displaymenutag.html

sturts_menu 的源代码 主要提过了常用的menu菜单样式

<a name="128" href="#128">128</a> <em>     * If the page is null, and the forward attribute exists,</em>
<a name="129" href="#129">129</a> <em>     * it's value will be looked up in struts-config.xml.</em>
<a name="130" href="#130">130</a> <em>     *</em>
<a name="131" href="#131">131</a> <em>     *                                     FIXME - ssayles - 121102</em>
<a name="132" href="#132">132</a> <em>     * Ideally, this should happen at menu initialization but</em>
<a name="133" href="#133">133</a> <em>     * I was unable to find a reliable way to get the context path</em>
<a name="134" href="#134">134</a> <em>     * outside of a request.  The performance impact is probably</em>
<a name="135" href="#135">135</a> <em>     * negligable, but it would be better to check for this only once.</em>
<a name="136" href="#136">136</a> <em>     *</em>
<a name="137" href="#137">137</a> <em>     * @param menu The menu component to set the location for.</em>
<a name="138" href="#138">138</a> <em>     */</em>
<a name="139" href="#139">139</a>     <strong>protected</strong> <strong>void</strong> setPageLocation(<a href="../../../../net/sf/navigator/menu/MenuComponent.html">MenuComponent</a> menu) throws MalformedURLException, JspException {
<a name="140" href="#140">140</a>         HttpServletRequest request = (HttpServletRequest) pageContext.getRequest();
<a name="141" href="#141">141</a>         setLocation(menu);
<a name="142" href="#142">142</a>         String url = menu.getLocation();
<a name="143" href="#143">143</a> 
<a name="144" href="#144">144</a>         <em class="comment">// Check if there are parameters on the value</em>
<a name="145" href="#145">145</a>         <strong>if</strong> ((url != <strong>null</strong>) &amp;&amp; (url.indexOf(<span class="string">"${"</span>) > -1)) {
<a name="146" href="#146">146</a>             String queryString = <strong>null</strong>;
<a name="147" href="#147">147</a> 
<a name="148" href="#148">148</a>             <strong>if</strong> (url.indexOf(<span class="string">"?"</span>) > -1) {
<a name="149" href="#149">149</a>                 queryString = url.substring(url.indexOf(<span class="string">"?"</span>) + 1);
<a name="150" href="#150">150</a>                 url = url.substring(0, url.indexOf(queryString));
<a name="151" href="#151">151</a>             }
<a name="152" href="#152">152</a> 
<a name="153" href="#153">153</a>             <em class="comment">// variable is in the URL</em>
<a name="154" href="#154">154</a>             <strong>if</strong> (queryString != <strong>null</strong>) {
<a name="155" href="#155">155</a>                 menu.setUrl(url + parseString(queryString, request));
<a name="156" href="#156">156</a>             } <strong>else</strong> {
<a name="157" href="#157">157</a>                 <em class="comment">// parse the URL, rather than the queryString</em>
<a name="158" href="#158">158</a>                 menu.setUrl(parseString(url, request).toString());
<a name="159" href="#159">159</a>             }
<a name="160" href="#160">160</a>         } <strong>else</strong> {
<a name="161" href="#161">161</a>             menu.setUrl(url);
<a name="162" href="#162">162</a>         }
<a name="163" href="#163">163</a> 
<a name="164" href="#164">164</a>         HttpServletResponse response = (HttpServletResponse) pageContext.getResponse();
<a name="165" href="#165">165</a>         <strong>if</strong> (menu.getUrl() != <strong>null</strong>) {
<a name="166" href="#166">166</a>             menu.setUrl(response.encodeURL(menu.getUrl()));
<a name="167" href="#167">167</a>         }
<a name="168" href="#168">168</a> 
<a name="169" href="#169">169</a>         <em class="comment">// do all contained menus</em>
<a name="170" href="#170">170</a>         <a href="../../../../net/sf/navigator/menu/MenuComponent.html">MenuComponent</a>[] subMenus = menu.getMenuComponents();
<a name="171" href="#171">171</a> 
<a name="172" href="#172">172</a>         <strong>if</strong> (subMenus.length > 0) {
<a name="173" href="#173">173</a>             <strong>for</strong> (<strong>int</strong> i = 0; i &lt; subMenus.length; i++) {
<a name="174" href="#174">174</a>                 <strong>this</strong>.setPageLocation(subMenus[i]);
<a name="175" href="#175">175</a>             }
<a name="176" href="#176">176</a>         }
<a name="177" href="#177">177</a>     }
<a name="178" href="#178">178</a> 
<a name="179" href="#179">179</a>     <strong>protected</strong> <strong>void</strong> setLocation(<a href="../../../../net/sf/navigator/menu/MenuComponent.html">MenuComponent</a> menu) throws MalformedURLException {
<a name="180" href="#180">180</a>         <em class="comment">// if the location attribute is null, then set it with a context relative page</em>
<a name="181" href="#181">181</a>         <em class="comment">// attribute if it exists</em>
<a name="182" href="#182">182</a>         <strong>if</strong> (menu.getLocation() == <strong>null</strong>) {
<a name="183" href="#183">183</a>             <strong>try</strong> {
<a name="184" href="#184">184</a>                 <strong>if</strong> (menu.getPage() != <strong>null</strong>) {
<a name="185" href="#185">185</a>                     HttpServletRequest request = (HttpServletRequest) pageContext.getRequest();
<a name="186" href="#186">186</a>                     menu.setLocation(request.getContextPath() + getPage(menu.getPage()));
<a name="187" href="#187">187</a>                     HttpServletResponse response = (HttpServletResponse) pageContext.getResponse();
<a name="188" href="#188">188</a>                     menu.setLocation(response.encodeURL(menu.getLocation()));
<a name="189" href="#189">189</a>                 } <strong>else</strong> <strong>if</strong> (menu.getForward() != <strong>null</strong>) {
<a name="190" href="#190">190</a>                     menu.setLocation(TagUtils.getInstance().computeURL(pageContext, menu.getForward(),
<a name="191" href="#191">191</a>                                         <strong>null</strong>, <strong>null</strong>, <strong>null</strong>, menu.getModule(), <strong>null</strong>, <strong>null</strong>, false));
<a name="192" href="#192">192</a>                 } <strong>else</strong> <strong>if</strong> (menu.getAction() != <strong>null</strong>) {
<a name="193" href="#193">193</a>                     <em class="comment">// generate Struts Action URL,</em>
<a name="194" href="#194">194</a>                     <em class="comment">// this will append Context Path (if any),</em>
<a name="195" href="#195">195</a>                     <em class="comment">// Servlet Mapping (path mapping or extension mapping)</em>
<a name="196" href="#196">196</a>                     <em class="comment">// Module Prefix (if any) &amp; Session ID (if any)</em>
<a name="197" href="#197">197</a>                     menu.setLocation(TagUtils.getInstance().computeURL(pageContext, <strong>null</strong>, <strong>null</strong>, <strong>null</strong>,
<a name="198" href="#198">198</a>                                         menu.getAction(), menu.getModule(), <strong>null</strong>, <strong>null</strong>, false));
<a name="199" href="#199">199</a>                 }
<a name="200" href="#200">200</a>             } <strong>catch</strong> (NoClassDefFoundError e) {
<a name="201" href="#201">201</a>                 <strong>if</strong> (menu.getForward() != <strong>null</strong>) {
<a name="202" href="#202">202</a>                     <strong>throw</strong> <strong>new</strong> MalformedURLException(<span class="string">"forward '"</span> + menu.getForward() + <span class="string">"' invalid - no struts.jar"</span>);
<a name="203" href="#203">203</a>                 } <strong>else</strong> <strong>if</strong> (menu.getAction() != <strong>null</strong>) {
<a name="204" href="#204">204</a>                     <strong>throw</strong> <strong>new</strong> MalformedURLException(<span class="string">"action '"</span> + menu.getAction() + <span class="string">"' invalid - no struts.jar"</span>);
<a name="205" href="#205">205</a>                 }
<a name="206" href="#206">206</a>             }
<a name="207" href="#207">207</a>         }
<a name="208" href="#208">208</a>     }
<a name="209" href="#209">209</a> 
<a name="210" href="#210">210</a>     <em>/**</em>
<a name="211" href="#211">211</a> <em>     * Returns the value with page prepended with a "/"</em>
<a name="212" href="#212">212</a> <em>     * if it is not already.</em>
<a name="213" href="#213">213</a> <em>     *</em>
<a name="214" href="#214">214</a> <em>     * @param page The value for the page.</em>
<a name="215" href="#215">215</a> <em>     */</em>
<a name="216" href="#216">216</a>     <strong>protected</strong> String getPage(String page) {
<a name="217" href="#217">217</a>         <strong>if</strong> (page.startsWith(<span class="string">"/"</span>)) {
<a name="218" href="#218">218</a>             <strong>return</strong> page;
<a name="219" href="#219">219</a>         } <strong>else</strong> {
<a name="220" href="#220">220</a>             page = <span class="string">"/"</span> + page;
<a name="221" href="#221">221</a>         }
<a name="222" href="#222">222</a> 
<a name="223" href="#223">223</a>         <strong>return</strong> page;
<a name="224" href="#224">224</a>     }
<a name="225" href="#225">225</a>     
<a name="226" href="#226">226</a>     <strong>private</strong> StringBuffer parseString(String str, HttpServletRequest request) {
<a name="227" href="#227">227</a>         StringBuffer sb = <strong>new</strong> StringBuffer();
<a name="228" href="#228">228</a> 
<a name="229" href="#229">229</a>         <strong>while</strong> (str.indexOf(<span class="string">"${"</span>) >= 0) {
<a name="230" href="#230">230</a>             sb.append(str.substring(0, str.indexOf(<span class="string">"${"</span>)));
<a name="231" href="#231">231</a> 
<a name="232" href="#232">232</a>             String variable = str.substring(str.indexOf(<span class="string">"${"</span>) + 2, str.indexOf(<span class="string">"}"</span>));
<a name="233" href="#233">233</a>             String value = String.valueOf(pageContext.findAttribute(variable)); 
<a name="234" href="#234">234</a> 
<a name="235" href="#235">235</a>             <strong>if</strong> (value == <strong>null</strong>) {
<a name="236" href="#236">236</a>                 <em class="comment">// look for it as a request parameter</em>
<a name="237" href="#237">237</a>                 value = request.getParameter(variable);
<a name="238" href="#238">238</a>             }
<a name="239" href="#239">239</a> 
<a name="240" href="#240">240</a>             <em class="comment">// is value still null?!</em>
<a name="241" href="#241">241</a>             <strong>if</strong> (value == <strong>null</strong>) {
<a name="242" href="#242">242</a>                 log.warn(<span class="string">"Value for '"</span> + variable +
<a name="243" href="#243">243</a>                         <span class="string">"' not found in pageContext or as a request parameter"</span>);
<a name="244" href="#244">244</a>             }
<a name="245" href="#245">245</a> 
<a name="246" href="#246">246</a>             sb.append(value);
<a name="247" href="#247">247</a>             str = str.substring(str.indexOf(<span class="string">"}"</span>) + 1, str.length());
<a name="248" href="#248">248</a>         }
<a name="249" href="#249">249</a> 
<a name="250" href="#250">250</a>         <strong>return</strong> sb.append(str);
<a name="251" href="#251">251</a>     }
<a name="252" href="#252">252</a> 
<a name="253" href="#253">253</a>     <strong>public</strong> <strong>void</strong> release() {
<a name="254" href="#254">254</a>         <strong>this</strong>.name = <strong>null</strong>;
<a name="255" href="#255">255</a>         <strong>this</strong>.target = <strong>null</strong>;
<a name="256" href="#256">256</a>     }
<a name="257" href="#257">257</a> }
</pre>
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