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Cookbook-struts1.3.8案例分析－Logic Tags

Cookbook-struts1.3.8案例分析－Logic Tags

l Logic Tags

入口Action配置

<action path="/prepareLogic"            type="examples.logic.PrepareLogicAction">            <forward name="success" path="/jsp/logic/Logic.jsp" /> </action>

SuccessAction，继承自Action，execute方法如下

public ActionForward execute(         ActionMapping mapping,         ActionForm form,         HttpServletRequest request,         HttpServletResponse response)         throws Exception {         //往Request范围内放置一些变量         TestBean bean = new TestBean();         request.setAttribute("testBean", bean);         ArrayList items = new ArrayList();         request.setAttribute("items", items);         request.setAttribute("intValue", new Integer(7));         request.setAttribute("stringValue", "Hello, world!");         /* Collection of custom beans */         ArrayList books = new ArrayList();         books.add(new BookBean("0596003285", "Programming Jakarta Struts"));         books.add(new BookBean("1930110502", "Struts in Action"));         books.add(new BookBean("1861007817", "Professional Struts Applications"));         books.add(new BookBean("0672324725", "Struts Kick Start"));         books.add(new BookBean("0471213020", "Mastering Jakarta Struts"));         books.add(new BookBean("1558608621", "The Struts Framework"));         books.add(new BookBean("0971661901", "Struts Fast Track"));         request.setAttribute("books", books);         ActionErrors errors = new ActionErrors();         errors.add(ActionMessages.GLOBAL_MESSAGE,             new ActionMessage("errors.detail", "This is a global error #1"));         errors.add(ActionMessages.GLOBAL_MESSAGE,             new ActionMessage("errors.detail", "This is a global error #2"));         errors.add("test",             new ActionMessage("errors.detail", "This is a test error"));         ActionMessages messages = new ActionMessages();         messages.add(ActionMessages.GLOBAL_MESSAGE,             new ActionMessage("message.detail", "This is global message #1"));         messages.add(ActionMessages.GLOBAL_MESSAGE,             new ActionMessage("message.detail", "This is global message #2"));         messages.add("test",             new ActionMessage("message.example.simple"));         //设置Message和Error         saveMessages(request, messages);         saveErrors(request, errors);         // Forward to the form         return mapping.findForward("success"); }

JSP文件对Bean标签的处理

对cookie的判断，显示与否 <logic:present cookie="JSESSIONID">     <p>Session cookie is present.</p> </logic:present> <logic:notPresent cookie="UNKNOWN">     <p>UNKNOWN cookie is not present.</p> </logic:notPresent> 参数判断，显示与否 <logic:present parameter="param">     <bean:parameter name="param" id="test"/>     <p><bean:write name="test"/></p> </logic:present> <logic:notPresent parameter="param">     <p>Parameter 'param' not present.     <html:link action="/prepareLogic?param=The parameter is present">         Redisplay page with parameter present.      </html:link>     </p> </logic:notPresent> Request范围内存在判断，显示与否 <h3>Bean</h3> <logic:present name="testBean">     <p>'testBean' is present.</p> </logic:present> <logic:notPresent name="anotherTestBean">     <p>'anotherTestBean' is not present.</p> </logic:notPresent> 上下文变量的属性存在判断，显示与否 <logic:present name="testBean" property="fred">     <p>'fred' property is present on 'testBean'</p> </logic:present> <logic:notPresent name="testBean" property="fred">     <p>'fred' property is not present on 'testBean'</p> </logic:notPresent> <logic:present name="testBean" property="stringValue">     <p>'stringValue' property is present on 'testBean'</p> </logic:present> 集合是否为空判断，是否显示 <logic:present name="items">     <p>'items' was found.</p> </logic:present> <logic:empty name="items">     <p>'items' is empty</p> </logic:empty> <logic:notEmpty name="items">     <p>'items' is not empty</p> <%--   <bean:size collection="items" id="itemsSize"/>     <p>Items has <bean:write name="itemsSize" /> items.</p> --%>   </logic:notEmpty> 大小比较 <logic:equal name="intValue" value="7">     <p>intValue == 7</p> </logic:equal> <logic:greaterEqual name="intValue" value="7">     <p>intValue &gt;= 7</p> </logic:greaterEqual> <logic:greaterEqual name="intValue" value="6">     <p>intValue &gt;= 6</p> </logic:greaterEqual> <logic:greaterThan name="intValue" value="6">     <p>intValue &gt; 6</p> </logic:greaterThan> <logic:lessEqual name="intValue" value="7">     <p>intValue &lt;= 7</p> </logic:lessEqual> <logic:lessEqual name="intValue" value="8">     <p>intValue &lt;= 8</p> </logic:lessEqual> <logic:lessThan name="intValue" value="8">     <p>intValue &lt; 8</p> </logic:lessThan> 模糊匹配 <logic:match name="stringValue" value="world">     <p>stringValue matches 'world'</p> </logic:match> <logic:notMatch name="stringValue" value="earth">     <p>stringValue does not match 'earth'</p> </logic:notMatch> <logic:notMatch name="stringValue" value="world">     <p>stringValue does not match 'world'</p> </logic:notMatch> 迭代集合 <logic:iterate name="books" id="book" indexId="index">     <li><bean:write name="book" property="title"/></li> </logic:iterate> <logic:iterate name="books" id="book" offset="2" length="3">     <li><bean:write name="book" property="title"/></li> </logic:iterate> 显示错误集合 <logic:messagesPresent> <p>Global errors:</p> <ul>  <html:messages id="error" property="<%=ActionErrors.GLOBAL_MESSAGE%>">  <li><bean:write name="error"/></li>  </html:messages> </ul> <p>Errors for 'test':</p> <ul>  <html:messages id="error" property="test">  <li><bean:write name="error"/></li>  </html:messages> </ul> </logic:messagesPresent> <logic:messagesNotPresent>     <p>There are no errors</p> </logic:messagesNotPresent> 显示消息 <logic:messagesPresent message="true">  <ul>  <html:messages id="msg" message="true" property="<%=ActionMessages.GLOBAL_MESSAGE%>">  <li><bean:write name="msg"/></li>  </html:messages>  </ul> <p>Messages for 'test':</p> <ul>  <html:messages id="msg" property="test" message="true">  <li><bean:write name="msg"/></li>  </html:messages> </ul> </logic:messagesPresent> <logic:messagesNotPresent message="true">     <p>There are no messages</p> </logic:messagesNotPresent>

posted on 2008-07-08 02:19 MingIsMe 阅读(160) 评论(0)  编辑  收藏 所属分类: 16 案例分析