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)); Ts=TaRwWf
} \qG` ts
for(int i=0;i<nEndPos.length-1;i++) CA$|3m9)NM
{ X6r<#n|l
nEndPos = nStartPos[i+1]; zY4y]k8D*
} Fy6Lz.baB
nEndPos[nEndPos.length-1] = nFileLength; ?g*.7Wc
} L0%W;m
} <{Rz1CMc
'XYjo&w
=6fJUy^M\
//启动子线程 l u{6
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; M4d4b
for(int i=0;i<nStartPos.length;i++) :V)=/mR
{ ):L0{W{
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (J(SwL|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), YXU2UIY<~
nStartPos,nEndPos,i); ]yFO~4Nu
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ] J|#WtS
fileSplitterFetch.start(); !\Xrl) $j{
} $c+:dO|Fb
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wwa)VgoS[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); tjne[p
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ojIGfQV
nEndPos = " + nFileLength); )g U#[}6H
// fileSplitterFetch[nPos.length-1].start(); g+4x
uXG$YDKqC
sbhUW>%.
//等待子线程结束 C,<FV+r=^
//int count = 0; oHu7<r
//是否结束while循环 S\k(0Sv9D
boolean breakWhile = false; _.W;hf`
h}oV)z6
%;GRR (K
while(!bStop) #Qu|9Q[QH
{ +ul.P)1J6
write_nPos(); T{'oR .g,
Utility.sleep(500); G{a_\'7
breakWhile = true; es$<Vkbp
|Ur$H!oe?'
]<_v;Q<t
for(int i=0;i<nStartPos.length;i++) s|:j~>53
{ bWZzb&
if(!fileSplitterFetch.bDownOver) eQ=6< ^KZ
{ 9A\\2Zz6F
breakWhile = false; AC?a:{./
break; !]z4'*)W
} O&dh<
} W#x~x|(c
if(breakWhile) [F,s=,S'M
break; 0v3 8LBH)
v/Xz.?a\jF
j4(f1
//count++; G98fBw
//if(count>4) IfCa6g<&(
// siteStop(); 0A75)T=lQ
} Bthp_cSmLs
?y[i6yN9
4(8BWP~.y2
System.err.println("文件下载结束！"); O<?.iF%
} 7VfPS5se
catch(Exception e){e.printStackTrace ();} U\"FYTC
} v dU)
jhka;m
FaG&U
//获得文件长度 srS5-fs
public long getFileSize() ,esUls'nz'
{ [O3)s]|
int nFileLength = -1; 9*[!ux7h
try{ |7miT!y8
URL url = new URL(siteInfoBean.getSSiteURL()); 4tp}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )u=a+T
httpConnection.setRequestProperty("User-Agent","NetFox"); /jn0Xh
[Lid%2O3ZR
19\ V@d^
int responseCode=httpConnection.getResponseCode(); i6:O9Km
if(responseCode>=400) 7{OD/*|
{ a#/~rNRY
processErrorCode(responseCode); 6lQP+! EF
return -2; //-2 represent access is error RJD(c#r$
} ooN?x31
>#5jO9
m*>gG{3;
String sHeader; }FkF1?C
:-T[)Q+-3
+,4u1`c|$
for(int i=1;;i++) ^ `[T0X
{ QM=Y}
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); '#612iZo
//Utility.log(in.readLine()); A+"'8%o9}
sHeader=httpConnection.getHeaderFieldKey(i); Es1T{<G|w
if(sHeader!=null) *HQ>tvUh
{ zi+NQOhR
if(sHeader.equals("Content-Length")) "Q1oSpF
{ W`jKe-jF
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); lnrs4s Km
break; =n_>7@9l
} &^F'ME
} -EWC3,3
else 4FJA+
break; SA,+oq(
} ded:yho
} )p 8P\Rl
catch(IOException e){e.printStackTrace ();} ]l=iKl
catch(Exception e){e.printStackTrace ();} aydf# [F
*#o2b-[V
])Z p|?Y
Utility.log(nFileLength); W!b'nRkq
,+'VQa"]
-^$IjK-N
return nFileLength; < _<?p&
} \|R\pS}4
k6|/ik9C
7,R ~2ss5z
//保存下载信息（文件指针位置） PED5>90
private void write_nPos() /9 |BAQ:v;
{ s[u*~A
try{ U%aDkC+M
output = new DataOutputStream(new FileOutputStream(tmpFile)); pT<I!,~
output.writeInt(nStartPos.length); -)!;45
for(int i=0;i<nStartPos.length;i++) 3\a VZx!
{ eY'RDQa
// output.writeLong(nPos); 'F^"+Xi
output.writeLong(fileSplitterFetch.nStartPos); #UqE%g`J
output.writeLong(fileSplitterFetch.nEndPos); 2;ac&j1
} &MJ`rj[%
output.close(); J!5&Nc
} #} `pj}tQ
catch(IOException e){e.printStackTrace ();} cwI3ANV
catch(Exception e){e.printStackTrace ();} S1_):JvV
} tx}=c5
3q0S}<h al
#i-b|J+%
//读取保存的下载信息（文件指针位置） U{8x.CJ]
private void read_nPos() 9&OhCrxW-
{ n@//d.T
try{ NxN~"bfh
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); qE{L42
int nCount = input.readInt(); )bK3%>H#
nStartPos = new long[nCount]; Y?JB%%WWI
nEndPos = new long[nCount]; C&RZdh,$
for(int i=0;i<nStartPos.length;i++) %[k"A
{ OBnvY2)Ri
nStartPos = input.readLong(); Qsr+f~"W
nEndPos = input.readLong(); (bGk=q=M
} NnO%D^P]
input.close(); u~1 ,88&U
} .N Z
catch(IOException e){e.printStackTrace ();} eZmwF@
catch(Exception e){e.printStackTrace ();} kwrM3nq
} }n?D#Pk,
]oyWJ#8
>$;,1N $bd
private void processErrorCode(int nErrorCode) opon"{
{ 3Hhu]5
System.err.println("Error Code : " + nErrorCode); #++D|oE
} X="]q|Z
+pbP;zu
c=4z+_K
//停止文件下载 B8?j"AF
public void siteStop() Vu Ey`c
{ 1cd3m
bStop = true; ~R~MC(5N[
for(int i=0;i<nStartPos.length;i++) Gn 1
fileSplitterFetch.splitterStop(); #e&LyYx4
snyA
7O'u5N
} 9K=K,6 b
} /Ca M(^W
//负责部分文件的抓取 #[sJKW
**FileSplitterFetch.java ,?VYrL
*/ 8k?V&J `
package NetFox; LBnlaH.
fY 10a_@x
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import java.io.*; zTfl#%
import java.net.*; DfVSG1g
4\14HcTcK
sxPvi0>
public class FileSplitterFetch extends Thread { IgKrcpK#}?
<P-AlHYV-
a#+;BH1
String sURL; //File URL #[y2nK3zF
long nStartPos; //File Snippet Start Position |5\: E}1
long nEndPos; //File Snippet End Position 8j8~?=$a6Q
int nThreadID; //Thread's ID Kj#h9e
boolean bDownOver = false; //Downing is over MO *7:hI
boolean bStop = false; //Stop identical NX?6 (lO,
FileAccessI fileAccessI = null; //File Access interface dXDuO
Q VWVZ >l
-z>m]YDH
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException SHqz&2u
{ N`7+]T
this.sURL = sURL; /n3SE0Y
this.nStartPos = nStart; P7;q^jlB
this.nEndPos = nEnd; "QM2YJ55m`
nThreadID = id; )H%RwV#
fileAccessI = new FileAccessI(sName,nStartPos);//定位 be>KG ZU0
} vw/GAljflu
pm:#@sl
+"PME1
public void run() VoNk.h"T
{ K9S(Xip
while(nStartPos < nEndPos && !bStop) XknbcA|
{ |i- S}M
1N+ju"2R
gX/?
try{ py9`q7F
URL url = new URL(sURL); 9zaSA,}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7lG,.W|
httpConnection.setRequestProperty("User-Agent","NetFox"); z<8WN[fB
String sProperty = "bytes="+nStartPos+"-"; 6V-JyTcxGI
httpConnection.setRequestProperty("RANGE",sProperty); ;:P}s4p
Utility.log(sProperty); 3+V.9TL'a
UZu.B!4
u\=yY.
InputStream input = httpConnection.getInputStream(); &&te(DC\
//logResponseHead(httpConnection); Bx0=D:j
8!7`F.BX
x^y&<tA
byte[] b = new byte[1024]; __ G=xf
int nRead; cd)}a_9
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) sb</-']a
{ *TYOsD**9
nStartPos += fileAccessI.write(b,0,nRead); ]u"x=S93
//if(nThreadID == 1) =${ImMwj
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &e5,\TQ
} MG74,D.f
I3dUI~}u
kTo{W]9]
Utility.log("Thread " + nThreadID + " is over!"); fs*OR2YG7
bDownOver = true; $H1igYc
//nPos = fileAccessI.write (b,0,nRead); "Fqrk>Q~
} G_6!w//
catch(Exception e){e.printStackTrace ();} #=I5_u
} H2E'i\
} -<^3!C >
kl#)0yqN0
oNRp
//打印回应的头信息 p+Icq!aH5
public void logResponseHead(HttpURLConnection con) iL3k8:x
{ T0K*!j}O
for(int i=1;;i++) p.!p6ve){
{ ivPX_#QI
String header=con.getHeaderFieldKey(i); _6C,w`[[6
if(header!=null) 4m6%HV8{}[
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ' y_2"
Utility.log(header+" : "+con.getHeaderField(header)); =v~$&@
else @<44wMp
break; Z^GXKOeq
} h($Jo
} DO ,7vMO
tDNo; f
(0zYS_mA
public void splitterStop() l#|M.V6G
{ &F|Wk,y
bStop = true; qQCds}<w
} tMr$N[@r
2G}@s.iE
?,FL"ye
} }Z% j=c"d
LgA>,.
AI3\eH+
/* nLBi}T
**FileAccess.java !9EbG
*//文件访问(定位，写) QykHB k
package NetFox; pcPRkYT[M
import java.io.*; Is}?:ET
RH&}'4JE:
o.>Yj)U
public class FileAccessI implements Serializable{ Rlx
KL8WT6!RZ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 qnf\K}
RandomAccessFile oSavedFile; bs_rw+
long nPos; _H$Z}2g<z
~D!Y] SK
8iN@n8O
public FileAccessI() throws IOException Hv|(V3-
{ {fu[&@XV
this("",0); ufS0UD8%H
} hPrE
n16TQe"8
*ZF:LOnU
public FileAccessI(String sName,long nPos) throws IOException s:Z1 ZAxv
{ gOm%?sg
oSavedFile = new RandomAccessFile(sName,"rw"); 3H,>[&d
this.nPos = nPos; n|!O .+\b
oSavedFile.seek(nPos); No(S#,vJ;
} 5 OF*PBZ
q??N,
Ox+}JB [
public synchronized int write(byte[] b,int nStart,int nLen) ( ALsc@K
{ d$v{oC}
int n = -1; 8:}$L)[V
try{ 3vF-SgCV
oSavedFile.write(b,nStart,nLen); " {Nw K
n = nLen; S{qn^\0
} L'}^Av_+
catch(IOException e) Oa-~}hN
{ I}1<epd ,
e.printStackTrace (); t[x[X4
} 4mF=A$Q_/
8!Q0:4Vb
QlWkK.<Z3_
return n; ?+y# t?
} pt8#cU\
7'TXR[
g<N3 L[
} $ iU~p
;q" ,Bs
> V%3w7
/* vX"jL
**SiteInfoBean.java gj1l9>f>]a
*/ aKkY)
package NetFox; YX19QG%
He)dm5#fg
UQ)7uYQ5
public class SiteInfoBean { ;X[23A{
p|R]/C0f
Rj{D#5
private String sSiteURL; //Site's URL QD*(wj
private String sFilePath; //Saved File's Path -vBk,;^>
private String sFileName; //Saved File's Name ({p@Ay
private int nSplitter; //Count of Splited Downloading File Op:7EdT#
ED R*1!d
d)jX%Z$LC
public SiteInfoBean() o$bD?Zn
{//nSplitter的缺省值为5 dG'5: ,n/
//default value of nSplitter is 5 C$fQ[@
this("","","",5); j=TG&#e
} K6z-brvw"
K9f7,/
1F }mlyS
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) E9n7P'8
{ %#b+ =J
sSiteURL= sURL; ^tFgkzXm
sFilePath = sPath; `PvGfmYOl
sFileName = sName; T1pMe{
this.nSplitter = nSpiltter; vxx7aPjC
'C|yUsBC
a+{95"4
} K>fY9`Whm
gSu3\keF
IDr$Vu4LCW
public String getSSiteURL() E[E[Za^Y
{ RVb}R<yU+
return sSiteURL; Z )dz
} ZVmgQ7m
OQZ\/~o 5
EL-1o02-
public void setSSiteURL(String value) IEJp!P,E
{ 7U{g'<
sSiteURL = value; [!E~pW%|n
} ;yK:.Vg
Z]Iyj 97
Gn%gSH/
public String getSFilePath() [sH[bmLR
{ JK9}Kb};
return sFilePath; {BKr/) H
} H&zhYKw
SvR? nN|
4`+hX'
public void setSFilePath(String value) Oy/+uw^
{ {,rVA(I@
sFilePath = value; Zf%6U[{ T
} ;qT7BUh(%
^atBf![
27Ve$Q8]v
public String getSFileName() v J.sa&\H
{ sd~T
return sFileName; =!%+ sem
} I7nZ9n|KU
Pkw` o #
U4@W{P02
public void setSFileName(String value) 'F@#.Op`
{ /^z5;aG
sFileName = value; wFJ?u?b0Q
} lfp'D+#p{
.2 /$ !'E
!xxu~j^T
public int getNSplitter() v/yt C/WH"
{ R83Me#&
return nSplitter; p4OiCAW;
} =a.avOZ
q"[8u ]j
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public void setNSplitter(int nCount) 2!35Tj"RFE
{ $xf{m9 8
nSplitter = nCount; ,@Izx
} 6M`N| %
} Q+\?gU]
D,rs)
&LS&O
/* C%csQ m
**Utility.java -a[]#v9
*/ v*7lJNN.
package NetFox; ?Q)z5i'g#
eY1$smh t
HwH Wi
public class Utility { 5/O;&[lYy
?X.MKNbp
bvMa|;f1
public Utility() 3:h9cO/9
{ -B-nTS`
cR1dGNcp/@
yw%5W=<
} f:h.O# d>
tzhkdG
//线程睡眠 TKsze]/q
public static void sleep(int nSecond) Uaho.(_GP
{ ='0f#>0Q
try{ #~r+
Thread.sleep(nSecond); jyt#C7mj-A
} )k8=< =s
catch(Exception e) lnFOD+y9
{ ~\%MJ3
e.printStackTrace (); #w4=kWJ[
} q1Si*?2W
} s}d1 k
S3=M k~_&
//日志 .f V-puE
public static void log(String sMsg) I"]5B
{ b&;1b<BwD
System.err.println(sMsg); XK (y ?Y1
} l0 H,TT~2
3 G?^/nB
pH%cbBm
public static void log(int sMsg) Ab<4F7
{ -k p~pe*T
System.err.println(sMsg); ,))UQ7N
} [UVxtMJ
} $C UmRi{T
,Z;z}{.hq
nz|;6?LCLY
/* '|b {
**TestMethod.java q9RCXo>Y+1
*/ d]OoJK9&&
package NetFox; bc"E=z
}TZ5/zn.Dw
B8^tIq
public class TestMethod { 3:i4DBp,i
bUC-}
fn zj@_{|
public TestMethod() @xJ qG"
{ ///xx/weblogic60b2_win.exe j w)Lofn
try{ ~a[]4\m;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); oQC*d}_E}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); R$&|*0
SiteFileFetch fileFetch = new SiteFileFetch(bean); {R7>-Y[4)2
fileFetch.start(); nu] k<^I5|
} ={?}[E
catch(Exception e){e.printStackTrace ();} O/wl";-
{_1^ GIIS
Z1FO.[FV
} zi23k=
M#JOX/
SzR0Mu3uK
public static void main(String[] args) [IVT0 i
{ w|x=^
new TestMethod(); H(ht{.sjI
} )EYsqj
} %Yg;s'F>#q
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