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 LI 9(@
} C=>IJ'G
for(int i=0;i<nEndPos.length-1;i++) [uD G;We=
{ I@/+=
nEndPos = nStartPos[i+1]; Ri mz~}+
} TKBW2
nEndPos[nEndPos.length-1] = nFileLength; Q'qz(G0
} =AIeYUh
} M6o"|\
$vK(Qm
[DzZ:8
//启动子线程 n3Q Rn^
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; LW '3m5
for(int i=0;i<nStartPos.length;i++) 1ms(03dp
{ oW \k%Vj
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $]t3pAI[H0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), oDBv5
nStartPos,nEndPos,i); +zf[Im%E
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); GLE/ 1
fileSplitterFetch.start(); 7`_`V&3s
} :[C"}mR1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), o!-kwtw`l
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); cA8A^Iv:0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 6A23H7
nEndPos = " + nFileLength); Cl>{vSN
// fileSplitterFetch[nPos.length-1].start(); JULns#tx}
{\62c;.
ZGZ1Q/WH
//等待子线程结束 o/~Rf1
//int count = 0; 3yw`%$d5
//是否结束while循环 t#BQB<GI
boolean breakWhile = false; UHT2a9rG
o;5ns
#<*=)[
while(!bStop) wFX>y^ 1
{ mx3p/p
write_nPos(); ZD;1{
Utility.sleep(500); x@*!MC#
breakWhile = true; ?)V?6"fFP
_ ,~D]JYE
O.Xhi+
for(int i=0;i<nStartPos.length;i++) O=;}VZ<9
{ _my!YS5n
if(!fileSplitterFetch.bDownOver) .Gq]Mrim9G
{ +Cg[!6[#
breakWhile = false; =Y`e?\#`
break; Lsb`,:
} FX,kmre3
} KqhE=2,
if(breakWhile) i_<GSUTTr/
break; vg;9"A!(
'74*-yd
*)u%KYGr
//count++; H05xt$J
//if(count>4) % db
// siteStop(); V3v/hV:
} J-d>#'Wb|
mP[ZlS~"
/JbO$A
System.err.println("文件下载结束！"); q)rxv7Iu\
} ]7DS>%mY(
catch(Exception e){e.printStackTrace ();} jWNF3\
} KzWqHq
gO%oA} !i
p|9Eue3j2
//获得文件长度 %s*F~E
public long getFileSize() .6HHUy
{ $3)Z>p
int nFileLength = -1; e.VR9O]G
try{ -ztgirU
URL url = new URL(siteInfoBean.getSSiteURL()); _Qd CV`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O~DdMW
httpConnection.setRequestProperty("User-Agent","NetFox"); 6O\a\z
h"ZR`?h
L)yc_ d5
int responseCode=httpConnection.getResponseCode(); !}I+)@~\w
if(responseCode>=400) ={[9kR i
{ Ce`#J6lT
processErrorCode(responseCode); #Pr w2u
return -2; //-2 represent access is error V<ExR@|}.%
} Gk-49|qIV
VbfTdRD-
2C[xrZa^
String sHeader; o_R_
ffI z>Of:
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for(int i=1;;i++) d8ck].m=
{ ni~1)"U.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *c>B,
//Utility.log(in.readLine()); zr@HYl
sHeader=httpConnection.getHeaderFieldKey(i); <:ptNGR
if(sHeader!=null) < VrHWJo
{ J>N^FR9
if(sHeader.equals("Content-Length")) &3CC |
{ 6BH P#B2j
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); @5tGI U;1
break; %Fp1c K
} p,K!'\
} JDP/vNq
else (,^jgv|I
break; `BzjDI:a
} G7SmlFn?
} lOEB ,/P
catch(IOException e){e.printStackTrace ();} OKV/=]GS
catch(Exception e){e.printStackTrace ();} kO/]mNLG
u{8:VX
Bv{DZ?{s
Utility.log(nFileLength); =.(~`ici~
;Q\MH t*
6Ij'z9nJw
return nFileLength; AR3v,eOs
} 9^g?/8
I4(z'C
EZJ[+ -Q;
//保存下载信息（文件指针位置） O)%s_/UX
private void write_nPos() =O??W8u
{ X|4_}b>x
try{ ~%?LFR'
output = new DataOutputStream(new FileOutputStream(tmpFile)); [ XBVES8
output.writeInt(nStartPos.length); .1YiNmW=
for(int i=0;i<nStartPos.length;i++) Jk}Dj0o
{ D* QZR;D#.
// output.writeLong(nPos); p5`={'>-
output.writeLong(fileSplitterFetch.nStartPos); AQjf\i
output.writeLong(fileSplitterFetch.nEndPos); wu~?P`
} LXS)(-&
output.close(); ICD;a
} -jk-ve
catch(IOException e){e.printStackTrace ();} =`E{QCW
catch(Exception e){e.printStackTrace ();} Ft<B[bQ
} ycj\5+g
Rj!9pwvT
75W@B}dZd
//读取保存的下载信息（文件指针位置） WwF2Ry^a
private void read_nPos() cI (}
{ Wxa</n8S[n
try{ Nq"J[l*+g
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -)9aY.
int nCount = input.readInt(); 0mR^%+~
nStartPos = new long[nCount]; cP^c}e*;NS
nEndPos = new long[nCount]; N7UGgn=
for(int i=0;i<nStartPos.length;i++) QC<O=<$Q[
{ CXh>'K
nStartPos = input.readLong(); w`X0^<Fv
nEndPos = input.readLong(); o:PdPuZVR
} "5@\"L
input.close(); se*!OiOt
} 2Dw}o;1'
catch(IOException e){e.printStackTrace ();} X}ft7;Jpy
catch(Exception e){e.printStackTrace ();} D9%t67s
} )QW p[bV
ZmAo9>'Kg
@n^2UJ
private void processErrorCode(int nErrorCode) q{uv?{I
{ ;( [^+_/
System.err.println("Error Code : " + nErrorCode); a[ yyEgm2
} y`a]##1j$M
mGh8/Xt
V6kJoSyde
//停止文件下载 I78Q8W(5
public void siteStop() 1otE:bi
{ UId?a}J
bStop = true; ?)2;W
for(int i=0;i<nStartPos.length;i++) f0"_ {\
fileSplitterFetch.splitterStop(); K;*B$2Z#k
[7Liken
go?}M]c%7
} NeR1}W
} N) '|l0x0
//负责部分文件的抓取 b8&z~'ieR
**FileSplitterFetch.java h~5gHx/a
*/ r1[#_A`Yn
package NetFox; !|~yf3
A`nzqe#(1
u?SxaGEa
import java.io.*; '}9 %12\^h
import java.net.*; Q.g44>
*T2kxN,Ik
7Cx-yv
public class FileSplitterFetch extends Thread { t/J|<Ooj?
O{Y*a )"
o#hFK'&~
String sURL; //File URL >0S(se$
long nStartPos; //File Snippet Start Position Le2rc*T
long nEndPos; //File Snippet End Position 7`HKa@
int nThreadID; //Thread's ID o?5;l`.L}
boolean bDownOver = false; //Downing is over g9AA)Ykp
boolean bStop = false; //Stop identical B4{F)Zb
FileAccessI fileAccessI = null; //File Access interface & Tkl-{I
u-R;rf5%k
1AQ3<
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 8=-#LVo~c
{ " nLWvV1
this.sURL = sURL; SI/3Dz[
this.nStartPos = nStart; E=]$nE]b
this.nEndPos = nEnd; Dop,_94G
nThreadID = id; 5`)[FCQ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <q:2' 4o
} 8TCbEPS@Q
ZM_-g4[H
FDTC?Ii O
public void run() $k^& X `
{ =\gK<Xh
while(nStartPos < nEndPos && !bStop) ^C~t)U
{ ;aDYw [
Q|7;Zsd:
@=qWwt4~
try{ K~A@>~vFb
URL url = new URL(sURL); %<\tN^rP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Id{Ix(O
httpConnection.setRequestProperty("User-Agent","NetFox"); ~;@\9oPpz%
String sProperty = "bytes="+nStartPos+"-"; yAQ)/u[|
httpConnection.setRequestProperty("RANGE",sProperty); G$t:#2
Utility.log(sProperty); R<Ct{f!
vu3zZMl
emG1Wyl
InputStream input = httpConnection.getInputStream(); o$Z]qhq
//logResponseHead(httpConnection); P.3kcZ
P(B&*1X
B3Ws)nF"
byte[] b = new byte[1024]; 6 -IThC
int nRead; H={5>;8G
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0}-MWbG
{ RY]jY | E
nStartPos += fileAccessI.write(b,0,nRead); qU^`fIa
//if(nThreadID == 1) ' pfkbmJ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); },,K6*P
} @Uqcym.
7W=s.Gy7G\
?tkd5kE
Utility.log("Thread " + nThreadID + " is over!"); t8uaNvUM}e
bDownOver = true; vs{xr*Ft
//nPos = fileAccessI.write (b,0,nRead); F@1Eg
} p*|Ct
catch(Exception e){e.printStackTrace ();} 8r.3t\o)X
} Yq%r\[%*
} Ur(< ]
%8lWJwb7u
95*=&d
//打印回应的头信息 7upN:7D-
public void logResponseHead(HttpURLConnection con) `FByME
{ ><{Lh@{
for(int i=1;;i++) Tz{-L%*#
{ J )UCy;Y
String header=con.getHeaderFieldKey(i); Bs\&'=l
if(header!=null) e\! ic
//responseHeaders.put(header,httpConnection.getHeaderField(header)); vq1u!SY
Utility.log(header+" : "+con.getHeaderField(header)); D:XjJMW3r
else $|K-wN[
break; j=Z;M1
} J'*`K>wV
} v4r%'bA
CPJ%<+4%b
jR"ACup(
public void splitterStop() <1E5[9 q
{ _@O.EksY3r
bStop = true; 90">l^HX=
} ' [%?j?2r
( c +M"s
F+/#ugI
} 4]no#lVRJ
*C,1x5
<h*$bx]9 +
/* JxQGL{) >
**FileAccess.java gZ6tbp,X
*//文件访问(定位，写) p*~b5'+ C+
package NetFox; Z(BZGO<
import java.io.*; aA-s{af
LuWY}ste
vpoJ{TPO
public class FileAccessI implements Serializable{ 14yzGhA
{$'oKJy*
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 dyt.(2
RandomAccessFile oSavedFile; )pw53,7>aN
long nPos; uwu`ms7z 2
`}#n#C)
2Jqr"|sw
public FileAccessI() throws IOException 66HxwY3a
{ Nh+XlgXG
this("",0); ~;I'.TW
} %Ktlez:S
[ip}f4K
TchByN6oN<
public FileAccessI(String sName,long nPos) throws IOException |qtZb}"|
{ J+YoAf`hi
oSavedFile = new RandomAccessFile(sName,"rw"); Ns.{$'ll
this.nPos = nPos; h`:B8+k
oSavedFile.seek(nPos); c4M]q4]F
} kjj?X|Un
<'vtnz
9KMtPBZ
public synchronized int write(byte[] b,int nStart,int nLen) dwVo"_Yr
{ |?ma?
int n = -1; K&;/hdS=F
try{ F`57;)F
oSavedFile.write(b,nStart,nLen); I GB)
n = nLen; k];fQ7}m<0
} (ljoD[kZ
catch(IOException e) e4-7&8N+
{ @"0n8y
e.printStackTrace (); j4E`O%@^
} #XeabcOQ
LR y&/d
0yL%Pjn6
return n; #w;%{C[D
} fU'[lZ
B)s%B'
K<fB]44Y
} 'V}4_3#q
9tIE+RD
j_}f6d/h
/* 7?2<W-n
**SiteInfoBean.java d2*uY.,
*/ >C/O >g
package NetFox; K(Ak+&[
W"1=K]B
VevDW }4q*
public class SiteInfoBean { nh>lDfJV<
)0{ZZ-beG
y@\J7 h:
private String sSiteURL; //Site's URL }Pj;9ivz
private String sFilePath; //Saved File's Path &Tk@2<5=
private String sFileName; //Saved File's Name @!%HEs!# #
private int nSplitter; //Count of Splited Downloading File d?4-"9Y
Fy^MI*}BZ
YBQ{/"v%|
public SiteInfoBean() hvF>Tu]^r
{//nSplitter的缺省值为5 dA$qzQ
//default value of nSplitter is 5 K"VRHIhfg
this("","","",5); |%fM*F^7/
} 6='x}Qb\H
!p(N DQm
Ky)*6QOw
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^zR*s |1Q
{ {Zf 9} !qF
sSiteURL= sURL; _yc&'Wq
sFilePath = sPath; ?9;r|G
sFileName = sName; 2E0$R%\
this.nSplitter = nSpiltter; Hs(U|BXU
DQ= /Jr~
I5w>*F
} 8J8@0
N@\`DO
io*iA<@Gx
public String getSSiteURL() Dh .<&ri
{ m]'P3^<{P
return sSiteURL; n!%'%%o2v
} X!f` !tZ:{
9oxn-)6JC
qp2&Z8S\D
public void setSSiteURL(String value) pFwhvw
{ CF/8d6}Vf
sSiteURL = value; z460a[Wl
} Mtq^6`JJ'
2Z*^)ZQB
a VIh|v
public String getSFilePath() 6>F]Z)]}
{ <CGJ:% AY
return sFilePath; N3?hu}
} #~6au6LMC
5U<;6s
\mDBOC0eK
public void setSFilePath(String value) BVv{:m{w
{ '"J``=
sFilePath = value; RV_+-m{]
} i" >kF@]c8
ZGQz@H5
|]j2T8_=
public String getSFileName() GaLQ/V2R
{ e2L4E8ST<
return sFileName; qruv^#_l
} JG=z~STz
{[[/*1r|
:U/x(
public void setSFileName(String value) i E)Fo.H
{ Q a3+9
sFileName = value; D@o8Gerq~
} '*n2<y
)jed@?
yo_;j@BGR
public int getNSplitter() 4,?ZNyl
{ 3nX={72<b
return nSplitter; -)p| i~j^A
} ]rc=oP;
'+E\-X
4'`y5E
public void setNSplitter(int nCount) [K"&1h<>
{ 8d8GYTl b)
nSplitter = nCount; KN"<f:u
} )(l=_[1Z5
} ~?uch8H
qt4^e7o
0M|Jvw'n|
/* )P #MUC
**Utility.java eWTbHF
*/ X"O^4MnvI
package NetFox; Q7XlFjzcm
{V5eHn9/Q'
<,I]=+A
public class Utility { AMc`qh
y~;w`5;|
8&UwnEk<
public Utility() %2<u>=6byG
{ SX@zDuM
Y@Ti2bI`v
B%/N{i*Z
} @&GfCg5Cb
29r(Y
//线程睡眠 _X]S`e1F
public static void sleep(int nSecond) Vl%jpjqP
{ (v1~p3H
try{ 'uU{.bq
Thread.sleep(nSecond); _e94
} 41NVF_R6J
catch(Exception e) %mMPALN]{
{ w}r~Wk^dLI
e.printStackTrace (); K#4Toc#=V
} IhPX/P
} QT7PCHP
B dKD%CJ[
//日志 @"'$e_jj"
public static void log(String sMsg) fE,Io3
{ 0=V -{
System.err.println(sMsg); -1c{Jo
} <^fvTb&*
sH /08Z
=w2_1F"
public static void log(int sMsg) /'Q2TLy=
{ xBg.QV
System.err.println(sMsg); ":V,&o9n
} \2VYDBi?|
} ysFp`
[WW ~SOJe
(I\qTfN4
/* QBL|n+
**TestMethod.java iuS*Vw
*/ )T!3du:M
package NetFox; l&oc/$&|[
POt8G
NH0uK
public class TestMethod { ~(K{D D7[N
9jW"83*5
#0'%51Jcl
public TestMethod() #7|73&u(
{ ///xx/weblogic60b2_win.exe raCgctYVq
try{ D%!GY1wdn
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); vnD `+y
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); sG8G}f
SiteFileFetch fileFetch = new SiteFileFetch(bean); pT'jX^BU
fileFetch.start(); )Rr0f 8
} }-H)jN^
catch(Exception e){e.printStackTrace ();} >S'IrnH'!
S0mzDLgE
T1WH
} i16kPU
c[X:vDUX
vx}W.6C}
public static void main(String[] args) *5d6Q
{ dBEm7.nh
new TestMethod(); !?5YXI,
} M}x]\#MMY
} {{@*
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