listitem>
        <para>org.springframework.expression</para>
      </listitem>

      <listitem>
        <para>org.springframework.instrument</para>
      </listitem>

      <listitem>
        <para>org.springframework.jdbc</para>
      </listitem>

      <listitem>
        <para>org.springframework.jms</para>
      </listitem>

      <listitem>
        <para>org.springframework.orm</para>
      </listitem>

      <listitem>
        <para>org.springframework.oxm</para>
      </listitem>

      <listitem>
        <para>org.springframework.test</para>
      </listitem>

      <listitem>
        <para>org.springframework.transaction</para>
      </listitem>

      <listitem>
        <para>org.springframework.web</para>
      </listitem>

      <listitem>
        <para>org.springframework.web.portlet</para>
      </listitem>

      <listitem>
        <para>org.springframework.web.servlet</para>
      </listitem>
    </itemizedlist>

    <sidebar id="new-in-3-intro-spring-jar">
      <title>Note:</title>

      <para>The spring.jar artifact that contained almost the entire framework
      is no longer provided.</para>
    </sidebar>

    <para>We are now using a new Spring build system as known from Spring Web
    Flow 2.0. This gives us:</para>

    <itemizedlist>
      <listitem>
        <para>Ivy-based "Spring Build" system</para>
      </listitem>

      <listitem>
        <para>consistent deployment procedure</para>
      </listitem>

      <listitem>
        <para>consistent dependency management</para>
      </listitem>

      <listitem>
        <para>consistent generation of OSGi manifests</para>
      </listitem>
    </itemizedlist>
  </section>

  <section id="new-in-3-features-overview">
    <title>Overview of new features</title>

    <para>This is a list of new features for Spring 3.0. We will cover these
    features in more detail later in this section.</para>

    <itemizedlist>
      <listitem>
        <para>Spring Expression Language</para>
      </listitem>

      <listitem>
        <para>IoC enhancements/Java based bean metadata</para>
      </listitem>

      <listitem>
        <para>Comprehensive REST support</para>
      </listitem>

      <listitem>
        <para>@MVC additions</para>
      </listitem>

      <listitem>
        <para>Declarative model validation</para>
      </listitem>

      <listitem>
        <para>Early support for Java EE 6</para>
      </listitem>
    </itemizedlist>

    <section id="new-feature-java5">
      <title>Core APIs updated for Java 5</title>

      <para>BeanFactoryinterface returns typed bean instancesas far as
      possible <itemizedlist>
          <listitem>
            <para>T getBean(Stringname, Class&lt;T&gt; requiredType)</para>
          </listitem>

          <listitem>
            <para>Map&lt;String, T&gt; getBeansOfType(Class&lt;T&gt;
            type)</para>
          </listitem>
        </itemizedlist></para>

      <para>Spring's TaskExecutorinterface extends
      <classname>java.util.concurrent.Executor</classname> now <itemizedlist>
          <listitem>
            <para>extended AsyncTaskExecutor supports standard Callables with
            Futures</para>
          </listitem>
        </itemizedlist></para>

      <para>New Java 5 based converter API and SPI <itemizedlist>
          <listitem>
            <para>stateless ConversionService and Converters</para>
          </listitem>

          <listitem>
            <para>superseding standard JDK PropertyEditors</para>
          </listitem>
        </itemizedlist></para>

      <para>Typed ApplicationListener&lt;E&gt;</para>
    </section>

    <section id="new-feature-el">
      <title>Spring Expression Language</title>

      <para>Spring introduces an expression language which is similar to
      Unified EL in its syntax but offers significantly more features. The
      expression language can be used when defining XML and Annotation based
      bean definitions and also serves as the foundation for expression
      language support across the Spring portfolio. Details of this new
      functionality can be found in the chapter <link
      linkend="expressions">Spring Expression Language (SpEL).</link></para>

      <para>The Spring Expression Language was created to provide the Spring
      community with a single well supported expression language that can used
      across all the products in the Spring portfolio. Its language features
      are driven by the requirements of the projects in the Spring portfolio,
      including tooling requirements for code completion support within the
      eclipse based SpringSource Tool Suite.</para>

      <para>The following is an example of how the Expression Language can be
      used to configure some properties of a database setup <programlisting
      language="xml">&lt;bean class="mycompany.RewardsTestDatabase"&gt;
    &lt;property name="databaseName"
        value="#{systemProperties.databaseName}"/&gt;
    &lt;property name="keyGenerator"
        value="#{strategyBean.databaseKeyGenerator}"/&gt;
&lt;/bean&gt;
</programlisting></para>

      <para>This functionality is also available if you prefer to configure
      your components using annotations: <programlisting language="java">@Repository 
public class RewardsTestDatabase {

    @Value("#{systemProperties.databaseName}")
    public void setDatabaseName(String dbName) { … }

    @Value("#{strategyBean.databaseKeyGenerator}")
    public voidsetKeyGenerator(KeyGenerator kg) { … }
}
</programlisting></para>
    </section>

    <section id="new-feature-java-config">
      <title>The Inversion of Control (IoC) container</title>

      <section id="new-java-configuration">
        <title>Java based bean metadata</title>

        <para>Some core features from the <ulink
        url="http://www.springsource.org/javaconfig"><link
        linkend="???">JavaConfig</link></ulink> project have been added to the
        Spring Framework now. This means that the following annotations are
        now directly supported: <itemizedlist>
            <listitem>
              <para>@Configuration</para>
            </listitem>

            <listitem>
              <para>@Bean</para>
            </listitem>

            <listitem>
              <para>@Primary</para>
            </listitem>

            <listitem>
              <para>@Lazy</para>
            </listitem>

            <listitem>
              <para>@Import</para>
            </listitem>

            <listitem>
              <para>@Value</para>
            </listitem>
          </itemizedlist></para>

        <para>Here is an example of a Java class providing basic configuration
        using the new JavaConfig features: <programlisting language="java">@Configuration 
public class AppConfig{ 
    @Value("#{jdbcProperties.url}") String jdbcUrl; 
    @Value("#{jdbcProperties.username}") String username; 
    @Value("#{jdbcProperties.password}") String password; 

    @Bean 
    public FooServicefooService() { 
        return new FooServiceImpl(fooRepository()); 
    }

    @Bean 
    public FooRepositoryfooRepository() { 
        return new HibernateFooRepository(sessionFactory()); 
    }

    @Bean 
    public SessionFactorysessionFactory() { 
        // wire up a session factory using 
        // AnnotationSessionFactoryBean 
        asFactoryBean.setDataSource(dataSource()); 
        return (SessionFactory) asFactoryBean.getObject(); 
    } 

    @Bean 
    public DataSourcedataSource() { 
        return new DriverManagerDataSource(jdbcUrl, 
        username, password); 
    } 
}
</programlisting> To get this to work you need to add the following component
        scanning entry in your minimal application context XML file.
        <programlisting language="java">&lt;context:component-scan 
    base-package="com.myco.config"/&gt;</programlisting></para>
      </section>

      <section>
        <title>Factory Bean definitions using annotations</title>

        <para>FactoryBeans can be defined within a Spring component definition
        and registered using standard component-scanning techniques. See <link
        linkend="beans-factorybeans-annotations">Factory Bean Definitions
        using annotations</link> for more information</para>
      </section>
    </section>

    <section id="new-feature-rest">
      <title>The Web Tier</title>

      <para>Work in progress ...</para>

      <section>
        <title>Comprehensive REST support</title>

        <para>Server-side support for building RESTful applications has been
        provided as an extension of the existing annotation driven MVC web
        framework. Client-side support is provided by the
        <classname>RestTemplate</classname> class in the spirit of other
        template classes such as <classname>JdbcTemplate</classname> and
        <classname>JmsTemplate</classname>. Both server and client side REST
        functionality make use of
        <interfacename>HttpConverter</interfacename>s to facilitate the
        conversion between objects and their representation in HTTP request
        and replies. </para>

        <para>The <classname>MarhsallingHttpMessageConverter</classname> uses
        the Object to XML mapping functionality in the
        <literal>org.springframework.oxm</literal> package. This functionality
        had previously been part of Spring Web Services. More information on
        the use of the <literal>org.springframework.oxm</literal> can be found
        in the  <link linkend="oxm">Marshalling XML using O/X Mappers</link> chapter.</para>

        <para>Refer to the section on <link linkend="rest">REST support</link>
        for more information.</para>
      </section>

      <section>
        <title>@MVC additions</title>

        <para>Additional annotations such as
        <classname>@CookieValue</classname> and
        <classname>@RequestHeaders</classname> have been added. See <link
        linkend="mvc-ann-cookievalue">Mapping cookie values with the
        @CookieValue annotation</link> and <link
        linkend="mvc-ann-requestheader">Mapping request header attributes with
        the @RequestHeader annotation</link> for more information.</para>

        <para>Work in progress ...</para>
      </section>
    </section>

    <section id="new-feature-validation">
      <title>Declarative model validation</title>

      <para>Hibernate Validator, JSR 303</para>

      <para>Work in progress...</para>
    </section>

    <section id="new-feature-jee-6">
      <title>Early support for Java EE 6</title>

      <para>JSF 2.0, JPA 2.0, etc</para>

      <para>Work in progress...</para>
    </section>
  </section>
</chapter>