html篇

    <!-- 下载文件 -->
<div>
<a (click)="getFile()">点我测试post方式下载文件</a>
</div><!-- 上传单个文件 -->
<div>
<input type="file" (change)="uploadFile($event)" name="value" value="测试上传单个文件"/>
</div><!-- 上传多个文件 -->
<div >
<input type="file" multiple (change)="uploadFiles($event)" name="files" value="测试上传单个文件"/>
</div>

组件方法篇

export class PostDownloadComponent implements OnInit {baseUrl = "http://localhost:8098/";constructor(private http: Http) { }ngOnInit() {}// post方式下载文件getFile() {let head = new Headers({ 'Content-Type': 'application/json' });let url = this.baseUrl + "user/exportExcel";let body = ["343434", "343434", "34342323", "34rty6y654"];let b = JSON.stringify(body);let options = new RequestOptions({ headers: head, responseType: 3 });return this.http.post(url, b, options).toPromise().then(res => {let file = new File([res.json()], "mm.xls", { type: "application/vnd.ms-excel" });var objUrl = URL.createObjectURL(file);window.open(objUrl);URL.revokeObjectURL(objUrl)});}// post方式上传单个文件uploadFile(event) {let file: FormData = new FormData();let fileList: FileList = event.target.files;if (fileList.length > 0) {let file: File = fileList[0];let formData: FormData = new FormData();formData.append('value', file, file.name);let headers = new Headers();headers.append('Accept', 'application/json');let options = new RequestOptions({ headers: headers });let url = this.baseUrl + "user/importExcel";this.http.post(url, formData, options).toPromise().then(res => {console.log(res.json())})}}// post方式上传多个文件uploadFiles(event) {let fileList: FileList = event.target.files;const fileLength = fileList.length;const formData: FormData = new FormData();for (let index = 0; index < fileLength; index++) {let singleFile = fileList.item(index);// files 这个名字和spring mvc controller参数的名字要对应  formData.append('files', singleFile);}let headers = new Headers();headers.append('Accept', 'application/json');let options = new RequestOptions({ headers: headers });let url = this.baseUrl + "user/importExcelList";this.http.post(url, formData, options).toPromise().then(res => {console.log(res.json())})}}

Java后台篇

@Controller
@RequestMapping("user")
public class UserController {@Autowiredprivate UserService userService;@RequestMapping("/selectUser")public UserVO selectUserById(Long userId) {return userService.selectUserById(userId);}@RequestMapping(value = "/exportExcel", method = RequestMethod.POST)public void exportExcel(HttpServletRequest request, HttpServletResponse response, @RequestBody String[] str) {HSSFWorkbook wb = new HSSFWorkbook();HSSFSheet sheet = wb.createSheet();HSSFRow row1 = sheet.createRow(0);HSSFCell cell = row1.createCell(0);cell.setCellValue("学院考试成绩一览表");sheet.addMergedRegion(new CellRangeAddress(0, 0, 0, 3));List<UserVO> list = new ArrayList<>(10);for (int i = 0; i < 4; i++) {UserVO vo = new UserVO();vo.setEmail("15732622312@11.com");vo.setPassWord(String.valueOf(i));vo.setUserName("wgp" + i);vo.setPhone("110" + i);list.add(vo);}int len = list.size();HSSFRow ro = sheet.createRow(1);ro.createCell(0).setCellValue("姓名");ro.createCell(1).setCellValue("密码");ro.createCell(2).setCellValue("邮箱");ro.createCell(3).setCellValue("手机号");for (int i = 0; i < len; i++) {HSSFRow ro1 = sheet.createRow(i + 2);ro1.createCell(0).setCellValue(list.get(i).getUserName());ro1.createCell(1).setCellValue(list.get(i).getPassWord());ro1.createCell(2).setCellValue(list.get(i).getEmail());ro1.createCell(3).setCellValue(list.get(i).getPhone());}try {OutputStream out = response.getOutputStream();wb.write(out);response.setHeader("Content-disposition", "attachment; filename=details.xls");
//            response.setContentType("application/msexcel");response.setContentType("application/vnd.ms-excel");out.close();} catch (IOException e) {e.printStackTrace();}}@RequestMapping(value = "/importExcel", method = RequestMethod.POST)@ResponseBodypublic ResultData importExcel(@RequestParam("value") MultipartFile file) {System.out.println(file.getOriginalFilename());System.out.println(file.getName());String fileName = file.getOriginalFilename();int len = fileName.lastIndexOf(".");String prefix = fileName.substring(0, fileName.lastIndexOf("."));String stufix = fileName.substring(len, fileName.length());OutputStream out = null;try {out = new FileOutputStream("D:" + prefix + System.currentTimeMillis() + ".xls");out.write(file.getBytes());out.close();} catch (Exception e) {e.printStackTrace();return new ResultData("1", "fail", false);}return new ResultData("0", "successfully", true);}@RequestMapping(value="/importExcelList",method = RequestMethod.POST)@ResponseBodypublic ResultData importExcelList(@RequestParam("files") List<MultipartFile> files) {int length = files.size();try {for (int i = 0; i < length; i++) {String fileName = files.get(i).getOriginalFilename();int len = fileName.lastIndexOf(".");String prefix = fileName.substring(0, fileName.lastIndexOf("."));String stufix = fileName.substring(len, fileName.length());OutputStream out = null;out = new FileOutputStream("D://test//" + prefix + System.currentTimeMillis() + stufix);out.write(files.get(i).getBytes());out.close();}} catch (Exception e) {e.printStackTrace();return new ResultData("1", "fail", false);}return new ResultData("0", "successfully", true);}}

问题篇

前天不要加上 multipart/form-data的header，加上这个纯属画蛇添足。

后台要加上 common-fileuploadjar包。

纯属demo篇

加入项目还需做美化，验证，规范代码等处理。