春天上传文件的问题(Spring upload file problems)

我需要从浏览器上传文件到服务器。我用弹簧3.2作为我的web框架。

所以我配置我的应用程序是这样的。

1 - 我的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">

    <context-param>
        <param-name>contextClass</param-name>
        <param-value>org.springframework.web.context.support.AnnotationConfigWebApplicationContext</param-value>
    </context-param>

    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>racoonsoft.chaos.settings</param-value>
    </context-param>

    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

    <servlet>
        <servlet-name>MyServlet</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value></param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>MyServlet</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

    <welcome-file-list>
        <welcome-file>admin/library</welcome-file>
    </welcome-file-list>

</web-app>

2 - MainConfig类

@Configuration
@Import({WebConfig.class })
public class MainConfig {
    @Bean
    public static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() {
        return new PropertySourcesPlaceholderConfigurer();
    }

    @Bean
    public static ScheduledAnnotationBeanPostProcessor scheduledAnnotationBeanPostProcessor() {
        return new ScheduledAnnotationBeanPostProcessor();
    }

    @Bean
    public static StandardServletMultipartResolver multipartResolver() {
        StandardServletMultipartResolver resolver = new StandardServletMultipartResolver();
        return resolver;
    }
}

3 - 控制器来处理多上传

@Controller
@MultipartConfig(fileSizeThreshold=1024*1024*2, // 2MB
        maxFileSize=1024*1024*10,      // 10MB
        maxRequestSize=1024*1024*50)
public class FileUpload
{
    public static final int UPLOAD_RESULT_OK = 100000;
    @Autowired
    BookDao book_dao;

    @RequestMapping(value = "/admin/library/upload_file", method = RequestMethod.POST)
    public String saveFiles(@RequestParam("file-file") MultipartFile file) throws IOException
    {
        if (!file.isEmpty())
        {
            byte[] bytes = file.getBytes();
            return "redirect:caps/total_fail";
        }
        else
        {
            return "redirect:caps/total_fail";
        }
    }
}

4 - JSP在这里我把我的表单提交文件

...<form method="post" action="/admin/library/upload_file" enctype="multipart/form-data">
                <input type="text" name="name"/>
                <input type="file" name="file-file"/>
                <input type="submit"/>
            </form>...

当我提交我的形式我得到一个异常

org.springframework.web.bind.MissingServletRequestParameterException: Required MultipartFile parameter 'file-file' is not present
    org.springframework.web.method.annotation.RequestParamMethodArgumentResolver.handleMissingValue(RequestParamMethodArgumentResolver.java:202)

我不知道为什么。当我删除@RequestParam annotaion我有我的方法调用，但文件参数= NULL。什么是我的问题吗？

Answer 1:

我通过添加以下到我的Spring配置文件，解决了这个问题：

<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver" />

（我得到的错误是“org.springframework.web.bind.MissingServletRequestParameterException：必需MultipartFile参数‘MYFILE’不存在

Answer 2:

我可以做到这一点

@Override
    protected void customizeRegistration(ServletRegistration.Dynamic registration) {

        MultipartConfigElement multipartConfigElement = new MultipartConfigElement("/",100000, 200000, 50000);

        registration.setMultipartConfig(multipartConfigElement);

    }

Answer 3:

@ user64141是正确的，但如果使用Java的配置而不是XML，尝试

@Bean
public MultipartResolver multipartResolver() {
    return new CommonsMultipartResolver();
}

Answer 4:

您还需要MultipartFilter配置为你的web应用。据其Javadoc中，它解决了使用MultipartResolver多请求（但你已经配置了一个）。您需要将其映射到（的一部分）的控制器，处理文件上传请求路径。

首先，添加MultipartFilter到你的web.xml：

<filter>
    <filter-name>multipartFilter</filter-name>
    <filter-class>org.springframework.web.multipart.support.MultipartFilter</filter-class>
</filter>

接下来，过滤器映射到需要接受文件上传的URL（的一部分）：

<filter-mapping>
    <filter-name>multipartFilter</filter-name>
    <url-pattern>/admin/library/upload_file</url-pattern>
</filter-mapping>