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<!DOCTYPE document [
  <!ENTITY project SYSTEM "project.xml">
]>
<document url="globalresources.html">

  &project;

  <properties>
    <author email="remm@apache.org">Remy Maucherat</author>
    <author email="yoavs@apache.org">Yoav Shapira</author>
    <title>The GlobalNamingResources Component</title>
  </properties>

<body>

<section name="Table of Contents">
<toc/>
</section>

<section name="Introduction">

  <p>The <strong>GlobalNamingResources</strong> element defines the global
  JNDI resources for the <a href="server.html">Server</a>.</p>

  <p>These resources are listed in the server's global JNDI resource context.
   This context is distinct from the per-web-application JNDI contexts
  described in
  the <a href="../jndi-resources-howto.html">JNDI Resources How-To</a>.
  The resources defined in this element are <strong>not</strong> visible in
  the per-web-application contexts unless you explicitly link them with
  <a href="context.html#Resource_Links">&lt;ResourceLink&gt;</a> elements.
  </p>

</section>


<section name="Attributes">

</section>


<section name="Nested Components">

</section>


<section name="Special Features">


  <subsection name="Environment Entries">

  <p>You can configure named values that will be made visible to all
    web applications as environment entry resources by nesting
    <code>&lt;Environment&gt;</code> entries inside this element. For
    example, you can create an environment entry like this:</p>
<source><![CDATA[<GlobalNamingResources ...>
  ...
  <Environment name="maxExemptions" value="10"
         type="java.lang.Integer" override="false"/>
  ...
</GlobalNamingResources>]]></source>

    <p>This is equivalent to the inclusion of the following element in the
    web application deployment descriptor (<code>/WEB-INF/web.xml</code>):
    </p>
<source><![CDATA[<env-entry>
  <env-entry-name>maxExemptions</env-entry-name>
  <env-entry-value>10</env-entry-value>
  <env-entry-type>java.lang.Integer</env-entry-type>
</env-entry>]]></source>
    <p>but does <em>not</em> require modification of the deployment descriptor
    to customize this value.</p>

    <p>The valid attributes for an <code>&lt;Environment&gt;</code> element
    are as follows:</p>

    <attributes>

      <attribute name="description" required="false">
        <p>Optional, human-readable description of this environment entry.</p>
      </attribute>

      <attribute name="name" required="true">
        <p>The name of the environment entry to be created, relative to the
        <code>java:comp/env</code> context.</p>
      </attribute>

      <attribute name="override" required="false">
        <p>Set this to <code>false</code> if you do <strong>not</strong> want
        an <code>&lt;env-entry&gt;</code> for the same environment entry name,
        found in the web application deployment descriptor, to override the
        value specified here.  By default, overrides are allowed.</p>
      </attribute>

      <attribute name="type" required="true">
        <p>The fully qualified Java class name expected by the web application
        for this environment entry.  Must be a legal value for
        <code>&lt;env-entry-type&gt;</code> in the web application deployment
        descriptor.</p>
      </attribute>

      <attribute name="value" required="true">
        <p>The parameter value that will be presented to the application
        when requested from the JNDI context.  This value must be convertible
        to the Java type defined by the <code>type</code> attribute.</p>
      </attribute>

    </attributes>

  </subsection>


  <subsection name="Resource Definitions">

    <p>You can declare the characteristics of resources
    to be returned for JNDI lookups of <code>&lt;resource-ref&gt;</code> and
    <code>&lt;resource-env-ref&gt;</code> elements in the web application
    deployment descriptor by defining them in this element and then linking
    them with <a href="context.html#Resource_Links">&lt;ResourceLink&gt;</a>
    elements
    in the <code><strong>&lt;Context&gt;</strong></code> element.

    You <strong>MUST</strong> also define any other needed parameters using
    attributes on the Resource element, to configure
    the object factory to be used (if not known to Tomcat already), and
    the properties used to configure that object factory.</p>

    <p>For example, you can create a resource definition like this:</p>
<source><![CDATA[<GlobalNamingResources ...>
  ...
  <Resource name="jdbc/EmployeeDB" auth="Container"
            type="javax.sql.DataSource"
     description="Employees Database for HR Applications"/>
  ...
</GlobalNamingResources>]]></source>

    <p>This is equivalent to the inclusion of the following element in the
    web application deployment descriptor (<code>/WEB-INF/web.xml</code>):</p>
<source><![CDATA[<resource-ref>
  <description>Employees Database for HR Applications</description>
  <res-ref-name>jdbc/EmployeeDB</res-ref-name>
  <res-ref-type>javax.sql.DataSource</res-ref-type>
  <res-auth>Container</res-auth>
</resource-ref>]]></source>

    <p>but does <em>not</em> require modification of the deployment
    descriptor to customize this value.</p>

    <p>The valid attributes for a <code>&lt;Resource&gt;</code> element
    are as follows:</p>

    <attributes>

      <attribute name="auth" required="false">
        <p>Specify whether the web Application code signs on to the
        corresponding resource manager programmatically, or whether the
        Container will sign on to the resource manager on behalf of the
        application.  The value of this attribute must be
        <code>Application</code> or <code>Container</code>.  This
        attribute is <strong>required</strong> if the web application
        will use a <code>&lt;resource-ref&gt;</code> element in the web
        application deployment descriptor, but is optional if the
        application uses a <code>&lt;resource-env-ref&gt;</code> instead.</p>
      </attribute>

      <attribute name="closeMethod" required="false">
        <p>Name of the zero-argument method to call on a singleton resource when
        it is no longer required. This is intended to speed up clean-up of
        resources that would otherwise happen as part of garbage collection.
        This attribute is ignored if the <code>singleton</code> attribute is
        false. If not specified, no default is defined and no close method will
        be called.</p>
        <p>For Apache Commons DBCP 2 and Apache Tomcat JDBC connection pools
        you can use <code>closeMethod="close"</code>. Note that Apache Commons
        DBCP 2 requires this to be set for a clean shutdown. When using the
        default Tomcat connection pool (based on DBCP 2) Tomcat will set this
        attribute automatically unless it is explicitly set to the empty
        string.</p>
      </attribute>

      <attribute name="description" required="false">
        <p>Optional, human-readable description of this resource.</p>
      </attribute>

      <attribute name="name" required="true">
        <p>The name of the resource to be created, relative to the
        <code>java:comp/env</code> context.</p>
      </attribute>

      <attribute name="scope" required="false">
        <p>Specify whether connections obtained through this resource
        manager can be shared.  The value of this attribute must be
        <code>Shareable</code> or <code>Unshareable</code>.  By default,
        connections are assumed to be shareable.</p>
      </attribute>

      <attribute name="singleton" required="false">
        <p>Specify whether this resource definition is for a singleton resource,
        i.e. one where there is only a single instance of the resource. If this
        attribute is <code>true</code>, multiple JNDI lookups for this resource
        will return the same object. If this attribute is <code>false</code>,
        multiple JNDI lookups for this resource will return different objects.
        This attribute must be <code>true</code> for
        <code>javax.sql.DataSource</code> resources to enable JMX registration
        of the DataSource. The value of this attribute must be <code>true</code>
        or <code>false</code>. By default, this attribute is <code>true</code>.
        </p>
      </attribute>

      <attribute name="type" required="true">
        <p>The fully qualified Java class name expected by the web
        application when it performs a lookup for this resource.</p>
      </attribute>

    </attributes>


  </subsection>

  <subsection name="Resource Links">
    <p>Use <a href="context.html#Resource_Links"><code>&lt;ResourceLink&gt;</code></a>
    elements to link resources from the global context into
    per-web-application contexts. Here is an example of making a custom
    factory available to an application, based on the example definition in the
    <a href="../jndi-resources-howto.html#Generic_JavaBean_Resources">
    JNDI Resource How-To</a>:
    </p>

    <source><![CDATA[<Context>
  <ResourceLink
    name="bean/MyBeanFactory"
    global="bean/MyBeanFactory"
    type="com.mycompany.MyBean"
  />
</Context>]]></source>

   </subsection>

  <subsection name="Transaction">

    <p>You can declare the characteristics of the UserTransaction
    to be returned for JNDI lookup for <code>java:comp/UserTransaction</code>.
    You <strong>MUST</strong> define an object factory class to instantiate
    this object as well as the needed resource parameters as attributes of the
    <code>Transaction</code>
    element, and the properties used to configure that object factory.</p>

    <p>The valid attributes for the <code>&lt;Transaction&gt;</code> element
    are as follows:</p>

    <attributes>

      <attribute name="factory" required="true">
        <p>The class name for the JNDI object factory.</p>
      </attribute>

    </attributes>

  </subsection>

</section>


</body>


</document>
