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)); k*xMe-
} d v8q&_
for(int i=0;i<nEndPos.length-1;i++) 2'>
{ JDbRv'F:(
nEndPos = nStartPos[i+1]; P*=M?:Jb,
} fXo$1!
nEndPos[nEndPos.length-1] = nFileLength; pi?$h"y7Q
} CEQs}bz
} JU>F&g/|
'YFy6rds
+!"GYPUXy
//启动子线程 LN=6u
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *;E\,,Io
for(int i=0;i<nStartPos.length;i++) 8.`*O
{ tfz"9PV80
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mz-sazgV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _!qi`A
nStartPos,nEndPos,i); :v$][jZ2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nF"NXYa
fileSplitterFetch.start(); qcVmt1"
} ;RR\ Hwix
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $p(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); K9\r2w'T'
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >`E (K X
nEndPos = " + nFileLength); &9j*Y
// fileSplitterFetch[nPos.length-1].start(); eDkJ+5b
:{8,O-
8uh^%La8b.
//等待子线程结束 ,8Eg/
//int count = 0; fYgEiap
//是否结束while循环 rt8"U<~
boolean breakWhile = false; NuEcTww
uT#4"G9A[
y=HM]EH>
while(!bStop) %]"eN{Uvn
{ n{*A<-vL
write_nPos(); {JGXdp:SB
Utility.sleep(500); jjJvyZi~J
breakWhile = true; $j(laD#AR
7!;48\O]w
m#Y[EPF=|
for(int i=0;i<nStartPos.length;i++) BV"l;&F[
{ L9Z\|L5
if(!fileSplitterFetch.bDownOver) bJ!(co6t
{ c3aBPig\D
breakWhile = false; rbw~Ml0
break; y8.3tp
} k-jlYHsA
} &P pb2
if(breakWhile) "=Xky,k
break; '.gLqm}%
mb GL)NI
yg WwUpY
//count++; yd=NafPM
//if(count>4) VX6M4<8
// siteStop(); 'hNRIM1
} V*,6_-^l
nN'>>'@>
p3Z[-2I
System.err.println("文件下载结束！"); K3;~|U-l
} Xs Ey8V
catch(Exception e){e.printStackTrace ();} c&"OhzzJK'
} ET\>cxSp
werTwe2Q
E0t%]?1
//获得文件长度 UA3!28Y&E3
public long getFileSize() qZ<|A%WQ
{ a/Ik^:>m
int nFileLength = -1; Nm{J=`
try{ -Pp =)_O
URL url = new URL(siteInfoBean.getSSiteURL()); :"Gd;~p.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Sp-M:,H3H
httpConnection.setRequestProperty("User-Agent","NetFox"); Yu+;vjbK-
19]O;
`st^i$A
int responseCode=httpConnection.getResponseCode(); %) /Bl.{}<
if(responseCode>=400) 70F(`;
{ ? 4v"y@v
processErrorCode(responseCode); k=
return -2; //-2 represent access is error GLiD,QX<
} R<Uu(-O-
y.aeXlc[
LL%s$>c65A
String sHeader; uB;PaZG?{
lPA:ho/`:
3J}/<&wv
for(int i=1;;i++) zgPUW z X=
{ }JM02R~I
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ekPn`U
//Utility.log(in.readLine()); ,|^ lqY
sHeader=httpConnection.getHeaderFieldKey(i); H=@S+4_bK
if(sHeader!=null) y{9<>28
{ [pzo[0G 'v
if(sHeader.equals("Content-Length")) S{S.H?{F
{ 8,&pX ga
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 1$v1:6
break; 7hAc6M$h;
} A 6j>KTU
} oV;I8;#\J
else rrrn8b6
break; #@Rtb\9
} Ou5,7Ne
} C<E;f]d
catch(IOException e){e.printStackTrace ();} 55V&[>|K5
catch(Exception e){e.printStackTrace ();} +nKf ^rG
JQ<9~J
4mci@1K#^
Utility.log(nFileLength); ."h>I @MH
`{+aJ0<S
>U62vX"
return nFileLength; qlg?'l$03)
} I,7n-G_'
oLc
v"V?
//保存下载信息（文件指针位置） pKhV<MFB
private void write_nPos() 9;L50q>s
{ pP*`b<|
try{ %0lJ(hm
output = new DataOutputStream(new FileOutputStream(tmpFile)); yL"pzD`[H
output.writeInt(nStartPos.length); 9V?:!%J
for(int i=0;i<nStartPos.length;i++) ,K8(D<{
{ =P`l+k3
// output.writeLong(nPos); yr q){W
output.writeLong(fileSplitterFetch.nStartPos); +<7a$/L?4
output.writeLong(fileSplitterFetch.nEndPos); lQt* LWd[
} (R^Ca7F
output.close(); A08{]E#v>
} L=)Arj@q
catch(IOException e){e.printStackTrace ();} X0BBJ(e
catch(Exception e){e.printStackTrace ();} R zn%!d^$>
} !^IAn
x`Ik747^v
o]WG8Mo-
//读取保存的下载信息（文件指针位置） X@^"@
private void read_nPos() N6uKFQL:{
{ 4L/8Hj#g
try{ (E<QA
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /u pDbP.O
int nCount = input.readInt(); 3sz?49tX
nStartPos = new long[nCount]; &DX
nEndPos = new long[nCount]; i4\m/&of3y
for(int i=0;i<nStartPos.length;i++) [8rl{~9E
{ X.)D"+xnH
nStartPos = input.readLong(); tRmH6
nEndPos = input.readLong(); gB}UzEj^<
} V"W)u#4,
input.close(); *S\/l-D
} :'K%&e?7s
catch(IOException e){e.printStackTrace ();} $#HUxwx4
catch(Exception e){e.printStackTrace ();} Sj9NhtF]f
} M|\C@,F]8
|s{[<;
=(]||1.
private void processErrorCode(int nErrorCode) %z5P%F'5
{ PXDwTuyc
System.err.println("Error Code : " + nErrorCode); +HfZs"x
} ehr,+GX
5 $: q
5}he)2*uD
//停止文件下载 Fy-|E>@]D
public void siteStop() .J.| S4D
{ Y]9C8c)
bStop = true; 50Y^##]&
for(int i=0;i<nStartPos.length;i++) ?%wM8?
fileSplitterFetch.splitterStop(); p<AzpkU,A
Vv~:^6il
@Yzc?+x
} :yE7jXB
} }@NT#hD
//负责部分文件的抓取 5d5q0bb
**FileSplitterFetch.java ;(~H(]D
*/ W6L}T,epX
package NetFox; [y1 x`WOk9
[cvtF(,
&+-]!^2o
import java.io.*; @DK;i_i
import java.net.*; 0OPpALl
[XDr-5Dm
#`b5kqQm
public class FileSplitterFetch extends Thread { k5TPzm=y{
X7{ h/^
X)k+BJ
String sURL; //File URL zx=AT
long nStartPos; //File Snippet Start Position drEND`,@6|
long nEndPos; //File Snippet End Position Yn1CU
int nThreadID; //Thread's ID Fc.1)yh.
boolean bDownOver = false; //Downing is over :}}~ $$&
boolean bStop = false; //Stop identical ~@N0$S
FileAccessI fileAccessI = null; //File Access interface RlnJlY/
?j-;;NNf
E-XFW]I
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Ialbz\;F2%
{ )R]gJ_,c
this.sURL = sURL; m9m]q&hx
this.nStartPos = nStart; [m{uJdj\
this.nEndPos = nEnd; kKil]L
nThreadID = id; " H;iAv
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +Rb0:r>kU
} aIW W[xZ
v#o<. Ig
$H2HVJ
public void run() (&ABfm/t
{ d vTsbs/6
while(nStartPos < nEndPos && !bStop) P1Chmg
{ SVc5mS|up
Lyj0$wbH`
3f^~mTY9>]
try{ KMZEUmY1R1
URL url = new URL(sURL); Y~ ( <H e?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #Hyfjj
httpConnection.setRequestProperty("User-Agent","NetFox"); 2*9rhOK*
String sProperty = "bytes="+nStartPos+"-"; yHt `kb2
httpConnection.setRequestProperty("RANGE",sProperty); O]N 8QH
Utility.log(sProperty); ~Y /55uC
1E|~;wo\
rP7~R
InputStream input = httpConnection.getInputStream(); t_Rpeav
//logResponseHead(httpConnection); Bq)aA)gF
d:1TSJff%/
Nw=mSW^E
byte[] b = new byte[1024]; s0bWg$
int nRead; yqKERdm
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *cnxp-)ub
{ UJ8V%0
nStartPos += fileAccessI.write(b,0,nRead); oiY&O]}
//if(nThreadID == 1) E^<.;
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \4r?=5v*
} X`E3lgfqT
8!q$8]M
.<|.nK`6
Utility.log("Thread " + nThreadID + " is over!"); 9Di@r!Db
bDownOver = true; Lavm
//nPos = fileAccessI.write (b,0,nRead); Q'n]+%YN
} !mtq?LV
catch(Exception e){e.printStackTrace ();} PK7 kpC
} }xE}I<M
} =9@t6
7)y9%-}
D%=FCmL5@=
//打印回应的头信息 ,@*Srrw
public void logResponseHead(HttpURLConnection con) uY'77,G_J
{ i9%cpPrg8
for(int i=1;;i++) S0uEz;cE
{ !p#+I=
String header=con.getHeaderFieldKey(i); /"*eMe!=
if(header!=null) 07:N)y,
//responseHeaders.put(header,httpConnection.getHeaderField(header)); aur4Ky> :
Utility.log(header+" : "+con.getHeaderField(header)); V=LJ_T"z0
else si|DxDx
break; wqyrs|P
} Q+]9Glz9
} y@?t[A#v
:-Al}7
j/<z[qr
public void splitterStop() 16N+
{ WMw]W&
bStop = true; 4`Z8EV
} |-SImxV
-Bl!s^-'
*U69rbYI
} vQiKpO*
= g[Cs*
bEz1@"~ p
/* %]15=7#'y
**FileAccess.java 5/>W(,5}
*//文件访问(定位，写) 78[5@U
package NetFox; 0nbQKoF
import java.io.*; *>,CG:`D
&+Iv"9
2/]74d8
public class FileAccessI implements Serializable{ ZXR#t?D
`43X? yQ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 YLEa;MR
RandomAccessFile oSavedFile; a7Fc"s*
long nPos; 6]*~!al?
ueM[&:g&MU
e<;^P(g`E
public FileAccessI() throws IOException RXF%A5FXh
{ 2UF ,W]
this("",0); s/"?P/R
} X>`5YdT~+
6mH --!j
+"Ui@^
public FileAccessI(String sName,long nPos) throws IOException <7;AK!BH
{ +9[/> JM
oSavedFile = new RandomAccessFile(sName,"rw"); f;w7YO+$p9
this.nPos = nPos; ^*fZ
oSavedFile.seek(nPos); :GaK.W q
} iO,_0Y4
D@cv{ _M/
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public synchronized int write(byte[] b,int nStart,int nLen) ]U8VU
{ b+g(=z+
int n = -1; a9=pZ1QAG
try{ DG!H8^
oSavedFile.write(b,nStart,nLen); [z^db0PU
n = nLen; v,] &[`
} Z.]=u(=a
catch(IOException e) EGKj1_ml
{ aj71oki)
e.printStackTrace (); GWU"zWli]z
} W]t!I}yPR
cxNb!G
SX4"HadV>
return n; P})Iwk|Z
} 8<VO>WA>E
L:(>ON
E(;V.=I
} l-Q.@hG
;hsem,C h7
)TmqE<[
/* !)}3[h0
**SiteInfoBean.java Y<vsMf_U
*/ YR{%pZp
package NetFox; jv C.T]<B
.=nx5yz
![{>$Q?5
public class SiteInfoBean { ;B'5B]A3
NX?IM8\t
Y)-)owx7
private String sSiteURL; //Site's URL J9kmIMq-C
private String sFilePath; //Saved File's Path Wxi|(}
private String sFileName; //Saved File's Name sU/R$Nbr
private int nSplitter; //Count of Splited Downloading File |Mm9QF;iA
H</Mh*Fl2G
99\;jz7
public SiteInfoBean() ?ep'R&NV
{//nSplitter的缺省值为5 F>0[v|LG
//default value of nSplitter is 5 UA{tmIC\
this("","","",5); U%7| iK
} ~_z"So'|F_
nJvDkh#h1
Jf/X3\0N7
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) mv,<#<-W
{ "K"]/3`k-
sSiteURL= sURL; AV%?8-
sFilePath = sPath; cNX0.7Ls
sFileName = sName; [^cflmV
this.nSplitter = nSpiltter; d=TZaVL$$
x tJ_azt
%|3I|'%Y
} (\Iz(N["G
: *~}\M*
8+L,a_q-
public String getSSiteURL() wClX3l>y
{ M%3\]&
return sSiteURL; rl\$a2_+
} [F^qa/vJ10
:`9hgd/9
+EmT+$>J
public void setSSiteURL(String value) nj (/It
{ ~4YLPMGKl
sSiteURL = value; ^&AhWm7\
} ;Jn"^zT
^k'?e"[gTs
]<pnHh+2A
public String getSFilePath() 6a+w/IO3OU
{ ha;Xali ]
return sFilePath; fI/?2ZH
} Y\.ds%G
_e ]jz2j
`sS\8~A
public void setSFilePath(String value) uG|d7LS,%
{ Y4\BHFq
sFilePath = value; acSm+t
} _?vh#6F
"!9hcv-;
Gj~1eS
public String getSFileName() B]`!L/
{ n>)'!
return sFileName; 0g-bApxz*&
} %~V+wqu
sG/mmZHYzr
9(9+h]h+3
public void setSFileName(String value) .%.kEJh`
{ JJ50(h)U
sFileName = value; ]%{.zl!
} x2#5"/~4
BEQ$p) h
8sDbvVh1F
public int getNSplitter() r((2.,\Z
{ B@:c8}2.
return nSplitter; +0w~Skd,
} >q'xW=Y j\
j.3#rxq
+<G |Ru-
public void setNSplitter(int nCount) YF+hN\
{ h\oAW?^
nSplitter = nCount; >@NH Al
} B!`Dj,_
} 4Y):d!'b
F{:ZHCm
;XJK*QDN
/* !)jw o=l}J
**Utility.java y:U'3G-
*/ e}x}Fj</(
package NetFox; Wc}opp
E+Jh4$x{
y_^w|
public class Utility { QT1(= wK3
hSxlj7Eo^T
9uXuV$.
public Utility() C~do*rnM^
{ GM.2bA(y
Kn9O=?Xh;
T ;Ga G
} hK!Z~
HT]v S}s
//线程睡眠 <b-BJ2],k
public static void sleep(int nSecond) oYYns%r}{
{ A)5-w`1
try{ - nWs@\
Thread.sleep(nSecond); [x{S ,?6
} U=?hT&w\S
catch(Exception e) [C GFzxz$
{ /UJ@e
e.printStackTrace (); omxBd#;F$
} pNOVyyo>BW
} Mo+mO&B
S(7_\8h
//日志 ?e? mg
public static void log(String sMsg) &*G+-cF
{ Km~\^(a '
System.err.println(sMsg); !J34yro+s
} V:M$-6jv
O"otzla
oo{5:
public static void log(int sMsg) F^5<o
{ ZE#f{qF(
System.err.println(sMsg); btq`[gAF\
} xy@1E;
} 'xNPy =#
eqt+EiH
DRldRm/
/* O[p;IG`
**TestMethod.java KRS_6G],{
*/ zj!&12w%3
package NetFox; Ua.7_Em
> ,L'A;c}
FzOr#(^
public class TestMethod { ,2F4S5F~rC
1vcI`8%S+u
\`w!v,aM$
public TestMethod() s52c`+
{ ///xx/weblogic60b2_win.exe %IS'R`;3
try{ p100dJvq
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); oE+s8Q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); h&7]Bp
SiteFileFetch fileFetch = new SiteFileFetch(bean); a8T<f/qW k
fileFetch.start(); \Vis
} >3H/~ Y
catch(Exception e){e.printStackTrace ();} =d/\8\4
!GkwbHr+p
r`]&{0}23
} I)~&6@Jn
e&dE>m
|H67ny&K^&
public static void main(String[] args) t<O5_}R%d
{ 8?S32Gdu
new TestMethod(); ^'S0A=1
} +w Oa
} @Taj++ua
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