java通过MultipartFile进行文件、图片上传和下载，以及文件流

╰半橙微兮° 2021-09-07 06:02 371阅读 0赞

package com.fh.controller;
    
    
    import com.fh.util.UuidUtil;
    import org.apache.commons.io.IOUtils;
    import org.apache.ibatis.javassist.tools.reflect.CannotCreateException;
    import org.apache.shiro.SecurityUtils;
    import org.apache.shiro.authc.UsernamePasswordToken;
    import org.apache.shiro.authz.annotation.RequiresPermissions;
    import org.apache.shiro.authz.annotation.RequiresUser;
    import org.apache.shiro.session.Session;
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestMethod;
    import org.springframework.web.bind.annotation.ResponseBody;
    import org.springframework.web.multipart.MultipartFile;
    import javax.annotation.Resource;
    import javax.imageio.ImageIO;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    import javax.servlet.http.HttpSession;
    import java.awt.*;
    import java.awt.image.BufferedImage;
    import java.io.*;
    import java.net.URLDecoder;
    import java.net.URLEncoder;
    import java.text.ParseException;
    import java.util.Random;
    
    @Controller
    @RequestMapping(value = "/")
    public class MainController {
    
        //图片上传接口
        public static String  upLoadFile(MultipartFile file, HttpServletRequest request) {
            if (file == null) {
                return  "文件不能为空";
            }
    
    
            String fileName = file.getOriginalFilename();
            int index = fileName.lastIndexOf(".");
            if (index < 0){
            return  "文件格式不能为空"; 
            } else {
                String fileType = fileName.substring(fileName.lastIndexOf(".") + 1, fileName.length());
                if (",jpg,jpeg,png,pdf".indexOf(fileType) < 0){
            return  "文件类型不合法，只支持jpg、jpeg、png和pdf格式的文件";  
                }
            }
    
    
            String path = "";
            try {
                String id = storeFile(file.getOriginalFilename(), file.getInputStream(), file.getContentType());
                path = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort()
                        + request.getContextPath() + "/downFile?fileUrl=" + URLEncoder.encode(id, "UTF-8");
            } catch (Exception e) {
                e.printStackTrace();
                System.out.println( "======================================  文件上传失败  =======================");
            }
            return path;
        }
    
        //    d:/test/files/ 这里上传地址是写死的，正常开发是需要写到配置文件里面读取的
        public static String storeFile(String fileName, InputStream inputStream, String contentType) throws Exception {
            FileOutputStream out = null;
            File file2 = null;
            try {
                file2 = new File( "d:/test/files/" + UuidUtil.get32UUID() + "/" + fileName);
                if (!file2.getParentFile().exists()) {
                    file2.getParentFile().mkdirs();
                }
                boolean flag = file2.createNewFile();
                if (!flag) {
                    throw new CannotCreateException("文件无法被创建");
                }
                out = new FileOutputStream(file2);
                byte[] tmp = new byte[1024];
                int i = -1;
                while ((i = inputStream.read(tmp)) != -1) {
                    out.write(tmp, 0, i);
                }
                //return URLEncoder.encode(file2.getAbsolutePath(), "UTF-8");
            } catch (Exception e) {
                e.printStackTrace();
                System.out.println("======================================  文件上传失败  ================================");
            } finally {
                IOUtils.closeQuietly(out);
                IOUtils.closeQuietly(inputStream);
            }
            return URLEncoder.encode(file2.getAbsolutePath(), "UTF-8");
        }
    
    
    
        //图片回显查看接口
        @RequestMapping(value="/downFile")
        public void viewPic(String fileUrl, HttpServletResponse response) {
            try {
                String path = URLDecoder.decode(fileUrl, "UTF-8");
                File file = new File(path);
                response.addHeader("Content-Length", "" + file.length());
                writeFile(path, response);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    
    
        public void writeFile(String id, HttpServletResponse response) {
            try {
                String name = id.substring(id.lastIndexOf(java.io.File.separator) + java.io.File.separator.length(), id.length());
                renderResponseFileHeader(name, response);
                writeFile(name, id, response.getOutputStream());
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    
    
        public static void writeFile(String title, String path, OutputStream outputStream) throws Exception {
            InputStream in = null;
            try {
                // 4.获取要下载的文件输入流
                in = new FileInputStream(path);
                int len = 0;
                // 5.创建数据缓冲区
                byte[] buffer = new byte[1024];
                // 6.通过response对象获取OutputStream流
                // 7.将FileInputStream流写入到buffer缓冲区
                while ((len = in.read(buffer)) > 0) {
                    // 8.使用OutputStream将缓冲区的数据输出到客户端浏览器
                    outputStream.write(buffer, 0, len);
                }
                IOUtils.closeQuietly(outputStream);
            } finally {
                IOUtils.closeQuietly(in);
            }
        }
    
        public static void  renderResponseFileHeader(String fileName, HttpServletResponse response) throws Exception {
            response.setHeader("Content-Disposition",
                    "attachment; filename=" + java.net.URLEncoder.encode(fileName, "UTF-8"));
        }
    
    
        //通过文件路径获取文件名称
        public static String getFileName(String path) throws Exception {
            path = URLDecoder.decode(path, "UTF-8");
            String name = path.substring(path.lastIndexOf(java.io.File.separator) + java.io.File.separator.length(), path.length());
            return name;
        }
    
    
    
    
        //删除图片的同时也要删除服务端存储的图片，减少垃圾文件，优化硬盘空间
    	@RequestMapping(value = "/imgPath", produces = "application/json;charset=utf-8")
    	@ResponseBody
    	public ResponseJson detail(String imgPathString) {
    		//boolean file = FileUtils.deletePhysicalFile(imgPathString);
            boolean file = deletePhysicalFile(imgPathString);
    		return new ResponseJson(Constants.CODE_SUCCESS, file);
    	}
    
         //删除物理文件   //删除服务端存储的图片
        public static boolean deletePhysicalFile(String fileUrl) {
            if (fileUrl == null || fileUrl.length() == 0) return false;
            String path = null;
            boolean isDelete = false;
            try {
                String splitReg = "/downFile\\?fileUrl=";
                String[] fileUrlStrs = fileUrl.split(splitReg);
                path = fileUrlStrs[fileUrlStrs.length - 1];
                path = URLDecoder.decode(path, "UTF-8");  //  UTF-8  编码反编译 解密
                path = URLDecoder.decode(path, "UTF-8");  //  UTF-8  编码反编译 解密
            } catch (Exception e) {
                e.printStackTrace();
            }
            File file = new File(path);
            if (file.exists()) {
                if (file.delete()) {
                    String filePath = file.getParent();
                    deleteEmptyDirectory(filePath);
                }
                isDelete = true;
            }
            return isDelete;
        }
        public static void deleteEmptyDirectory(String path){
            File fileDir = new File(path);
            if (fileDir.listFiles().length > 0)
                return;
            else {
                fileDir.delete();
            }
        }
    
    
    
    
    }