FileController.java

package apijson.boot;

import java.io.*;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Objects;

//import javax.annotation.PostConstruct;

import org.springframework.core.io.InputStreamResource;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.multipart.MultipartFile;

import com.alibaba.fastjson2.JSONObject;

import apijson.demo.DemoParser;

/**文件相关的控制器，包括上传、下载、浏览等
 * @author : ramostear
 * @modifier : Lemon
 * @date : 2019/3/8 0008-15:35
 */
@Controller
public class FileController {

	public static final String HOME_DIR = System.getProperty("user.home");

	private static final String WINDOWS_DIR = HOME_DIR+ "\\upload\\";

	private static final String MAC_DIR = HOME_DIR + "/upload/";

	private static final String LINUX_DIR = HOME_DIR + "/upload/";

	private static String fileUploadRootDir = null;

    static {
		// 判断文件夹是否存在，不存在就创建
		String osName = System.getProperty("os.name");
		if (osName.startsWith("Mac OS")) {
			// 苹果
			fileUploadRootDir = MAC_DIR;
		} else if (osName.startsWith("Windows")) {
			// windows
			fileUploadRootDir = WINDOWS_DIR;
		} else {
			// unix or linux
			fileUploadRootDir = LINUX_DIR;
		}

		File directories = new File(fileUploadRootDir);
		if (directories.exists()) {
			System.out.println("文件上传根目录已存在");
		} else { // 如果目录不存在就创建目录
			if (directories.mkdirs()) {
				System.out.println("创建多级目录成功");
			} else {
				System.out.println("创建多级目录失败");
			}
		}
	}

	public static final List<String> IMG_SUFFIXES = Arrays.asList("jpg", "jpeg", "png");
	private static List<String> fileNames = null;
	@GetMapping("/files")
	@ResponseBody
	public JSONObject files() {
		File dir = new File(fileUploadRootDir);
		if (fileNames == null || fileNames.isEmpty()) {
			List<String> names = new ArrayList<>();
			File[] files = dir.listFiles(new FileFilter() {
				@Override
				public boolean accept(File file) {
					String name = file == null ? null : file.getName();
					int ind = name == null ? -1 : name.lastIndexOf(".");
					String suffix = ind < 0 ? null : name.substring(ind + 1);
					boolean isImg = suffix != null && IMG_SUFFIXES.contains(suffix.toLowerCase());
					if (isImg) {
						names.add(name);
					}
					return isImg;
				}
			});

			fileNames = names;
		}

		JSONObject res = new JSONObject();
		res.put("data", fileNames);
		return new DemoParser().extendSuccessResult(res);
	}

	@PostMapping(value = "/upload", consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
	@ResponseBody
	public JSONObject upload(@RequestParam("file") MultipartFile file) {
		try {
			File convertFile = new File(fileUploadRootDir + file.getOriginalFilename());
			FileOutputStream fileOutputStream;
			fileOutputStream = new FileOutputStream(convertFile);
			fileOutputStream.write(file.getBytes());
			fileOutputStream.close();

			if (fileNames != null && ! fileNames.isEmpty()) {
				fileNames.add(file.getOriginalFilename());
			}

			JSONObject res = new JSONObject();
			res.put("path", "/download/" + file.getOriginalFilename());
			res.put("size", file.getBytes().length);
			return new DemoParser().extendSuccessResult(res);
		} 
		catch (Exception e) {
			e.printStackTrace();
			return new DemoParser().newErrorResult(e);
		}
	}

	@GetMapping("/download/{fileName}")
	@ResponseBody
	public ResponseEntity<Object> download(@PathVariable(name = "fileName") String fileName) throws FileNotFoundException {

		File file = new File(fileUploadRootDir + fileName);
		InputStreamResource resource = new InputStreamResource(new FileInputStream(file));

		HttpHeaders headers = new HttpHeaders();
		headers.add("Content-Disposition", String.format("attachment;filename=\"%s", fileName));
		headers.add("Cache-Control", "no-cache,no-store,must-revalidate");
		headers.add("Pragma", "no-cache");
		headers.add("Expires", "0");

		ResponseEntity<Object> responseEntity = ResponseEntity.ok()
				.headers(headers)
				.contentLength(file.length())
				.contentType(MediaType.parseMediaType("application/txt"))
				.body(resource);

		return responseEntity;
	}



}