Spring mvc upload and download file demo (upload to mysql)

spring mvc upload file code:

@RequestMapping(value = "/attach/upload")
	  @ControllerLogAnnotation(moduleName="Service Management-Contract Management-Attachment",option="Upload")
	    public void upload( String contractId,
	    					  @RequestParam(value = "file", required = false) MultipartFile file,
	    					  RedirectAttributes redirectAttributes, HttpServletResponse response) {
	        String fileName = file.getOriginalFilename();
	        
	        JSONObject jsonObject= new JSONObject();
	        try {
	            InputStream fileInputStream = file.getInputStream();

	            String extension = FilenameUtils.getExtension(fileName);
	            
	            ContractAttach attach = new ContractAttach();
	            
	            attach.setAttachName(fileName);
	            attach.setContractId(contractId);
	            byte[] attachContent =FileCopyUtils.copyToByteArray(fileInputStream);  
	            attach.setAttachContent(attachContent);
	            service.addObj(attach);
	            
	            
	          
	            
	            jsonObject = JsonResultBuilder.success(true).msg("Upload successful!").json();
	            
	            
	        } catch (Exception e) {
// redirectAttributes.addFlashAttribute("message", "Process deployment failed!");
	        	jsonObject = JsonResultBuilder.success(false).msg("Upload failed!").json();
	            logger.error("Upload failed!", e);
	        }

	        
	        writeJson(response,jsonObject);
	        
	    }

 Data mysql, write big data directly to the database.

entity:

@Entity
@Table(name = "t_contract_attach")
public class ContractAttach implements java.io.Serializable {

	// Fields

	private String id;
	private String contractId;
//	private String attach;
	
//	@Lob
// private Blob attachContent; //hibernate4 has canceled createBlob
	
	private byte[] attachContent;
	private String attachName;
..
@Column(name = "contract_id")
	public String getContractId() {
		return contractId;
	}

	@Column(name = "attach")
	public byte[] getAttachContent() {
		return attachContent;
	}
}

 The table

 can upload any file at this time, zip, rar, txt, jpg, etc. However, if the upload file is too large, an error is reported: MySQL big data can only have a maximum of 1M data by default, and you need to modify max_allowed_packet  . How to change it, see MySQL max_allowed_packet settings and problems . At the same time, the parameters in spring mvc should also be set

	<!-- Upload file interception, set the maximum upload file size 10M=10*1024*1024(B)=10485760 bytes -->  
	<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">  
		<property name="maxUploadSize" value="${web.maxUploadSize}" />  
	</bean>

 

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There is nothing to say about downloading, look at the code:

Just get a href in the foreground to connect to the background

  @RequestMapping(value = "/attach/exportFile/{attachId}")
		@ControllerLogAnnotation(moduleName="Service Management-Contract Management-Attachment",option="download")
	  public ResponseEntity<byte[]> exportFile( @PathVariable("attachId")String attachId,
			 HttpServletResponse response) throws IOException {
	        
	        ContractAttach attach = service.uniqueEntity(ContractAttach.class, "id", attachId);
	        String fileName = attach.getAttachName();
	        byte[] attachContent = attach.getAttachContent();
	        HttpHeaders headers = new HttpHeaders();    
	        headers.setContentDispositionFormData("attachment", fileName);   
	        headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);   
	        return new ResponseEntity<byte[]>(attachContent,    
	                                          headers, HttpStatus.CREATED);    
		  
	  }

 Download reference: http://blog.csdn.net/clj198606061111/article/details/20743769