spring mvc 上传下载文件demo（上传入mysql里面）_mysql

spring mvc 上传文件代码：

 @RequestMapping(value = "/attach/upload")    @ControllerLogAnnotation(moduleName="服务管理-合同管理-附件",option="上传")       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("上传成功！").json();                                      } catch (Exception e) { //          redirectAttributes.addFlashAttribute("message", "流程部署失败！");           jsonObject = JsonResultBuilder.success(false).msg("上传失败！").json();              logger.error("上传失败！", e);          }                     writeJson(response,jsonObject);                 }

 数据mysql，直接写大数据到数据库的。

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已经取消createBlob    private byte[] attachContent;  private String attachName; .. @Column(name = "contract_id")  public String getContractId() {   return contractId;  }   @Column(name = "attach")  public byte[] getAttachContent() {   return attachContent;  } }

 表

 此时可以上传任意文件，zip,rar,txt,jpg等等。但是如果上传文件过大会报错：mysql大数据默认只能最大1M数据，需要修改max_allowed_packet ，怎么改，看MySQL max_allowed_packet设置及问题。 同时应该也设置spring mvc里面的参数

 <!-- 上传文件拦截，设置最大上传文件大小   10M=10*1024*1024(B)=10485760 bytes -->    <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">     <property name="maxUploadSize" value="${web.maxUploadSize}" />    </bean>

——————————-

下载没什么好说的，看代码：

前台弄个href连接到后台就行

  @RequestMapping(value = "/attach/exportFile/{attachId}")   @ControllerLogAnnotation(moduleName="服务管理-合同管理-附件",option="下载")    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);             }

 下载参考:http://blog.csdn.net/clj198606061111/article/details/20743769