文件工具类 读取文件转成字节、字节转文件

读取文件

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

jdk8读取文件

    public static byte[] fileToByte(String filePath) throws Exception {
        return Files.readAllBytes(Paths.get(filePath));
    }

保存文件内容

    public static void byteToFile(byte[] content, String fileName, String filePath) {
        File file;
        //创建文件目录
        File dir = new File(filePath);
        if (!dir.exists() && !dir.isDirectory()) {
            dir.mkdirs();
        }
        BufferedOutputStream bos = null;
        java.io.FileOutputStream fos = null;
        try {
            file=new File(filePath + fileName);
            fos = new java.io.FileOutputStream(file);
            bos = new BufferedOutputStream(fos);
            bos.write(content);
        } 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();
                }
            }
        }
    }