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)); g)~"-uQQ
} K@@[N17/8
for(int i=0;i<nEndPos.length-1;i++) fnO>v/&B
{ 1lQO`CmR6M
nEndPos = nStartPos[i+1]; \ssqIRk
} w97%5[-T
nEndPos[nEndPos.length-1] = nFileLength; 2~*.X^dR
} S_56!
} _0e;&2')
_ye74$#
NXDuO_#
//启动子线程 zH+a*R
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; CrI:TB>/"
for(int i=0;i<nStartPos.length;i++) },G5!3
{ gflu!C6
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), LYyOcb[x
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &,~Oi(SX5
nStartPos,nEndPos,i); aRF}FE,u
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]eZrb%B.
fileSplitterFetch.start(); R<x~KJ11c
} pbePxOG
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4XXuj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); loFApBD=$^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", sDnXgCcS!
nEndPos = " + nFileLength); a@V`EEZ
// fileSplitterFetch[nPos.length-1].start(); "_T8Km008
Ves x$!F#
jpek=4E
//等待子线程结束 KI{B<S3*Z
//int count = 0; h#rziZ(
//是否结束while循环 6Z3L=j
boolean breakWhile = false; u3ns-e
$UGX vCR
a$ FO5%o
while(!bStop) K_sHZ
{ V t@]
write_nPos(); yd4\%%]
Utility.sleep(500); m<uBRI*I
breakWhile = true; "WE*ED
tjTnFP/=
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for(int i=0;i<nStartPos.length;i++) Dm0Ts~
{ +:?"P<'
if(!fileSplitterFetch.bDownOver) wXnluE
{ )4BLm
breakWhile = false; -3On^Wj]
break; Zf~Z&"C)
} Q9h;`G 7t
} E2~&GkU.UN
if(breakWhile) (W4H?u@X0
break; >")<pUQ
Q,m1mIf
U^.kp#x#
//count++; 6<h ==I
//if(count>4) n6]8W^g
// siteStop(); %RS8zN
} =7212('F
oF0BBs$
QlCs,bT
System.err.println("文件下载结束！"); .>Fy ]Cqoh
} r0fxEYze&
catch(Exception e){e.printStackTrace ();} yO`HL'SMo
} B LI 9(@
6_wj,7
[uD G;We=
//获得文件长度 ,`O.0e4pn
public long getFileSize() L|H:&|F
{ $)6%LG_@
int nFileLength = -1; Hlj_oDL
try{ ydm2'aV
URL url = new URL(siteInfoBean.getSSiteURL()); U+FI^Xrt#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); kMP3PS
httpConnection.setRequestProperty("User-Agent","NetFox"); Mo~zq.
$"[5]{'J
_^ny(zy(
int responseCode=httpConnection.getResponseCode(); $zUHka
if(responseCode>=400) Yg kd1uI.
{ l" P3lKS
processErrorCode(responseCode); oDBv5
return -2; //-2 represent access is error +zf[Im%E
} 7U,[Ruu
\]=''C=J
M\rZr3
String sHeader; kt;uB X3
]5Mq^@mD'
F2:nL`]b[
for(int i=1;;i++) ZtLZW/`
{ K*[`s'Ip-
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $WS?/H0C
//Utility.log(in.readLine()); P")1_!
sHeader=httpConnection.getHeaderFieldKey(i); |.EC>D/
if(sHeader!=null) &kp`1kv":
{ ]oIP;J:&
if(sHeader.equals("Content-Length")) _(%;O:i
{ QxI^Bx
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <tx`#,
break; *'ffMnSZ
} r(6$.zx
} a 0+W-#G
else 64R~ $km
break; ly~tB LH}
} 1@S(v L3a
} NwbX]pDT
catch(IOException e){e.printStackTrace ();} EwX:^1f
catch(Exception e){e.printStackTrace ();} bDADFitSo
:.bBV]6q
.Gq]Mrim9G
Utility.log(nFileLength); +Cg[!6[#
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0wnC"2GUX
return nFileLength; eOUv#F
} ,?/AIL]_
9T;DFUM
fIwG9cR
//保存下载信息（文件指针位置） *mtS\J
private void write_nPos() 3 =-XA2zJ
{ ]r.95|V*
try{ {&,MkWgG
output = new DataOutputStream(new FileOutputStream(tmpFile)); fuao*L]
output.writeInt(nStartPos.length); Lh rU fy
for(int i=0;i<nStartPos.length;i++) G'IRqO*]
{ @b{I0+li"/
// output.writeLong(nPos); uP NZ^lM
output.writeLong(fileSplitterFetch.nStartPos); 6s(.ul
output.writeLong(fileSplitterFetch.nEndPos); %&}gt+L(M
} tx_h1[qi
output.close(); h= Mmd
} 'LW~_\
catch(IOException e){e.printStackTrace ();} m[8?d~
catch(Exception e){e.printStackTrace ();} $;VY`n
} (F=q/lK$
*pj^d><
:xy4JRcF
//读取保存的下载信息（文件指针位置） i!u:]14>
private void read_nPos() mGP&NOR0^y
{ >\4"k4d}
try{ Bh ,GQHJ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); X-k$6}D
int nCount = input.readInt(); EaN1xb(DYa
nStartPos = new long[nCount]; ag{cm'.
nEndPos = new long[nCount]; h}&1 7M
for(int i=0;i<nStartPos.length;i++) bSgdVP-
{ #Pr w2u
nStartPos = input.readLong(); ;%B:1Z
nEndPos = input.readLong(); VbfTdRD-
} 2C[xrZa^
input.close(); O0RV>Ml'&
} .{,fb
catch(IOException e){e.printStackTrace ();} ,0\Pr
catch(Exception e){e.printStackTrace ();} d8ck].m=
} ni~1)"U.
/ht-]Js$G
*Eg[@5;QA
private void processErrorCode(int nErrorCode) _MxKfah'
{ B:rzM:BQ
System.err.println("Error Code : " + nErrorCode); 4"~F
} Zg=jDPt}
HIsB)W&%@
@5tGI U;1
//停止文件下载 p,K!'\
public void siteStop() JDP/vNq
{ D/&nEMp6
bStop = true; T0v{qQ
for(int i=0;i<nStartPos.length;i++) J-5E# v
fileSplitterFetch.splitterStop(); eJ+@<+vr;x
[Ufx=BPx3
}UX0 eI4
} |f{(MMlj
} u{8:VX
//负责部分文件的抓取 Bv{DZ?{s
**FileSplitterFetch.java =.(~`ici~
*/ ;Q\MH t*
package NetFox; 6Ij'z9nJw
;Z!x\{-L
9^g?/8
import java.io.*; J. $U_k
import java.net.*; 2F#DJN#
^?R8>97_?
8fWk C<f}
public class FileSplitterFetch extends Thread { 'bn$"A"{o
A Qm!7,
'n/L1Fn
String sURL; //File URL D]'/5]~z<
long nStartPos; //File Snippet Start Position BFvRU5&Sz
long nEndPos; //File Snippet End Position Pq3m(+gf
int nThreadID; //Thread's ID @FaK/lKK
boolean bDownOver = false; //Downing is over k7)<3f3&S.
boolean bStop = false; //Stop identical 'mYUAVmSC#
FileAccessI fileAccessI = null; //File Access interface 7u<C&Z/
P-?R\(QYtR
U0@Qc}y
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException T7LO}(I.&
{ {66P-4Ev(
this.sURL = sURL; =`E{QCW
this.nStartPos = nStart; Ft<B[bQ
this.nEndPos = nEnd; VI k]`)#
nThreadID = id; ^SWV!rrg
fileAccessI = new FileAccessI(sName,nStartPos);//定位 b*TQKYT
} w)Z-, J
;.{J>Q/U,
j]'ybpMT"
public void run() l]~mB~
{ H:]'r5sw
while(nStartPos < nEndPos && !bStop) fb?YDM
{ 'cPE7uNT
@M!nAQ8hY
@&f~#Xe
try{ ukc<yc].+?
URL url = new URL(sURL); Jxsch\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Nin7AOO
httpConnection.setRequestProperty("User-Agent","NetFox"); 89P'WFOFK
String sProperty = "bytes="+nStartPos+"-"; J936o3F_
httpConnection.setRequestProperty("RANGE",sProperty); tJII-\3"
Utility.log(sProperty); k]=lo'bF4
=^mBj?(V7
D9%t67s
InputStream input = httpConnection.getInputStream(); )QW p[bV
//logResponseHead(httpConnection); d8J(~$tXQN
n+D93d9LP
+o|I@7f
byte[] b = new byte[1024]; Xk`'m[
int nRead; MQMc=Z4d
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) bkS-[rW
{ e/R$Sfj]
nStartPos += fileAccessI.write(b,0,nRead); _g%,/y 9y
//if(nThreadID == 1) _<u>? Qt
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]N{jF$
} :&J1#% t
,'%*z
*:"p*qV*
Utility.log("Thread " + nThreadID + " is over!"); 5%]O'h
bDownOver = true; +wGFJLHJ
//nPos = fileAccessI.write (b,0,nRead); `]4tJJy$
} WSqo\]
catch(Exception e){e.printStackTrace ();} }ws(:I^
} j5!pS xOC
} =y0h\<[
M.``o1b
K$c?:?wmo
//打印回应的头信息 !|~yf3
public void logResponseHead(HttpURLConnection con) A`nzqe#(1
{ u?SxaGEa
for(int i=1;;i++) =)f5JwZPG
{ #Q/xQ`+|.
String header=con.getHeaderFieldKey(i); yX%NFXD
if(header!=null) Oid;s!-S6
//responseHeaders.put(header,httpConnection.getHeaderField(header)); O #5`mo
Utility.log(header+" : "+con.getHeaderField(header)); /)<Xoa
else ~(}nd
break; +Uxtxl'
} ?0?+~0sI
} ^?S lM
V|)nUsU
& Tkl-{I
public void splitterStop() u-R;rf5%k
{ 1AQ3<
bStop = true; ~\u~>mtchu
} 9#1Jie$
G8lTIs4u;
=8AL>:_
} :'Tq5kE
R= .UbY
%afz{a5
/* <q:2' 4o
**FileAccess.java 8TCbEPS@Q
*//文件访问(定位，写) ZM_-g4[H
package NetFox; 7T?T0x3>
import java.io.*; MCTTm^8O
?OC&=}
^C~t)U
public class FileAccessI implements Serializable{ ;aDYw [
Q|7;Zsd:
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 mV.26D<c
RandomAccessFile oSavedFile; \RmU6(;IQ
long nPos; %<\tN^rP
Id{Ix(O
~;@\9oPpz%
public FileAccessI() throws IOException yAQ)/u[|
{ QeQxz1
this("",0); z'}z4^35,
} @+hO,WXN
]u47]L#
&/$3>MD2`
public FileAccessI(String sName,long nPos) throws IOException ~vKDB$2
{ /;WFRp.
oSavedFile = new RandomAccessFile(sName,"rw"); $?y\3GX
this.nPos = nPos; H(DI /"N
oSavedFile.seek(nPos); gH/(4h
} <*z9:jzQ
e?<$H\
&XB1=b5
public synchronized int write(byte[] b,int nStart,int nLen) {CQI*\O
{ 3^]Kd
int n = -1; smPZ%P}P+c
try{ h%&2M58:
oSavedFile.write(b,nStart,nLen); bq z*90
n = nLen; K Vnz{cx`
} -;o0)DwZ
catch(IOException e) -932[+
{ ; g\rY
e.printStackTrace (); mV|Z5=f
} ~Hvf"bvK|
KQCF "
*/j[n$K>~`
return n; +K48c,gt?
} BP=<TRp.
.2SD)<}(9
/\m>PcPa
} nBtKSNT#Q
te+r.(p
gP?.io9Oi
/* "cGjHy\j`
**SiteInfoBean.java m]&y&oz
*/ uXVs<im
package NetFox; v dPb-z4
$|K-wN[
j=Z;M1
public class SiteInfoBean { R2y~+tko?
s\.\z[1
.`^wRpa2M
private String sSiteURL; //Site's URL i*e'eZ;)
private String sFilePath; //Saved File's Path Dj{=Y`Tw
private String sFileName; //Saved File's Name 'e8O \FOf
private int nSplitter; //Count of Splited Downloading File u(g9-O
EO"G(v
(#rhD}
public SiteInfoBean() 4B@Ir)^(*
{//nSplitter的缺省值为5 >uwd3XW5
//default value of nSplitter is 5 4)d"}j
this("","","",5); +krDmU9(
} bEb+oRI
IhXP~C6
)odz/\9n3c
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |\N))K-2D
{ du&9mOrr
sSiteURL= sURL; 6,(S}x YDZ
sFilePath = sPath; R!2E`^{Wl
sFileName = sName; K*N8Vpz(
this.nSplitter = nSpiltter; [q~3$mjQ
3PEW0b*]Pf
$`_xP1bUT
} t^7}j4lk
VTn6@z_ x
vO8CT-)
public String getSSiteURL() >Slu?{l'
{ YT<(2u#Ng
return sSiteURL; O[R
} Z>hGqFZ0{
kI,O9z7A7
8)="Ee
public void setSSiteURL(String value) Cf3<;Mp<
{ -o YJ&r
sSiteURL = value; 9O-*iK
} c@{M),C~E
IaGF{O3.
59k-,lyU,
public String getSFilePath() x%55:8{
{ tF!-}{c"k
return sFilePath; ZvSEa{
} FIpJ>E"n
E*83N@i
m>+e;5
public void setSFilePath(String value) /}=cv>S5V
{ :7pt=IA
sFilePath = value; \/?&W[TF
} `,Y/!(:;
Q=#Wk$1.
*zWf8X
public String getSFileName() j4E`O%@^
{ V0y_c^x
return sFileName; x_#'6H\1ga
} bOK0^$k
+6f[<^K#
z}2
public void setSFileName(String value) CwsC)]{/o
{ L%I8no-Q
sFileName = value; /086qB|
} yVH>Q-{
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L!^^3vn
public int getNSplitter() YH{FTVOt{C
{ 3'[ g2JR
return nSplitter; .%_=(C<E
} rG{,8*
TTz_w-68
[+b&)jN*2
public void setNSplitter(int nCount) P;ovPyoO
{ DaqpveKa
nSplitter = nCount; F,JqHa9
} 89J7hnJC
} o*xft6U
-\M;bQV[C
d?4-"9Y
/* Fy^MI*}BZ
**Utility.java en29<#8TO
*/ {r1}ACw{
package NetFox; UKf0cU
Ia-nA|LBxI
xU'% 6/G
public class Utility { V)cL=4G
`<* tp@
^qV6khg
public Utility() ]/odp/jm
{ MO_;8v~0
h2vD*W
AHn Yfxv_
} z:JJ>mxV
SHN'$f0Mb
//线程睡眠 YfVZ59l4y6
public static void sleep(int nSecond) bw OG|\
{ ?V4bz2#!1O
try{ R<e ~Cb-
Thread.sleep(nSecond); pSS8 %r%S'
} "M=1Eb$6=
catch(Exception e) n<Z1i)
{ {'[S.r`
e.printStackTrace (); S&F
} @+!u{
} f9La79v
/xkF9
//日志 @xN)mi
public static void log(String sMsg) "i;"
{ a fUOIM
System.err.println(sMsg); U )J/so)
} ^-26K|{3
/U@Y2$TOF
@tPptB
public static void log(int sMsg) d8M8O3
{ oVeC@[U
System.err.println(sMsg); +XL|bdK
} u51Lp
} p/'09FY+U
0-Vx!(
!Bn,f2
/* y/!jC]!+c
**TestMethod.java gtRs||
*/ z#\YA]1
package NetFox; ]xN)>A2
GaLQ/V2R
I'%ASZ
public class TestMethod { a,KqTQB
b1-'q^M
0v'!(&m
public TestMethod() wZKEUJpQ
{ ///xx/weblogic60b2_win.exe 8U7X/L
try{ aX|LEZ;D>
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); gR@,"6b3
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); yPVK>em5
SiteFileFetch fileFetch = new SiteFileFetch(bean); +X!QH/ 8
fileFetch.start(); _Wgpk0
} t(=Z@9)]4F
catch(Exception e){e.printStackTrace ();} lIgAc!q(
eX <@qa4<
lH%-#2]
} OjfumZL#
`6 ?.ihV
"i~~Q'=7
public static void main(String[] args) )UAkg
{ ZA'Qw2fF0
new TestMethod(); )(l=_[1Z5
} "E%3q3|"l
} &T\,kq>)
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