Struts标签库

一.html标签

1.html元素的标签:

a1.<html:link forward="index"> 链接<global-forwards>中的name </html:link>

a2. <html:link href="http://www.baidu.com" > 链接到站点外 </html:link>

a3. <html:link page="/HtmlBasic.do">同一个应用 </html:link>

如:包含请求参数: <html:link page="/HtmlBasic.do?prop1=abc&amp;prop2=123" />

包含单个请求变量:<% String stringBean = "Value to Pass on URL";

pageContext.setAttribute("stringBean", stringBean);%>

<html:link page="/HtmlBasic.do" paramId="urlParamName" paramName="stringBean" />

<jsp:useBean id="javaBean" scope="page" class="CustomerBean" />

<jsp:setProperty name="javaBean" property="name" value="weiqin" /> //要有范围

<html:link page="/Html" paramId="url" paramName="javaBean" paramProperty="name"/>

包含多个请求变量: <% java.util.HashMap myMap = new java.util.HashMap();

myMap.put("myString", new String("myStringValue") );

myMap.put("myArray", new String[] { "str1", "str2", "str3" });

pageContext.setAttribute("map", myMap);%>

<html:link page="/HtmlBasic.do" name="map"> url </html:link>

b.<html:img>: <html:img page="/struts-power.gif" /> //也可以包含单个或多个请求变量

<html:img src="/struts-power.gif" paramId="urlParamName" paramName="stringBean" />

<html:img page="/struts-power.gif" name="map" />

2.基本表单标签:<html:form>,<html:text>,<html:hidden>,<html:submit>,<html:reset>

<html:cancel>Cancel</html:cancel> :Action中的取消事件:

FormBasicForm fbf = (FormBasicForm) form;

if (isCancelled(request)) { fbf.setStatus("Cancel was pressed!");

return (mapping.findForward("success")); }//表示取消选中

else { fbf.setStatus("Submit was pressed!");

return (mapping.findForward("success")); }

3.下拉列表和多选列表

<html:select property="colors" size="6" multiple="true" > // multiple下拉可多选

<html:option value="htmlselect.orange">Orange</html:option> //基本的页面输入

<html:option value="red" bundle="htmlselect.Colors" key="red"/>//从资源文件中显示

<% Vector colorCollection = new Vector(); colorCollection.add(

new org.apache.struts.util.LabelValueBean("Pink", "htmlselect.pink"));

colorCollection.add( // Pink为label htmlselect.pink为value

new org.apache.struts.util.LabelValueBean("Brown", "htmlselect.brown"));

pageContext.setAttribute("colorCollection", colorCollection); %>

<html:options collection="colorCollection" property="value" //实际值

labelProperty="label" /> </html:select>// labelProperty显示值

4.显示错误消息: errors.add(ActionMessages.GLOBAL_MESSAGE, new ActionMessage("key") );

a.显示全局:<html:errors property="org.apache.struts.action.GLOBAL_MESSAGE"/>

b.显示特定字段: errors.add("checkbox1", new ActionMessage("error.checkbox"));

<html:errors property="checkbox1" bundle="HtmlErrors" /> //bundle资源文件

5.显示信息<html:messages>:

a.<html:messages id=”message” message=”true”/>//如果为true则从全局中搜索

则:ActionMessages actionMessages=new ActionMessages();

actionMessages.add(ActionMessages.GLOBAL_MESSAGE,new ActionMessage(“key”));

saveMessages(request,actionMessages);

b.从一定的范围中查找:<html:messages id=”message”>

<bean:write name=”message” /> </html:messages>

则:protected void saveMessages(HttpServletRequest request,ActionMessages messages){

...request.setAttribute(GLOBAL_MESSAGE_key,messages); }

二:Struts Bean标签

1.访问http请求信息和JSP对象

a. <bean:cookie id="cookie" name="cookiedemo" value="firsttime"/> // value为默认值

<% if (cookie.getValue().equals("firsttime")) {

Cookie c = new Cookie("cookiedemo", "Hi Linda!");

c.setComment("A test cookie");c.setMaxAge(3600);response.addCookie(c);} %>

输出: <bean:write name="cookie" property="value"/>

b. <bean:header id="lang" name="Accept-Language"/> <bean:write name="lang"/>

c. <bean:page id="this_session" property="session"/>//检索JSP范围,隐含对象

<bean:write name="this_session" property="creationTime"/>

d. <bean:parameter id="arg1" name="testarg" value="noarg"/> // value为默认值

<bean:write name="arg1"/>

检索多值：<bean:parameter id="arg2" multiple="yes" name="testarg" value="noarg"/>

通过链接传递参数：<html:link page="/this.jsp?testarg=123&testarg=456&testarg=789">

循环输出：<% for (int i=0; i <arg2.length; i++) {out.write(arg2[i] + "<BR>");} %>

2．访问WEB应用资源： <message-resources parameter="res" key="special" />

a. <bean:message key="hello" arg0="Linda" /> //默认资源文件中：hello=Hello,{0}

<% request.setAttribute("stringBean","hello"); SomeBean bean=new SomeBean();

bean.setName("hello"); request.setAttribute("someBean",bean); %>

通过变量名或javaBean得到key值再访问资源文件：

<bean:message bundle="special" name="stringBean"/>// bundle不能省,只能访问资源文件

<bean:message bundle="special" name="someBean" property="name"/>

b. <bean:include>同<jsp:include>,但将WEB资源存放在一个变量中，有forward,page,href

<bean:include id="tp1" page="/testpage1.jsp"/> <bean:write name="tp1" filter="false"/>

<bean:include id="tp2" forward="testpage2"/> <bean:write name="tp2" filter="false"/>

3.定义或输出javaBean，bean:write标签filter为true时会将特殊符号转换成普通字符串

a.value属性：<bean:define id="name" value="lib"/><bean:write name="name"/>

name和property属性：<% request.setAttribute("sessionBean", session); %>

<bean:define id="contextBean" name="sessionBean" property="servletContext"/>

// contextBean为javax.servlet.ServletContext类型，实例化

<bean:write name="contextBean" property="servletContextName"/>

name和type属性（用于复制）：<bean:define id="contextBean_copy" name="contextBean"

type="javax.servlet.ServletContext"/>

<bean:write name="contextBean_copy" property="majorVersion"/>