首先,用 FtpClient.GetDownloadStream() 方法得到一个对应于FTP服务器上文件的Stream,然后把这个Stream传给Zip.GetZipInputStream()方法,得到一个ZipInputStream,然后使用Zip.ReadStream()方法一行一行读取储蓄流水账文件到byte[]中去,这样就取得了我们所需的数据,就象储蓄流水账文件就存放在本地硬盘上一样,避免了下载文件和解压文件。
我最近要写一个供有相关权限的管理人员查询大额资金明细的程序,界面如下:
所需的数据文件是放在报表服务器上,每天一个压缩文件,该压缩文件中除了所需的储蓄流水账文件外,还有很多其他的文件。如果先把该压缩文件从报表服务器下载到应用服务器上,再进行解压缩处理的话,一是多下载了该压缩文件中我们不需要的其他文件,二是还必须在应用服务器上建立以SessionID等方法标识的临时文件,以免其他用户也在进行查询时文件名冲突,三是使用完毕后还必须删除该临时文件。
我的处理方法是如下:
using (ZipInputStream zs = Zip.GetZipInputStream((new FtpClient(Pub.Ftp1Uri, Pub.Ftp1User, Pub.Ftp1Pswd)).
GetDownloadStream(Path.Combine(Pub.Ftp1EPath, zipFileName)), binFileName, out size))
{
if (size % Pub.P_R2 != 0) throw new ApplicationException("文件长度错: " + binFileName);
byte [] bs = new byte[Pub.P_R2];
long recs = size / Pub.P_R2;
for (long rec = 0; rec < recs; rec++)
{
Zip.ReadStream(zs, bs);
...
}
首先,用 FtpClient.GetDownloadStream() 方法得到一个对应于FTP服务器上文件的Stream,然后把这个Stream传给Zip.GetZipInputStream()方法,得到一个ZipInputStream,然后使用Zip.ReadStream()方法一行一行读取储蓄流水账文件到byte[]中去,这样就取得了我们所需的数据,就象储蓄流水账文件就存放在本地硬盘上一样,避免了下载文件和解压文件。具体代码如下:
1
using System;
2
using System.IO;
3
using System.Net;
4
5
namespace Skyiv.Util
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{
7
sealed class FtpClient
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{
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Uri uri;
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string userName;
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string password;
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13
public FtpClient(string uri, string userName, string password)
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{
15
this.uri = new Uri(uri);
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this.userName = userName;
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this.password = password;
18
}
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20
public Stream GetDownloadStream(string sourceFile)
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{
22
Uri downloadUri = new Uri(uri, sourceFile);
23
if (downloadUri.Scheme != Uri.UriSchemeFtp) throw new ArgumentException("URI is not an FTP site");
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FtpWebRequest ftpRequest = (FtpWebRequest)WebRequest.Create(downloadUri);
25
ftpRequest.Credentials = new NetworkCredential(userName, password);
26
ftpRequest.Method = WebRequestMethods.Ftp.DownloadFile;
27
return ((FtpWebResponse)ftpRequest.GetResponse()).GetResponseStream();
28
}
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/**//*public */void Download(string sourceFile, string destinationFile)
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{
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using (Stream reader = GetDownloadStream(sourceFile))
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{
34
using (BinaryWriter bw = new BinaryWriter(new FileStream(destinationFile, FileMode.Create)))
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{
36
for (;;)
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{
38
int c = reader.ReadByte();
39
if (c == -1) break;
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bw.Write((byte)c);
41
}
42
}
43
}
44
}
45
}
46
}
47
1
using System;
2
using System.IO;
3
using ICSharpCode.SharpZipLib.Zip;
4
5
namespace Skyiv.Util
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
{
7
static class Zip
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{
9
public static void ReadStream(Stream inStream, byte [] bs)
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{
11
int offset = 0;
12
int count = bs.Length;
13
do
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{
15
int size = inStream.Read(bs, offset, count);
16
if (size <= 0) break;
17
offset += size;
18
count -= size;
19
} while (count > 0);
20
if (count != 0) throw new ApplicationException("Zip.ReadStream(): 读输入流错");
21
}
22
23
public static ZipInputStream GetZipInputStream(string zipFileName, string fileName, out long fileLength)
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{
25
return GetZipInputStream(File.OpenRead(zipFileName), fileName, out fileLength);
26
}
27
28
public static ZipInputStream GetZipInputStream(Stream zipStream, string fileName, out long fileLength)
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{
30
ZipInputStream zs = new ZipInputStream(zipStream);
31
ZipEntry theEntry;
32
while ((theEntry = zs.GetNextEntry()) != null)
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{
34
if (Path.GetFileName(theEntry.Name) != fileName) continue;
35
fileLength = theEntry.Size;
36
return zs;
37
}
38
fileLength = -1;
39
return null;
40
}
41
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/**//*public */static void UnzipFile(string zipFile, string baseStr, params string [] fileList)
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{
44
UnzipFile(File.OpenRead(zipFile), baseStr, fileList);
45
}
46
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/**//*public */static void UnzipFile(Stream zipStream, string baseStr, params string [] fileList)
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{
49
using (ZipInputStream zs = new ZipInputStream(zipStream))
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{
51
ZipEntry theEntry;
52
byte[] data = new byte[4096];
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while ((theEntry = zs.GetNextEntry()) != null)
{
54
if (Array.IndexOf(fileList, Path.GetFileName(theEntry.Name)) < 0) continue;
55
using (FileStream sw = new FileStream(baseStr+Path.GetFileName(theEntry.Name), FileMode.Create))
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{
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while (true)
{
58
int size = zs.Read(data, 0, data.Length);
59
if (size <= 0) break;
60
sw.Write(data, 0, size);
61
}
62
}
63
}
64
}
65
}
66
}
67
}
68
1
void MakeData(DateTime workDate, short brno, short currtype, decimal startAmt)
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{
3
Pub.SetNOVA(workDate);
4
string zipFileName = string.Format("e-{0:yyyyMMdd}-{1:D4}-0000{2}.zip", workDate, Pub.Zone, Pub.IsNOVAv12 ? "-2" : "");
5
string binFileName = string.Format("e-{0:yyyyMMdd}-pfsjnl.bin", workDate);
6
long size;
7
DataTable dt = MakeDataTable();
8
using (ZipInputStream zs = Zip.GetZipInputStream((new FtpClient(Pub.Ftp1Uri, Pub.Ftp1User, Pub.Ftp1Pswd)).
9
GetDownloadStream(Path.Combine(Pub.Ftp1EPath, zipFileName)), binFileName, out size))
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{
11
if (size % Pub.P_R2 != 0) throw new ApplicationException("文件长度错: " + binFileName);
12
byte [] bs = new byte[Pub.P_R2];
13
long recs = size / Pub.P_R2;
14
for (long rec = 0; rec < recs; rec++)
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{
16
Zip.ReadStream(zs, bs);
17
if (Etc.Encode.GetString(bs,Pub.P_R2_RevTran,Pub.L_Revtran) != "0") continue; // 反交易标志
18
for (int i = 0; i < 2; i++)
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{
20
bool isDebit = (i == 0);
21
if (int.Parse(Etc.Encode.GetString(bs,(isDebit?Pub.P_R2_Drcurr:Pub.P_R2_Crcurr),Pub.L_Curr)) != currtype) continue;
22
decimal amt0 = decimal.Parse(Etc.Encode.GetString(bs,(isDebit?Pub.P_R2_Amount1:Pub.P_R2_Amount2),Pub.L_Bal)) / 100;
23
if (Math.Abs(amt0) < startAmt) continue;
24
string account = Etc.Encode.GetString(bs,(isDebit?Pub.P_R2_Draccno:Pub.P_R2_Craccno),Pub.L_Accno);
25
if (!DbBranch.IsMyAccount(account, brno)) continue;
26
string customer = Etc.Encode.GetString(bs,Pub.P_R2_Notes1,Pub.L_Notes1).Trim('@', ' ');
27
short nodeno = short.Parse(Etc.Encode.GetString(bs,Pub.P_R2_Brno,Pub.L_Brno));
28
int code = int.Parse(Etc.Encode.GetString(bs,Pub.P_R2_Trxcode,Pub.L_Trxcode));
29
DataRow dr = dt.NewRow();
30
dr["No"] = nodeno;
31
dr["Name"] = DbBranch.GetBrief(DbBranch.IsAllNode(brno), nodeno);
32
dr["Teller"] = int.Parse(Etc.Encode.GetString(bs,Pub.P_R2_Teller,Pub.L_Teller));
33
dr["Account"] = IcbcEtc.FormatAccount19(account);
34
dr["User"] = customer;
35
dr["Flag"] = (isDebit ? "借" : "贷");
36
dr["Amt"] = amt0;
37
dr["Memo"] = Etc.Encode.GetString(bs,Pub.P_R2_Cashnote,Pub.L_Cashnote);
38
dr["Code"] = code;
39
dr["TrName"] = DbTrxCode.GetNewName(code);
40
dt.Rows.Add(dr);
41
}
42
}
43
}
44
DataView dv = dt.DefaultView;
45
dv.Sort = "Flag DESC, Amt DESC";
46
dgMain.DataSource = dv;
47
dgMain.DataBind();
48
}
49
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