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)); FTf<c0
} {mTytT
for(int i=0;i<nEndPos.length-1;i++) 8P2 J2IU
{ :O-1rD
nEndPos = nStartPos[i+1]; :P+\p=
} fU+Pn@'
nEndPos[nEndPos.length-1] = nFileLength; 3BQ!qO17^d
} -VT+O+9_A
} 1m@^E:w
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M.[rLJZ4
//启动子线程 L,LNv
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; xDLG=A%]z
for(int i=0;i<nStartPos.length;i++) 0-d>I@j
{ GJA`l8`SQ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \Qy$I-Du
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), tTanW2C
nStartPos,nEndPos,i); v)X\GmW7w
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7cTk@Gq
fileSplitterFetch.start(); rcN 9.1
} @It>*B yB.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), z rfUQO
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); '{b1!nC;
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =O$M_1lp
nEndPos = " + nFileLength); u bW]-U=T
// fileSplitterFetch[nPos.length-1].start(); {XCf-{a]~
</`yd2>
r 2:2,5_
//等待子线程结束 yxWO[ Z
//int count = 0; Ond'R'3\E
//是否结束while循环 s Be7"^
boolean breakWhile = false; ipE]}0q
98XVa\|tl
L=; -x9
while(!bStop) s>n(`?@L
{ /~p+j{0L3W
write_nPos(); p9eRZVy/
Utility.sleep(500); E%N2k|%8d_
breakWhile = true; pv)`%<
4=8QZf0\
j]rz]k
for(int i=0;i<nStartPos.length;i++) iEyeX0nm
{ |I;$M;'r&
if(!fileSplitterFetch.bDownOver) gb|Q%LS9R
{ )?! [}t
breakWhile = false; 5VW|fI
break; #'baPqdO
} hsRvr`#m|
} Y"g.IK`V
if(breakWhile) E0n6$5Uc?
break; ^Q<mV*~
3>M&D20Z
tz NlJ~E
//count++; e.d #wyeX
//if(count>4) ,MPB/j^o5!
// siteStop(); 7r#ymQ
} y[};J vk
`_ %S
nuQ]8-,
System.err.println("文件下载结束！"); I?#85l{>
} Lo.rvt
catch(Exception e){e.printStackTrace ();} {y=W6uP
} DE$q+j0P
W*DVi_\$y
w8Q<r.
//获得文件长度 $lA V6I.
public long getFileSize() ?tdd3ai>
{ 38ES($
int nFileLength = -1; zdl%iop3e
try{ eYUr-rN+)z
URL url = new URL(siteInfoBean.getSSiteURL()); `$LWmm#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _9H*agRe
httpConnection.setRequestProperty("User-Agent","NetFox"); ,QIF &
^[E'1$D
M,5j5<7
int responseCode=httpConnection.getResponseCode(); C;+(Zp
if(responseCode>=400) +yob)%
{ f"u*D,/sS
processErrorCode(responseCode); eK_*2=;XRW
return -2; //-2 represent access is error }T^cEfX
} >Hb^P)3
mbRqJT>@
g>0XxjP4
String sHeader; RgdysyB
8(g:HR*;
`nXVE+E@
for(int i=1;;i++) ?<&O0'Q
{ jxaD&4Fs8
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); YYEJph@06q
//Utility.log(in.readLine()); >Iewx Gb>
sHeader=httpConnection.getHeaderFieldKey(i); 9Ya<My
if(sHeader!=null) nMfFH[I4
{ ZoB*0H-
if(sHeader.equals("Content-Length")) c3*t_!@oC
{ B&+`)E{KB
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $mmup|;(
break; =p^He!
} X:a`B(@S
} v8gdU7Ll,
else 8[CB>-9
break; GuZ( &G6*
} l.\re"Q
} {qW~"z*
catch(IOException e){e.printStackTrace ();} H.<a`mm8
catch(Exception e){e.printStackTrace ();} l+V,DCE
FlfI9mm
- K%,^6
Utility.log(nFileLength); tkQH\5
KIA 2"KbjG
Nw&!}#m
return nFileLength; !Fw?H3X!"q
} fP tm0.r
F/m^?{==~*
F62V3 Xy
//保存下载信息（文件指针位置） F-D]TRG/*]
private void write_nPos() $@d9<83=
{ W3vi@kb]
try{ 72sD0)?A
output = new DataOutputStream(new FileOutputStream(tmpFile)); g~7Ri-"
output.writeInt(nStartPos.length); jztq.2-c#
for(int i=0;i<nStartPos.length;i++) kt[:@Nda9
{ 4!asT;`'
// output.writeLong(nPos); LA_3=@2.H
output.writeLong(fileSplitterFetch.nStartPos); i |{Dd%4vK
output.writeLong(fileSplitterFetch.nEndPos); Am8x74?
} aK,z}l(N
output.close(); VL[R(a6c <
} JOjoiA
catch(IOException e){e.printStackTrace ();} 8<mjh0F-,
catch(Exception e){e.printStackTrace ();} ) xbO6V
} VIP7OHJh
mrm^e9*Z
K.G$]H
//读取保存的下载信息（文件指针位置） ug{R 3SS
private void read_nPos() -p-B2?)A
{ "#v=IJy&r
try{ ZpUCfS)|&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =fm]Dl9h*
int nCount = input.readInt(); c4_`Ew^k
nStartPos = new long[nCount]; Qn ^bVhG+
nEndPos = new long[nCount]; ?[*0+h`en
for(int i=0;i<nStartPos.length;i++) >0{S
{ Tirux ;
nStartPos = input.readLong(); x^"ES%*
nEndPos = input.readLong(); AtR?J"3E
} %Pksv}
input.close(); ^QuiH'
} :K\mN/ x
catch(IOException e){e.printStackTrace ();} V\V)<BARe
catch(Exception e){e.printStackTrace ();} J$~<V IX
} s>0Nr
"NRDNqj(
!*2%"H*
private void processErrorCode(int nErrorCode) Bl9jkq ]
{ ZVeaTK4_ t
System.err.println("Error Code : " + nErrorCode); ;['[?wk
} kNu'AT#3|
9Pw0m=4
JQ:Ri
//停止文件下载 pZ#ap<|>I
public void siteStop() mDh1>>K'~
{ [m+iQVk'
bStop = true; i{D=l7j|w
for(int i=0;i<nStartPos.length;i++) !_2n
fileSplitterFetch.splitterStop(); X0-IRJ[
g*w<*
-@>BHC
} nW"q
} fC}R4f7C
//负责部分文件的抓取 6h3HDFS7s
**FileSplitterFetch.java T0)"1D<l
*/ cI]WrI2CQa
package NetFox; [![%9'+P
3:%QB9qc]'
+i\&6HGK;-
import java.io.*; %3HVFhl
import java.net.*; Pmi#TW3X
v#=`%]mL
`Q+moX
public class FileSplitterFetch extends Thread { V|)>{Xdn
~)?
H A}f,),G
String sURL; //File URL B*htN
long nStartPos; //File Snippet Start Position eT'nl,e|
long nEndPos; //File Snippet End Position ::n;VY2&
int nThreadID; //Thread's ID K;7f?52
boolean bDownOver = false; //Downing is over jkiTj~WE-
boolean bStop = false; //Stop identical "uLjIIl
FileAccessI fileAccessI = null; //File Access interface }FF W|f
@DW[Z`X
"o& E2#
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException yGg,$WM
{ ]4+s$rG
this.sURL = sURL; _md=Q$9!m
this.nStartPos = nStart; A?G IBjs
this.nEndPos = nEnd; 'gQidf
nThreadID = id; (h']a!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 k7tYa;C
} * y^OV_n-8
~}Z\:#U
Oo?,fw
public void run() )hwV`2>l
{ `ovtHl3Q
while(nStartPos < nEndPos && !bStop) iAY!oZR(WT
{ hzI*{
> Oh?%%6
7\o!HMfK
try{ %7Kooq(i
URL url = new URL(sURL); j?b\+rr
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ck#"*],
httpConnection.setRequestProperty("User-Agent","NetFox"); UDf9FnG}L
String sProperty = "bytes="+nStartPos+"-"; 1Xy]D
httpConnection.setRequestProperty("RANGE",sProperty); Gf8s?l
Utility.log(sProperty); AvR2_
^4%Zvl
/8@m<CW2Y
InputStream input = httpConnection.getInputStream(); 3E}EBJLsZ
//logResponseHead(httpConnection); DjMf,wX-{
=1dI>M>tm
I[o*RKT'"
byte[] b = new byte[1024]; A5#y?Aq
int nRead; _eLWQ|6Fx
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) elJ)4Em
{ (_* wt]"'
nStartPos += fileAccessI.write(b,0,nRead); P[t$\FS
//if(nThreadID == 1) 3*DXE9gA9
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `,wu}F85
} F{k+7Ftc
\(I6_a_{
7#;vG>]
Utility.log("Thread " + nThreadID + " is over!"); eT"Uxhs-}
bDownOver = true; mzL[/B#>M
//nPos = fileAccessI.write (b,0,nRead); mxrG)n6Y
} yh;Y,;4
catch(Exception e){e.printStackTrace ();} rl:KJ\*D
} oN[Th
} NTs;FX~g[
:lcea6iO
B~r}c4R{7
//打印回应的头信息 V6iL5&
public void logResponseHead(HttpURLConnection con) BpAB5=M0
{ ]/]ju$l9Z
for(int i=1;;i++) h?@G$%2
{ .uZ7 -l
String header=con.getHeaderFieldKey(i); eN0P9.eqM
if(header!=null) q5&Ci`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); L^9HH)Jc
Utility.log(header+" : "+con.getHeaderField(header)); Ru%|}sfd
else /<)-q-W;
break; DrS~lTf=>
} upn8n vy4(
} T!q_/[i~7
~HLRfL?
ph30'"[Z}
public void splitterStop() _[Gb)/@mM
{ wV<7pi
bStop = true; ,-*iCs<
} 2@@l{Y0f6
g%J./F=@3
irxz l3
} wuK=6RL
0TE@xqW
pV`$7^#X
/* 9$WJ"]
**FileAccess.java a4GWuozl
*//文件访问(定位，写) ?_4^le[;
package NetFox; p]LnE`v
import java.io.*; ki\uTD`mf
4be> `d5j
(}H ,ng'4
public class FileAccessI implements Serializable{ n`5WXpz4;
u]vPy ria
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Y^lQX~I2{
RandomAccessFile oSavedFile; wz#[:2
long nPos; 2ChWe}f
=3+L#P=i9
~@M7&%]
public FileAccessI() throws IOException xEoip?O?7F
{ 8GB]95JWwp
this("",0); MQw9X
} v4<j
8]*Q79
O k(47nC
public FileAccessI(String sName,long nPos) throws IOException 3ut_Bt\
{ PZ]5Hf1"
oSavedFile = new RandomAccessFile(sName,"rw"); ?MZ:_'2p
this.nPos = nPos; edN8-P(
oSavedFile.seek(nPos); qpgU8f
} *FPg#a+
`!Ln|_,d
QWhp:]}
public synchronized int write(byte[] b,int nStart,int nLen) x`2pr
{ 6o lV+
int n = -1; rgR?wXW]jE
try{ -N^=@Yx)
oSavedFile.write(b,nStart,nLen); Sr7@buF
n = nLen; +{vQSFW
} /#\?1)jCK
catch(IOException e) c,BAa*]K
{ m^0A?jBrR
e.printStackTrace (); M7p8^NL
} eiB(VOJ
(-2R{!A
PJwEA
return n; 6aSM*S)
} =tq7z =k
fv|%Ocm
*^6k[3VY
} Q0SW;o7
cUM_ncYOP
:~r#LRgc
/* =#'+"+lQ }
**SiteInfoBean.java W:>J864!
*/ 0~.)GG%R>D
package NetFox; z@n+7p`w
g5<ZS3tQ
"o<D;lO
public class SiteInfoBean { hs,5LV)|y
ZpTi:3>
{6YxN&
private String sSiteURL; //Site's URL 9dw0<qw1%
private String sFilePath; //Saved File's Path PIpWa$b
private String sFileName; //Saved File's Name &08Tns"
private int nSplitter; //Count of Splited Downloading File !xJFr6G~8
m^Rd Iy)
X%35XC.n
public SiteInfoBean() B,:23[v
{//nSplitter的缺省值为5 %N1T{
//default value of nSplitter is 5 'iGMn_&
this("","","",5); R>` ih&,)
} D~7%};D[
TA<hj[-8
@Z,qu2~|!
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 'H FwP\HX
{ p0?o<AA%O
sSiteURL= sURL; &7lk2Q\
sFilePath = sPath; 0rGj|@+;
sFileName = sName; mnQal>0~
this.nSplitter = nSpiltter; u`nt\OF
bQ i<0|S
Kl!DKeF
} y K=S!7p\
MQjG<O\
L>i<dD{
public String getSSiteURL() TIKEg10I
{ PlF89-
return sSiteURL; [Aa[&RX+9
} \;'_|bu3.
'"'D.,[W2
CuF%[9[cT
public void setSSiteURL(String value) oPp!*$V
{ k q/t]%(
sSiteURL = value; !XkymIX~O.
} c&0;wgieg
5/zf x
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public String getSFilePath() 4o)(d=q
{ j\%?<2dj=
return sFilePath; #_?426Wfs
} qr7 X-[&
_K*\}un2
N`y}Gs
public void setSFilePath(String value) <W=~UUsn
{ {d&X/tT
sFilePath = value; \9[NH/.Z{
} ^aGZJiyJ
G5y]^P
C.b,]7i
public String getSFileName() UIC\CP d
{ 4r68`<mn[
return sFileName; $]Q*E4(kV9
} wrZ7Sr!/V
Gp?ToS2^d
!$%/ rQ9
public void setSFileName(String value) $.suu^>^w
{ +#de8/x
sFileName = value; 7,) 67G;
} *qeic e%E
f}Ne8]U/Hc
RT8_@8
public int getNSplitter() XhHel|!g:
{ s$SU vo1J
return nSplitter; CF4Oh-f
} ~#HH;q_7m
#;qFPj- v
}a #b$]Y
public void setNSplitter(int nCount) !q7;{/QM6
{ J_y<0zF**
nSplitter = nCount; J]kP`
} \Y>#^b?
} i5L+8kx4
I>YtWY|ed
!4qps$p{
/* =,/A\F
**Utility.java O]$*EiO\
*/ hB2s$QS
package NetFox; LP0;n\
,N))=/
BCa90
public class Utility { :$GL.n-?
)$9C`d[
Xj})?{FP
public Utility() ]|((b/L3
{ 9:K
:e0R7sj
c|R3,<Q]
} [#,X$O>
i SAidK,
//线程睡眠 YP .%CD(K
public static void sleep(int nSecond) Mi%1+
{ )LMBxyS
try{ DS[l,x
Thread.sleep(nSecond); w/^0tZ~
} 0?&aV_:;X
catch(Exception e) FgHB1x4;
{ r=P$iG'&
e.printStackTrace (); NBbY## w0
} 8Jib|#!
} 2'O!~8U
)l[7;ZIw$
//日志 1Hk<_no5
public static void log(String sMsg) 2U+z~
{ -f|+
System.err.println(sMsg); x`=5l`
} 0-&sJ
O+8ApicjTc
%unK8z
public static void log(int sMsg) (Aov}I+
{ &:cTo(C'
System.err.println(sMsg); Lct+cKKU
} :;hBq4h
} 5@%=LPV
|qudJucV
zx]M/=7,V#
/* L[[H&#\
**TestMethod.java ~i_R%z:y
*/ J1y2Qw$G
package NetFox; 8L9S^ '
~]_jKe4W
m(7_ZiL=
public class TestMethod { 6Nd_YX
:R|2z`b!
!f]3Riw-=,
public TestMethod() ?H7p6mu
{ ///xx/weblogic60b2_win.exe k9VQ6A
try{ C>K"ZJ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 0?4^.N n3
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); u!EulAl
SiteFileFetch fileFetch = new SiteFileFetch(bean); 0,D9\ Ebd
fileFetch.start(); ?$8 ,j+&I
} =B{$U~}
catch(Exception e){e.printStackTrace ();} &MGgO\|6
#<V'gE
@SVEhk#
} $}h_EI6hS
WZO 0u
>5@ 0lYhH
public static void main(String[] args) T.Y4L
{ ABYW1K=
new TestMethod(); kU9AfAe
} FVLA^$5c
} "e};?|y
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