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)); pmIQD"
} }T4"#'`
for(int i=0;i<nEndPos.length-1;i++) \7*9l%
{ !=|3^A
nEndPos = nStartPos[i+1]; 2/qfK+a
} b\dBt#mB!
nEndPos[nEndPos.length-1] = nFileLength; l|U=(aA]h
} osPX%k!yw
} Q5{i#F7nJm
9IC"p<D
T3%yV*F,
//启动子线程 ~*THL0]~
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $PHKI B(
for(int i=0;i<nStartPos.length;i++) 2O`uzT$
{ c i_XcG
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Wi hQj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), gWv/3hWWB
nStartPos,nEndPos,i); ?fCLiK
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >77 /e@
fileSplitterFetch.start(); }g5h"N\$o
} K?(ls$
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j#3}nJB%#i
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); j}#48{
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", :7@"EW
nEndPos = " + nFileLength); Yf7n0Etd,
// fileSplitterFetch[nPos.length-1].start(); .e"De-u
LL#7oBJdM
!gW$A-XD
//等待子线程结束 vA;ml$
//int count = 0; !ck=\3pr
//是否结束while循环 Y}(v[QGV
boolean breakWhile = false; 6V*@ {
4US8B=jk
TW:vL~L
while(!bStop) k2,n:7
{ V.:a6>]
write_nPos(); = 14'R4:
Utility.sleep(500); ]J5[ZVz
breakWhile = true; it D%sKo
{~[H"h537t
KFCuv15w,3
for(int i=0;i<nStartPos.length;i++) ORp6
{ f|w+}z
if(!fileSplitterFetch.bDownOver) .A&Ey5
{ +2|X 7wA
breakWhile = false; >"5^]o2?~l
break; NnGQ=$e
} KaBze67<|
} J &u&G7#S
if(breakWhile) Bl3G_Ep
break; =_D82`p
9Rb-QI
lWd)(9Kj
//count++; =}Bq"m
//if(count>4) DTlM}
// siteStop(); T,`'qZ>
} MDGcK/$')f
--Dw8FR9
A WMR0I
System.err.println("文件下载结束！"); }sd-X`lZ
} xAjLn*d|N
catch(Exception e){e.printStackTrace ();} L!3{ASIN0
} ^qIp+[/'
mhnD1}9,Ih
`0=0IPVd
//获得文件长度 |.*),t3 (w
public long getFileSize() gmj a2F,
{ c zL[W2l
int nFileLength = -1; zVGjXuNa
try{ 42Tjbten_u
URL url = new URL(siteInfoBean.getSSiteURL()); ]Qkto4DQ5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !5?#^q
httpConnection.setRequestProperty("User-Agent","NetFox"); [j 'Ogm7"
jF Bq>
fP&F$"o8
int responseCode=httpConnection.getResponseCode(); d[kb]lC
if(responseCode>=400) n-}:D<\7
{ yodJGGAzk
processErrorCode(responseCode); 4+$<G/K
return -2; //-2 represent access is error ~Rs|W;
} 9hmCvQgtf
\-#~)LB]M
xX{uDMYa;
String sHeader; L<1"u.3Z`}
9bMM-~
wI1[I
for(int i=1;;i++) {iYu x;(
{ 4CW/
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); U#Wc!QN-t
//Utility.log(in.readLine()); J= ia
sHeader=httpConnection.getHeaderFieldKey(i); x +q"%9.c
if(sHeader!=null) *O)_D bj
{ 8v*>~E/0
if(sHeader.equals("Content-Length")) A AH-Dj|&l
{ fh b&_T
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); K.*?\)&
break; N`8!h:yL
} f0IljY!.
} d?v#gW
else 83412@&
break; )XnG.T{0|
} wf=#w}f
} uZ]B?Z%y#
catch(IOException e){e.printStackTrace ();} bhOyx
catch(Exception e){e.printStackTrace ();} 5y(irbk7
r{YyKSL1*K
L`R,4mI.W
Utility.log(nFileLength); vk5pnCM^3
xv$^%(Ujp
T!"<Kv]J
return nFileLength; >m:.5][yu
} xp)#a_}
8!VjXj"
lE?e1mz{
//保存下载信息（文件指针位置） JjfNH ~
private void write_nPos() yD#w@yG
{ 8MX/GF;F
try{ `RthX\Tof
output = new DataOutputStream(new FileOutputStream(tmpFile)); $\81WsL'
output.writeInt(nStartPos.length); Eh!%NeO
for(int i=0;i<nStartPos.length;i++) d%t]:41=Z
{ umcbIi('
// output.writeLong(nPos); W#u}d2mP
output.writeLong(fileSplitterFetch.nStartPos); T55l-.>
output.writeLong(fileSplitterFetch.nEndPos); )_GM&-
} I%e7:cs>
output.close(); JV36@DVQ
} 7Kk rfJqN
catch(IOException e){e.printStackTrace ();} }h+a8@
catch(Exception e){e.printStackTrace ();} D4 {gt\V
} :54|Z5h|
#7lkj:j4
fOE:~3Q
//读取保存的下载信息（文件指针位置） i#kRVua/
private void read_nPos() c*RZbE9k
{ K[~Wj8W0
try{ $#]?\psf
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Qc[[@=S%
int nCount = input.readInt(); reu[}k~
nStartPos = new long[nCount]; IH\k_Yf#u
nEndPos = new long[nCount]; 2O<Sig=
for(int i=0;i<nStartPos.length;i++) )P|%=laE8
{ >z>UtT:
nStartPos = input.readLong(); F#X\}MvEU
nEndPos = input.readLong(); ~q4DePVE
} *VHBTO9
input.close(); 4TwU0N+>
} _q6+]
catch(IOException e){e.printStackTrace ();} ua|qL!L+
catch(Exception e){e.printStackTrace ();} oxO}m7ULH
} oq8~PTw
e!tgWYN
<'P|g
private void processErrorCode(int nErrorCode) a(x[+ El
{ aCGPtA'
System.err.println("Error Code : " + nErrorCode); U|{WtuR
} vbDw2
:&?#~NFH
D1o 8Wo
//停止文件下载 ?z:xQ*#X
public void siteStop() 82O`<Ci
{ "MoV*U2s,
bStop = true; "5{Yn!-:
for(int i=0;i<nStartPos.length;i++) LTzf&TZbx5
fileSplitterFetch.splitterStop(); ^ / f*5k
2<ef&?ljk
/R|"/B0
} )z/j5tnvm
} +S;8=lzuV
//负责部分文件的抓取 s3J T1TX
**FileSplitterFetch.java d57(#)`
*/ mG?a)P
package NetFox; KOi%zE%
WCR+ZXI?1
elKQge
import java.io.*; nJ*NI)
import java.net.*; /jj!DO#
_xUhDu%
oC4rL\d{
public class FileSplitterFetch extends Thread { (/k,q
(]7@0d88
,P auP~L
String sURL; //File URL NA/+bgyuT>
long nStartPos; //File Snippet Start Position {F@;45)o
long nEndPos; //File Snippet End Position zh/+1
int nThreadID; //Thread's ID Bj@&c>
boolean bDownOver = false; //Downing is over }Ecm
boolean bStop = false; //Stop identical ARQ1H0_B
FileAccessI fileAccessI = null; //File Access interface QRdb~f;<hj
n8:2Z>
.-RWlUe;,
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]nfS vPb
{ N"E\o,_
this.sURL = sURL; ioa 1n=j
this.nStartPos = nStart; i w m7M
this.nEndPos = nEnd; A%Bz52yg
nThreadID = id; c$e~O-OVD?
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =WO{h48]
} xHD!8B)
.zegG=q
\2NiI]t]
public void run() qZ1fQN1yG
{ 0 ?2#SM
while(nStartPos < nEndPos && !bStop) YLFTf1G9
{ r5s*"z
}\gpO0Ox
Uj!L:u2b
try{ 4 Qw;r
URL url = new URL(sURL); @&EP& $*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $7BD~U
httpConnection.setRequestProperty("User-Agent","NetFox"); k?S-peyRO
String sProperty = "bytes="+nStartPos+"-"; 58v5Z$%--
httpConnection.setRequestProperty("RANGE",sProperty); u[dI81`
Utility.log(sProperty); VKR6i
YO,GZD`-o
pkk0?$l",
InputStream input = httpConnection.getInputStream(); E&[ox[g{
//logResponseHead(httpConnection); ~4\bR
7,+:QY@
)%MBo.NL
byte[] b = new byte[1024]; rcyH2)Y/e
int nRead; 7gJy xQ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @l;f';+
{ /1OhW>W3eH
nStartPos += fileAccessI.write(b,0,nRead); c69C=WQ
//if(nThreadID == 1) ~z< ? Wh
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); SnXYq7`t
} F[?t"d
7 'f>
KRXe\Sx
Utility.log("Thread " + nThreadID + " is over!"); `mWg$e,
bDownOver = true; 9]7^/g*!
//nPos = fileAccessI.write (b,0,nRead); vkt)!hl `
} q g%<>B&"
catch(Exception e){e.printStackTrace ();} Zmp ^!|=X!
} h[lh01z
} 5k\61(*s
kwyvd`J8
(JF\%Yj/
//打印回应的头信息 7vHU49DV
public void logResponseHead(HttpURLConnection con) 54'z"S:W
{ 3gGF?0o
for(int i=1;;i++) FD`V39##
{ IzL yn
String header=con.getHeaderFieldKey(i); TnKe"TA|9
if(header!=null) Zd5frc$
//responseHeaders.put(header,httpConnection.getHeaderField(header)); zCco/]h
Utility.log(header+" : "+con.getHeaderField(header)); Zd~Z`B} &
else 9xWeVlfQ
break; n=yFw\w'
} `Y(/G"]
} ChBZGuO:
XS1>ti|<
/sYD+*a
public void splitterStop() qQ|v~^
{ ey Cg *
bStop = true; F5*Xx g}N
} Rq\.RR](
)fC^h=Qp
w-\GrxlbX
} J@)6]d/,
QGYmQ9m{kL
Wm"W@LPx5
/* \.*aC)
**FileAccess.java lJKU^?4S8
*//文件访问(定位，写) 7d9%L}+q
package NetFox; IRcZyry
import java.io.*; :Tjo+vw7$H
xl<Cstr
e<IT2tv>u
public class FileAccessI implements Serializable{ J[<:-$E
\Mi y+<8$
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9 s>JdAw?
RandomAccessFile oSavedFile; XLzHm&;
long nPos; ~A6QX8a
0_%u(?
BGUP-_&
public FileAccessI() throws IOException 8WaVs6
{ 7[8PSoo
this("",0); paiF ah
} km8[azB o
+='.uc_
j[c|np4k\
public FileAccessI(String sName,long nPos) throws IOException SFh6'v'1N@
{ Z,Q)\W<'-
oSavedFile = new RandomAccessFile(sName,"rw"); R[Pyrs!H
this.nPos = nPos; M#2DI?S@
oSavedFile.seek(nPos); Mb+cXdZb
} \E0Uj>9+[
mF#{"
<S5Am%vo
public synchronized int write(byte[] b,int nStart,int nLen) PiM@iS
{ Y.=v!*p?}
int n = -1; !v94FkS>
try{ {HQ?
oSavedFile.write(b,nStart,nLen); 7]G3yt->
n = nLen; Dmn6{jyP
} ;JDxl-~
catch(IOException e) 72Ft?;R
{ Bm.%bA>
e.printStackTrace (); \J:/l|h
} R`A@F2
/1g_Uv;
M2mte#h
return n; MSsboSxA
} mZ*!$P:vy"
@/XA*9]l
hcwKi
} fY$M**/,
XkOsnI8n
_KC()OIeC
/* B&`#`]
**SiteInfoBean.java dz&8$(f,
*/ i5q VQo
package NetFox; wjQu3 ,Cj
'$;S?6$eW
5c!~WckbJ
public class SiteInfoBean { 9SXFiZA(r
DNC2]kS<
8"Hy'JA$O
private String sSiteURL; //Site's URL s9@/(_
private String sFilePath; //Saved File's Path t|%wVj?_
private String sFileName; //Saved File's Name f9F@G&&Ugg
private int nSplitter; //Count of Splited Downloading File [C9->`(`
ON\_9\kv
'eZUNX
public SiteInfoBean() J9zSBsp_
{//nSplitter的缺省值为5 %sbDH
//default value of nSplitter is 5 @|idlIey
this("","","",5); "i(k8+iK
} Bc`jkO.q
z*"zXLC
5iwJdm
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) L"P$LEk
{ SBgBZm}%
sSiteURL= sURL; 3g`uLA X>u
sFilePath = sPath; :q<8:,rP
sFileName = sName; 00[Uk'Q*5
this.nSplitter = nSpiltter; k$j>_U? P
6DD"Asi+
nM>oG'm[n
} LaG./+IP
pMe'fC~*
MOKg[j
public String getSSiteURL() 0V@u]
{ c-(,%0G0
return sSiteURL; pPuE-EDk
} cLEBcTx
odD^xg"L
kG^DHEne
public void setSSiteURL(String value) /Q8E12
{ x$tx!%,)/S
sSiteURL = value; FO&U{(Q
} K?8{y
rzsb(
[kM)K'-
public String getSFilePath() vT#zc)j
{ QX1QYwcmG
return sFilePath; ~k'KS 7c
} ]v{f!r=}
;!v2kVuS]
R'`q0MoN1
public void setSFilePath(String value) /GD4GWv :
{ yZj:Kp+7
sFilePath = value; =* oFs|v
} zxTcjC)y
^2rNty,nH
s`B]+
public String getSFileName() !`LaX!bmp
{ ,]+P#eXgE
return sFileName; cah1'Y
} ^mz&L|h
R@N I
a{v1[i\
public void setSFileName(String value) Ne!F p
{ /g BB
sFileName = value; d!mtSOh
} ms@*JCL!t
[p^N].K$
X`JWYb4
public int getNSplitter() "7mYs)=
{ RB`Emp&T
return nSplitter; # -e
} WvQK$}Ax4N
*$~H=4t
DN3#W w2[r
public void setNSplitter(int nCount) BQu_)@
{ kclClB:PS
nSplitter = nCount; W ZdEfY{
} %5Hsd
} \ 'G%%%;4
#9M6 q
^x-vOGlR
/* uu@Y]0-
**Utility.java (&HAjB
*/ :34]}`-
package NetFox; `?r]OVe{y
S{'/=Px+
ErIAS6HS'
public class Utility { yr?*{;
a+sHW<QeS
AV{3f`
public Utility() 7N9~nEU
{ #-*7<wN
91d@/z
. J[2\"W
} t[*;v
o8Vtxnkg
//线程睡眠 u>SGa @R)
public static void sleep(int nSecond) exT O#*o
{ wTb7 xBI
try{ Whp;wAz
Thread.sleep(nSecond); B7BXS*_b
} zea=vx>`
catch(Exception e) v'gP,UO-%D
{ )[_A{#&
e.printStackTrace (); 29]-s Utqv
} 3 r4QB
} k]?M^jrm
)NAC9:8!
//日志 GG%X1c8K
public static void log(String sMsg) {uH 4j4)2
{ `2`Nu:r^
System.err.println(sMsg); DID&fj9m
} GPlAQk
pie<jZt
*qdf?'R
public static void log(int sMsg) hd{Vz{;W
{ ?|!167/O
System.err.println(sMsg); /^ *GoB
} 3 d $
} _%^t[4)q
Z)}q=NjA
7oaa)
/* !_0kn6S5
**TestMethod.java uis;S)+
*/ Pl^-]~
package NetFox; Y*nzOD$
4bXAA9"
94C)63V
public class TestMethod { bL*;6TzRK
SxV(.i'
\|^fG9M~
public TestMethod() %~%1Is`4J
{ ///xx/weblogic60b2_win.exe P5M+usx
try{ zWvG];fsN
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); R{{d4=:S
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); n.zVCKNH
SiteFileFetch fileFetch = new SiteFileFetch(bean); 'A@[a_
fileFetch.start(); Bfhw0v]Z
} GBOz,_pw
catch(Exception e){e.printStackTrace ();} $[9,1.?C
c*MSd
"a;z
} $__e7
nsR^TD;
Cr0 \7
public static void main(String[] args) q@ !p
{ lsmzy_gV7
new TestMethod(); R:=C
} FkJa+ZA
} Kp,}7%hDw!
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