dwr印证唯一性 _Web前端

dwr验证唯一性
web.xml中配置DWR：

<!-- 配置DWR的核心Servlet开始 -->
	<!-- 配置DWR的核心Servlet -->
	<servlet>
		<servlet-name>dwr</servlet-name>
		<servlet-class>org.directwebremoting.servlet.DwrServlet</servlet-class>
		<!-- 指定处于开发阶段 -->
		<init-param>
			<param-name>debug</param-name>
			<param-value>true</param-value>
		</init-param>
		<!-- 增加服务器的加载能力 -->
		<init-param>
			<param-name>pollAndCometEnabled</param-name>
			<param-value>true</param-value>
		</init-param>
		<load-on-startup>1</load-on-startup>
	</servlet>
	<!-- 配置DWR的核心Servlet结束 -->

Dwr.xml的配置文件（和web.xml同目录下）：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE dwr PUBLIC
"-//GetAhead Limited//DTD Direct Web Remoting 2.0//EN" "http://getahead.org/dwr/dwr20.dtd">
<dwr>
	<allow>
		<!-- 声明java到javascript转换过程中用到的类 -->
		<convert converter="bean" match="org.com.model.Employee" />
		<!-- 使用Spring创造器去创建和远程调用beans -->
		<!-- creartor属性指定类实例的创建方式，javascript属性指定在浏览器的引用名 -->
		<create creator="spring" javascript="EmployeeDWR">
			<!-- value 属性注入Spring中的实例 -->
			<param name="beanName" value="employeeManager" />
			<!-- 显式的引入可调用的方法 -->
			<include method="checkEmppoyeeName" />
		</create>
	</allow>
</dwr>

dao层：

        /**
	 * 查询用户名
	 */
	public int check(String userName) {
		List<Employee> list =this.getHibernateTemplate().find("from Employee where userName=?",userName);
		if(list!=null && list.size()>0){
			return 1;
		}
		return 0;
	}

Service层：

 //检查员工用户名唯一性（DWR中调用）
	public int checkEmployee(String userName) {
		return this.employeeDao.check(userName);
	}

DWR前台页面：

<%@ page language="java" contentType="text/html; charset=gb2312"
    pageEncoding="gb2312"%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>Insert title here</title>
 <script type='text/javascript' src='../dwr/interface/EmployeeDWR.js'></script>
 <script type='text/javascript' src='../dwr/engine.js'></script>
<script type='text/javascript' src='../dwr/util.js'></script>
<script type="text/javascript">
	function checkname(){
			var username=document.getElementById("userName");
			var check1=document.getElementById("check1");
			if(username.value==""){
					check1.innerHTML="<font color='red'>用户名不能为空！</font>";
					username.focus();
			}
			else{
				check1.innerHTML="";
				EmployeeDWR.checkEmppoyeeName(username.value,putCheckValue);	
			}
	}
	function putCheckValue(data){
		var username=document.getElementById("userName");
		var check1=document.getElementById("check1");
		if(data==1){
			check1.innerHTML="<font color='red'>此用户名已用，请重新填写！</font>";
			username.focus();
		}
		else{
			check1.innerHTML="<font color='green'>此用户名可用！</font>";	
		}
	}
</script>
</head>
<body>
	
	<table>
		<tr>
			<td><input type="text" name="userName" id="userName" onblur="checkname();"/><span id="check1"/></td>
		</tr>
	</table>
</body>
</html>