首先我用到了两张表
我们以书本表和书本文件表为例： 表结构分明
能看到书本表中的bookimage列段是书本文件表的主键
废话不多说直接上代码 一、添加pom依赖
<dependency> <groupId>commons-fileupload</groupId> <artifactId>commons-fileupload</artifactId> <version>1.3.3</version> </dependency>二、在Spring-mvc.xml文件上配置传解析器(CommonsMultipartResolver)
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> <!-- 必须和用户JSP 的pageEncoding属性一致，以便正确解析表单的内容 --> <property name="defaultEncoding" value="UTF-8"></property> <!-- 文件最大大小(字节) 1024*1024*50=50M--> <property name="maxUploadSize" value="52428800"></property> <!--resolveLazily属性启用是为了推迟文件解析，以便捕获文件大小异常--> <property name="resolveLazily" value="true"/> </bean>三、我定义了三个实体类
public class Book implements Serializable{ private Integer id; private String bookname; private Float price; private String booktype; private String bookimage; public Book(Integer id, String bookname, Float price, String booktype, String bookimage) { this.id = id; this.bookname = bookname; this.price = price; this.booktype = booktype; this.bookimage = bookimage; } public Book() { super(); } public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getBookname() { return bookname; } public void setBookname(String bookname) { this.bookname = bookname; } public Float getPrice() { return price; } public void setPrice(Float price) { this.price = price; } public String getBooktype() { return booktype; } public void setBooktype(String booktype) { this.booktype = booktype; } public String getBookimage() { return bookimage; } public void setBookimage(String bookimage) { this.bookimage = bookimage; } @Override public String toString() { return "Book{" + "id=" + id + ", bookname='" + bookname + '\'' + ", price=" + price + ", booktype='" + booktype + '\'' + ", bookimage='" + bookimage + '\'' + '}'; } } public class BookFile implements Serializable{ private String fileId; private String realName; private String contentType; private Date createdate; public BookFile(String fileId, String realName, String contentType, Date createdate) { this.fileId = fileId; this.realName = realName; this.contentType = contentType; this.createdate = createdate; } public BookFile() { super(); } public String getFileId() { return fileId; } public void setFileId(String fileId) { this.fileId = fileId; } public String getRealName() { return realName; } public void setRealName(String realName) { this.realName = realName; } public String getContentType() { return contentType; } public void setContentType(String contentType) { this.contentType = contentType; } public Date getCreatedate() { return createdate; } public void setCreatedate(Date createdate) { this.createdate = createdate; } } public class BookFileVo extends BookFile implements Serializable{ private Integer id;//书本id private MultipartFile bookFile;//书本文件（图片） public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public MultipartFile getBookFile() { return bookFile; } public void setBookFile(MultipartFile bookFile) { this.bookFile = bookFile; } }注意：bookFileVo是继承于bookFile 四、Controller层
@Controller @RequestMapping("/bookFile") public class BookFileController { private final String DEFUALT_PATH="/uploads"; @Autowired private IBookService bookServicel; @Autowired private IBookFileService bookFileService; @RequestMapping("/upload") public String upload(HttpServletRequest request, BookFileVo bookFileVo){ //拿到bookFileVo中的MultiparFile 可以把他看作上传的图片 MultipartFile bookFile = bookFileVo.getBookFile(); Book book=new Book(); String fileId= UUID.randomUUID().toString().replace("-", ""); book.setBookimage(fileId); book.setId(bookFileVo.getId()); bookFileVo.setFileId(fileId); bookFileVo.setContentType(bookFile.getContentType()); bookFileVo.setRealName(bookFile.getOriginalFilename()); //调用Servicel层的方法 作用是改变书本bookimage 新增bookFile bookServicel.updateBookImage(book,bookFileVo); //上传文件 String relativePath=DEFUALT_PATH+ File.separator+bookFile.getOriginalFilename();//拿到文件名称 String realPath=request.getServletContext().getRealPath(relativePath); //转换成绝对路径 try { bookFile.transferTo(new File(realPath)); //上传文件 一行代码 }catch (Exception e){ e.printStackTrace(); } return "redirect:/book/queryBookPager"; //重定向跳转到jsp } }updateBookImage方法
/* * 要执行两条sql语句 * */ @Override @Transactional public void updateBookImage(Book book,BookFile bookFile) { bookMapper.updateBookImage(book); bookFileMapper.insert(bookFile); }文件上传其实很简单 就一行代码 bookFile.transferTo(new File(realPath));前面只是做铺垫。
文件下载 在Controller层定义方法
@Controller @RequestMapping("/bookFile") public class BookFileController { private final String DEFUALT_PATH="/uploads"; @Autowired private IBookService bookServicel; @Autowired private IBookFileService bookFileService; @RequestMapping(value="/download") public ResponseEntity<byte[]> download(HttpServletRequest request,@RequestParam String fileId){ try{ //先根据文件id查询对应图片信息 BookFile bookFile = bookFileService.selectByPrimaryKey(fileId); //上传文件 String relativePath=DEFUALT_PATH+ File.separator+bookFile.getRealName();//得到相对路径 String realPath=request.getServletContext().getRealPath(relativePath);//转为绝对路径 //下载关键代码 File file=new File(realPath); HttpHeaders headers = new HttpHeaders();//http头信息 String downloadFileName = new String(bookFile.getRealName().getBytes("UTF-8"),"iso-8859-1");//设置编码 headers.setContentDispositionFormData("attachment", downloadFileName); headers.setContentType(MediaType.APPLICATION_OCTET_STREAM); //MediaType:互联网媒介类型 contentType：具体请求中的媒体类型信息 return new ResponseEntity<byte[]>(FileUtils.readFileToByteArray(file),headers, HttpStatus.OK); }catch (Exception e){ e.printStackTrace(); } return null; } }Service层：
@Service public class BookFileServiceImpl implements IBookFileService { @Autowired private BookFileMapper bookFileMapper; @Override public BookFile selectByPrimaryKey(String fileId) { return bookFileMapper.selectByPrimaryKey(fileId); } }ok 完毕 应该很好理解把
