如何从Spring控制器返回视频

Question

我有一个简单的Spring Boot控制器，它将视频字节作为资源返回

@Override
public ResponseEntity<Resource> getVideoFileAsVideo(final Long videoId) {
final Resource videoResource = videoService.getVideoFile(videoId);
final VideoDto video = videoService.getVideoById(videoId);
return ResponseEntity.ok()
.contentType(MediaType.parseMediaType("video/" + video.getFileExtension()))
.header(HttpHeaders.CONTENT_DISPOSITION, String.format("attachment; filename=video_%s.%s", videoId, video.getFileExtension()))
.body(videoResource);
}

我犯了这个错误。如何解决？

org.springframework.http.converter.HttpMessageNotWritableException: No converter for [class java.util.ImmutableCollections$List12] with preset Content-Type 'video/mp4'
at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:313) ~[spring-webmvc-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.HttpEntityMethodProcessor.handleReturnValue(HttpEntityMethodProcessor.java:226) ~[spring-webmvc-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
at org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:82) ~[spring-web-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:124) ~[spring-webmvc-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.ExceptionHandlerExceptionResolver.doResolveHandlerMethodException(ExceptionHandlerExceptionResolver.java:403) ~[spring-webmvc-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
at org.springframework.web.servlet.handler.AbstractHandlerMethodExceptionResolver.doResolveException(AbstractHandlerMethodExceptionResolver.java:61) ~[spring-webmvc-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
at org.springframework.web.servlet.handler.AbstractHandlerExceptionResolver.resolveException(AbstractHandlerExceptionResolver.java:141) ~[spring-webmvc-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
at org.springframework.web.servlet.handler.HandlerExceptionResolverComposite.resolveException(HandlerExceptionResolverComposite.java:80) ~[spring-webmvc-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
```

Answer 1

检查资源对象导入包。当我使用此代码时，返回视频字节数组。您是否尝试返回字节数组而不是资源？

InputStream is = getClass().getClassLoader().getResourceAsStream("sample.mp4");
byte[] videoResource = IOUtils.toByteArray(is);
return ResponseEntity.ok()
.contentType(MediaType.parseMediaType("video/mp4"))
.header(HttpHeaders.CONTENT_DISPOSITION, String.format("attachment; filename=video_%s.%s", 1, "mp4"))
.body(videoResource);