如何在 Spring Rest Call 中使用 GridFS 发送从 Mongo 检索到的图像？

Question

我使用 Spring 数据和 GridFs 模板

从 Mongo 数据库中检索了图像

所以我不知道如何将检索到的输入流返回给用户。

Say they requested for the http://host.com/apple as a spring rest call . Now my application process the request by using the name apple it retrieves the apple image from a mongodb database . Now without saving anywhere i want to display the response as an image to user that will show http://host.com/apple image in the browser. How exactly i need to implement this ?

您能否分享任何用于处理 Rest Call 中的图像请求的代码存储库？

Controller Code

 @RestController
    public class GreetingController {

    @RequestMapping("/image")
    public GridFSDBFile imageReponse() {
        App.getImage();
        return App.getImageResponse();
    }
}

此函数将从 mongodb

public static GridFSDBFile getImageResponse() {
        try {

            ApplicationContext context = new FileSystemXmlApplicationContext(
                    "file:C:\workspace\gs-rest-service-complete\spring-config.xml");
            FileStorageDao fileStorageDao = (FileStorageDao) context
                    .getBean("fileStorageDao");

            GridFSDBFile retrive = fileStorageDao.retrive("audi.jpg");
            return retrive;
        } catch (Exception e) {
            System.out.println("IOException:-" + e.getMessage());
        } finally {
            System.out.println("Clean up herer:-");
        }
        return null;

    }

错误

Whitelabel Error Page

This application has no explicit mapping for /error, so you are seeing this as a fallback.

Fri Sep 04 17:21:05 IST 2015
There was an unexpected error (type=Internal Server Error, status=500).
Could not write content: No serializer found for class com.mongodb.gridfs.GridFSDBFile$MyInputStream and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS) ) (through reference chain: com.mongodb.gridfs.GridFSDBFile["inputStream"]); nested exception is com.fasterxml.jackson.databind.JsonMappingException: No serializer found for class com.mongodb.gridfs.GridFSDBFile$MyInputStream and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS) ) (through reference chain: com.mongodb.gridfs.GridFSDBFile["inputStream"])

Answer 1

我已经使用了 spring 引导和休息，如果您使用的是最新版本的 spring，即 Spring 4.1[=，则以下代码将起作用17=]

@RequestMapping(value = "/image", method = RequestMethod.GET) @ResponseBody public ResponseEntity<InputStreamResource> getImage() { GridFSDBFile gridFsFile = App.getImageResponse(); return ResponseEntity.ok() .contentLength(gridFsFile.getLength()) .contentType(MediaType.parseMediaType(gridFsFile.getContentType())) .body(new InputStreamResource(gridFsFile.getInputStream())); }

我关注了这个post，看看。 Spring MVC: How to return image in @ResponseBody?

如何在 Spring Rest Call 中使用 GridFS 发送从 Mongo 检索到的图像？

How to send an retrieved image from Mongo using GridFS in Spring Rest Call?

java

rest

spring

mongodb

gridfs-stream