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)); *18J$
} MPJ0>Ly
for(int i=0;i<nEndPos.length-1;i++) )B Xl|V,
{ 5R#:ALwX:
nEndPos = nStartPos[i+1]; Q".p5(<
} lp]q%P
nEndPos[nEndPos.length-1] = nFileLength; dcN4N5r
} S)A;!}RK6
} Ns[.guWu-
7FP @ vng
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//启动子线程 \ id(P3M
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; FVoKNaK-
for(int i=0;i<nStartPos.length;i++) +hMF\@
{ KRj3??b
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nZkMyRk
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), boIFN;Aq"
nStartPos,nEndPos,i); q%Lw#f
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); M_F4I$V4
fileSplitterFetch.start(); DOWZhD
} T;B/Wm!x
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :J6FI6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }+ TA+;
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", uulzJbV,K
nEndPos = " + nFileLength); O>arCr=H
// fileSplitterFetch[nPos.length-1].start(); S >\\n^SbT
a(+u"Kr z
i8(n(
//等待子线程结束 ~ePtK~,dv
//int count = 0; _v=zFpR
//是否结束while循环 \1#!%I=.
boolean breakWhile = false; &d[%
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3_c4+u"6
while(!bStop) [[8h*[:
{ ig:z[k?
write_nPos(); \&%y4=y<sE
Utility.sleep(500); v!rOT/I
breakWhile = true; ut9R]01:
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for(int i=0;i<nStartPos.length;i++) VV=6v;u`
{ ]hA]o7k
if(!fileSplitterFetch.bDownOver) ;5}y7#4C
{ R~XNF/QMl
breakWhile = false; 5?gZw;yiv%
break; ~2?UEv6
} &Zm1(k6&K
} /)xQ# yfX
if(breakWhile) 0:k MnHn\
break; 0XrOOYmx
))#_@CwRr
BjbpRQ,
//count++; '3ZYoA%
//if(count>4) o|c"W}W
// siteStop(); cjBHczkY
} t)*A#
{]:B80I;2
0'tm.,
System.err.println("文件下载结束！"); n(el
} /pnQKy.
catch(Exception e){e.printStackTrace ();} zH?&FtO
} ,DWC=:@X
fm^)u"
38(|a5
//获得文件长度 JWs?az
public long getFileSize() W|[k]A` 2
{ sh8(+hg
int nFileLength = -1; T1~,.(#
try{ q e;O Ox
URL url = new URL(siteInfoBean.getSSiteURL()); vpqMKyy
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %c,CfhEV%&
httpConnection.setRequestProperty("User-Agent","NetFox"); 55|.MXzq
{_*$X
>{kPa|
int responseCode=httpConnection.getResponseCode(); JQWW's}
if(responseCode>=400) vD4<G{
{ lIL{*q(
processErrorCode(responseCode); ,V:RE y
return -2; //-2 represent access is error TGQDt|+Z
} $^"_Fox]A\
dq$CCOC^F
3q0^7)m0
String sHeader; &T/}|3S
HA%r:Px
nXF|AeAco
for(int i=1;;i++) z6Jfu:_N!
{ b'~IFNt*^
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); i3\6*$Ug
//Utility.log(in.readLine()); wPU<jAQyp
sHeader=httpConnection.getHeaderFieldKey(i); <S%kwS
if(sHeader!=null) >c:- ;(k
{ f:K`MW
if(sHeader.equals("Content-Length")) ; +E@h=?
{ #pw=HHq*(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); (-rw]=Qu
break; /Q[M2DN@
} }]?U. ]-
} C:d$
else #NLLlEE
break; az ?2
} $C !Mk
} 0NWtu]9QC
catch(IOException e){e.printStackTrace ();} cxQ8/0^
catch(Exception e){e.printStackTrace ();} 0^{?kg2o_
-#?p16qz5
N%&D(_
Utility.log(nFileLength); spt='!)4
n/]$k4h
~.wDb,*
return nFileLength; wUz)9n 6j
} qP0_#l&
j?n:"@!G/
+~A<&7[}
//保存下载信息（文件指针位置） #%i-{t+_>
private void write_nPos() i\?P>:)
{ p;rGaLo:u
try{ {1ic*cZS
output = new DataOutputStream(new FileOutputStream(tmpFile)); nu#_,x<LS
output.writeInt(nStartPos.length); p@7[w@B\c
for(int i=0;i<nStartPos.length;i++) (^Kcyag4
{ D;0xROW8{
// output.writeLong(nPos); U'acVcD
output.writeLong(fileSplitterFetch.nStartPos); 1$Pn;jg:
output.writeLong(fileSplitterFetch.nEndPos); h8!;RN[
} H-,RzL/
output.close(); ){oVVLs
} Uwqm?]
catch(IOException e){e.printStackTrace ();} a/wkc*}}/
catch(Exception e){e.printStackTrace ();} \o j#*aL^
} xBC:%kG~#
IlcFW
rn?:utP
//读取保存的下载信息（文件指针位置） txwTJScg
private void read_nPos() ZSTpA,+6
{ lAwOp
try{ e[@q{.
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); mTzzF9n"Y
int nCount = input.readInt(); Y(]&j`%
nStartPos = new long[nCount]; ,1YnWy*
nEndPos = new long[nCount]; #)BdN
for(int i=0;i<nStartPos.length;i++) k+S 6)BQ7U
{ &,Xs=Lvmq
nStartPos = input.readLong(); ;U|^Tsuc`
nEndPos = input.readLong(); h?:lO3)TL=
} zAxwM-`
input.close(); THmX=K4=?
} ZK[S'(6q
catch(IOException e){e.printStackTrace ();} }hFjl4`xa
catch(Exception e){e.printStackTrace ();} o?J>mpC
} ZC1U
z.[ Ok
m dC.M$
private void processErrorCode(int nErrorCode) B94mh
{ F=hfbCF5x
System.err.println("Error Code : " + nErrorCode); uj-q@IKe
} o"x&F
[D H@>:"dd
%L./U$
//停止文件下载 ?~aM<rcZ
public void siteStop() N+?kFob
{ N3nk\)V\E
bStop = true; R?Q@)POW
for(int i=0;i<nStartPos.length;i++) WQ]~TGW
fileSplitterFetch.splitterStop(); 9k^;]jE
e6f!6a+%
i%W,Y8\uf*
} LTY@}o]\U
} 1px:(8]{
//负责部分文件的抓取 0=8.8LnN(
**FileSplitterFetch.java F^=|NlU&%
*/ 5U[;T]{)e
package NetFox; v5t`?+e
y)v'0q
G2kr~FG
import java.io.*; 4\?I4|{pC
import java.net.*; *Df|D/,WE
Y1 i!
nFlj`k<]Y
public class FileSplitterFetch extends Thread { 'PlKCn`(w
nYuZg6K
jK&kQ
String sURL; //File URL mLO{~ruu
long nStartPos; //File Snippet Start Position IrXC/?^h
long nEndPos; //File Snippet End Position eN%Ks
int nThreadID; //Thread's ID Y:VM5r)
boolean bDownOver = false; //Downing is over I,AI$A
boolean bStop = false; //Stop identical q5[%B K
FileAccessI fileAccessI = null; //File Access interface 4kA/W0 VG
h"YIAQ',
d*1@lmV*
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ZBJYpeGe
{ b=QO^
this.sURL = sURL; odquAqn
this.nStartPos = nStart; 0}Xkj)R,
this.nEndPos = nEnd; COj50t/
nThreadID = id; "0g1'az}
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &K`[SX=
} [6 !/
{61NLF\0H
9r7QE&.
public void run() D|Z,eench
{ P!m~tu}B
while(nStartPos < nEndPos && !bStop) @-;-DB]j
{ :f^O!^N
1`m ~c
B\}E v&
try{ W?'!}g(~
URL url = new URL(sURL); x-U^U.i@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Uz H)fB
httpConnection.setRequestProperty("User-Agent","NetFox"); gW6lMyiLb
String sProperty = "bytes="+nStartPos+"-"; ag?@5q3J}
httpConnection.setRequestProperty("RANGE",sProperty); L"tj DAV
Utility.log(sProperty); ^?toTU
DSy,#yA
/Yx 1S'5
InputStream input = httpConnection.getInputStream(); PF!Q2t5c3
//logResponseHead(httpConnection); f b_tda",}
eF}Q8]da
'oEFNC9V
byte[] b = new byte[1024]; GA6Z{U{XS
int nRead; r,MgIv(L
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) n\*>mp)
{ ^C):yxNP
nStartPos += fileAccessI.write(b,0,nRead); t3Q;1#Zf
//if(nThreadID == 1) 9))%tYN
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ygUvO3Z
} 0'|#Hi7@
: Ot\l
h.4;-&
Utility.log("Thread " + nThreadID + " is over!"); pLBp[GQ
bDownOver = true; J*,Ed51&7
//nPos = fileAccessI.write (b,0,nRead); c1CP12
} j>?H^fB
catch(Exception e){e.printStackTrace ();} _QBd3B%
} 8+ B.x
} bg_Zf7{
UY{ Uo@k9x
uiE9#G
//打印回应的头信息 1w+&Y;d|
public void logResponseHead(HttpURLConnection con) 5]p>&|Ud
{ }.2pR*W
for(int i=1;;i++) VrO$SmH
{ v[r:1T@
String header=con.getHeaderFieldKey(i); /n?5J`6
if(header!=null) m2{z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); tJ.LPgfZ
Utility.log(header+" : "+con.getHeaderField(header)); / vje='[!
else vo uQ.utl
break; .(CzsupY_q
} tmK@Veb*a'
} TR{8A^XhE8
\#2,1W@
?_W "=WpC
public void splitterStop() )R9>;CuC9?
{ G5=(3V%
bStop = true; 1(hgSf1WH
} qJ"dkT*
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$NG}YOP)@
} `z5j
BIbcm,YQ
%'4dgk
/* jDgiH}
**FileAccess.java ^bL.|vB
*//文件访问(定位，写) eiP>?8
package NetFox; )@1_Dm@0b
import java.io.*; pwd7I
wm*`
=#T6,[5
public class FileAccessI implements Serializable{ ^o:0 Y}v=
*M+:GH/5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8xg:ItJaA0
RandomAccessFile oSavedFile; )5d&K8@
long nPos; +*)B;)P
Kj}hb)HU
(sJ{27b_
public FileAccessI() throws IOException _rs!6tp
{ A_Sl#e
this("",0); 9<[RXY
} }#EiL !Pv
c4L5"_#`x-
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public FileAccessI(String sName,long nPos) throws IOException EW#.)@-
{ #1u4Hi(x5
oSavedFile = new RandomAccessFile(sName,"rw"); vh?({A#>.E
this.nPos = nPos; ^"6xE nA]
oSavedFile.seek(nPos); 'n!;7*
} B`RbXk68q
1/gY]ghL
;?zb (2
public synchronized int write(byte[] b,int nStart,int nLen) >?U(w<
{ O~fRcf:Q
int n = -1; ,a^_ ~(C
try{ _jU6[y|XLh
oSavedFile.write(b,nStart,nLen); I7BfA,mZ7
n = nLen; H0tjN&O_
} )u\"xxcV
catch(IOException e) q$b/T+-ec
{ HewVwD<C
e.printStackTrace (); Zn#ri 8S
} s(Kf%ZoE
)]>=Uo
]Z<{ ~
return n; s'~_pP
} qhF/iUE
Om>6<3n
JWMIZ{/M
} g"#R>&P
_k5KJKvr
vuDp_p*]S
/* JguE#ob2
**SiteInfoBean.java oPzt1Y
*/ fcJ#\-+E
package NetFox; `'Z ;+h]
;EL!TzL:8
rU.ew~
public class SiteInfoBean { zFB$^)v"<
z<^HohT
tBrd+}e2*
private String sSiteURL; //Site's URL Q9%N>h9
private String sFilePath; //Saved File's Path VD36ce9
private String sFileName; //Saved File's Name _e~EQ[,
private int nSplitter; //Count of Splited Downloading File <0R?#^XBZB
u^ngD64
wF@qBDxg
public SiteInfoBean() d+2I+O03
{//nSplitter的缺省值为5 [.Kia >
//default value of nSplitter is 5 iOki ZN+d>
this("","","",5); QdC>fy
} ]0m4esK`
VCbnS191*
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public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) y3;G<9K2c]
{ ix7N q7!N
sSiteURL= sURL; &)xoR4!2
sFilePath = sPath; bmt2~!
sFileName = sName; ub,Sj{Mq"
this.nSplitter = nSpiltter; 2+"#
@*%5"~F
@zd)]O]xH?
} Gt6$@ji4u
lpSM p
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public String getSSiteURL() J]N-^ld\\
{ L2Gm0 v
return sSiteURL; ]MUuz'<
} Eg w?
8uT@$./
bE]2:~
public void setSSiteURL(String value) M5Pvc
{ uERc\TZ
sSiteURL = value; ]dk~C?H
} lW^RwNcd
_5.7HEw>/
1S.nqOfx
public String getSFilePath() $stJ+uh
{ J tYnBg?[E
return sFilePath; #@y4/JS&2
} 6"jq/Pu
~Qzm!Po,
'Ur$jW
public void setSFilePath(String value) 5p=T*Y
{ z4{|?0=C
sFilePath = value; Eer rIV
} v9M;W+J
"hs`Y4U
#{ `(;83
public String getSFileName() Nv #vfh9}P
{ #G9S[J=xe
return sFileName; Q3z-v&^E9
} 7z F29gC
6AZ/whn#
Pfi '+I`s
public void setSFileName(String value) bX5>qqB]
{ 1{nXmtvr
sFileName = value; Y}nE/bmx&9
} eCk}B$ 2
'y;[ fwo7
iSIj ?.
public int getNSplitter() g%RL9-z
{ e-{k;V7b
return nSplitter; <K4'|HU/
} @uT\.W:Q2
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193Q
public void setNSplitter(int nCount) sl/#1B
{ pjHUlQ
nSplitter = nCount; .rN5A+By`
} g-Z>1V
} ;wTl#\|w0
m./lrz
|910xd`Z
/* %4+r&
**Utility.java C4Bh#C
*/ {!'AR`|
package NetFox; g4I(uEJk
*Pw;;#\B
7c4\'dt#
public class Utility { z#bOFVg#
hofZpM
9:YiLoz?
public Utility() mpXco *!_
{ Ay2Vz>{
Tfs7SC8ta
pS*vwYA
} >RF[0s'-
$S=lm {
//线程睡眠 [T~O%ly7x&
public static void sleep(int nSecond) 2x3&o|J
{ <\2,7K{{+;
try{ j"J2&Y2
Thread.sleep(nSecond); 0gfa7+Y
} >9Ub=tZm
catch(Exception e) .T4"+FTzP
{ NaB8cLURp
e.printStackTrace (); %2bZeZ
} J/R=O>
} C x$|7J=O
nmS3
//日志 MCL5a@BX)
public static void log(String sMsg) ykX}T6T
{ ~A [ Ju%R
System.err.println(sMsg); bWUo(B#*I
} c%Kv"Z%f
m3P%E8<Q#
$&k zix
public static void log(int sMsg) vL\wA_z"<H
{ eP[azC"G[
System.err.println(sMsg); rK}*Uwut
} q.uIZ
} q;t T*B W
?<xGO@b .
L;E9"7Jo
/* [ ecYpE<
**TestMethod.java 2/qfK+a
*/ ]}~*uT}>
package NetFox; i nF&Pv
O'A''}M
D8BK/E-
public class TestMethod { URX>(Y}g9^
MDl
`m@06Q
public TestMethod() yhgHwES"
{ ///xx/weblogic60b2_win.exe ~\:+y
try{ HrEZ]iQ@O0
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); hY/SR'8
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7PHvsd"]p
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2syKYHV
fileFetch.start(); Ny p5=
} ;:8_H0X'K
catch(Exception e){e.printStackTrace ();} >L?/Ph%d
K,?M5n '
I_'vVbK+>
} %L<VnY#%u
Wi hQj
BLuILE:$
public static void main(String[] args) s1:UCv-%
{ $zyY"yWRZ
new TestMethod(); <yE(p
} :$dGcX}
} =>4>Z_q
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