在SpringMVC框架下实现文件的上传和下载示例
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2024-03-07 14:18:33
在eclipse中的javaee环境下:导入必要的架包
web.xml的配置文件:
在eclipse中的javaee环境下:导入必要的架包
web.xml的配置文件:
<?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" 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"> <!-- 配置springmvc的dispatcherservlet --> <servlet> <servlet-name>springdispatcherservlet</servlet-name> <servlet-class>org.springframework.web.servlet.dispatcherservlet</servlet-class> <init-param> <param-name>contextconfiglocation</param-name> <param-value>classpath:springmvc.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>springdispatcherservlet</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> <!-- 配置 hiddenhttpmethodfilter: 把 post 请求转为 delete、put 请求 --> <filter> <filter-name>hiddenhttpmethodfilter</filter-name> <filter-class>org.springframework.web.filter.hiddenhttpmethodfilter</filter-class> </filter> <filter-mapping> <filter-name>hiddenhttpmethodfilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> </web-app>
spring的bean的配置文件springmvc.xml;
<?xml version="1.0" encoding="utf-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/xmlschema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xsi:schemalocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd"> <!-- 配置自动扫描的包 --> <context:component-scan base-package="com.atguigu.springmvc"></context:component-scan> <!-- 配置视图解析器 --> <bean class="org.springframework.web.servlet.view.internalresourceviewresolver"> <property name="prefix" value="/web-inf/views/"></property> <property name="suffix" value=".jsp"></property> </bean> <!-- default-servlet-handler 将在 springmvc 上下文中定义一个 defaultservlethttprequesthandler, 它会对进入 dispatcherservlet 的请求进行筛查, 如果发现是没有经过映射的请求, 就将该请求交由 web 应用服务器默认的 servlet 处理. 如果不是静态资源的请求,才由 dispatcherservlet 继续处理 一般 web 应用服务器默认的 servlet 的名称都是 default. 若所使用的 web 服务器的默认 servlet 名称不是 default,则需要通过 default-servlet-name 属性显式指定 --> <mvc:default-servlet-handler/> <!-- 一般都会配置这个 <mvc:annotation-driven ></mvc:annotation-driven>, 由于。。。requestmapping请求实现不了,使用这个,会使requestmapping请求一定实现 --> <mvc:annotation-driven ></mvc:annotation-driven> <!-- 配置 multipartresolver ,即配置文件上传的属性--> <bean id="multipartresolver" class="org.springframework.web.multipart.commons.commonsmultipartresolver"> <!-- 默认的字符编码 --> <property name="defaultencoding" value="utf-8"></property> <!-- 上传文件的大小 ,最大上传大小--> <property name="maxuploadsize" value="1024000"></property> </bean> </beans>
handler类方法:实现文件的上传和下载的方法
@controller public class springmvctest { @autowired private employeedao employeedao; //实现文件的下载 //需要说明的是文件的上传和下载不需要其他配置 @requestmapping("testresponseentity") public responseentity<byte[]> testresponseentity(httpsession session) throws ioexception{ byte[] body=null; servletcontext servletcontext=session.getservletcontext(); ///files/abc.txt:所要下载文件的地址 inputstream in=servletcontext.getresourceasstream("/files/abc.txt"); body=new byte[in.available()]; in.read(body); httpheaders headers=new httpheaders(); //响应头的名字和响应头的值 headers.add("content-disposition", "attachment;filename=abc.txt"); httpstatus statuscode=httpstatus.ok; responseentity<byte[]> response=new responseentity<byte[]>(body, headers, statuscode); return response; } //文件上传, @requestmapping("/testfileupload") public string testfileupload(@requestparam("desc") string desc, @requestparam("file") multipartfile file) throws ioexception{ system.out.println("desc:"+desc); system.out.println("originalfilename"+file.getoriginalfilename()); system.out.println("inputstream"+file.getinputstream()); return "success"; } }
jsp页面:index.jsp:
<%@ 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> <meta http-equiv="content-type" content="text/html; charset=utf-8"> <title>insert title here</title> </head> <body> <center> <!-- 文件上传的表单 --> <form action="testfileupload" method="post" enctype="multipart/form-data"> file:<input type="file" name="file"/> desc:<input type="text" name="desc"/> <input type="submit" value="submit"/> </form> <br><br> <!-- 文件的下载 --> <a href="testresponseentity" rel="external nofollow" >test responseentity</a> </center> </body> </html>
success.jsp页面:显示文件上传成功
<%@ 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> <meta http-equiv="content-type" content="text/html; charset=utf-8"> <title>insert title here</title> </head> <body> <h3>success page</h3> </body> </html>
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