SpringBoot使用webxml后上传文件异常multipart-form is disabled
今天遇到了上传文件的一个问题，项目环境是Springboot+JSP。因为使用了公司内部的框架，所以也需要使用web.xml。
一、表单+后台处理代码
<form method="post" action="<c:url value="/student/commit"/>" enctype="multipart/form-data">
<input type="text" name="name"/>
<input type="file" name="file"/>
<input type="submit"/>
</form>
@RequestMapping(value = "/commit", method = RequestMethod.POST)
public String commit(@RequestParam("name") String name,
@RequestParam("file") MultipartFile file) {
logger.info(name);
try {
logger.info(file.getInputStream().toString());
} catch (IOException e) {
e.printStackTrace();
}
return "/student/commit";
}
一个非常简单的文件上传，错误里的 no multi-part configuration has been provided 是什么意思，未提供文件上传的配置？
可我分明在 spring-web.xml 里加入了相应的配置。
我再仔细看，Could not parse multipart servlet request，没有 servlet 的配置？
异常堆栈：
2019-08-20 15:56:44.084 ERROR 5104 --- [esin-port-80-48] o.s.b.w.servlet.support.ErrorPageFilter : Forwarding to error page from request [/admin/student/import.do] due to exception [Failed to parse multipart servlet request; nested exception is javax.servlet.ServletException: multipart-form is disabled; check @MultipartConfig annotation on 'geli-springboot'.]
org.springframework.web.multipart.MultipartException: Failed to parse multipart servlet request; nested exception is javax.servlet.ServletException: multipart-form is disabled; check @MultipartConfig annotation on 'geli-springboot'.
at org.springframework.web.multipart.support.StandardMultipartHttpServletRequest.handleParseFailure(StandardMultipartHttpServletRequest.java:123) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.web.multipart.support.StandardMultipartHttpServletRequest.parseRequest(StandardMultipartHttpServletRequest.java:114) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.web.multipart.support.StandardMultipartHttpServletRequest.<init>(StandardMultipartHttpServletRequest.java:87) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.web.multipart.support.StandardServletMultipartResolver.resolveMultipart(StandardServletMultipartResolver.java:87) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.checkMultipart(DispatcherServlet.java:1176) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1011) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1005) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:908) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:159) ~[javaee-16.jar:na]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:882) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:97) ~[javaee-16.jar:na]
at com.caucho.server.dispatch.ServletFilterChain.doFilter(ServletFilterChain.java:109) ~[resin.jar:4.0.62]
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.22.jar:9.0.22]
at com.caucho.server.dispatch.FilterFilterChain.doFilter(FilterFilterChain.java:89) [resin.jar:4.0.62]
at org.gelivable.web.EnvFilter.doFilter(EnvFilter.java:83) [geli-spring-boot-3.0.1.jar:na]
at com.caucho.server.dispatch.FilterFilterChain.doFilter(FilterFilterChain.java:89) [resin.jar:4.0.62]
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:118) [spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at com.caucho.server.dispatch.FilterFilterChain.doFilter(FilterFilterChain.java:89) [resin.jar:4.0.62]
at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:92) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:118) [spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at com.caucho.server.dispatch.FilterFilterChain.doFilter(FilterFilterChain.java:89) [resin.jar:4.0.62]
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:118) [spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at com.caucho.server.dispatch.FilterFilterChain.doFilter(FilterFilterChain.java:89) [resin.jar:4.0.62]
at org.springframework.boot.web.servlet.support.ErrorPageFilter.doFilter(ErrorPageFilter.java:128) [spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE]
at org.springframework.boot.web.servlet.support.ErrorPageFilter.access$000(ErrorPageFilter.java:66) [spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE]
at org.springframework.boot.web.servlet.support.ErrorPageFilter$1.doFilterInternal(ErrorPageFilter.java:103) [spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:118) [spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.boot.web.servlet.support.ErrorPageFilter.doFilter(ErrorPageFilter.java:121) [spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE]
at com.caucho.server.dispatch.FilterFilterChain.doFilter(FilterFilterChain.java:89) [resin.jar:4.0.62]
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200) [spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:118) [spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at com.caucho.server.dispatch.FilterFilterChain.doFilter(FilterFilterChain.java:89) [resin.jar:4.0.62]
at org.gelivable.web.AbstractAuthFilter.doFilter(AbstractAuthFilter.java:56) [geli-spring-boot-3.0.1.jar:na]
at com.caucho.server.dispatch.FilterFilterChain.doFilter(FilterFilterChain.java:89) [resin.jar:4.0.62]
at org.gelivable.web.EnvFilter.doFilter(EnvFilter.java:83) [geli-spring-boot-3.0.1.jar:na]
at com.caucho.server.dispatch.FilterFilterChain.doFilter(FilterFilterChain.java:89) [resin.jar:4.0.62]
at com.caucho.server.webapp.WebAppFilterChain.doFilter(WebAppFilterChain.java:156) [resin.jar:4.0.62]
at com.caucho.server.webapp.AccessLogFilterChain.doFilter(AccessLogFilterChain.java:95) [resin.jar:4.0.62]
at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:314) [resin.jar:4.0.62]
at com.caucho.server.http.HttpRequest.handleRequest(HttpRequest.java:843) [resin.jar:4.0.62]
at com.caucho.network.listen.TcpSocketLink.dispatchRequest(TcpSocketLink.java:1393) [resin.jar:4.0.62]
at com.caucho.network.listen.TcpSocketLink.handleRequest(TcpSocketLink.java:1349) [resin.jar:4.0.62]
at com.caucho.network.listen.TcpSocketLink.handleRequestsImpl(TcpSocketLink.java:1333) [resin.jar:4.0.62]
at com.caucho.network.listen.TcpSocketLink.handleRequests(TcpSocketLink.java:1241) [resin.jar:4.0.62]
at com.caucho.network.listen.TcpSocketLink.handleAcceptTaskImpl(TcpSocketLink.java:1037) [resin.jar:4.0.62]
at com.caucho.network.listen.ConnectionTask.runThread(ConnectionTask.java:117) [resin.jar:4.0.62]
at com.caucho.network.listen.ConnectionTask.run(ConnectionTask.java:93) [resin.jar:4.0.62]
at com.caucho.network.listen.SocketLinkThreadLauncher.handleTasks(SocketLinkThreadLauncher.java:175) [resin.jar:4.0.62]
at com.caucho.network.listen.TcpSocketAcceptThread.run(TcpSocketAcceptThread.java:61) [resin.jar:4.0.62]
at com.caucho.env.thread2.ResinThread2.runTasks(ResinThread2.java:173) [resin.jar:4.0.62]
at com.caucho.env.thread2.ResinThread2.run(ResinThread2.java:118) [resin.jar:4.0.62]
Caused by: javax.servlet.ServletException: multipart-form is disabled; check @MultipartConfig annotation on 'geli-springboot'.
at com.caucho.server.http.AbstractCauchoRequest.getParts(AbstractCauchoRequest.java:246) ~[resin.jar:4.0.62]
at org.springframework.web.multipart.support.StandardMultipartHttpServletRequest.parseRequest(StandardMultipartHttpServletRequest.java:94) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]
... 52 common frames omitted
二、谜题之解
我这才意识到，SpringMVC 是依赖 Servlet 的，虽然 SpringMVC 能识别 Servlet，但它底层的 Servlet 也许还不能识别文件上传。
SpringMVC 官网的 refference 去看文档，果然，我发现了一些猫腻：
Once Servlet 3.0 multipart parsing has been enabled in one of the above mentioned ways you can add the StandardServletMultipartResolver to your Spring configuration
在配置 SpringMVC 的 StandardServletMultipartResolver 之前必须先配置 Servlet，官网提供的方案有：
- 1.mark the DispatcherServlet with a “multipart-config” section in web.xml(在 web.xml 文件中的 DispatcherServlet 元素里，加上一个 multipart-config)
- 2.with a javax.servlet.MultipartConfigElement in programmatic Servlet registration
- 3.in case of a custom Servlet class possibly with a javax.servlet.annotation.MultipartConfig annotation on your Servlet class
我选择了第一种方案，打开 webapp/WEB-INFO 目录下的 web.xml，往 DispatcherServlet 里加了一行
<multipart-config/>
再运行项目，就可以正常地上传文件了。
web.xml 全部内容如下：
<?xml version="1.0" encoding="UTF-8"?>
<web-app
version="3.0"
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_3_0.xsd">
<display-name>geli-springboot</display-name>
<servlet>
<servlet-name>geli-springboot</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:application-servlet.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
<!--让Servlet支持文件上传-->
<multipart-config/>
</servlet>
<servlet-mapping>
<servlet-name>geli-springboot</servlet-name>
<url-pattern>*.do</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
<welcome-file>/admin/login.jsp</welcome-file>
</welcome-file-list>
</web-app>
参考文档：
https://www.iloveqyc.com/2016/06/03/springmvc-upload-file-fail-servlet/
https://juejin.im/post/5a730f895188257a6d634f0a#heading-6
Spring揭秘--寻找遗失的web.xml