序言
现在，绝大部分的应用程序在很多的情况下都需要使用到文件上传与下载的功能，在本文中结合hap利用spirng mvc实现文件的上传和下载，包括上传下载图片、上传下载文档。前端所使用的技术不限，本文重点在于后端代码的实现。希望可以跟随我的一步步实践，最终轻松掌握在hap中的文件上传和下载的具体实现。
案例
1. 数据库设计
表结构
SET FOREIGN_KEY_CHECKS=0;
-- ----------------------------
-- Table structure for tb_fruit
-- ----------------------------
DROP TABLE IF EXISTS `tb_fruit`;
CREATE TABLE `tb_fruit` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`fruitName` varchar(255) DEFAULT NULL,
`picturePath` varchar(255) DEFAULT NULL,
`filePath` varchar(255) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8;
字段描述
Id 主键自增
fruitName 水果名称
picturePath 图片路径
filePath 附件2. 先使用代码生成工具根据表结构生成对应的测试
dto层：
package hbi.core.test.dto; /**Auto Generated By Hap Code Generator**/ import com.hand.hap.mybatis.annotation.ExtensionAttribute; import org.hibernate.validator.constraints.Length; import javax.persistence.GeneratedValue; import javax.persistence.Id; import javax.persistence.Table; @Table(name = "tb_fruit") public class Fruit{ public static final String FIELD_ID = "id"; public static final String FIELD_FRUITNAME = "fruitname"; public static final String FIELD_PICTUREPATH = "picturepath"; public static final String FIELD_FILEPATH = "filepath"; @Id @GeneratedValue private Long id; @Length(max = 255) private String fruitname; @Length(max = 255) private String picturepath; @Length(max = 255) private String filepath; //省略get/set方法... } controller层：
package hbi.core.test.controllers; import com.hand.hap.attachment.exception.FileReadIOException; import com.hand.hap.core.IRequest; import com.hand.hap.core.exception.TokenException; import com.hand.hap.system.controllers.BaseController; import com.hand.hap.system.dto.ResponseData; import hbi.core.test.dto.Fruit; import hbi.core.test.service.IFruitService; import net.sf.json.JSONObject; import org.apache.commons.lang.StringUtils; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.validation.BindingResult; import org.springframework.web.bind.annotation.*; import org.springframework.web.multipart.MultipartFile; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.*; import java.net.URLEncoder; import java.text.SimpleDateFormat; import java.util.*; @Controller public class FruitController extends BaseController { @Autowired private IFruitService service; /** * word文件路径 */ private String wordFilePath="/u01/document/userfile"; /** * 图片文件路径 */ private String userPhotoPath = "/u01/document/userphoto"; /** * 文件最大 5M */ public static final Long FILE_MAX_SIZE = 5*1024*1024L; /** * 允许上传的图片格式 */ public static final List<String> IMG_TYPE = Arrays.asList("jpg", "jpeg", "png", "bmp"); /** * 允许上传的文档格式 */ public static final List<String> DOC_TYPE = Arrays.asList("pdf", "doc", "docx"); /** * ContentType */ public static final Map<String, String> EXT_MAPS = new HashMap<>(); static { // image EXT_MAPS.put("jpg", "image/jpeg"); EXT_MAPS.put("jpeg", "image/jpeg"); EXT_MAPS.put("png", "image/png"); EXT_MAPS.put("bmp", "image/bmp"); // doc EXT_MAPS.put("pdf", "application/pdf"); EXT_MAPS.put("ppt", "application/vnd.ms-powerpoint"); EXT_MAPS.put("doc", "application/msword"); EXT_MAPS.put("doc", "application/wps-office.doc"); EXT_MAPS.put("docx", "application/vnd.openxmlformats-officedocument.wordprocessingml.document"); } /** * @author jiaqing.xu@hand-china.com * @date 2017/9/4 17:23 * @param wordFile photoFile fruitName * @return List<Fruit> * @description 保存水果信息 */ @RequestMapping(value = {"/api/public/upload/fruit/submit"}, method = RequestMethod.POST) @ResponseBody public List<Fruit> fruitSubmit(@RequestParam(value = "wordFile", required = true) MultipartFile wordFile,@RequestParam(value = "photoFile", required = true) MultipartFile photoFile, @RequestParam(value="fruitName",required = true) String fruitName,HttpServletRequest request){ IRequest requestContext = createRequestContext(request); //上传word文件到磁盘 Map<String,Object> result1 = uploadFile(wordFile,wordFilePath,DOC_TYPE,null); //上传图片文件到磁盘 Map<String, Object> result2 = uploadFile(photoFile,userPhotoPath, IMG_TYPE, 200); List<Fruit> list = new ArrayList<>(); //如果创建成功则保存相应路径到数据库 if((boolean)result1.get("success")&&(boolean)result2.get("success")){ Fruit fruit = new Fruit(); fruit.setFruitname(fruitName); //设置图片路径 fruit.setPicturepath((String) result2.get("path")); //设置附件路径 fruit.setFilepath((String) result1.get("path")); //插入
fruit = service.insertSelective(requestContext,fruit);
list.add(fruit);
}
return list; } /** * @author jiaqing.xu@hand-china.com * @date 2017/9/4 16:18 * @param * @return * @description 【通用】 上传文件到磁盘的某一个目录 */ public Map<String, Object> uploadFile(MultipartFile file, String path, List<String> fileTypes, Integer ratio){ Map<String, Object> results = new HashMap<>(); results.put("success", false); if(file == null || file.getSize() < 0 || StringUtils.isBlank(file.getOriginalFilename())){ results.put("message", "文件为空"); return results; } if(file.getSize() > FILE_MAX_SIZE){ results.put("message", "文件最大不超过" + FILE_MAX_SIZE/1024/1024 + "M"); return results; } String originalFilename = file.getOriginalFilename(); if(!fileTypes.contains(originalFilename.substring(originalFilename.lastIndexOf(".")+1))){ results.put("message", "文件格式不正确"); return results; } SimpleDateFormat formatter = new SimpleDateFormat("yyyyMMddHHmmssSSS"); String datetime = formatter.format(new Date()); String yearmonth = datetime.substring(0, 6); // 在基础路径上加上年月路径 String fileDir = path + "/" + yearmonth; // 文件名以 [_时间戳_随机数#原文件名]的形式 随机数防止重复文件名 String randomNumber = String.valueOf((Math.random() * 90000) + 10000).substring(0, 5); String fileName = "_" + datetime + randomNumber + "=" + originalFilename; // 文件路径 String filePath = fileDir + "/" + fileName; try { // 创建目录 File dir = new File(fileDir); if(!dir.exists() && !dir.isDirectory()){ dir.mkdirs(); } // 文件输入流 InputStream is = file.getInputStream(); // 输出流 OutputStream os = new FileOutputStream(filePath); // 输出文件到磁盘 int len = 0; byte[] buffer = new byte[2048]; while((len = is.read(buffer, 0, 2048)) != -1){ os.write(buffer, 0, len); } os.flush(); os.close(); is.close(); //向结果中保存状态消息和存储路径 results.put("success", true); results.put("message", "SUCCESS"); results.put("path", filePath); // 压缩图片 if(ratio != null){ //ImgExif.ExifInfoToRotate(filePath); ImgCompress imgCompress = new ImgCompress(filePath); imgCompress.setFileName(filePath); imgCompress.resizeByWidth(ratio); } } catch (Exception e) { e.printStackTrace(); results.put("message", "ERROR"); return results; } return results; } /** * @author jiaqing.xu@hand-china.com * @date 2017/9/4 17:23 * @param * @return * @description 【通用】 读取上传的文件 将文件以流的形式输出 */ @RequestMapping(value = "/api/public/read/file") public void readFile(@RequestParam String path, HttpServletResponse response) throws FileReadIOException, TokenException { Map<String, Object> results = new HashMap<>(); try { File file = new File(path); if(!file.exists()){ results.put("success", false); results.put("message", "文件不存在"); JSONObject jsonObject = JSONObject.fromObject(results); response.getWriter().write(jsonObject.toString()); return; } // 类型 String contentType = EXT_MAPS.get(path.substring(path.lastIndexOf(".") + 1)); // 设置头 response.addHeader("Content-Disposition", "attachment;filename=\"" + URLEncoder.encode(path.substring(path.indexOf("=") + 1), "UTF-8") + "\""); response.setContentType(contentType + ";charset=UTF-8"); response.setHeader("Accept-Ranges", "bytes"); // 输出文件 InputStream is = new FileInputStream(file); OutputStream os = response.getOutputStream(); int len = 0; byte[] buffer = new byte[2048]; while ((len = is.read(buffer, 0, 2048)) != -1){ os.write(buffer, 0, len); } os.flush(); os.close(); is.close(); } catch (IOException e) {
e.printStackTrace();
}
}
}
说明：
（1）文件保存路径wordFilePath、 水果照片保存路径userPhotoPath可以通过配置文件进行配置。
（2）其中保存的文件的路径在项目的根路径下，比如我的项目在D盘的某一个文件夹下，则生成的word文件的位置为D盘/u01/document/userfile路径下.
3. postman测试
注意点：在使用postman测试时，使用post请求，参数中body为form-data,依次将需要的参数填写到对应的位置。
返回后的数据为插入数据库中的记录。
4. 运行结果
数据库中插入的新的记录：
磁盘中的word文件：
磁盘中的图片：
浏览器进行下载测试：
