Author: markt Date: Mon Dec 14 18:11:45 2009 New Revision: 890421 URL: http://svn.apache.org/viewvc?rev=890421&view=rev Log: Fix https://issues.apache.org/bugzilla/show_bug.cgi?id=47769 Reword JNDI docs in an attempt to make clear why resource-ref elements appear to be optional
Modified: tomcat/tc5.5.x/trunk/container/webapps/docs/changelog.xml tomcat/tc5.5.x/trunk/container/webapps/docs/jndi-resources-howto.xml Modified: tomcat/tc5.5.x/trunk/container/webapps/docs/changelog.xml URL: http://svn.apache.org/viewvc/tomcat/tc5.5.x/trunk/container/webapps/docs/changelog.xml?rev=890421&r1=890420&r2=890421&view=diff ============================================================================== --- tomcat/tc5.5.x/trunk/container/webapps/docs/changelog.xml (original) +++ tomcat/tc5.5.x/trunk/container/webapps/docs/changelog.xml Mon Dec 14 18:11:45 2009 @@ -152,6 +152,11 @@ replacement in configuration files. (markt) </fix> <fix> + <bug>47769</bug>: Clarify the JNDI docs with repect to use of + <resource-ref> and related elements, specifically when they are + required and when they may be omitted. (markt) + </fix> + <fix> <bug>48381</bug>: Add information on how Tomcat treats host names to the host configuration documentation. (markt) </fix> Modified: tomcat/tc5.5.x/trunk/container/webapps/docs/jndi-resources-howto.xml URL: http://svn.apache.org/viewvc/tomcat/tc5.5.x/trunk/container/webapps/docs/jndi-resources-howto.xml?rev=890421&r1=890420&r2=890421&view=diff ============================================================================== --- tomcat/tc5.5.x/trunk/container/webapps/docs/jndi-resources-howto.xml (original) +++ tomcat/tc5.5.x/trunk/container/webapps/docs/jndi-resources-howto.xml Mon Dec 14 18:11:45 2009 @@ -37,32 +37,26 @@ instance for each web application running under it, in a manner that is compatible with those provided by a <a href="http://java.sun.com/j2ee">Java2 Enterprise Edition</a> application -server. +server. The J2EE standard provides a standard set of elements in the +<code>/WEB-INF/web.xml</code> file to reference/define resources.</p> -The J2EE standard provides a standard set of elements in -the <code>/WEB-INF/web.xml</code> file to reference resources; resources -referenced in these elements must be defined in an application-server-specific configuration. -</p> - -<p>For Tomcat 5, these entries in per-web-application -<code>InitialContext</code> are configured in the -<code><strong><Context></strong></code> elements that can be specified -in either <code>$CATALINA_HOME/conf/server.xml</code> or, preferably, -the per-web-application context XML file (either <code>META-INF/context.xml</code>). -</p> +<p>See the following Specifications for more information about programming APIs +for JNDI, and for the features supported by Java2 Enterprise Edition (J2EE) +servers, which Tomcat emulates for the services that it provides:</p> +<ul> +<li><a href="http://java.sun.com/products/jndi">Java Naming and Directory + Interface</a> (included in JDK 1.4 onwards)</li> +<li><a href="http://java.sun.com/j2ee/download.html">J2EE Platform + Specification</a> (in particular, see Chapter 5 on <em>Naming</em>)</li> +</ul> -<p>Tomcat 5 maintains a separate namespace of global resources for the -entire server. These are configured in the -<a href="config/globalresources.html"> -<code><strong><GlobalNameingResources></strong></code></a> element of -<code>$CATALINA_HOME/conf/server.xml</code>. You may expose these resources to -web applications by using -<code><strong><ResourceLink></strong></code> elements. -</p> - -<p>The resources defined in these elements -may be referenced by the following elements in the web application deployment -descriptor (<code>/WEB-INF/web.xml</code>) of your web application:</p> +</section> + +<section name="web.xml configuration" > + +<p>The following elements may be used in the web application deployment +descriptor (<code>/WEB-INF/web.xml</code>) of your web application to define +resources:</p> <ul> <li><code><strong><env-entry></strong></code> - Environment entry, a single-value parameter that can be used to configure how the application @@ -77,46 +71,25 @@ that do not require authentication information.</li> </ul> -<p>The <code>InitialContext</code> is configured as a web application is -initially deployed, and is made available to web application components (for -read-only access). All configured entries and resources are placed in -the <code>java:comp/env</code> portion of the JNDI namespace, so a typical -access to a resource - in this case, to a JDBC <code>DataSource</code> - -would look something like this:</p> - -<source> -// Obtain our environment naming context -Context initCtx = new InitialContext(); -Context envCtx = (Context) initCtx.lookup("java:comp/env"); - -// Look up our data source -DataSource ds = (DataSource) - envCtx.lookup("jdbc/EmployeeDB"); - -// Allocate and use a connection from the pool -Connection conn = ds.getConnection(); -... use this connection to access the database ... -conn.close(); -</source> - -<p>See the following Specifications for more information about programming APIs -for JNDI, and for the features supported by Java2 Enterprise Edition (J2EE) -servers, which Tomcat emulates for the services that it provides:</p> -<ul> -<li><a href="http://java.sun.com/products/jndi/#download">Java Naming and - Directory Interface</a> (included in JDK 1.4, available separately for - prior JDK versions)</li> -<li><a href="http://java.sun.com/j2ee/download.html">J2EE Platform - Specification</a> (in particular, see Chapter 5 on <em>Naming</em>)</li> -</ul> - +<p>Providing that Tomcat is able to identify an appropriate resource factory to +use to create the resource and that no further configuration information is +required, Tomcat will use the information in <code>/WEB-INF/web.xml</code> to +create the resource.</p> </section> +<section name="context.xml configuration"> -<section name="Configuring JNDI Resources"> +<p>If Tomcat is unable to identify the appropriate resource factory and/or +additional configuration information is required, additional Tomcat specific +configuration must be specified before Tomcat can create the resource. +Tomcat specific resource configuration is entered in +the <a href="config/context.html"><code><Context></code></a> elements that +can be specified in either <code>$CATALINA_BASE/conf/server.xml</code> or, +preferably, the per-web-application context XML file +(<code>META-INF/context.xml</code>).</p> -<p>Each available JNDI Resource is configured based on inclusion of the -following elements in the <code><strong><Context></strong></code> +<p>Tomcat specific resource configuration is performed using the following +elements in the <a href="config/context.html"><code><Context></code></a> element:</p> <ul> @@ -144,25 +117,70 @@ </ul> <p>Any number of these elements may be nested inside a -<a href="config/context.html"><Context></a> element (to be associated -only with that particular web application).</p> +<a href="config/context.html"><code><Context></code></a> element and will +be associated only with that particular web application.</p> -<p>In addition, the names and values of all <code><env-entry></code> -elements included in the web application deployment descriptor -(<code>/WEB-INF/web.xml</code>) are configured into the initial context as -well, overriding corresponding values from <code>conf/server.xml</code> +<p>If a resource has been defined in a +<a href="config/context.html"><code><Context></code></a> element it is not +necessary for that resource to be defined in <code>/WEB-INF/web.xml</code>. +However, it is recommended to keep the entry in <code>/WEB-INF/web.xml</code> +to document the resource requirements for the web application.</p> + +<p>Where the same resource name has been defined for a +<code><env-entry></code> element included in the web application +deployment descriptor (<code>/WEB-INF/web.xml</code>) and in an +<code><Environment></code> element as part of the +<a href="config/context.html"><code><Context></code></a> element for the +web application, the values in the deployment descriptor will take precedence <strong>only</strong> if allowed by the corresponding -<code><Environment></code> element (by setting the -<code>override</code> attribute to "true").</p> +<code><Environment></code> element (by setting the <code>override</code> +attribute to "true").</p> -<p>Global resources can be defined in the server-wide JNDI context, by adding -the resource elements described above to the -<a href="config/globalresources.html"><GlobalNamingResources></a> -child element of the <a href="config/server.html"><Server></a> -element and using a +</section> + +<section name="Global configuration"> + +<p>Tomcat 5 maintains a separate namespace of global resources for the +entire server. These are configured in the +<a href="config/globalresources.html"> +<code><strong><GlobalNameingResources></strong></code></a> element of +<code>$CATALINA_BASE/conf/server.xml</code>. You may expose these resources to +web applications by using a <a href="config/context.html#Resource Links"><ResourceLink></a> to include it in the per-web-application context.</p> +<p>If a resource has been defined using a +<a href="config/context.html#Resource Links"><ResourceLink></a>, it is not +necessary for that resource to be defined in <code>/WEB-INF/web.xml</code>. +However, it is recommended to keep the entry in <code>/WEB-INF/web.xml</code> +to document the resource requirements for the web application.</p> + +</section> + +<section name="Using resources"> + +<p>The <code>InitialContext</code> is configured as a web application is +initially deployed, and is made available to web application components (for +read-only access). All configured entries and resources are placed in +the <code>java:comp/env</code> portion of the JNDI namespace, so a typical +access to a resource - in this case, to a JDBC <code>DataSource</code> - +would look something like this:</p> + +<source> +// Obtain our environment naming context +Context initCtx = new InitialContext(); +Context envCtx = (Context) initCtx.lookup("java:comp/env"); + +// Look up our data source +DataSource ds = (DataSource) + envCtx.lookup("jdbc/EmployeeDB"); + +// Allocate and use a connection from the pool +Connection conn = ds.getConnection(); +... use this connection to access the database ... +conn.close(); +</source> + </section> --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@tomcat.apache.org For additional commands, e-mail: dev-h...@tomcat.apache.org