<span style="font-size:18px;"><strong>Struts.xml</strong>配置文件
<!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN" "http://struts.apache.org/dtds/struts-2.0.dtd">
<struts>
<include file="struts-default.xml"></include>
<package name="ajax" extends="struts-default">
<action name="ajax_*" class="com.test.action.AjaxAction" method="{1}">
<result name="SUCCESS">/ajax.jsp</result>
<result type="stream">
<param name="inputName">inputStream</param>
</result>
</action>
</package>
</struts></span>
AjaxAction
package com.test.action;
import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.StringBufferInputStream;
import java.io.StringReader;
import java.io.UnsupportedEncodingException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts2.ServletActionContext;
import com.opensymphony.xwork2.ActionSupport;
public class AjaxAction extends ActionSupport {
private InputStream inputStream;
public InputStream getInputStream() {
return inputStream;
}
public String execute() throws Exception {
return SUCCESS;
}
public String checkUser() throws Exception {
HttpServletRequest request = ServletActionContext.getRequest();
// 获取 ajax 传递的 name 参数值
Object name = request.getParameter("name");
Object password = request.getParameter("password");
System.out.println("name=>" + name);
// 返回 StringBufferInputStream 对象，新的 jdk 里面已经不推荐使用，但推荐使用的 StringReader
// 并不是 InputStream 接口的实现类，这个比较蛋疼，可以使用下面 test 里面其他的实现类来传递
inputStream = new StringBufferInputStream(transcoding("哈哈,"+name +password));
return SUCCESS;
}
public String test() throws Exception {
// 返回 ByteArrayInputStream 对象至前台，注意跟上面的编码上的区别
inputStream = new ByteArrayInputStream("乱码测试".getBytes("utf-8"));
return SUCCESS;
}
private String transcoding(String str) {
try {
return new String(str.getBytes("utf-8"), "iso-8859-1");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
return str;
}
}
ajax.jsp
<span style="font-size:18px;"><%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>ajax</title>
</head>
<body>
<form>
用户名：<input type="text" id="nameId"/><br/>
密码：<input type="text" id="passwordId"/><br/>
<span id="nameId2"><span></span></span><br/>
<span id="msgId"></span><br/>
<input type="button" onclick="checkUserName()" value="提交"/>
</form>
</body>
</html>
<script type="text/javascript">
var xhr ;
// 初始化 xhr 对象
// return value : 1 : IE , 2 , Mozila , 0 : create xhr error ;
function createXHR(){
// 1,创建xhr 对象 .
if( window.ActiveXObject ){
xhr = new ActiveXObject( "Microsoft.XMLHTTP" ) ;
return 1 ;
}else if( window.XMLHttpRequest ){
xhr = new XMLHttpRequest();
return 2 ;
}else{
return 0 ;
}
}
// ////////// 验证用户名是否存在 ////////////////////
// 将用户填写的用户名发送给服务器端验证
function checkUserName(){
var ret = createXHR();
if( ret == 0 ){
alert( "create xhr error" ) ;
}else{
// 在xhr中注册用于处理应答的函数(handleCheck)
xhr.onreadystatechange = handleCheck ;
/*
* //使用Get方式向服务器发送请求 .
* var url = makeQueryString( "/ajax/reg.jsp" );
* xhr.open( "get" , url ) ;
* xhr.send( null );
*/
// 通过Post 形式向服务器发送数据 .
var url = "http://localhost:8080/ajax/ajax_checkUser.action" ;
xhr.open( "post" , url ) ;
xhr.setRequestHeader( "Content-Type" , "application/x-www-form-urlencoded" ) ;
xhr.send( makeQueryString( null ) ) ;
}
}
// 在指定的URL上添加参数
function makeQueryString( url ){
var name = document.getElementById( "nameId" ).value ;
var password = document.getElementById( "passwordId" ).value ;
var queryString ;
if( url == null ){
return "name=" + name ;
}else{
return url + "?name=" + name +"&password=" + password;
}
}
function handleCheck(){
document.getElementById( "nameId2" ).firstChild.innerHTML="用户名不能为空";
// 通信过程结束 .
// readyState : 1: 初始化阶段 2 ：连接建立阶段 3 : 通信中阶段 4 ： 通信结束
if( xhr.readyState == 4 ){
// status==200,表示服务器运行正常,其他值代表错误
if( xhr.status == 200 ){
processResult();
}else if(document.getElementById( "nameId" ).value==""){
document.getElementById( "nameId2" ).firstChild.nodeValue="用户名不能为空";
document.getElementById( "nameId2" ).color="red";
}
}
}
function processResult(){
// 获得应答内容 ,把应答内容显示在网页上
var span = document.getElementById( "msgId" ) ;
span.innerHTML = xhr.responseText ;
}
</script></span>
web.xml
<span style="font-size:18px;"><?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">
<filter>
<filter-name>struts2</filter-name>
<filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
</filter>
<filter>
<filter-name>struts-cleanup</filter-name>
<filter-class>
com.test.filter.SetCharacterEncodingFilter
</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>utf-8</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>struts-cleanup</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>*.action</url-pattern>
</filter-mapping>
</web-app></span>SetCharacterEncodingFilter
<span style="font-size:18px;">package com.test.filter;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
public class SetCharacterEncodingFilter implements Filter {
protected String encoding = null;
protected FilterConfig filterConfig = null;
protected boolean ignore = true;
public void destroy() {
this.encoding = null;
this.filterConfig = null;
}
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain)
throws IOException, ServletException {
if (ignore || (request.getCharacterEncoding() == null)) {
String encoding = selectEncoding(request);
if (encoding != null)
request.setCharacterEncoding(encoding);
}
chain.doFilter(request, response);
}
public void init(FilterConfig filterConfig) throws ServletException {
this.filterConfig = filterConfig;
this.encoding = filterConfig.getInitParameter("encoding");
String value = filterConfig.getInitParameter("ignore");
if (value == null)
this.ignore = true;
else if (value.equalsIgnoreCase("true"))
this.ignore = true;
else if (value.equalsIgnoreCase("yes"))
this.ignore = true;
else
this.ignore = false;
}
protected String selectEncoding(ServletRequest request) {
return (this.encoding);
}
}
</span>