技術標籤：javaspringboot上傳下載

import cn.hutool.core.date.DateUtil;
import com.tsms.common.utils.StringUtils;
import com.tsms.common.utils.file.FileTypeUtils;
import com.tsms.common.utils.file.MimeTypeUtils;
import org.apache.commons.lang3.ArrayUtils;

import javax.servlet.http.HttpServletRequest;
import
 
 javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.LinkOption;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.attribute.BasicFileAttributeView;
import
 
 java.nio.file.attribute.BasicFileAttributes;
import java.util.Date;

/**
 * 檔案工具類
 *
 * @author 雲諾
 * @Description:
 * @date 2021/1/11 5:34
 * @Version
 */
public class FileUtil {

    public static String FILENAME_PATTERN = "[a-zA-Z0-9_\\-\\|\\.\\u4e00-\\u9fa5]+";

    /**
     * 輸出指定檔案的byte陣列
     *
     * @param filePath 檔案路徑
     * @param os 輸出流
     * @return
     */
 

    public static void writeBytes(String filePath, OutputStream os) throws IOException
    {
        FileInputStream fis = null;
        try
        {
            File file = new File(filePath);
            if (!file.exists())
            {
                throw new FileNotFoundException(filePath);
            }
            fis = new FileInputStream(file);
            byte[] b = new byte[1024];
            int length;
            while ((length = fis.read(b)) > 0)
            {
                os.write(b, 0, length);
            }
        }
        catch (IOException e)
        {
            throw e;
        }
        finally
        {
            if (os != null)
            {
                try
                {
                    os.close();
                }
                catch (IOException e1)
                {
                    e1.printStackTrace();
                }
            }
            if (fis != null)
            {
                try
                {
                    fis.close();
                }
                catch (IOException e1)
                {
                    e1.printStackTrace();
                }
            }
        }
    }

    /**
     * 刪除檔案
     *
     * @param filePath 檔案
     * @return
     */
    public static boolean deleteFile(String filePath)
    {
        boolean flag = false;
        File file = new File(filePath);
        // 路徑為檔案且不為空則進行刪除
        if (file.isFile() && file.exists())
        {
            file.delete();
            flag = true;
        }
        return flag;
    }

    /**
     * 檔名稱驗證
     *
     * @param filename 檔名稱
     * @return true 正常 false 非法
     */
    public static boolean isValidFilename(String filename)
    {
        return filename.matches(FILENAME_PATTERN);
    }

    /**
     * 檢查檔案是否可下載
     *
     * @param resource 需要下載的檔案
     * @return true 正常 false 非法
     */
    public static boolean checkAllowDownload(String resource)
    {
        // 禁止目錄上跳級別
        if (StringUtils.contains(resource, ".."))
        {
            return false;
        }

        // 檢查允許下載的檔案規則
        if (ArrayUtils.contains(MimeTypeUtils.DEFAULT_ALLOWED_EXTENSION, FileTypeUtils.getFileType(resource)))
        {
            return true;
        }

        // 不在允許下載的檔案規則
        return false;
    }

    /**
     * 下載檔名重新編碼
     *
     * @param request 請求物件
     * @param fileName 檔名
     * @return 編碼後的檔名
     */
    public static String setFileDownloadHeader(HttpServletRequest request, String fileName) throws UnsupportedEncodingException
    {
        final String agent = request.getHeader("USER-AGENT");
        String filename = fileName;
        if (agent.contains("MSIE"))
        {
            // IE瀏覽器
            filename = URLEncoder.encode(filename, "utf-8");
            filename = filename.replace("+", " ");
        }
        else if (agent.contains("Firefox"))
        {
            // 火狐瀏覽器
            filename = new String(fileName.getBytes(), "ISO8859-1");
        }
        else if (agent.contains("Chrome"))
        {
            // google瀏覽器
            filename = URLEncoder.encode(filename, "utf-8");
            filename = filename.replace("+", " ");
        }
        else
        {
            // 其它瀏覽器
            filename = URLEncoder.encode(filename, "utf-8");
            filename = filename.replace("+", " ");
        }
        return filename;
    }

    /**
     * 下載檔名重新編碼
     *
     * @param response 響應物件
     * @param realFileName 真實檔名
     * @return
     */
    public static void setAttachmentResponseHeader(HttpServletResponse response, String realFileName) throws UnsupportedEncodingException
    {
        String percentEncodedFileName = percentEncode(realFileName);

        StringBuilder contentDispositionValue = new StringBuilder();
        contentDispositionValue.append("attachment; filename=")
                .append(percentEncodedFileName)
                .append(";")
                .append("filename*=")
                .append("utf-8''")
                .append(percentEncodedFileName);

        response.setHeader("Content-disposition", contentDispositionValue.toString());
    }

    /**
     * 百分號編碼工具方法
     *
     * @param s 需要百分號編碼的字串
     * @return 百分號編碼後的字串
     */
    public static String percentEncode(String s) throws UnsupportedEncodingException
    {
        String encode = URLEncoder.encode(s, StandardCharsets.UTF_8.toString());
        return encode.replaceAll("\\+", "%20");
    }
    /**
     * @param filePath: 檔案路徑
     * @Description: 獲取檔案建立時間
     * @Author: 雲諾
     * @date 2021/1/11 5:35
     * @return: java.lang.String 檔案建立時間，若無法獲取建立時間（linux中），返回檔案修改時間
     */
    public static String getFileCreateTime(String filePath) {
        File file = new File(filePath);
        try {
            Path path = Paths.get(filePath);
            BasicFileAttributeView basicview = Files.getFileAttributeView(path, BasicFileAttributeView.class, LinkOption.NOFOLLOW_LINKS);
            BasicFileAttributes attr = basicview.readAttributes();
            long l = attr.creationTime().toMillis();
            Date date = new Date(l);
            String createtime = DateUtil.formatDateTime(date);
            return createtime;
        } catch (Exception e) {
            // 獲取建立時間失敗，返回修改時間
            long l = file.lastModified();
            Date date = new Date(l);
            String modifiedTime = DateUtil.formatDateTime(date);
            return modifiedTime;
        }
    }

    /**
     * 輸出指定檔案的byte陣列
     *
     * @param fis 檔案輸入流
     * @param os       輸出流
     * @return
     * @Title: writeBytes
     * @Description:
     * @author 雲諾
     */
    public static void writeBytes(InputStream fis, OutputStream os) throws IOException {

        try {
            if (fis == null) {
                throw new FileNotFoundException();
            }
            byte[] b = new byte[1024];
            int length;
            while ((length = fis.read(b)) > 0) {
                os.write(b, 0, length);
            }
        } catch (IOException e) {
            throw e;
        } finally {
            if (os != null) {
                try {
                    os.close();
                } catch (IOException e1) {
                    e1.printStackTrace();
                }
            }
            if (fis != null) {
                try {
                    fis.close();
                } catch (IOException e1) {
                    e1.printStackTrace();
                }
            }
        }
    }
}