C#使用GZipStream实现压缩和解压缩

前言

我们在项目中，有可能会遇到存入到数据库或者传输的数据量比较大，这个时候，就可以考虑在存入数据库或者发送传输之前，将数据压缩下，当从数据库中取出时，再解压还原数据。

正文

废话不多说，我封装了一个工具类用于压缩和解压数据，代码如下：

 using System;
 using System.IO;
 using System.IO.Compression;
 using System.Text;

 namespace Test
 {
     public class GZipUtils
     {
         /// <summary>
         /// 压缩指定字符串
         /// </summary>
         /// <param name="str">待压缩字符串</param>
         /// <returns>返回压缩后的字节数组</returns>
         public static byte[] Compress(string str)
         {
             if (string.IsNullOrEmpty(str)) return null;

             byte[] bytes = Encoding.UTF8.GetBytes(str);
             return Compress(bytes);
         }

         /// <summary>
         /// 压缩指定字节数组
         /// </summary>
         /// <param name="bytes">待压缩字节数组</param>
         /// <returns>返回压缩后的字节数组</returns>
         public static byte[] Compress(byte[] bytes)
         {
             if (bytes == null || bytes.Length <= ) return bytes;

             using (var compressedStream = new MemoryStream())
             {
                 using (var compressionStream = new GZipStream(compressedStream, CompressionMode.Compress))
                 {
                     compressionStream.Write(bytes, , bytes.Length);
                 }
                 return compressedStream.ToArray();
             }
         }

         /// <summary>
         /// 压缩指定字符串到指定文件中
         /// </summary>
         /// <param name="compressData">待压缩字符串</param>
         /// <param name="zipFilePath">压缩后的文件路径</param>
         public static void CompressToFile(string compressData, string zipFilePath)
         {
             if (!string.IsNullOrEmpty(compressData))
             {
                 byte[] bytes = Encoding.UTF8.GetBytes(compressData);
                 using (var originalStream = new MemoryStream(bytes))
                 {
                     using (FileStream compressedStream = File.Create(zipFilePath))
                     {
                         using (GZipStream compressionStream = new GZipStream(compressedStream, CompressionMode.Compress))
                         {
                             originalStream.CopyTo(compressionStream);
                         }
                     }
                 }
             }
         }

         /// <summary>
         /// 从指定字节数组解压出字符串
         /// </summary>
         /// <param name="bytes">待解压的字节数组</param>
         /// <returns>返回解压后的字符串</returns>
         public static string DecompressToString(byte[] bytes)
         {
             var result = Decompress(bytes);
             if (result == null || result.Length <= ) return string.Empty;

             return Encoding.UTF8.GetString(result);
         }

         /// <summary>
         /// 从指定字节数组解压出字节数组
         /// </summary>
         /// <param name="bytes">待解压的字节数组</param>
         /// <returns>返回解压后的字节数组</returns>
         public static byte[] Decompress(byte[] bytes)
         {
             if (bytes == null || bytes.Length <= ) return bytes;

             using (var originalStream = new MemoryStream(bytes))
             {
                 using (var decompressedStream = new MemoryStream())
                 {
                     using (var decompressionStream = new GZipStream(originalStream, CompressionMode.Decompress))
                     {
                         decompressionStream.CopyTo(decompressedStream);
                     }
                     return decompressedStream.ToArray();
                 }
             }
         }

         /// <summary>
         /// 从指定文件中解压出字符串
         /// </summary>
         /// <param name="zipFilePath">待解压的文件路径</param>
         /// <returns>返回解压后的字符串</returns>
         public static string DecompressFromFile(string zipFilePath)
         {
             if (File.Exists(zipFilePath))
             {
                 using (FileStream originalStream = File.Open(zipFilePath, FileMode.Open))
                 {
                     using (MemoryStream decompressedStream = new MemoryStream())
                     {
                         using (GZipStream decompressionStream = new GZipStream(originalStream, CompressionMode.Decompress))
                         {
                             decompressionStream.CopyTo(decompressedStream);
                         }
                         byte[] bytes = decompressedStream.ToArray();
                         return Encoding.UTF8.GetString(bytes);
                     }
                 }
             }
             return string.Empty;
         }
     }
 }

参考文档

1. C# 关于GZipStream压缩与解压缩数据丢失问题

2. GZipStream 类 (System.IO.Compression)