spring-boot - PUT 方法中缺少 Spring Boot MultipartResolver

Question

我正在使用 Spring 创建一个 REST 服务并得到一个异常告诉我以下内容。

Expected MultipartHttpServletRequest: is a MultipartResolver configured?

当我将 method=RequestMethod.PUT 更改为 method=RequestMethod.POST 时，它正在工作。

为什么我在 PUT 上得到这个异常而不在 POST 上得到这个异常？

@Configuration
@ComponentScan("io.myservice")
@EnableAutoConfiguration
@EnableCaching
@EnableAsync(mode = ASPECTJ)
public class Application implements AsyncConfigurer {

static org.slf4j.Logger LOG = LoggerFactory.getLogger(Application.class);

public static final String MAX_FILE_SIZE = "2MB";
public static final String MAX_REQUEST_SIZE = "2MB";
public static final String FILE_SIZE_THRESHOLD = "2MB";

@Value("${app.dir.incoming}")
public String createdDir;

@Bean
public LocalValidatorFactoryBean localValidatorFactoryBean() {
    return new LocalValidatorFactoryBean();
}

@Bean
MultipartConfigElement multipartConfigElement() {
    String absTempPath = new File(createdDir).getAbsolutePath();
    MultipartConfigFactory  factory = new MultipartConfigFactory();
    factory.setMaxFileSize(MAX_FILE_SIZE);
    factory.setMaxRequestSize(MAX_REQUEST_SIZE);
    factory.setFileSizeThreshold(FILE_SIZE_THRESHOLD);
    factory.setLocation(absTempPath);
    return factory.createMultipartConfig();
}

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

@Override
@Bean
public ThreadPoolTaskExecutor getAsyncExecutor() {
    ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
    executor.setCorePoolSize(2);
    executor.setMaxPoolSize(2);
    executor.setQueueCapacity(5);
    executor.initialize();
    return executor;
}

@Bean
public SimpleCacheManager cacheManager(){
    SimpleCacheManager cacheManager = new SimpleCacheManager();
    List<Cache> caches = new ArrayList<Cache>();
    caches.add(cacheBean());
    cacheManager.setCaches(caches );
    return cacheManager;
}

@Bean
public Cache cacheBean(){
    Cache  cache = new ConcurrentMapCache("default");
    return cache;
}

public static void main(String[] args) throws IOException {
    SysOutOverSLF4J.sendSystemOutAndErrToSLF4J();
    run(Application.class, args);
}
}


@RequestMapping(value="/converter", method=RequestMethod.PUT)
@ResponseBody
public String convert(MultipartFile file) {
    LOG.info("received new file to convert")
}


Caused by: java.lang.IllegalArgumentException: Expected MultipartHttpServletRequest: is a MultipartResolver configured?
at org.springframework.util.Assert.notNull(Assert.java:112)
at org.springframework.web.method.annotation.RequestParamMethodArgumentResolver.resolveName(RequestParamMethodArgumentResolver.java:171)
at org.springframework.web.method.annotation.AbstractNamedValueMethodArgumentResolver.resolveArgument(AbstractNamedValueMethodArgumentResolver.java:89)
at org.springframework.web.method.support.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:79)
at org.springframework.web.method.support.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:157)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:124)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:749)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:689)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:938)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:870)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961)
... 37 common frames omitted

Answer 1

Spring 使用的多部分支持不支持其他请求方法，然后 POST .对于 StandardServletMultipartResolver 这是在该类中硬编码的。

对于 CommonsMultipartResolver 它被硬编码在 ServletFileUpload 中来自 Apache Commons Fileupload 的实用程序类项目。

Form-based File Upload in HTML (RFC1867)关于这一点并不是很明确，但唯一提到使用的 HTTP 方法是 POST。

简而言之，目前框架只支持 POST，您可以通过重新实现一些类来解决它，但如果它有效(尤其是使用默认的 Servlet 3.0 文件上传支持)可能取决于您的容器。