利用AJAX是想JSP页面的单个控件的后台校验-优快云博客

本文介绍了一个使用JSP实现的菜单添加功能，其中包括了前端表单验证和后端数据重复检查的过程。通过JavaScript实现了对分类名称和排序字段的即时验证，并利用Ajax技术向服务器发送请求检查数据是否已存在。

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xml:

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ include file="../../../../common/common-js.jsp"%>
<%@ include file="../../../../common/common-taglibs.jsp"%>
<%@ include file="../../../../common/common-css.jsp"%>
<%@taglib prefix="s" uri="/struts-tags"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme() + "://"
+ request.getServerName() + ":" + request.getServerPort()
+ path + "/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">

<title>My JSP 'addMenu.jsp' starting page</title>

a:hover {
text-decoration: underline;
}

tr {
background-color: #D8E4F2;
}
</style>
<script type="text/javascript">
function addMenu11() {
var common_d0020 = document.getElementById("d0020").value;
var common_d0030 = document.getElementById("d0030").value;
if (common_d0020.replace(/^\s*|\s*$/g, '') == "") {
alert("分类名称不能为空，请重新输入！");
} else if (common_d0030.replace(/^\s*|\s*$/g, '') == "") {
alert("排序不能为空，请重新输入！");
} else if (common_d0020.length > 50) {
alert("分类名称长度不超过50，请重新输入！");
} else if (common_d0030.length > 20) {
alert("排序长度超过20，请重新输入！");
} else {
document.forms[0].action = "{ctx}/menuCategoriesManager/addMenu.do";
document.forms[0].submit();
}

}

function checkNull(temp) {
if (temp.replace(/^\s*|\s*$/g, '') == "") {
return false;
} else {
return true;
}
}

</script>
</head>

action里的方法：

/**
* 校验输入不重复
*
* @return
*/
public String checkData() throws Exception {
try {
String reponseText = "";
String d0020 = "";
HttpServletRequest request2 = ServletActionContext.getRequest();
String d0020value = request2.getParameter("tempd0020");
String d0030 = request2.getParameter("tempd0030");
if (d0020value != null) {
d0020 = new String(d0020value.getBytes("ISO8859-1"), "GB2312");

}
int size = 0;
if (null != d0020 && !"".equals(d0020)) {
size = menucategoriesService.checkAjax(d0020);
if (size != 0) {
reponseText = "分类名称重复，请重新输入";
}
}
if (null != d0030 && !"".equals(d0030)) {
size = menucategoriesService.checkAjax3(d0030);
if (size != 0) {
reponseText = "排列序号重复，请重新输入";
}
}
HttpServletResponse response = ServletActionContext.getResponse();
response.setContentType("text/plain");
response.setCharacterEncoding("UTF-8");
PrintWriter out = response.getWriter();
out.println(reponseText);
out.flush();
out.close();
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
return null;
}