文件相关操作

文件下载

/*
* 下载文件
*/
public void downloadFile(String proname, String fileName, HttpServletResponse resp) {
    try {
        ProjectEntity projectEntity = projectMapping.getProjectByName(proname);
        ProductEntity productEntity = 	productMapping.getProductByProductId(projectEntity.getProProductId());
        ProductOutsourceEntity productOutsourceEntity = 	productOutsourceMapping.getProductOutsourceByOutId(productEntity.getOutId());
        //获取文件名
        String strUrl = productOutsourceEntity.getFileUrl();
        String filename = strUrl.substring(strUrl.lastIndexOf("/")+1);
        filename = new String(filename.getBytes("iso8859-1"),"UTF-8");

        String path = strUrl;
        File file = new File(path);
        //如果文件不存在
        if(!file.exists()){
        log.info("下载文件不存在");
        }
        //解决下载文件时文件名乱码问题
        byte[] fileNameBytes = filename.getBytes(StandardCharsets.UTF_8);
        filename = new String(fileNameBytes, 0, fileNameBytes.length, 	StandardCharsets.ISO_8859_1);
        resp.reset();
        resp.setContentType("application/octet-stream");
        resp.setCharacterEncoding("utf-8");
        resp.setContentLength((int) file.length());
        //设置响应头，控制浏览器下载该文件
        resp.setHeader("content-disposition", "attachment;filename=" + filename);
        try{
        //读取要下载的文件，保存到文件输入流
        BufferedInputStream bis = new BufferedInputStream(new FileInputStream(path));
        //创建输出流
        OutputStream os  = resp.getOutputStream();
        //缓存区
        byte[] buff = new byte[1024];
        int i = 0;
        //循环将输入流中的内容读取到缓冲区中
        while ((i = bis.read(buff)) != -1) {
                        os.write(buff, 0, i);
                        os.flush();
                    }
        //关闭
        bis.close();
        os.close();   	         
                } catch (IOException e) {
                    log.error("{}",e);
                    log.info("下载失败");
                }
                log.info("下载成功");
    } catch (Exception e) {
        // TODO 自动生成的 catch 块
        e.printStackTrace();
    }
}

文件夹下载

与文件下载不一样，需要先压缩再下载。本例子的服务器中文件URL已知，所以未用mapping层查询数据库，可根据需要加上。

Service:

/*
    * 下载文件夹
    */
public void downloadFile(String proname, String fileName, HttpServletResponse resp) {
    try {
        //下载后的文件
        String name=Constants.FILEPATH + Constants.PROJECT + proname + "/product/outsource"+".zip";
        zipUtil zc = new zipUtil(name);
        List<String> list=new ArrayList<>();
        //服务器存储的URL
        list.add(Constants.FILEPATH + Constants.PROJECT + proname + "/product/outsource");
        //可继续添加要一起压缩的文件夹或文件
        //list.add("");
        String[] strings = new String[list.size()];
        list.toArray(strings);
        File file=null;
        try {
            zc.compress(strings);//压缩
            file=new File(name);
            downLoad.downloadZip(file,resp);//下载
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            if(file!=null){
                file.delete();//把生成的压缩文件删除
            }
        }
    } catch (Exception e) {
        // TODO 自动生成的 catch 块
        e.printStackTrace();
    }
}

Utile:

建立两个工具包

（1）压缩文件夹

public class ZipCompressorUtil {
    static final int BUFFER = 8192; 
    /**
        * 压缩的文件夹
        */
    private File zipFile1111;
    
    public ZipCompressorUtil(String pathName) {
        zipFile1111 = new File(pathName);
    }
    /**
        * 遍历需要压缩文件集合
        * @param pathName
        * @throws IOException
        */
    public void compress(String... pathName) throws IOException {
        ZipOutputStream out =null;
        FileOutputStream fileOutputStream=null;
        CheckedOutputStream cos=null;
        try {
            fileOutputStream = new FileOutputStream(zipFile1111);
            cos = new CheckedOutputStream(fileOutputStream,new CRC32());
            out = new ZipOutputStream(cos);
            String basedir = "";
            for (int i=0;i<pathName.length;i++){
                compress(new File(pathName[i]), out, basedir);
            }
        } catch (Exception e) {
            throw new RuntimeException(e);
        }finally {
            if(out!=null){
                out.close();
            }
            if(fileOutputStream!=null){
                fileOutputStream.close();
            }
            if(cos!=null){
                cos.close();
            }
        }
    }
    /**
        * 压缩
        * @param file
        * @param out
        * @param basedir
        */
    private void compress(File file, ZipOutputStream out, String basedir) throws IOException {
        // 判断是目录还是文件
        if (file.isDirectory()) {
            this.compressDirectory(file, out, basedir);
        } else {
            this.compressFile(file, out, basedir);
        }
    }
    /**
        * 压缩一个目录
        * */
    private void compressDirectory(File dir, ZipOutputStream out, String basedir) throws IOException {
        if (!dir.exists()){
            return;
        }
        File[] files = dir.listFiles();
        for (int i = 0; i < files.length; i++) {
            // 递归
            compress(files[i], out, basedir + dir.getName() + "/");
        }
    }
    /**
        * 压缩一个文件
        *
        * */
    private void compressFile(File file, ZipOutputStream out, String basedir) throws IOException {
        if (!file.exists()) {
            return;
        }
        BufferedInputStream bis =null;
        try {
            bis = new BufferedInputStream(new FileInputStream(file));
            ZipEntry entry = new ZipEntry(basedir + file.getName());
            out.putNextEntry(entry);
            int count;
            byte[] data = new byte[BUFFER];
            while ((count = bis.read(data, 0, BUFFER)) != -1) {
                out.write(data, 0, count);
            }
        } catch (Exception e) {
            throw new RuntimeException(e);
        }finally {
            if(bis!=null){
                bis.close();
            }
        }   
    }	    
}

（2）下载文件夹

public class DownLoadUtil {
    /**
     * 下载压缩包
     * @param file
     * @param response
     * @return
     */
    public static HttpServletResponse downloadZip(File file,HttpServletResponse response) {
        InputStream fis = null;
        OutputStream toClient = null;
        try {
            // 以流的形式下载文件。
             fis = new BufferedInputStream(new FileInputStream(file.getPath()));
            byte[] buffer = new byte[fis.available()];
            fis.read(buffer);
            // 清空response
            response.reset();
             toClient = new BufferedOutputStream(response.getOutputStream());
            response.setContentType("application/octet-stream");
     
            //如果输出的是中文名的文件，在此处就要用URLEncoder.encode方法进行处理
            response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(file.getName(), "UTF-8"));
            toClient.write(buffer);
            toClient.flush();
        } catch (IOException ex) {
            ex.printStackTrace();
        }finally{
            try {
                File f = new File(file.getPath());
                f.delete();
               if(fis!=null){
                   fis.close();
               }
               if(toClient!=null){
                   toClient.close();
               }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return response;
    }
}

文件删除

/**
* 删除文件
* @param fileName
* @return
*/
public static boolean deleteFile(String fileName) {
    File file = new File(fileName);
     // 如果文件路径只有单个文件
    if (file.exists() && file.isFile()) {
         if (file.delete()) {
            System.out.println("删除文件" + fileName + "成功！");
            return true;
          } else {
            System.out.println("删除文件" + fileName + "失败！");
            return false;
          }
    } else {
        System.out.println(fileName + "不存在！");
        return false;
    }
}

文件夹删除

/**
* 删除文件夹,里面用到了删除文件的函数，把上面文件删除的函数也引进来
*/
public static boolean deleteAllFile(String dir) {
    // 如果dir不以文件分隔符结尾，自动添加文件分隔符
    if (!dir.endsWith(File.separator))
        dir = dir + File.separator;
    File dirFile = new File(dir);
    // 如果dir对应的文件不存在，或者不是一个目录，则退出
    if ((!dirFile.exists()) || (!dirFile.isDirectory())) {
        System.out.println("删除文件夹失败：" + dir + "不存在！");
        return false;
    }
    boolean flag = true;
    // 删除文件夹中的所有文件包括子文件夹
    File[] files = dirFile.listFiles();
    for (int i = 0; i < files.length; i++) {
    // 删除子文件
        if (files[i].isFile()) {
            flag = deleteFile(files[i].getAbsolutePath());
            if (!flag)
            break;
        }
        // 删除子文件夹
        else if (files[i].isDirectory()) {
            flag = deleteAllFile(files[i].getAbsolutePath());
            if (!flag)
            break;
        }
    }
    if (!flag) {
        System.out.println("删除文件夹失败！");
        return false;
    }
    // 删除当前文件夹
    if (dirFile.delete()) {
        System.out.println("删除文件夹" + dir + "成功！");
        return true;
    } else {
        return false;
    }
}

文件上传（文件夹需自行压缩）

public String insertProductOutsource(ProductOutsourceEntity productOutsourceEntity,String proname, List<MultipartFile> file,HttpServletRequest req) { 
    // 判断参数有没有效
    if(productOutsourceEntity == null) {
        return Constants.FAILCODE;
    } 
    try {
        //获取当前时间
        Calendar calendar = Calendar.getInstance();
        String nowTime = (new SimpleDateFormat("yyyy-MM-dd_HH-mm-ss").format(calendar.getTime()));
        // 创建文件夹,文件名称与提交时间关联
        ProjectEntity projectEntity = projectMapping.getProjectByName(proname);
        String poId = signMapping.getSignById(projectEntity.getProSignId()).getPoId();
        String docPath = Constants.FILEPATH + Constants.PROJECT + proname + "/product/" + poId + "-outsource/"+nowTime+"/";

        File localPath = new File(docPath);
        if (!localPath.exists()) {  // 获得文件目录，判断目录是否存在，不存在就新建一个
            localPath.mkdirs();
                    }
        //存文件
        for (MultipartFile f : file) {
            String filename = f.getOriginalFilename();
            String path = docPath +filename;
            File filePath = new File(path); 
            BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream(filePath));// 保存文件到目录下
            out.write(f.getBytes());//在创建好的文件中写入f.getBytes()
            out.flush();
            out.close();
            productOutsourceEntity.setFileUrl(path);
            log.info("数据库中FileUrl储存"+productOutsourceEntity.getFileUrl());
        }

        productOutsourceMapping.insert(productOutsourceEntity);
        return Constants.SUCCESSCODE;
    } catch (Exception e) {
        // TODO: handle exception
        e.printStackTrace();
        req.setAttribute("error", "添加文件失败");
        return Constants.FAILCODE;
    }
}