using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.IO;
using System.IO.Compression;
namespace CSIBrowser.Client.Util
{
public class ZipHelper
{
/// <summary>
/// 将传入字符串以GZip算法压缩后，返回Base64编码字符
/// </summary>
/// <param name="rawString">需要压缩的字符串</param>
/// <returns>压缩后的Base64编码的字符串</returns>
public static string GZipCompressString(string rawString)
{
if (string.IsNullOrEmpty(rawString) || rawString.Length == 0)
{
return "";
}
else
{
byte[] rawData = System.Text.Encoding.UTF8.GetBytes(rawString.ToString());
byte[] zippedData = Compress(rawData);
return (string)(Convert.ToBase64String(zippedData));
}
}
/// <summary>
/// GZip压缩
/// </summary>
/// <param name="rawData"></param>
/// <returns></returns>
public static byte[] Compress(byte[] rawData)
{
MemoryStream ms = new MemoryStream();
GZipStream compressedzipStream = new GZipStream(ms, CompressionMode.Compress, true);
compressedzipStream.Write(rawData, 0, rawData.Length);
compressedzipStream.Close();
return ms.ToArray();
}
/// <summary>
/// 将传入的二进制字符串资料以GZip算法解压缩
/// </summary>
/// <param name="zippedString">经GZip压缩后的二进制字符串</param>
/// <returns>原始未压缩字符串</returns>
public static string GZipDecompressString(string zippedString)
{
if (string.IsNullOrEmpty(zippedString) || zippedString.Length == 0)
{
return "";
}
else
{
byte[] zippedData = Convert.FromBase64String(zippedString.ToString());
return (string)(System.Text.Encoding.UTF8.GetString(Decompress(zippedData)));
}
}
/// <summary>
/// ZIP解压
/// </summary>
/// <param name="zippedData"></param>
/// <returns></returns>
public static byte[] Decompress(byte[] zippedData)
{
MemoryStream ms = new MemoryStream(zippedData);
GZipStream compressedzipStream = new GZipStream(ms, CompressionMode.Decompress);
MemoryStream outBuffer = new MemoryStream();
byte[] block = new byte[1024];
while (true)
{
int bytesRead = compressedzipStream.Read(block, 0, block.Length);
if (bytesRead <= 0)
{
break;
}
else
{
outBuffer.Write(block, 0, bytesRead);
}
}
compressedzipStream.Close();
return outBuffer.ToArray();
}
}
}