Spring mvc send binary content from controller

Sometimes binary files such as images, documents are stored in the database; these binary files need then to be served dynamically

Below I'll show a code snippet showing how to handle this easily with Spring MVC

Before we begin just in case this is the list of libraries I used when coding this example :

• Spring 3+
• Spring Data JPA
• Eclipselink 2.4+
• Apache Tika
• Slugify

Resource class

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@Entity public class Resouce{       @Id @Column(name = "ID")     @GeneratedValue(strategy = GenerationType.IDENTITY)     private Long id;       @Column(name = "FILE_NAME", length = 200)     private String fileName;        @Column(name = "FILE")     @Lob     private byte[] file;      //SETTERS - GETTERS OMMITED }

404 exception

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@ResponseStatus(value = HttpStatus.NOT_FOUND) public class ResourceNotFoundException extends RuntimeException {   }

controller

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/**  * @author ulf  */ @Controller @RequestMapping("/resource") public class ResourceController{       // a basic Spring data repository     @Autowired     private ResourceRepostiory resourceRepository;             // simple tika instance for handling mimetype resolution     @Autowired     private Tika tika;       @RequestMapping(method = RequestMethod.GET)     public ResponseEntity<byte[]> resource(@RequestParam("resourceId") Long resourceId) throws IOException {           byte[] binary = null;         String fileName = "";                 Resouce resource= resourceRepository.findOne(resourceId);               if (resource!= null  && section.getFile() !=null ) {                 binary = section.getFile();                 fileName = section.getFileName();             }             if (binary == null) {             throw new ResourceNotFoundException();         } else {               String extension = FilenameUtils.getExtension(fileName);               // slugify the fileName to handle the Google Chrome error complaining of duplicate content disposition headers whenever the file name contains a ,             fileName = new Slugify(true).slugify(FilenameUtils.removeExtension(fileName)) +"."+extension;               HttpHeaders headers = new HttpHeaders();             headers.setContentType(MediaType.parseMediaType(mimetype(fileName)));             headers.setContentDispositionFormData(fileName, fileName);             headers.setCacheControl("must-revalidate, post-check=0, pre-check=0");             ResponseEntity<byte[]> responseEntity = new ResponseEntity<byte[]>(binary, headers, HttpStatus.OK);             return responseEntity;             }         }       private String mimetype(String fileName) {         return ConfigurableMimeFileTypeMap.getDefaultFileTypeMap().getContentType(fileName);     }     }     </byte[]></byte[]></byte[]>

And that's it you should now be able to serve resources dynamically based on their id