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)); b}axw+
} S3.Pqp_<
for(int i=0;i<nEndPos.length-1;i++) #IgY'L
{ )5p0fw
nEndPos = nStartPos[i+1]; >/-<,,<\C
} #knpZ'
nEndPos[nEndPos.length-1] = nFileLength; ^e)KEkh
} R ]HHbD&;
} <r_ldkZ
,US]
0f1*#8-6
//启动子线程 !m:SRNPg
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; BQ &|=a6
for(int i=0;i<nStartPos.length;i++) \V}?K0#bt
{ Z^s&]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -2bu`oD `
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), uh@ZHef[l
nStartPos,nEndPos,i); YJF!_kg.
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >u~ l_?
fileSplitterFetch.start(); :+Y+5:U]
} >f74]J=V
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0oc5ahp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); L%I@HB9-Q0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", UoBmS5
nEndPos = " + nFileLength); He~)i)co
// fileSplitterFetch[nPos.length-1].start(); 3/oVl 6
\M<C6m5
v2/@Pu!kg
//等待子线程结束 A]QgX5\sa
//int count = 0; #r>
//是否结束while循环 D&:,,Dp
boolean breakWhile = false; a%V6RyT4qW
y/Paq^Hd
P^T]Ubv"
while(!bStop) -n+=[M
{ c|IH|y
write_nPos(); Z!v)zH\
Utility.sleep(500); gT?:zd=;
breakWhile = true; Xw_AZ-|1D
FK{Vnj0
R~PD[.\u
for(int i=0;i<nStartPos.length;i++) L;wzvz\+
{ hZ[,.
if(!fileSplitterFetch.bDownOver) Q6]SsV?x
{ o@XhL9
breakWhile = false; p0>W}+8fF
break; *FmY4w
} !^:b?M
} 'QeCJ5p]
if(breakWhile) JPRo<jt=
break; &,JrhMr\
W0R<^5_
8t25wPlx
//count++; )E;B'^RVR
//if(count>4) U\s.fIr
// siteStop(); F^fL
} lhZXq!2p
>;:235'(M
GHaD32
System.err.println("文件下载结束！"); XOe)tz L
} #R-l2OO^]
catch(Exception e){e.printStackTrace ();} U["'>&B
} (kCzz-_\
J!YB_6b
5%Hw,h
//获得文件长度 @Fvp~]jCb
public long getFileSize() .!/w[Z]
{ DP_ ]\V<sT
int nFileLength = -1; $F2A
try{ {DlQTgP
URL url = new URL(siteInfoBean.getSSiteURL()); q|r^)0W
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); % 8u97f W
httpConnection.setRequestProperty("User-Agent","NetFox"); oG{0{%*@
lC|`DG-B
~>6d}7xs
int responseCode=httpConnection.getResponseCode(); (#KSwWo{ed
if(responseCode>=400) |zd+ \o
{ AWo\u!j
processErrorCode(responseCode); UNY O P{
return -2; //-2 represent access is error !Pd@0n4
} "Te[R%aP
8~* |muN.e
r}T(?KGx
String sHeader; '1P~"P3
?V&#nA
s3<gq x-&r
for(int i=1;;i++) V7DMn@Ckw
{ =[5F~--Tf
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); uC$!|I
//Utility.log(in.readLine()); lZ gX{
sHeader=httpConnection.getHeaderFieldKey(i); r`-=<@[
if(sHeader!=null) 5!-+5TJI
{ 6,Z.RT{5
if(sHeader.equals("Content-Length")) #w]UP#^io
{ ~xPU#m<
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); H.o=4[
break; BLaF++Fop
} uE E;~`G
} ERTjY%A
else 7C / ^Gw
break; yrvV<}
} AcHr X=O
} +6~ut^YiM.
catch(IOException e){e.printStackTrace ();} <Fo~|Nh|
catch(Exception e){e.printStackTrace ();} 7up~8e$_
T:/mk`>
{gT4Oq__
Utility.log(nFileLength); BcXPgM!Xqz
= q\TWz
9u?[{h.`B
return nFileLength; }vK8P r%
} ;}B6`v
S/,)X
NdxPC~Z+
//保存下载信息（文件指针位置） KwAc Ga}J
private void write_nPos() pG&#xRk
{ `_"loPu
try{ "50c<sZSB
output = new DataOutputStream(new FileOutputStream(tmpFile)); *(g0{V
output.writeInt(nStartPos.length); eL" +_lW
for(int i=0;i<nStartPos.length;i++) 3QhQpPk),
{ utzf7?nIS
// output.writeLong(nPos); WBN3:Y7
output.writeLong(fileSplitterFetch.nStartPos); @6"+x
output.writeLong(fileSplitterFetch.nEndPos); + *)Kyk
} xYp-Y"a.
output.close(); |1%eo.
} &v)/mc7D
catch(IOException e){e.printStackTrace ();} u~8=ikn+T
catch(Exception e){e.printStackTrace ();} %p;;aZG
} slnvrel
(&i c3/-
B=}s7$^
//读取保存的下载信息（文件指针位置） ZyX+V?4
private void read_nPos() N(J'h$E
{ A1Es>NK[qW
try{ XOL_vS24
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); MFyi#nq
int nCount = input.readInt(); U6?3 z
nStartPos = new long[nCount]; fnJx$PD~
nEndPos = new long[nCount]; .k -!/^
for(int i=0;i<nStartPos.length;i++) GLp~SeF#
{ 1<G,0Lt
nStartPos = input.readLong(); )vD:
nEndPos = input.readLong(); i~"lcgoO
} U! $/'Xi9
input.close(); qDS~|<Y5
} |mQC-=6t;Y
catch(IOException e){e.printStackTrace ();} qm/#kPlM
catch(Exception e){e.printStackTrace ();} (M#m BS
} P"{yV?CNg
@$fvhEkrT@
bx%Ky0Z
private void processErrorCode(int nErrorCode) oH(a*i
{ zDf96eK
System.err.println("Error Code : " + nErrorCode); zI= 9
} S&F[\4w5]
|R;`
m1D,#=C,_
//停止文件下载 8b"vXNB.f
public void siteStop() ':|E$@$W
{ ,7Dm p7
bStop = true; Qk2*=BVh
for(int i=0;i<nStartPos.length;i++) O/.8;.d;4Y
fileSplitterFetch.splitterStop(); 0nPg`@e.
G%fXHAs.+
fQxlYD'peb
} Z|B`n SzH
} Gs/G_E(T
//负责部分文件的抓取 SveP:uJA[
**FileSplitterFetch.java %O9P|04]3
*/ gI/SA
package NetFox; gb=tc`
*7{{z%5Pu
hAJ^(|
import java.io.*; d@?zCFD
import java.net.*; YF(bl1>YC
8dh ?JqX
&,QBJx<#
public class FileSplitterFetch extends Thread { gm$<U9L\v
;EsfHCi)
m~tv{#Y
String sURL; //File URL 79uAsI2-Y
long nStartPos; //File Snippet Start Position MKh}2B#S
long nEndPos; //File Snippet End Position =)%~QK{Y
int nThreadID; //Thread's ID 79 \SbB
boolean bDownOver = false; //Downing is over ]P2Wa
boolean bStop = false; //Stop identical Wb5n> *
FileAccessI fileAccessI = null; //File Access interface N97WI+`
mUfANlQ:
zG7y$\A
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException swg*fhJFB
{ MSb0J`
this.sURL = sURL; je74As[
this.nStartPos = nStart; n){u!z)Al
this.nEndPos = nEnd; GG(}#Z5h
nThreadID = id; b?-KC\}v
fileAccessI = new FileAccessI(sName,nStartPos);//定位 NftR2
} %~\I*v04
-+0!Fkt@,
&23{(]eO
public void run() geNvp0
{ V8G.KA "
while(nStartPos < nEndPos && !bStop) ~3$:C#"Dl
{ 8aY}b($*ZI
m[%P3
q4niA
try{ 8"ulAx74>
URL url = new URL(sURL); M y!;N1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;vUw_M{P=)
httpConnection.setRequestProperty("User-Agent","NetFox"); +vYVx<uTQ
String sProperty = "bytes="+nStartPos+"-"; au+a7~0~
httpConnection.setRequestProperty("RANGE",sProperty); lT8^BT
Utility.log(sProperty); l Ma||
;It1i`!R
ahR-^^'$
InputStream input = httpConnection.getInputStream(); 2U3WH.o
//logResponseHead(httpConnection); IIAm"=*
Y+C6+I<3
?^U1~5ff)
byte[] b = new byte[1024]; &g!yRvM!;Q
int nRead; Bam 4%G5
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) } DjbVYH
{ eK/rsr
nStartPos += fileAccessI.write(b,0,nRead); &ZJ$V
//if(nThreadID == 1) 8*sP
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Sr-!-eC
} T9AFL;1
[ak[ZXC,
mpzm6Ieu
Utility.log("Thread " + nThreadID + " is over!"); (wp?tMN5#
bDownOver = true; bKQ-PM&I/t
//nPos = fileAccessI.write (b,0,nRead); fK4NmdTV
} \O\veB8
catch(Exception e){e.printStackTrace ();} FD.L{
} 4Z/]7Ie
} |Gt]V`4
30QQnMH3
#Qd"d3QG
//打印回应的头信息 Gu%}B@4^
public void logResponseHead(HttpURLConnection con) TYedem<$
{ {+ WI>3
for(int i=1;;i++) 51puR8AG>
{ $kh6-y@
String header=con.getHeaderFieldKey(i); )z7+%nTO
if(header!=null) \Bn$b2j!%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); JjG>$z
Utility.log(header+" : "+con.getHeaderField(header)); ZRYHsl{F+
else +|Mi lwr
break; ^%x7:
} 7.B]B,]
} Cce{aY
%loe8yt
\)BDl
public void splitterStop() /pz(s+4=
{ yV5AVMo
bStop = true; 0GnbE2&
} BoXGoFn
$1myf Z
^qPS&G
} Ok_)C+o
rY(^6[!
\E,Fe:/g
/* yQ+C}8r5
**FileAccess.java lR3JyYY{X
*//文件访问(定位，写) U=ie| 3
package NetFox; v,mn=Q&9
import java.io.*; ?)XPY<
^BQ*l5K
si|b>R&Z
public class FileAccessI implements Serializable{ z*&r@P -
0& ?/TSC
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !J+< M~o}
RandomAccessFile oSavedFile; fQ~YBFhlr
long nPos; [X=Ot#?u ~
{1]Of'x'
ZTP&*+d
public FileAccessI() throws IOException 8(0q,7)y
{ G1:2MPH
this("",0); Qrt> vOUE7
} wvNddu>@
ceGo:Aa<)
JS!
public FileAccessI(String sName,long nPos) throws IOException I)F3sS45}
{ #zc{N"!
oSavedFile = new RandomAccessFile(sName,"rw"); j?P8&Fm<
this.nPos = nPos; Zkn1@a
oSavedFile.seek(nPos); >-YWq
} ,a?$F1Z-
"e~"-B7(\Y
ZYD3[" ~x
public synchronized int write(byte[] b,int nStart,int nLen) OcGHMGdn
{ w1P8p>vA1
int n = -1; e025m}%SU
try{ s1NRUV2E
oSavedFile.write(b,nStart,nLen); :1\QM'O
n = nLen; WjvD C"
} EcW$'>^
catch(IOException e) cakb.Q
{ ,-{2ai_
e.printStackTrace (); \%N | X
} p*Hbc|?{Q&
X?Mc"M
bol#[_~
return n; C/x<_VJzN/
} x?MSHOia`P
y~pJ|E
e6WKZ~ vo
} zE\@x+k.
{9C+=v?
MPmsW&
/* A1(=7ZKz
**SiteInfoBean.java b_T?jCyW
*/ fdRw:K8
package NetFox; G' 'l,\3
G\:^9!nwY~
QBiLH]qa
public class SiteInfoBean { &r Lg/UEV-
$zuemjW3p
?Em*yc@WD
private String sSiteURL; //Site's URL GP\Pk/E
private String sFilePath; //Saved File's Path -w:F8k ~
private String sFileName; //Saved File's Name pu +"bq
private int nSplitter; //Count of Splited Downloading File *PjW,
Q1?G7g]N
+]%d'h
public SiteInfoBean() 30v 3C7o=
{//nSplitter的缺省值为5 "' hc)58y
//default value of nSplitter is 5 |_J[n!~f7
this("","","",5); idr,s\$>
} 9(( QSX
aGYF\7
51k^?5cO
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) F!;0eS"xp
{ |Skk1#
sSiteURL= sURL; 9ZEF%&58Y
sFilePath = sPath; Zom7yI
sFileName = sName; O8N\
this.nSplitter = nSpiltter; Xbb('MoI63
1>SCY_Cv
~"+Fp&[9f
} *M_Gu{xc
1MCHwX3/
. 787+J?
public String getSSiteURL() FaNH+LPe
{ )TBG-<wt
return sSiteURL; \e/'d~F
} 9j[%Y?
t$z FsFTQ
D$RQD{*
public void setSSiteURL(String value) 9 1r"-%(r
{ idf~"a
sSiteURL = value; #Pz},!7
} iraO/KhD*3
q.OkZI0n
Et=N`k_gO
public String getSFilePath() FSqS]6b3
{ .`OdnLGy
return sFilePath; =_`4HDr
} 0~\Dd0W/:`
8S>T1st
|"Js iT
public void setSFilePath(String value) ~5HI9A4^
{ }7Si2S
sFilePath = value; 1X4v:rI
} #qk A*WP
#`C;@#xr
@t
public String getSFileName() DdTTWp/
{ lbv9 kk[
return sFileName; Y)>GwFK$
} l("Dw8H
)j40hrR
r`|/qP:T[
public void setSFileName(String value) vnXa4\Vdy
{ PX3rHKK{
sFileName = value; .VVY]>bJg@
} {ZH9W
Nkt(1?:-'
Eg?6$[U`8<
public int getNSplitter() cPxA R]'U
{ J3fcnI
return nSplitter; 'Pudy\Ab
} $-$^r;
wwS{V
;/W;M> ^
public void setNSplitter(int nCount) (63_
{ FLO#!G
nSplitter = nCount; |Ebwl]X2
} ~O~c^fLH(B
} WlF"[mU-
L{|V13?
m9UI3fBX
/* _yyQ^M/
**Utility.java Gw*n,*pz
*/ 0+0+%#?
package NetFox; e g#.f`
u0^: XwZ!
q"5iza__H
public class Utility { q&Sd+y&
E ?(
&inu mc
public Utility() 8H3|i7.1h
{ @eN x:}
)eNR4nF
e%&2tf4
} SUXRWFl
T^8t<S@`
//线程睡眠 iK6L\'k
public static void sleep(int nSecond) nsqs*$
{ N.C<Mo
try{ zR/d:P?
Thread.sleep(nSecond); >C~-*M9
} iIq='xwa9
catch(Exception e) mHo}, |
{ ^ad p<?q4
e.printStackTrace (); +$_W4lf|E2
} -$L53i&R
} <k'=_mC_
W6D|Rr.q
//日志 ow*) 1eo
public static void log(String sMsg) ci>+Zi6
{ eOjoxnD-$
System.err.println(sMsg); R:98'`X=
} D[m;rcl
U7.3`qd"
~]DGf(
public static void log(int sMsg) V<AT"vU[
{ 3qPj+@
System.err.println(sMsg); j0!Z 20
} !@!,7te
} 0&Q-y&$7
3(':4Tas
U[=VW0
/* 0b9K/a%sQv
**TestMethod.java I0=YIcH5
*/ 7wsn8_n9
package NetFox; zR(}X8fP
yHl1:cf(y
_6&x$*O
public class TestMethod { y]aV7 `]
q-gN0"z^6$
bR6.Xdt.n
public TestMethod() ps"DL4*
{ ///xx/weblogic60b2_win.exe N;7Xt9l
try{ m5SJB]a/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 7.$0LN/a!Z
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); pw*<tXH!
SiteFileFetch fileFetch = new SiteFileFetch(bean); V} Y %9V
fileFetch.start(); 7y:%^sl
} o ^L3Xiv
catch(Exception e){e.printStackTrace ();} kDS
Zf}]sW$H
6Yebc_, R
} eKNZ?!c=
*z;4. OX
Vo<V!G{
public static void main(String[] args) tvynl;Y/
{ b[Sd$ACd
new TestMethod(); j2SJ4tB /
} * F%Wf
} EV| 6._Z(D
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