http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); R9o3T)9V
} #EiOC.A=
for(int i=0;i<nEndPos.length-1;i++) [Y_6PR
{ A.<HOx&#
nEndPos = nStartPos[i+1]; 4oT1<n`r+
} Yxye?R-:
nEndPos[nEndPos.length-1] = nFileLength; <o^_il$W
} C`c;I7
} r>1M&Y=<
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$\l7aA5~
//启动子线程 -o<L%Y<n2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9^Q:l0|
for(int i=0;i<nStartPos.length;i++) >s}bq#x
{ a;J{'PHu
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F gM<2$h
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _D:#M
nStartPos,nEndPos,i); Z-`j)3Y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); JnCp'`
fileSplitterFetch.start(); 0[@9f1Nk4
} c#M'Mye
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $:kG>R@\t
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \TSt
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", eOa:%{Kj
nEndPos = " + nFileLength); :B?XNo
// fileSplitterFetch[nPos.length-1].start(); U`_(Lq%5W
,.tv#j|A
F23/|q{{
//等待子线程结束 ooY2"\o
//int count = 0; TQDb\d8,f
//是否结束while循环 %-!ruc"}
boolean breakWhile = false; 2mAXBqdm
8munw
AK\X{>$a!
while(!bStop) jZu">Eh,
{ |><hdBQXX<
write_nPos(); = R|?LOEK+
Utility.sleep(500); )=TD}Xb
breakWhile = true; (.a:jL$
xg~q'>
^~Nz8PCY
for(int i=0;i<nStartPos.length;i++) Z,/BPK<e
{ u1a5Vtel
if(!fileSplitterFetch.bDownOver) rMIr&T
{ n.]K"$230
breakWhile = false; 2'_xg~
break; 57e'a&}e
} uj|{TV>v9
} 8`Fo^c=j
if(breakWhile) WJBi#(SY
break; .a\b_[+W
WmTSxneo
rD)yEuYX
//count++; 8MgoAX,p
//if(count>4) )tGeQXVhbJ
// siteStop(); U2z1HIs
} !0:uM)_k
rmmN2+H
zRPXmu{t
System.err.println("文件下载结束！"); vwDnz/-
} ?1JVzZ4H
catch(Exception e){e.printStackTrace ();} =vLeOX
} \tTZN
BuMBnbT
tbD>A6&VM}
//获得文件长度 /gh=+;{
public long getFileSize() &gxRw l
{ `9rwu:3i
int nFileLength = -1; @Ong+^m|PC
try{ 5qtZ`1Hq
URL url = new URL(siteInfoBean.getSSiteURL()); Q{6Bhx *>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ss'#sPX
httpConnection.setRequestProperty("User-Agent","NetFox"); :U!knb"/>
Ijq1ns_tx8
UR6.zE4=_
int responseCode=httpConnection.getResponseCode(); ,<n >g;
if(responseCode>=400) xlG/$`Ab
{ YIo$
processErrorCode(responseCode); z/u;afB9q
return -2; //-2 represent access is error {Y-<#U~iH
} "1>I/CM
!a?$
]kA0C~4
String sHeader; &1Dq3%$c
@ qWgokf
=jIB5".
for(int i=1;;i++) T X.YTU
{ [YG\a5QK
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); @ SaU2
//Utility.log(in.readLine()); ]2\|<.
sHeader=httpConnection.getHeaderFieldKey(i); L A-H
if(sHeader!=null) j#d=V@=a
{ {_QXx
if(sHeader.equals("Content-Length")) tZmo= 3+:
{ <a7y]Py
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \xG>>A%
break; 8 hx4N
} @Z> {/
} ]TQ2PVN2
else R=P=?U.
break; Y`jvza%
} :xISS
} (#GOXz
catch(IOException e){e.printStackTrace ();} 7K3S\oPej
catch(Exception e){e.printStackTrace ();} -b+VzVJZ
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x!GHUz*:uz
Utility.log(nFileLength); X@KF}x's
"Mzb
h<2o5c|
return nFileLength; x`K<z J
} ?t++IEoP
8o43J;mA
eS(\E0%QI
//保存下载信息（文件指针位置） h^R EBPe
private void write_nPos() JVbR5"+.
{ I$!rNfrs
try{ zhtNL_
output = new DataOutputStream(new FileOutputStream(tmpFile)); a;JB8
output.writeInt(nStartPos.length); cM%I5F+n
for(int i=0;i<nStartPos.length;i++) }&A!h
{ :N$^x /{
// output.writeLong(nPos); DXu915
output.writeLong(fileSplitterFetch.nStartPos); FrBoE#
output.writeLong(fileSplitterFetch.nEndPos); |PR8P!'
} l"^'uGB'
output.close(); GlkTpX^b
} NrH2U Jm
catch(IOException e){e.printStackTrace ();} ^=:e9i3u
catch(Exception e){e.printStackTrace ();} _u TaN
} -t~l!!N(
(os}s8cIh
+{U0PI82
//读取保存的下载信息（文件指针位置） d-Vttxa6
private void read_nPos() c,nE@~ul2
{ I3`WY-uv
try{ 5%,5Xe4p
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Hhx"47:
int nCount = input.readInt(); 3V~871:-~
nStartPos = new long[nCount]; dbM~41C6
nEndPos = new long[nCount]; ssaEAm:
for(int i=0;i<nStartPos.length;i++) \6o%gpUkD
{ pw|f4c7AH
nStartPos = input.readLong(); =@(&xfTC
nEndPos = input.readLong(); J%ng8v5ex
} kt?G\H!}
input.close(); y%%D="
} aphfzo
catch(IOException e){e.printStackTrace ();} )D'SfNx#{
catch(Exception e){e.printStackTrace ();} eV:I :::
} MH@=Qqx#=t
<,!8xp7,~
y#F`yXUj
private void processErrorCode(int nErrorCode) GaV6h|6_
{ iAD'MB
System.err.println("Error Code : " + nErrorCode); 6.%M:j00E
} UhKC:<%
xgoG>~F
Qj;wklq
//停止文件下载 iUDNm|e
public void siteStop() U-~cVk+LI
{ 52Sq;X
bStop = true; N$>.V7H&
for(int i=0;i<nStartPos.length;i++) $yxwB/O(
fileSplitterFetch.splitterStop(); 3 RB+
.j"iJ/
]}7FTMGbY
} ipzv]c&
} 8~*<s5H
//负责部分文件的抓取 x!5b" "
**FileSplitterFetch.java ; kPx@C
*/ 8@;|x2=y
package NetFox; k1Z"Qmz
sa8JN.B
+tOmKY
import java.io.*; eS(hLXE!7
import java.net.*; <12ia"}
ToMvP B);
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public class FileSplitterFetch extends Thread { g7\MFertR^
|v,%!ps
{"{kWbXZ
String sURL; //File URL matW>D;J
long nStartPos; //File Snippet Start Position t&scvXh
long nEndPos; //File Snippet End Position Fg` P@hC
int nThreadID; //Thread's ID [+,%T;d;
boolean bDownOver = false; //Downing is over : :;YS9e
boolean bStop = false; //Stop identical aumWU{j=
FileAccessI fileAccessI = null; //File Access interface ~N "rr.w
\S#Mc
K"Vo'9R[_
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException !O|d,)$q
{ bloe|o!
this.sURL = sURL; 2gP^+.
this.nStartPos = nStart; Dp1FX"a)
this.nEndPos = nEnd; VpmwN`
nThreadID = id; ivTx6-]
fileAccessI = new FileAccessI(sName,nStartPos);//定位 wJ.?u]f@
} 6.#5Ra
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I*h%e,yIO
public void run() : jgvg$fd
{ n^}M*#
while(nStartPos < nEndPos && !bStop) a'zXLlXgGd
{ 2rxZN\gyL
T''PzY!Qf
wXUP%i]i=
try{ ng,64(wOY
URL url = new URL(sURL); =Sjr*)<@j
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 87&BF)]
httpConnection.setRequestProperty("User-Agent","NetFox"); + t%[$"$
String sProperty = "bytes="+nStartPos+"-"; @34Z/%A
httpConnection.setRequestProperty("RANGE",sProperty); !+bLhW`
Utility.log(sProperty); m.:2G
h\qQ%|X
Cu2eMUGt
InputStream input = httpConnection.getInputStream(); Y9}5&#
//logResponseHead(httpConnection); ~vL7$-:
1=U(ZX+u
5a8[0&hA 2
byte[] b = new byte[1024]; IZ9L ;"}
int nRead; CdBsd
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) s,z$Vt"h*K
{ ^)i5.o\
nStartPos += fileAccessI.write(b,0,nRead); :eHD{=
//if(nThreadID == 1) A(Tqf.,G
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4c})LAwd&
} *:r6E
?WVp,vP
LUPh!)8
Utility.log("Thread " + nThreadID + " is over!"); _aJo7
bDownOver = true; QmHj=s:x\
//nPos = fileAccessI.write (b,0,nRead); vw.rkAGY
} yM_ta '^$
catch(Exception e){e.printStackTrace ();} F+!w[}0
} U3UKu/Z
} K[,d9j`^
_1>Xk_
adCTo
//打印回应的头信息 "c+j2f'f
public void logResponseHead(HttpURLConnection con) jRn5)u
{ ~ShoU m[
for(int i=1;;i++) N*^iOm]Y
{ ?$chO|QY
String header=con.getHeaderFieldKey(i); MC'2;,
if(header!=null) ejFGeR
//responseHeaders.put(header,httpConnection.getHeaderField(header)); {pWb*~!k
Utility.log(header+" : "+con.getHeaderField(header)); E \p Qh
else Xl/SDm_p
break; rofGD9f
} ~8oti4
} 8D H~~by
Sa8KCWgWh
U{`Q_Uw@$:
public void splitterStop() 6np
{ rT#2'-f
bStop = true; L- '{
} k vuSE
pqT+lai)#
]3KMFV}
} ce&Q}_
xr*%:TwCta
CjQ)Bu*4
/* YK{E=<:
**FileAccess.java l-v(~u7
*//文件访问(定位，写) (GCeD-
package NetFox; e>zv+9'Q
import java.io.*; eb` !
Z&Qz"V>$
Tr6J+hS
public class FileAccessI implements Serializable{ $~;h}I
-J6G=+s/
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 RV=Z$
RandomAccessFile oSavedFile; uY_vX\;67z
long nPos; V7gv@<1<y
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w;OvZo|
public FileAccessI() throws IOException yIq. m=
{ %"jp':
this("",0); [X&VxTxr
} I$y6N"|
w7d<Ky_C
o9XT_!Cwg
public FileAccessI(String sName,long nPos) throws IOException ! ^ DQX=1
{ id?B<OM
oSavedFile = new RandomAccessFile(sName,"rw"); h>a/3a$g
this.nPos = nPos; W'xJh0o
oSavedFile.seek(nPos); #Fwf]{J
} *.,G;EC^
1;E^3j$
c e\|eN[
public synchronized int write(byte[] b,int nStart,int nLen) llE_-M2gH
{ P}re"<MD
int n = -1; L|`(u
try{ E9bc pup
oSavedFile.write(b,nStart,nLen); v<AFcY
n = nLen; AE@N:a
} `zP{E T_Y
catch(IOException e) }\?]uNH
{ ?= RC?K
e.printStackTrace (); 2mt S\bAF
} {/2 _"H3:
+ FG Xx
K;'s+ZD
return n; *dpKo&y
} xm*6I
#*tWhXU
{aoG60N
} 1 k\~%
uLq%Nu
S2\|bs7;J,
/* &_o.:SL|
**SiteInfoBean.java tj1M1s|a
*/ Nu[0X
package NetFox; &a9Y4~e::
3*C|"|lJ
5faY{;8
public class SiteInfoBean { v*lj>)L
Z1Pdnc7S[
*p.70,5,
private String sSiteURL; //Site's URL JW2~ G!@
private String sFilePath; //Saved File's Path ]w5j?h"b
private String sFileName; //Saved File's Name 17ol %3 M
private int nSplitter; //Count of Splited Downloading File HxnWM\p
sMDHg
rk)h_zN
public SiteInfoBean() -VafN
{//nSplitter的缺省值为5 \(4kEB2s$
//default value of nSplitter is 5 ;56mkP
this("","","",5); "~,3gNTzV
} %SC%#_7
1$RUhxT
:YUQKy
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) GS qt:<Qs
{ V+>.Gf
sSiteURL= sURL; B4RP~^
sFilePath = sPath; /DxeG'O
sFileName = sName; ;a9`z+ K
this.nSplitter = nSpiltter; ;NPbEPL[5
]1dnp]r
@#1T-*
} =2&Sw(6j
Z~Vups#+f
8-geBlCE,
public String getSSiteURL() \wb0%> 0
{ /s[D[:P_
return sSiteURL; 1MYA/l$
} TO]7%aB
zi?G wh~
F- l!i/
public void setSSiteURL(String value) =g^k$ Rc
{ \Pt_5.bTs[
sSiteURL = value; $/|2d4O:{
} >`)IdX
PlC8&$
p;P cD
public String getSFilePath() BW{&A&j
{ Q$:>yveR*
return sFilePath; lEr_4!h$rZ
} hMQh?sF/
b75en{aDi*
D"ecwx{%;C
public void setSFilePath(String value) Br}0dha3E
{ u8N"i),
sFilePath = value; Xd@_:ds
} "LkI'>3}
*$*V#,V-
b3^d!#KVM
public String getSFileName() )D8V;g(7F
{ <wj}y0(
return sFileName; 2&KM&NX~
} 2E_d$nsJ
~`!{5:v
F&)(G\
public void setSFileName(String value) ~7O.}RP0
{ jImw_Q
sFileName = value; N}X7g0>hV
} %WO4uOi:@
pUm|e5
]]!&>tOlI
public int getNSplitter() 1Farix1YDq
{ "H3DmsB
return nSplitter; y%@C-:
} 'E_~>
p)YI8nW
.u^4vVz
public void setNSplitter(int nCount) "iPX>{'En
{ Xb\de_8!
nSplitter = nCount; [l:}#5\]4
} ;(0|2I'"
} du_TiI
&A)u!l Ue
)Bpvi4O
/* ?8TIPz J
**Utility.java BU=;rz!;
*/ ZO\x|E!b
package NetFox; ~ "stI
;T\'|[bY
Vohd d_x
public class Utility { xt=ELzu$
k^e;V`(
lL6W:Fq@(
public Utility() Y9ipy_@_?
{ bO6LBSZx]
i=aK ?^+
xk@fBa }
} W*.6'u)9
s%Irh;Bs
//线程睡眠 344E4F"ph
public static void sleep(int nSecond) Fz1K*xx'
{ 0.!!rq,
try{ \ ix&U
Thread.sleep(nSecond); #J|DW C!#d
} !rPU5y*
catch(Exception e) ~=i<O&nai
{ jPA^SxM
e.printStackTrace (); U^Ulj/%6
} `2PvE4]%p
} aZB$%#'vR
o@W:PmKW
//日志 ^rssZQKY[
public static void log(String sMsg) ,!Q^"aOT:
{ j@C*kj;-
System.err.println(sMsg); b5t:">wC
} ?CO..l
D'Y=}I)8Dn
xG~7kj3
public static void log(int sMsg) Rr"D)|Y;C(
{ *z6m644H
System.err.println(sMsg); 1vUW$)?X
} 0.lOSAq
} PsCr[\Ul
AroYDR,3+
iZn<j'u
/* *e%(J$t
**TestMethod.java Gf\u%S!%
*/ 8}>s{u;W
package NetFox; 6 TSC7jO
1/<Z6 ?U
6hAMk<kx?i
public class TestMethod { &T2qi'
1ILAUtf)
ix!4s613w
public TestMethod() Z[G:
{ ///xx/weblogic60b2_win.exe +xn59V
try{ >NjgLJh
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 3w$Ib}7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5KRI}f
SiteFileFetch fileFetch = new SiteFileFetch(bean); H`EsFKw\%
fileFetch.start(); $Fik]TbQp
} ,Uu#41ZOKL
catch(Exception e){e.printStackTrace ();} 6):iu=/i/
q~G@S2=}0}
1rGi"kdf
} %IHra6
1,Ji|&Pwf
.j^=]3
public static void main(String[] args) m 7/b.B}
{ ^;mnP=`l[
new TestMethod(); 1qd(3A41
} xY$@^(Q\
} Zt"3g6S
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