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C#基础知识之SharpZipLib压缩解压的使用

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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。

二、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>
    /// 网上关于压缩的知识很多
    /// https://www.cnblogs.com/kissdodog/p/3525295.html
    /// </summary>
    public class ZipHelper
    {
        private const int BUFFER_LENGTH = 2048;
        #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)
        {
            if (compression < 0 || compression > 9)
            {
                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;
                for (int i = 0; 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, 0, buffer.Length);
                        entry.Size = fs.Length;
                        crc32.Reset();
                        crc32.Update(buffer);
                        entry.Crc = crc32.Value;
                        stream.PutNextEntry(entry);
                        stream.Write(buffer, 0, 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))
                        {
                            int size = 2048;
                            byte[] data = new byte[2048];
                            while (true)
                            {
                                size = s.Read(data, 0, data.Length);
                                if (size > 0)
                                {
                                    streamWriter.Write(data, 0, 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, 0, 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,0,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();
            int count = 0;
            using (MemoryStream o=new MemoryStream(data.Length))
            {
                byte[] buffer = new byte[BUFFER_LENGTH];
                while (!f.IsFinished)
                {
                    count = f.Deflate(buffer);
                    o.Write(buffer,0,count);
                }
                bytes = o.ToArray();
            }
            if (isClearData)
            {
                Array.Clear(data,0,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);
            int count = 0;
            using (MemoryStream o=new MemoryStream(data.Length))
            {
                byte[] buffer = new byte[BUFFER_LENGTH];
                while (!f.IsFinished)
                {
                    count = f.Inflate(buffer);
                    o.Write(buffer,0,count);
                }
                bytes = o.ToArray();
            }
            if (isClearData)
            {
                Array.Clear(data,0,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, 0, 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, 0, 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, 0, data.Length);
                        s.Flush();
                    }
                    bytes = o.ToArray();
                }
            }
            catch (SharpZipBaseException)
            {
            }
            catch (IndexOutOfRangeException)
            {
            }
            if (isClearData)
                Array.Clear(data, 0, 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();
                            int size = 0;
                            byte[] buffer = new byte[BUFFER_LENGTH];
                            while ((size = s.Read(buffer, 0, buffer.Length)) > 0)
                            {
                                o.Write(buffer, 0, size);
                            }
                        }
                    }
                    bytes = o.ToArray();
                }
            }
            catch (SharpZipBaseException)
            {
            }
            catch (IndexOutOfRangeException)
            {
            }
            if (isClearData)
                Array.Clear(data, 0, 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, 0, 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, 0, 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, 0, data.Length);
                    s.Flush();
                }
                bytes = o.ToArray();
            }
            if (isClearData)
                Array.Clear(data, 0, 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();
                        int size = 0;
                        byte[] buffer = new byte[BUFFER_LENGTH];
                        while ((size = s.Read(buffer, 0, buffer.Length)) > 0)
                        {
                            o.Write(buffer, 0, size);
                        }
                    }
                }
                bytes = o.ToArray();
            }
            if (isClearData)
                Array.Clear(data, 0, 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, 0, 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, 0, 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, 0, data.Length);
                    s.Flush();
                }
                bytes = o.ToArray();
            }
            if (isClearData)
                Array.Clear(data, 0, 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();
                        int size = 0;
                        byte[] buffer = new byte[BUFFER_LENGTH];
                        while ((size = s.Read(buffer, 0, buffer.Length)) > 0)
                        {
                            o.Write(buffer, 0, size);
                        }
                    }
                }
                bytes = o.ToArray();
            }
            if (isClearData)
                Array.Clear(data, 0, data.Length);
            return bytes;
        }
        #endregion
    }
}

View Code

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();      
        }
    }
}