定义上传文件的服务：
import org.springframework.web.multipart.MultipartFile;
import java.nio.file.Path;
public interface StorageService {
long save(MultipartFile file, String dst) throws Exception;
void deleteAll(Path path);
}
上传服务的接口实现：
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.util.FileSystemUtils;
import org.springframework.web.multipart.MultipartFile;
import java.io.File;
import java.nio.file.Files;
import java.nio.file.Path;
@Service
public class FileSystemStorageService implements StorageService {
@Autowired
public FileSystemStorageService() {
}
@Override
public long save(MultipartFile file, String uploadFilePath) throws Exception {
if (file.isEmpty()) {
throw new Exception("Failed to store empty file " + file.getOriginalFilename());
}
if (!Files.exists(Path.of(uploadFilePath))) {
try {
Files.createDirectory(Path.of(uploadFilePath));
} catch (Exception e) {
e.printStackTrace();
}
}
String filePath = uploadFilePath + file.getOriginalFilename();
File dest = new File(filePath);
long cnt = 0;
try {
cnt = Files.copy(file.getInputStream(), dest.toPath());
} catch (Exception e) {
e.printStackTrace();
}
return cnt;
}
@Override
public void deleteAll(Path rootLocation) {
FileSystemUtils.deleteRecursively(rootLocation.toFile());
}
}上面是基础的上传服务，写好后，开始写spring boot的controller控制器：
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;
import java.nio.file.Path;
@Controller
public class FileUploadController {
private final StorageService storageService;
@Value("${file.upload.path}")
private String uploadFilePath;
@Autowired
public FileUploadController(StorageService storageService) {
this.storageService = storageService;
}
@GetMapping("/upload_page")
public String uploadPage() {
//返回存放在resources/templates下面的my_file_upload.html文件。
return "my_file_upload.html";
}
//触发动作对应my_file_upload.html里面的form表单中的action
@PostMapping("/do_upload_action")
@ResponseBody
public String uploadFiles(@RequestPart MultipartFile file) {
String fileName = file.getOriginalFilename();
System.out.println("开始上传文件 " + fileName);
long cnt = 0;
try {
cnt = storageService.save(file, uploadFilePath);
} catch (Exception e) {
e.printStackTrace();
}
return "上传字节数 " + cnt;
}
@GetMapping("/delete_file")
@ResponseBody
public String deleteFile() {
storageService.deleteAll(Path.of(uploadFilePath));
return "删除完成";
}
}在FileUploadController里面用到了my_file_upload.html，my_file_upload.html需要放在resources/templates下面，my_file_upload.html代码内容：
<html>
<body>
<form method="post" action="/do_upload_action" enctype="multipart/form-data">
<input type="file" name="file"><br>
<hr>
<input type="submit" value="提交上传">
</form>
</body>
</html>my_file_upload.html里面的action="/do_upload_action"对应于FileUploadController中的uploadFiles（）函数。
最后，在application.properties里面定义默认的上传文件目录，这个路径是服务器的位置，即当浏览器（客户端）上传文件后，保存到application.properties定义的服务器上的这个文件目录下面。
file.upload.path=E:/web/application类：
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class SpringUploadfileApplication {
public static void main(String[] args) {
SpringApplication.run(SpringUploadfileApplication.class, args);
}
}至此完成。
