java - Spring MVC : HTTP 400 Error when trying to upload csv files

Question

问题:我按照本指南通过 Spring MVC 上传文件:https://spring.io/guides/gs/uploading-files/但是，当我这样做时，当我通过 .jsp 页面上的表单上传文件时，我不断收到以下错误:

HTTP Status 400 - Required String parameter 'name' is not present

type Status report

message Required String parameter 'name' is not present

description The request sent by the client was syntactically incorrect.

Apache Tomcat/7.0.52

问题:如何解决400错误并成功上传文件？

方法:按照指南，我创建了一个 Controller 类 TestController 和一个名为 handleFileUpload 的方法，该方法用于处理用户上传文件。我没有使用 multipartResolver bean，因为它给我带来了与 Apache Commons 相关的各种错误，我在之前的问题中发现了这个问题:https://stackoverflow.com/questions/35467250/unable-to-upload-a-file-using-spring-apache-commons-issue

代码

测试 Controller .java

    @Controller
    public class TestController {

       @RequestMapping(value="/upload", method=RequestMethod.POST)
       public @ResponseBody String handleFileUpload(@RequestParam("name") String name, @RequestParam("file") MultipartFile file) {
        if (!file.isEmpty()) {
            try {
                byte[] bytes = file.getBytes();
                BufferedOutputStream stream = new BufferedOutputStream(new FileOutputStream(new File(name)));
                stream.write(bytes);
                stream.close();
                return "You successfully uploaded " + name + "!";
            } catch (Exception e) {
                return "You failed to upload " + name + " => " + e.getMessage();
            }
        } else {
            return "You failed to upload " + name + " because the file was empty.";
        }
      }


    }

这是 index.jsp 中的表单。请记住，我在我的 jsp 页面中使用 TWBS，我不确定这是否会对此产生任何巨大影响。

<form method="POST" enctype="multipart/form-data" action="/upload">
    File to upload: <input type="file" name="file"><br/>
    Name: <input type="text" name="name"><br/><br/>
    <input type = "submit" value = "Upload"> Press here to upload the file!
</form>

---

更新 2.22.16Orest 的评论很有帮助，但是当我点击链接 ( http://www.concretepage.com/spring-4/spring-4-mvc-single-multiple-file-upload-example-with-tomcat ) 时，出现以下错误:

HTTP Status 500 - Servlet.init() for servlet mvc-dispatcher threw exception

type Exception report

message Servlet.init() for servlet mvc-dispatcher threw exception

description The server encountered an internal error that prevented it from fulfilling this request.

exception

javax.servlet.ServletException: Servlet.init() for servlet mvc-dispatcher threw exception
    org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
    org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
    org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
    org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
    org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1040)
    org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607)
    org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2441)
    org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2430)
    java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    java.lang.Thread.run(Thread.java:745)
root cause

java.lang.NoClassDefFoundError: org/apache/commons/fileupload/FileItemFactory
    java.lang.Class.getDeclaredMethods0(Native Method)
    java.lang.Class.privateGetDeclaredMethods(Class.java:2701)
    java.lang.Class.getDeclaredMethods(Class.java:1975)
    org.springframework.util.ReflectionUtils.getDeclaredMethods(ReflectionUtils.java:609)
    org.springframework.util.ReflectionUtils.doWithMethods(ReflectionUtils.java:521)
    org.springframework.util.ReflectionUtils.doWithMethods(ReflectionUtils.java:507)
    org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.determineCandidateConstructors(AutowiredAnnotationBeanPostProcessor.java:241)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.determineConstructorsFromBeanPostProcessors(AbstractAutowireCapableBeanFactory.java:1069)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1042)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:510)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
    org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
    org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
    org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
    org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
    org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:772)
    org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:838)
    org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:537)
    org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:667)
    org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:633)
    org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:681)
    org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:552)
    org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:493)
    org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:136)
    javax.servlet.GenericServlet.init(GenericServlet.java:158)
    org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
    org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
    org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
    org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
    org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1040)
    org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607)
    org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2441)
    org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2430)
    java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    java.lang.Thread.run(Thread.java:745)
root cause

java.lang.ClassNotFoundException: org.apache.commons.fileupload.FileItemFactory
    org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1718)
    org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1569)
    java.lang.Class.getDeclaredMethods0(Native Method)
    java.lang.Class.privateGetDeclaredMethods(Class.java:2701)
    java.lang.Class.getDeclaredMethods(Class.java:1975)
    org.springframework.util.ReflectionUtils.getDeclaredMethods(ReflectionUtils.java:609)
    org.springframework.util.ReflectionUtils.doWithMethods(ReflectionUtils.java:521)
    org.springframework.util.ReflectionUtils.doWithMethods(ReflectionUtils.java:507)
    org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.determineCandidateConstructors(AutowiredAnnotationBeanPostProcessor.java:241)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.determineConstructorsFromBeanPostProcessors(AbstractAutowireCapableBeanFactory.java:1069)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1042)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:510)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
    org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
    org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
    org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
    org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
    org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:772)
    org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:838)
    org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:537)
    org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:667)
    org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:633)
    org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:681)
    org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:552)
    org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:493)
    org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:136)
    javax.servlet.GenericServlet.init(GenericServlet.java:158)
    org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
    org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
    org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
    org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
    org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1040)
    org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607)
    org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2441)
    org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2430)
    java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    java.lang.Thread.run(Thread.java:745)
note The full stack trace of the root cause is available in the Apache Tomcat/7.0.52 logs.

Apache Tomcat/7.0.52

关于为什么我收到上述错误的注释:每当我将以下 bean 添加到我的 mvc-dispatcher-servlet.xml 时文件，当我尝试上传文件时出现上述错误:<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver" />

---

更新 #2 2.22.16oshi 想知道我的类路径中是否有正确的 jar。我正在使用 IntelliJ，它位于我的外部库文件夹中。请查看以下屏幕截图:

Answer 1

确保将所有必需的 .jar 文件包含在应用程序的 classpath 中。

根据报错，好像运行时没有找到jar文件

换句话说，所有必要的外部库(用于开发、编译)也需要在运行时包含在类路径中。

在 IntelliJ 中，您可以通过进入“项目结构 > 工件”面板来检查工件中包含的内容。

我不是 Eclipse 用户，但也有验证方法。