migration-3.1.xml

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<appendix xml:id="migration-3.1"
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  <title>Migrating to Spring Framework 3.1</title>

  <para>In this appendix we discuss what users will want to know when upgrading to
  Spring Framework 3.1. For a general overview of features, please see
  <xref linkend="new-in-3.1"/></para>

  <section xml:id="migration-3.1-component-scan">
    <title>Component scanning against the "org" base package</title>
    <para>Spring Framework 3.1 introduces a number of <literal>@Configuration</literal>
    classes such as <literal>org.springframework.cache.annotation.ProxyCachingConfiguration
    </literal> and
    <literal>org.springframework.scheduling.annotation.ProxyAsyncConfiguration</literal>.
    Because <literal>@Configuration</literal> is ultimately meta-annotated with Spring's
    <literal>@Component</literal> annotation, these classes will inadvertently be scanned
    and processed by the container for any component-scanning directive against the
    unqualified "org" package, e.g.:
    <programlisting language="xml">
        &lt;context:component-scan base-package="org"/&gt;</programlisting>
    Therefore, in order to avoid errors like the one reported in <link
    xl:href="https://jira.springsource.org/browse/SPR-9843">SPR-9843</link>,
    any such directives should be updated to at least one more level of qualification e.g.:
    <programlisting language="xml">
      &lt;context:component-scan base-package="org.xyz"/&gt;</programlisting>
    Alternatively, an <literal>exclude-filter</literal> may be used. See
    <link linkend="beans-scanning-filters"><literal>context:component-scan</literal></link>
    documentation for details.</para>
  </section>
</appendix>