Java FileUtils

/**
 * Created by xxx on 2023-11-06.
 */

import lombok.extern.slf4j.Slf4j;

import javax.servlet.http.HttpServletResponse;
import java.io.*;

@Slf4j
public class FileUtils {
    private static final int CACHE_SIZE = 1024;

    /**
     * 根据路径和文件名后缀创建文件
     *
     * @param path
     * @param suffix
     * @return
     */
    public static String buildFile(String path, String suffix) {
        //获取文件路径以及文件名
        if (suffix == null || suffix.equals("")) {
        } else {
            path = path + suffix;
        }
        File file = new File(path);
        //若文件不存在
        if (!file.exists()) {
            try {
                //创建文件
                file.createNewFile();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return path;
    }

    /**
     * 根据路径创建文件夹
     *
     * @param path
     * @return
     */
    public static String buildDirectory(String path) {
        File file = new File(path);
        //若文件不存在
        if (!file.exists()) {
            try {
                //创建文件
                file.mkdirs();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return path;
    }

    /**
     * 视频流传给前端
     *
     * @param response
     * @param bytes
     */
    public static void getVideoOutStream(HttpServletResponse response, byte[] bytes) {
        OutputStream outputStream = null;
        try {
            outputStream = response.getOutputStream();
            outputStream.write(bytes);
            outputStream.flush();
        } catch (Exception e) {
            log.error("error", e);
            throw new RuntimeException(e);
        } finally {
            try {
                outputStream.close();
            } catch (IOException e) {
                log.error("error", e);
            }
        }
    }

    /**
     * 将Byte数组转换成文件
     *
     * @param bytes    byte数组
     * @param filePath 文件路径  如 D://test/ 最后“/”结尾
     * @param fileName 文件名
     */
    public static void fileToBytes(byte[] bytes, String filePath, String fileName) {
        BufferedOutputStream bos = null;
        FileOutputStream fos = null;
        File file = null;
        try {
            if (!filePath.endsWith("/")) {
                filePath += "/";
            }
            file = new File(filePath + fileName);
            if (!file.getParentFile().exists()) {
                //文件夹不存在 生成
                file.getParentFile().mkdirs();
            }
            fos = new FileOutputStream(file);
            bos = new BufferedOutputStream(fos);
            bos.write(bytes);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (bos != null) {
                try {
                    bos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (fos != null) {
                try {
                    fos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }

    public static byte[] fileToBytes(File file) throws Exception {
        byte[] data = new byte[0];
        if (file.exists()) {
            FileInputStream in = new FileInputStream(file);
            ByteArrayOutputStream out = new ByteArrayOutputStream(2048);
            byte[] cache = new byte[CACHE_SIZE];
            int nRead = 0;
            while ((nRead = in.read(cache)) != -1) {
                out.write(cache, 0, nRead);
                out.flush();
            }
            out.close();
            in.close();
            data = out.toByteArray();
        }
        return data;
    }

}