dwr2 学习使用
在javaweb 开发中用户名验证 下拉框绑定 我使用最多的是dwr技术 因其简单 方便 直接调用java方法
一下是我初学时用的例子 dwr2.0
需要两个包dwr.jar ，commons-logging-1.0.4.jar
dwr配置java类 公开页面可以调用 文件WEB-INF下
web.xml 需要加载dwr
java类 供页面调用
js脚本文件
//调用页面
一下是我初学时用的例子 dwr2.0
需要两个包dwr.jar ，commons-logging-1.0.4.jar
dwr配置java类 公开页面可以调用 文件WEB-INF下
<dwr> <allow> <create creator="new" javascript="JsSortService"> <param name="class" value="DwrService"/> </create> </allow> </dwr>
web.xml 需要加载dwr
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
<servlet>
<servlet-name>dwr-invoker</servlet-name>
<servlet-class>
uk.ltd.getahead.dwr.DWRServlet
</servlet-class>
<init-param>
<param-name>debug</param-name>
<param-value>true</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>dwr-invoker</servlet-name>
<url-pattern>/dwr/*</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>
java类 供页面调用
import java.util.*;
@SuppressWarnings("unchecked")
public class DwrService {
private static Map bb;
static{
bb=Collections.synchronizedMap(new HashMap());
bb.put("猫", "001");
bb.put("猪", "002");
bb.put("狗", "003");
}
public String[] getdetal(){
return (String[])bb.keySet().toArray(new String[]{});
}
public static Map getbb(){
return bb;
}
public boolean isUser(String userName){
if(userName.equals("hello"))
return true;
return false;
}
}
js脚本文件
//绑定下拉框
function pp(map) {
alert("");
DWRUtil.removeAllOptions("book");
add("book", map);
}
function add(_id, _map) {
alert("");
var sel = document.getElementById(_id);
var opl = null;
if (sel != null) {
for (var prop in _map) {
opt = document.createElement("option");
opt.setAttribute("value", _map[prop]);
opt.appendChild(document.createTextNode(prop));
sel.appendChild(opt);
}
}
}
页面加载时调用函数
window.onload = function () {
JsSortService.getbb(pp);
};
//验证用户名
function checkUser(widget) {
var username = widget.value;
JsSortService.isUser(username, showUsermsg);
}
//用户名验证dwr返回函数
var showUsermsg = function (data) {
if (data) {
DWRUtil.setValue("usermsg", "<font color='red'>"+data+"</font>", {escapeHtml:false});
} else {
DWRUtil.setValue("usermsg", "<font color='green'>error</font>", {escapeHtml:false});
}
};
//调用页面
<%@ page language="java" import="java.util.*" pageEncoding="GB18030"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>My JSP 'index.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
<script type="text/javascript" src="dwr/engine.js"></script>
<script type="text/javascript" src="dwr/util.js"></script>
<script type="text/javascript" src="dwr/interface/JsSortService.js"></script>
<script type="text/javascript" src="sele.js"></script>
</head>
<body>
<form action="#">
<table border="0">
<tr>
<td><select id="book" onchange="javascript:alert('');"></select>
</td>
</tr>
<tr>
<td>用户名：</td>
<td><input type="text" name="username" id="username" value=""
onblur="checkUser(this);" /><span id="usermsg"></span>
</td>
</tr>
<tr>
<td>密码：</td>
<td><input type="password" name="userpwd" id="userpwd" value="">
</td>
</tr>
<tr>
<td><input type="submit" value="注册" />
</td>
<td><input type="reset" value="清空" />
</td>
</tr>
</table>
</form>
</body>
</html>