dwr异步上传图片

这里需要用到commons-fileupload-1.2.2和commons-io-2.3

This is the web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
	http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
	<servlet>
		<servlet-name>dwr-invoker</servlet-name>
		<servlet-class>org.directwebremoting.servlet.DwrServlet</servlet-class>
		<!-- 配置debug参数为true后，就可以访问DWR的控制台了，访问地址为http://ip:port/webApp/dwr/ -->
		<!-- 开发阶段可以开启控制台，但在产品交付时，务必关掉控制台 -->
		<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>
</web-app>

This is DWR Config File----dwr.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE dwr PUBLIC "-//GetAhead Limited//DTD Direct Web Remoting 3.0//EN"
"http://getahead.org/dwr/dwr30.dtd">
<dwr>
	<allow>
		<create creator="new" javascript="JSUserManager">
			<param name="class" value="com.jadyer.dwr.UserManager" />
		</create>
	</allow>
</dwr>

下面是用于提交上传操作的前台页面upload.jsp

<%@ page language="java" pageEncoding="UTF-8"%> <script type="text/javascript" src="<%=request.getcontextpath()%>/dwr/interface/JSUserManager.js"></script> <script type="text/javascript" src="<%=request.getcontextpath()%>/dwr/engine.js"></script> <script type="text/javascript" src="<%=request.getcontextpath()%>/dwr/util.js"></script> <script type="text/javascript"> function upload() { var file = dwr.util.getValue("myfile"); alert(file.value);//不同浏览器在此处得到的值,不一定相同....IE9得到的是含全路径的文件名,firefox12得到的是文件名 alert(file); JSUserManager.upload(file,file.value,function(data){ alert(data); }); } </script> <input type="file" id="myfile"/> <input type="button" value="上传文件" onclick="upload()"/>
最后是需要由DWR发布的UserManager.java package com.jadyer.dwr; import java.io.File; import java.io.IOException; import java.io.InputStream; import javax.servlet.http.HttpServletRequest; import org.apache.commons.io.FileUtils; import org.apache.commons.io.FilenameUtils; import org.directwebremoting.WebContextFactory; public class UserManager { /** * 上传文件 * @param is DWR会自动把dwr.util.getValue("myfile")转换为这里所需的InputStream * @param filename 不同浏览器传进来的值未必相同，IE9传是含全路径的文件名,firefox12传的是文件名 * @return 文件的真实名字 */ public String upload(InputStream is,String filename) throws IOException{ String realname = FilenameUtils.getName(filename); //获取文件的真实名字 HttpServletRequest request = WebContextFactory.get().getHttpServletRequest(); //获取Servlet API String realpath = request.getSession().getServletContext().getRealPath("/WEB-INF/upload"); FileUtils.copyInputStreamToFile(is,new File(realpath,realname)); return realname; } }
补充：记得建立//WEB-INF//upload//目录，其用于接收所上传的文件