| <html><head> |
| <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> |
| <title>5.2. Packages and Classes</title><link rel="stylesheet" href="css/stylesheet.css" type="text/css"><meta name="generator" content="DocBook XSL Stylesheets V1.75.0"><link rel="home" href="index.html" title="Apache Click"><link rel="up" href="ch05.html" title="Chapter 5. Best Practices"><link rel="prev" href="ch05.html" title="Chapter 5. Best Practices"><link rel="next" href="ch05s03.html" title="5.3. Page Auto Mapping"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">5.2. Packages and Classes</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="ch05.html">Prev</a> </td><th width="60%" align="center">Chapter 5. Best Practices</th><td width="20%" align="right"> <a accesskey="n" href="ch05s03.html">Next</a></td></tr></table><hr></div><div class="sect1" title="5.2. Packages and Classes"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="packages-classes"></a>5.2. Packages and Classes</h2></div></div></div><p> An excellent way to design your project package structure is to |
| classify packages initially by technology. So in a Click application all |
| of our pages would be contained under a <span class="package">page</span> package. |
| This also works very well with the Page automapping feature. |
| </p><p> |
| All the projects domain entity classes would be contained under a |
| <span class="package">entity</span> package, and service classes would be contained |
| under a <span class="package">service</span> directory. Note alternative names for the |
| <span class="package">entity</span> package include domain or model. We also typically |
| have a <span class="package">util</span> package for any stray classes which don't quite |
| fit into the other packages. |
| </p><p>In Java, package names are singular by convention, so we have a util |
| package rather than a utils package. |
| </p><p>An example project structure for a MyCorp web application is illustrated |
| below: |
| </p><div class="figure"><a name="example-project-structure"></a><div class="figure-contents"><span class="inlinemediaobject"><img src="images/best-practices/packages-classes.png" alt="Example project structure"></span></div><p xmlns:fo="http://www.w3.org/1999/XSL/Format" class="title"><i>Figure 5.1. Example project structure</i></p></div><br class="figure-break"><p>In this example application we use declarative role and path based security. |
| All the pages in the <span class="package">admin</span> package and directory require the |
| <code class="literal">"admin"</code> role to be access, while all the pages in the |
| <span class="package">user</span> package and directory require the <code class="literal">"user"</code> |
| role to be accessed. |
| </p><div class="sect2" title="5.2.1. Page Classes"><div class="titlepage"><div><div><h3 class="title"><a name="page-classes"></a>5.2.1. Page Classes</h3></div></div></div><p>A best practice when developing application Page classes is to |
| place common methods in a base page class. This is typically used for |
| providing access methods to application services and logger objects. |
| </p><p>For example the BasePage below provides access to Spring configured |
| service objects and a Log4J logger object: |
| </p><pre class="programlisting"><span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">public</span> <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">class</span> BasePage <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">extends</span> Page <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">implements</span> ApplicationContextAware { |
| |
| <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="com">/** The Spring application context. */</span> |
| <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">protected</span> ApplicationContext applicationContext; |
| |
| <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="com">/** The page Logger instance. */</span> |
| <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">protected</span> Logger logger; |
| |
| <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="com">/** |
| * Return the Spring configured Customer service. |
| * |
| * @return the Spring configured Customer service |
| */</span> |
| <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">public</span> CustomerService getCustomerService() { |
| <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">return</span> (CustomerService) getBean(<span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="str">"customerService"</span>); |
| } |
| |
| <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="com">/** |
| * Return the Spring configured User service. |
| * |
| * @return the Spring configured User service |
| */</span> |
| <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">public</span> UserService getUserService() { |
| <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">return</span> (UserService) getBean(<span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="str">"userService"</span>); |
| } |
| |
| <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="com">/** |
| * Return the page Logger instance. |
| * |
| * @return the page Logger instance |
| */</span> |
| <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">public</span> Logger getLogger() { |
| <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">if</span> (logger == null) { |
| logger = Logger.getLogger(getClass()); |
| } |
| <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">return</span> logger; |
| } |
| |
| <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="com">/** |
| * @see ApplicationContextAware#setApplicationContext(ApplicationContext) |
| */</span> |
| <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">public</span> <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">void</span> setApplicationContext(ApplicationContext applicationContext) { |
| <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">this</span>.applicationContext = applicationContext; |
| } |
| |
| <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="com">/** |
| * Return the configured Spring Bean for the given name. |
| * |
| * @param beanName the configured name of the Java Bean |
| * @return the configured Spring Bean for the given name |
| */</span> |
| <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">public</span> Object getBean(String beanName) { |
| <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">return</span> applicationContext.getBean(beanName); |
| } |
| |
| }</pre><p>Applications typically use a border template and have a |
| <code class="classname">BorderPage</code> which extends <code class="classname">BasePage</code> |
| and defines the template. For example: |
| </p><pre class="programlisting"><span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">public</span> <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">class</span> BorderPage <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">extends</span> BasePage { |
| |
| <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="com">/** The root Menu item. */</span> |
| <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">public</span> Menu rootMenu = <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">new</span> Menu(); |
| |
| <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="com">/** |
| * @see Page#getTemplate() |
| */</span> |
| <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">public</span> String getTemplate() { |
| <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="kwd">return</span> <span xmlns:fo="http://www.w3.org/1999/XSL/Format" class="str">"/border-template.htm"</span>; |
| } |
| }</pre><p>Most application pages subclass <code class="classname">BorderPage</code>, except |
| AJAX pages which have no need for a HTML border template and typically extend |
| <code class="classname">BasePage</code>. The <code class="classname">BorderPage</code> class |
| should not include common logic, other than that required for rendering the |
| border template. Common page logic should be defined in the |
| <code class="classname">BasePage</code> class. |
| </p><p>To prevent these base Page classes being auto mapped, and becoming |
| directly acessible web pages, ensure that there are no page templates which |
| could match their class name. For example the <code class="classname">BorderPage</code> |
| class above will not be auto mapped to <code class="filename">border-template.htm</code>. |
| </p></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="ch05.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="ch05.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="ch05s03.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Chapter 5. Best Practices </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> 5.3. Page Auto Mapping</td></tr></table></div></body></html> |
