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
<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>