问题描述
我在一个 JSP 页面和一个按钮中有多个不同类型的字段.这些字段是根据从我创建的元数据表中获取的信息生成的.
I have multiple fields of various types in a JSP page and one button. These fields are generated based on the info got from a metadata table that I have created.
由于我不知道存在多少和什么类型的字段,我给他们动态的id.我在我的 JSP 中使用 Struts 2 标签.
Since I don't know how many and what type of fields are present, I am giving dynamic id's to them. I am using Struts 2 tags in my JSP.
问题出在 <s:select> 标签上:当我在 id 属性中给出 scriplet 时,它会显示以下错误:
The issue is with the <s:select> tag: when I give scriplet within the id attribute, it displays the following error :
org.apache.jasper.JasperException:/success.jsp(83,12) 需要引用符号
org.apache.jasper.JasperException: /success.jsp(83,12) quote symbol expected
<s:if test="%{#masterColDO.controlType=='dropdown'}"> <s:select styleClass="login-textbox" style="width:130px" list="#masterColDO.validation" name="chngdColumnValues" id=<%="columnId" + count%> /> </s:if> <s:else> <input type=<s:property value="#masterColDO.controlType" /> class="login-textbox " name="chngdColumnValues" id=<%="columnId" + count%> /> </s:else>
Javascript如下:
Javascript is as follows:
var addUpdateBtnId = document.getElementById('addUpdateBtnId'); addUpdateBtnId.value='Update'; addUpdateBtnId.onclick = function() { onClickUpdateBtn(rowIndex); }; var selectedUpdateRow = xmlhttp.responseText.split(","); for(var i = 0; i < selectedUpdateRow.length; i++){ var columnElementId = "columnId"+i; document.getElementById(columnElementId).value = selectedUpdateRow[i]; } document.getElementById("columnId"+(primaryKeyPos-1)).readOnly = true;
推荐答案
Scriptlets 是旧的做事方式,你应该避免在 JSP 中编写 Java 代码;
Struts2 仅使用它的标签和 OGNL 帮助您实现相同的目标.
Scriptlets are the old way of doing things, you should avoid writing Java code in JSP's at all;
Struts2 helps you achieving the same goals using its tags and OGNL only.
<input/> 部分正在工作,因为您在 HTML 标记内注入了 scriptlet,这是允许的.
The <input /> part is working because you are injecting a scriptlet inside an HTML tag, that is allowed.
<s:select/> 部分不起作用,因为您在 Struts2 标记内注入了 scriptlet,这是不允许的.
The <s:select /> part is not working because you are injecting a scriptlet inside an Struts2 tag, that is not allowed.
为了让它工作,你应该使用 OGNL 中的 #attr 语法来访问 Scriptlets中声明的 Java 变量code> 并在 Page Context 中推送由你,像这样(完全未经测试):
To make it work, you should use #attr syntax in OGNL to access the Java variables declared in Scriptlets and pushed by you in the Page Context, like this (completely untested):
<% for (int counter=0;counter<myList.size();counter++) { // pushing it into the pageContext pageContext.setAttribute("counter",counter); %> <s:select cssClass="login-textbox" cssStyle="width:130px" list="#masterColDO.validation" name="chngdColumnValues" id="%{'columnId' + #attr['counter']}" /> <% } %>
但是,即使技术上可行,也不鼓励这样做.为此,您应该使用纯 Struts2 方式,如下所示:
However, even if it's technically possible, it is discouraged. You should use the pure Struts2 way for that, that would be the following:
<s:iterator value="myList" status="ctr"> <s:select cssClass="login-textbox" cssStyle="width:130px" list="#masterColDO.validation" name="chngdColumnValues" id="%{'columnId' + #ctr.index}" /> </s:iterator>
<小时>
P.S: Struts 标签没有任何 styleClass 属性;你可以使用 cssClass 和/或 cssStyle;
而且,如果 controlType 是一个字符串,你应该使用 .equals 而不是 ==: <s:if test="%{#masterColDO.controlType.equals('dropdown')}">.
P.S: Struts tags doesn't have any styleClass attribute; you can use cssClass and/or cssStyle;
And, if controlType is a String, you should use .equals instead of ==: <s:if test="%{#masterColDO.controlType.equals('dropdown')}">.