分享：基于GZIP压缩算法对数据压缩上传和下载解压

场景：数据量太大，上传到redis和下载耗时过长，可以将数据压缩后上传优化耗时问题；

/** 使用GZIP压缩算法对Redis上传JSON进行压缩上传和解压下载 */
@Component
@Slf4j
public class RedisZipJsonUtil {

  /**
   * 使用GZIP压缩算法对字节数组进行压缩
   *
   * @param jsonString
   * @return
   * @throws IOException
   */
  public byte[] compressWithGzip(String jsonString) throws IOException {
    GZIPOutputStream gzipOutputStream = null;
    ByteArrayOutputStream outputStream = null;
    try {
      // 使用GZIP压缩算法对JSON字符串进行压缩
      outputStream = new ByteArrayOutputStream();
      gzipOutputStream = new GZIPOutputStream(outputStream);
      gzipOutputStream.write(jsonString.getBytes());
      // gzipOutputStream.close();里面有finish操作，因此要在toByteArray前面，也可以单独执行
      gzipOutputStream.finish(); // 不进行finish操作数据会丢失或为空，因此要放在toByteArray前面
      return outputStream.toByteArray();
    } catch (IOException e) {
      log.error("redis数据压缩异常：{}", e.getMessage());
      e.printStackTrace();
    } finally {
      if (outputStream != null) {
        outputStream.close();
      }
      if (gzipOutputStream != null) {
        gzipOutputStream.close();
      }
    }
    return null;
  }

  /**
   * 使用GZIP解压缩算法对字节数组进行解压缩
   *
   * @param input
   * @return
   * @throws IOException
   */
  public String decompressWithGzip(byte[] input) throws IOException {
    GZIPInputStream gzipInputStream = null;
    ByteArrayInputStream inputStream = null;
    ByteArrayOutputStream outputStream = null;
    try {
      if (input != null) {
        int bufferSize = 1024;
        inputStream = new ByteArrayInputStream(input);
        gzipInputStream = new GZIPInputStream(inputStream, bufferSize);
        byte[] buffer = new byte[bufferSize];
        outputStream = new ByteArrayOutputStream();
        int len;
        while ((len = gzipInputStream.read(buffer)) != -1) {
          outputStream.write(buffer, 0, len);
        }
        outputStream.flush(); // 刷新清空
        // 将解压缩后的JSON字节数组转换为字符串
        return new String(outputStream.toByteArray());
      }
    } catch (IOException e) {
      log.error("redis数据解压缩异常：{}", e.getMessage());
      e.printStackTrace();
    } finally {
      if (outputStream != null) {
        outputStream.close();
      }
      if (inputStream != null) {
        inputStream.close();
      }
      if (gzipInputStream != null) {
        gzipInputStream.close();
      }
    }
    return null;
  }
}