如何用AngularJS，Spring-Boot实现文件上传？

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.7.9/angular.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/ng-file-upload@12.2.13/dist/ng-file-upload.min.js"></script>

var app = angular.module('myApp', ['ngFileUpload']);

<input type="file" ngf-select="uploadFile($file)">

app.controller('myCtrl', function($scope, Upload) {
  $scope.uploadFile = function(file) {
    Upload.upload({
      url: '/upload', // 上传文件的后端接口地址
      data: {file: file} // 上传的文件数据
    }).then(function(response) {
      // 上传成功的回调函数
      console.log('File uploaded successfully.');
    }, function(error) {
      // 上传失败的回调函数
      console.log('File upload failed.');
    });
  };
});

<dependencies>
  <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
  </dependency>
  <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-tomcat</artifactId>
    <scope>provided</scope>
  </dependency>
</dependencies>

@RestController
public class FileUploadController {
  
  @PostMapping("/upload")
  public String uploadFile(@RequestParam("file") MultipartFile file) {
    // 处理文件上传逻辑
    if (!file.isEmpty()) {
      try {
        // 获取文件名
        String fileName = file.getOriginalFilename();
        // 获取文件内容
        byte[] bytes = file.getBytes();
        // 文件保存路径
        String filePath = "/path/to/save/" + fileName;
        // 保存文件
        Files.write(Paths.get(filePath), bytes);
        return "File uploaded successfully.";
      } catch (IOException e) {
        e.printStackTrace();
        return "File upload failed.";
      }
    } else {
      return "File is empty.";
    }
  }
}