项目中使用 Velocity 将模板和生成的动态内容（HTML、XML等）合并保存到redis数据库中，考虑到压缩的文件容量会比较小，方便传输而且存储所使用的空间也会比较小，所以要压缩一下，读取的时候也要解压，所以就用到了SharpZipLib。SharpZipLib是一个完全用c#为. net平台编写的Zip、GZip、Tar和BZip2库。官网代码下载https://github.com/icsharpcode/SharpZipLib。如果要使用SharpZipLib,我们可以直接下载源码引入项目，也可以下载SharpZLib.dll。SharpZLib.dll可以从网上下载也可以通过代码自己生成dill。
压缩分为无损压缩和有损压缩，有损压缩指的是压缩之后就无法完整还原原始信息，但是压缩率可以很高，主要应用于视频、话音等数据的压缩，如果没必要完整还原信息，可以使用有损压缩，仅仅损失了一点信息，很难察觉；无损压缩则用于文件等等必须完整还原信息的场合，常见的无损压缩包括Zip、GZip、RAR、Tar、BZip2等。
一、如何使用SharpZipLib
1、项目中引用SharpZLib.dll。
2、本项目中，单独写了一个ZipHelper类，用来使用SharpZipLib中封装的压缩方式。zipHelper类时可以作为使用Zip、Tar、GZip、Lzw、BZip2压缩方式的入口。直接上ZipHelper类的代码吧
using SharpZipLib.BZip2;
using SharpZipLib.Checksum;
using SharpZipLib.Core.Exceptions;
using SharpZipLib.GZip;
using SharpZipLib.Tar;
using SharpZipLib.Zip;
using SharpZipLib.Zip.Compression;
using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
namespace SharpZipLibExample
{
/// <summary>
/// 网上关于压缩的只是很多
/// https://www.cnblogs.com/kissdodog/p/3525295.html
/// </summary>
public class ZipHelper
{
;
#region Zip
/// <summary>
/// Zip文件压缩
/// ZipOutputStream：相当于一个压缩包；
/// ZipEntry：相当于压缩包里的一个文件；
/// 以上两个类是SharpZipLib的主类。
/// </summary>
/// <param name="sourceFileLists"></param>
/// <param name="descFile">压缩文件保存的目录</param>
/// <param name="compression">压缩级别</param>
public static void ZipCompress(List<string> sourceFileLists, string descFile, int compression)
{
|| compression > )
{
throw new ArgumentException("错误的压缩级别");
}
if (!Directory.Exists(new FileInfo(descFile).Directory.ToString()))
{
throw new ArgumentException("保存目录不存在");
}
foreach (string c in sourceFileLists)
{
if (!File.Exists(c))
{
throw new ArgumentException(string.Format("文件{0} 不存在！", c));
}
}
Crc32 crc32 = new Crc32();
using (ZipOutputStream stream = new ZipOutputStream(File.Create(descFile)))
{
stream.SetLevel(compression);
ZipEntry entry;
; i < sourceFileLists.Count; i++)
{
entry = new ZipEntry(Path.GetFileName(sourceFileLists[i]));
entry.DateTime = DateTime.Now;
using (FileStream fs = File.OpenRead(sourceFileLists[i]))
{
byte[] buffer = new byte[fs.Length];
fs.Read(buffer, , buffer.Length);
entry.Size = fs.Length;
crc32.Reset();
crc32.Update(buffer);
entry.Crc = crc32.Value;
stream.PutNextEntry(entry);
stream.Write(buffer, , buffer.Length);
}
stream.CloseEntry();
}
}
}
/// <summary>
/// unZip文件解压缩
/// </summary>
/// <param name="sourceFile">要解压的文件</param>
/// <param name="path">要解压到的目录</param>
public static void ZipDeCompress(string sourceFile, string path)
{
if (!File.Exists(sourceFile))
{
throw new ArgumentException("要解压的文件不存在。");
}
if (!Directory.Exists(path))
{
throw new ArgumentException("要解压到的目录不存在！");
}
using (ZipInputStream s = new ZipInputStream(File.OpenRead(sourceFile)))
{
ZipEntry theEntry;
while ((theEntry = s.GetNextEntry()) != null)
{
string fileName = System.IO.Path.GetFileName(theEntry.Name);
if (fileName != string.Empty)
{
using (FileStream streamWriter = File.Create(path + @"\" + theEntry.Name))
{
;
];
while (true)
{
size = s.Read(data, , data.Length);
)
{
streamWriter.Write(data, , size);
}
else
{
break;
}
}
}
}
}
}
}
/// <summary>
/// 字符串压缩
/// </summary>
/// <param name="text">待压缩的字符串</param>
/// <returns>已压缩的字符串</returns>
public static string ZipCompress(string text)
{
string result = string.Empty;
byte[] data = Encoding.UTF8.GetBytes(text);
byte[] dData = ZipCompress(data);
result = Convert.ToBase64String(dData);
Array.Clear(dData, , dData.Length);
return result;
}
/// <summary>
/// 字符串解压
/// </summary>
/// <param name="text">待解压的字符串</param>
/// <returns>已解压的字符串</returns>
public static string ZipDeCompress(string text)
{
string result = string.Empty;
byte[] data = Convert.FromBase64String(text);
byte[] dData = ZipDeCompress(data);
result = Encoding.UTF8.GetString(dData);
Array.Clear(dData,,dData.Length);
return result;
}
/// <summary>
/// 字节数组压缩
/// </summary>
/// <param name="data">待压缩的字节数组</param>
/// <param name="isClearData">压缩完成后，是否清除待压缩字节数组里面的内容</param>
/// <returns>已压缩的字节数组</returns>
public static byte[] ZipCompress(byte[] data, bool isClearData = true)
{
byte[] bytes = null;
Deflater f = new Deflater(Deflater.BEST_COMPRESSION);
f.SetInput(data);
f.Finish();
;
using (MemoryStream o=new MemoryStream(data.Length))
{
byte[] buffer = new byte[BUFFER_LENGTH];
while (!f.IsFinished)
{
count = f.Deflate(buffer);
o.Write(buffer,,count);
}
bytes = o.ToArray();
}
if (isClearData)
{
Array.Clear(data,,data.Length);
}
return bytes;
}
/// <summary>
/// 字节数组解压缩
/// </summary>
/// <param name="data">待解压缩的字节数组</param>
/// <param name="isClearData">解压缩完成后，是否清除待解压缩字节数组里面的内容</param>
/// <returns>已解压的字节数组</returns>
public static byte[] ZipDeCompress(byte[] data, bool isClearData = true)
{
byte[] bytes = null;
Inflater f = new Inflater();
f.SetInput(data);
;
using (MemoryStream o=new MemoryStream(data.Length))
{
byte[] buffer = new byte[BUFFER_LENGTH];
while (!f.IsFinished)
{
count = f.Inflate(buffer);
o.Write(buffer,,count);
}
bytes = o.ToArray();
}
if (isClearData)
{
Array.Clear(data,,count);
}
return bytes;
}
#endregion
#region GZip
/// <summary>
/// 压缩字符串
/// </summary>
/// <param name="text">待压缩的字符串组</param>
/// <returns>已压缩的字符串</returns>
public static string GZipCompress(string text)
{
string result = string.Empty;
byte[] data = Encoding.UTF8.GetBytes(text);
byte[] cData = GZipCompress(data);
result = Convert.ToBase64String(cData);
Array.Clear(cData, , cData.Length);
return result;
}
/// <summary>
/// 解压缩字符串
/// </summary>
/// <param name="text">待解压缩的字符串</param>
/// <returns>已解压缩的字符串</returns>
public static string GZipDeCompress(string text)
{
string result = string.Empty;
byte[] data = Convert.FromBase64String(text);
byte[] cData = GZipDeCompress(data);
result = Encoding.UTF8.GetString(cData);
Array.Clear(cData, , cData.Length);
return result;
}
/// <summary>
/// 压缩字节数组
/// </summary>
/// <param name="data">待压缩的字节数组</param>
/// <param name="isClearData">压缩完成后，是否清除待压缩字节数组里面的内容</param>
/// <returns>已压缩的字节数组</returns>
public static byte[] GZipCompress(byte[] data, bool isClearData = true)
{
byte[] bytes = null;
try
{
using (MemoryStream o = new MemoryStream())
{
using (Stream s = new GZipOutputStream(o))
{
s.Write(data, , data.Length);
s.Flush();
}
bytes = o.ToArray();
}
}
catch (SharpZipBaseException)
{
}
catch (IndexOutOfRangeException)
{
}
if (isClearData)
Array.Clear(data, , data.Length);
return bytes;
}
/// <summary>
/// 解压缩字节数组
/// </summary>
/// <param name="data">待解压缩的字节数组</param>
/// <param name="isClearData">解压缩完成后，是否清除待解压缩字节数组里面的内容</param>
/// <returns>已解压的字节数组</returns>
public static byte[] GZipDeCompress(byte[] data, bool isClearData = true)
{
byte[] bytes = null;
try
{
using (MemoryStream o = new MemoryStream())
{
using (MemoryStream ms = new MemoryStream(data))
{
using (Stream s = new GZipInputStream(ms))
{
s.Flush();
;
byte[] buffer = new byte[BUFFER_LENGTH];
, buffer.Length)) > )
{
o.Write(buffer, , size);
}
}
}
bytes = o.ToArray();
}
}
catch (SharpZipBaseException)
{
}
catch (IndexOutOfRangeException)
{
}
if (isClearData)
Array.Clear(data, , data.Length);
return bytes;
}
#endregion
#region Tar
/// <summary>
/// 压缩字符串
/// </summary>
/// <param name="text">待压缩的字符串组</param>
/// <returns>已压缩的字符串</returns>
public static string TarCompress(string text)
{
string result = null;
byte[] data = Encoding.UTF8.GetBytes(text);
byte[] dData = TarCompress(data);
result = Convert.ToBase64String(dData);
Array.Clear(dData, , dData.Length);
return result;
}
/// <summary>
/// 解压缩字符串
/// </summary>
/// <param name="text">待解压缩的字符串</param>
/// <returns>已解压的字符串</returns>
public static string TarDeCompress(string text)
{
string result = null;
byte[] data = Convert.FromBase64String(text);
byte[] dData = TarDeCompress(data);
result = Encoding.UTF8.GetString(dData);
Array.Clear(dData, , dData.Length);
return result;
}
/// <summary>
/// 压缩字节数组
/// </summary>
/// <param name="data">待压缩的字节数组</param>
/// <param name="isClearData">压缩完成后，是否清除待压缩字节数组里面的内容</param>
/// <returns>已压缩的字节数组</returns>
public static byte[] TarCompress(byte[] data, bool isClearData = true)
{
byte[] bytes = null;
using (MemoryStream o = new MemoryStream())
{
using (Stream s = new TarOutputStream(o))
{
s.Write(data, , data.Length);
s.Flush();
}
bytes = o.ToArray();
}
if (isClearData)
Array.Clear(data, , data.Length);
return bytes;
}
/// <summary>
/// 解压缩字节数组
/// </summary>
/// <param name="data">待解压缩的字节数组</param>
/// <param name="isClearData">解压缩完成后，是否清除待解压缩字节数组里面的内容</param>
/// <returns>已解压的字节数组</returns>
public static byte[] TarDeCompress(byte[] data, bool isClearData = true)
{
byte[] bytes = null;
using (MemoryStream o = new MemoryStream())
{
using (MemoryStream ms = new MemoryStream(data))
{
using (Stream s = new TarInputStream(ms))
{
s.Flush();
;
byte[] buffer = new byte[BUFFER_LENGTH];
, buffer.Length)) > )
{
o.Write(buffer, , size);
}
}
}
bytes = o.ToArray();
}
if (isClearData)
Array.Clear(data, , data.Length);
return bytes;
}
#endregion
#region BZip
/// <summary>
/// 压缩字符串
/// </summary>
/// <param name="text">待压缩的字符串组</param>
/// <returns>已压缩的字符串</returns>
public static string BZipCompress(string text)
{
string result = null;
byte[] data = Encoding.UTF8.GetBytes(text);
byte[] dData = BZipCompress(data);
result = Convert.ToBase64String(dData);
Array.Clear(dData, , dData.Length);
return result;
}
/// <summary>
/// 解压缩字符串
/// </summary>
/// <param name="text">待解压缩的字符串</param>
/// <returns>已解压的字符串</returns>
public static string BZipDeCompress(string text)
{
string result = null;
byte[] data = Convert.FromBase64String(text);
byte[] dData = BZipDeCompress(data);
result = Encoding.UTF8.GetString(dData);
Array.Clear(dData, , dData.Length);
return result;
}
/// <summary>
/// 压缩字节数组
/// </summary>
/// <param name="data">待压缩的字节数组</param>
/// <param name="isClearData">压缩完成后，是否清除待压缩字节数组里面的内容</param>
/// <returns>已压缩的字节数组</returns>
public static byte[] BZipCompress(byte[] data, bool isClearData = true)
{
byte[] bytes = null;
using (MemoryStream o = new MemoryStream())
{
using (Stream s = new BZip2OutputStream(o))
{
s.Write(data, , data.Length);
s.Flush();
}
bytes = o.ToArray();
}
if (isClearData)
Array.Clear(data, , data.Length);
return bytes;
}
/// <summary>
/// 解压缩字节数组
/// </summary>
/// <param name="data">待解压缩的字节数组</param>
/// <param name="isClearData">解压缩完成后，是否清除待解压缩字节数组里面的内容</param>
/// <returns>已解压的字节数组</returns>
public static byte[] BZipDeCompress(byte[] data, bool isClearData = true)
{
byte[] bytes = null;
using (MemoryStream o = new MemoryStream())
{
using (MemoryStream ms = new MemoryStream(data))
{
using (Stream s = new BZip2InputStream(ms))
{
s.Flush();
;
byte[] buffer = new byte[BUFFER_LENGTH];
, buffer.Length)) > )
{
o.Write(buffer, , size);
}
}
}
bytes = o.ToArray();
}
if (isClearData)
Array.Clear(data, , data.Length);
return bytes;
}
#endregion
}
}
3、程序入口main
using System;
using System.Linq;
using System.Text;
namespace SharpZipLibExample
{
class Program
{
static void Main(string[] args)
{
string strContent = "夜，结束了一天的喧嚣后安静下来，伴随着远处路灯那微弱的光。风，毫无预兆地席卷整片旷野，撩动人的思绪万千。星，遥遥地挂在天空之中，闪烁着它那微微星光，不如阳光般灿烂却如花儿般如痴如醉。";
Console.WriteLine("原文：{0}",strContent);
#region 压缩
string compressContent = ZipHelper.BZipCompress(strContent);
Console.WriteLine("压缩后的内容：{0}；压缩后的内容大小：{1}", compressContent, Convert.FromBase64String(compressContent).Count().ToString());
#endregion
#region 解压缩
strContent = ZipHelper.BZipDeCompress(compressContent);
Console.WriteLine("解压缩后的内容：{0}；解压缩后的内容大小：{1}", strContent,Encoding.UTF8.GetBytes(strContent).Count().ToString());
#endregion
Console.ReadKey();
}
}
}
完整的Demo下载地址https://download.csdn.net/download/u011392711/10827889