上传下载 demo

	import org.apache.commons.io.IOUtils;
	import org.apache.commons.lang.StringUtils;
	import org.springframework.web.bind.annotation.GetMapping;
	import org.springframework.web.bind.annotation.PostMapping;
	import org.springframework.web.bind.annotation.RequestMapping;
	import org.springframework.web.bind.annotation.RestController;
	import org.springframework.web.multipart.MultipartFile;
	import javax.servlet.http.HttpServletRequest;
	import javax.servlet.http.HttpServletResponse;
	import java.io.File;
	import java.io.FileInputStream;
	import java.io.InputStream;
	import java.io.OutputStream;
	@RestController
	@RequestMapping("/file")
	public class FileController {
	/**
	* 参数名file与ControllerTest.whenUploadSuccess里new MockMultipartFile的第一个参数名要相同
	*/
	@PostMapping("/upload")
	public FileInfo update(MultipartFile file) throws Exception {
	System.out.println(file.getName());
	System.out.println(file.getOriginalFilename());
	System.out.println(file.getContentType());
	System.out.println(file.getSize());
	String path = "xxx";
	String extension = StringUtils.substringAfterLast(file.getOriginalFilename(), ".");
	File localFile = new File(path, System.currentTimeMillis() + "." + extension);
	file.transferTo(localFile);
	return new FileInfo(localFile.getAbsolutePath());
	}
	@GetMapping("/download")
	public void download(HttpServletRequest request, HttpServletResponse response) throws Exception {
	//从request中获取下载文件路径
	String filePath = request.getParameter("xxxx");
	//try ()里定义的InputStream和OutputStream会被自动释放，不需要在finally里手动释放，JDK 1.7后出现的此语法
	try (InputStream inputStream = new FileInputStream(filePath);
	OutputStream outputStream = response.getOutputStream()) {
	response.setContentType("application/x-download");
	//attachment;filename=指定默认下载文件名
	response.addHeader("Content-Disposition", "attachment;filename=download.txt");
	IOUtils.copy(inputStream, outputStream);
	outputStream.flush();
	}
	}
	}