java - spring上传文件问题

Question

我需要将文件从浏览器上传到服务器。我使用 spring 3.2 作为我的 web 框架。

所以我这样配置我的应用程序。

1 - 我有 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 - 处理分段上传的 Controller

@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 - 我放置表单以提交文件的 jsp

...<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>...

当我提交表单时，我得到了一个异常(exception)

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 注释时，我调用了我的方法，但文件参数 = null。我的问题是什么？

Answer 1

我通过将以下内容添加到我的 spring 配置文件来解决此问题:

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

(我得到的错误是“org.springframework.web.bind.MissingServletRequestParameterException:必需的MultipartFile参数'myFile'不存在