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)); ~pA;j7*
} YBCjcD[G
for(int i=0;i<nEndPos.length-1;i++) %<"11;0tp
{ qB39\j
nEndPos = nStartPos[i+1]; LAKZAi%O0
} ^kD?0Fm
nEndPos[nEndPos.length-1] = nFileLength; ^VIUXa
} G9a%N
} M"vcF5q
pkU e|V
u7C{>
//启动子线程 Hb+#*42v
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]dK]a:S
for(int i=0;i<nStartPos.length;i++) rO`g~>-
{ *0hiPj:
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (XwLKkw0n
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), uy9B8&Sr
nStartPos,nEndPos,i); IX*S:7S[
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )e2IT*7
fileSplitterFetch.start(); `p{!5
} vg.%.~!9
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -5cH$]1\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); cMWO_$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", qQcC[50
nEndPos = " + nFileLength); eq+o_R}CS
// fileSplitterFetch[nPos.length-1].start(); }J?fJ(
I:_*8el&d
QBw ZfX
//等待子线程结束 \l:g{GnoT
//int count = 0; 0xxzhlKNL
//是否结束while循环 A]+h<Y~}
boolean breakWhile = false; @NNLzqqY
>h[!gXL^
N Sh.g#
while(!bStop) B R:
{ xs I/DW
write_nPos(); mCt>s9a)H
Utility.sleep(500); 7L+X\oaB
breakWhile = true; BXo|CITso
Qkib;\2
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for(int i=0;i<nStartPos.length;i++) ?Bzi#Z
{ tvOAN|+F
if(!fileSplitterFetch.bDownOver) G; [AQ:Iy
{ UBi4itGD
breakWhile = false; $vLV< y07
break; ,/:a77
} bQy%$7UmX,
} P082.:q"
if(breakWhile) `zp2;]W
break; MH.,s@
hu|hOr8
YU=ZZEVi
//count++; $uw+^(ut
//if(count>4) E)JyKm.
// siteStop(); ^B5cNEO
} 6lWFxbh
e^NEj1
NoO+xLHw8
System.err.println("文件下载结束！"); 1mJ_I|98
} uvDoo6'
catch(Exception e){e.printStackTrace ();} H 1D;:n
} ' f$L
2]3HX3
MgQU6O<
//获得文件长度 "-n%874IT
public long getFileSize() ~J-|,ZMd
{ 5; PXF
int nFileLength = -1; b_jZL'en
try{ eqZ+no
URL url = new URL(siteInfoBean.getSSiteURL()); &U~r}=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !Gp3/<"Wy$
httpConnection.setRequestProperty("User-Agent","NetFox"); _`_IUuj$E
jN%p5nZ^EK
7vaN&%;E%
int responseCode=httpConnection.getResponseCode(); &@HNz6KO
if(responseCode>=400) ix9HSa{d
{ <i'u96
processErrorCode(responseCode); mp,e9Nd;
return -2; //-2 represent access is error N+M&d3H`
} f4k5R
;(Xe@OtW
`MsYgd
String sHeader; >I& jurU#
@qPyrgy
NVJ&C]H6
for(int i=1;;i++) N 2"3~ #
{ W/r mm*
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); uR;-eK
//Utility.log(in.readLine()); 48CI8[T
sHeader=httpConnection.getHeaderFieldKey(i); T5azYdzJy
if(sHeader!=null) QG|GXp_q`
{ zZ9<4"CIk
if(sHeader.equals("Content-Length")) 9*|3E"Vr
{ hY}/Y
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); v0C;j(2zb
break; ?JgO-.
} #t@x6Vt
} d{yIy'+0/
else )4~sQ^}
break; >4/L-y+
} :@ E1Pun?
} qggk:cN1
catch(IOException e){e.printStackTrace ();} Dk`4bYK
catch(Exception e){e.printStackTrace ();} }@14E-N=
;}WtJ&y=M
P-+M,>vNy[
Utility.log(nFileLength); ZSXRzH~0
lU$4NUwM
FKox0Jmh=
return nFileLength; /> 3
} KR=d"t Qw
2]D$|M?$~
'cZMRRc<
//保存下载信息（文件指针位置） =zm0w~']E!
private void write_nPos() V3mjbH>F
{ ;tp]^iB#
try{ S\9t4Ki_'
output = new DataOutputStream(new FileOutputStream(tmpFile)); @0z0m;8
output.writeInt(nStartPos.length); @fqV0l!GR
for(int i=0;i<nStartPos.length;i++) I f3{E
{ WQ[}&kY~
// output.writeLong(nPos); +_X,uvR
output.writeLong(fileSplitterFetch.nStartPos); ,g/ _eROJ
output.writeLong(fileSplitterFetch.nEndPos); G#w^:UL
} zg#m09[4
output.close(); f6B-~x<l
} \\S/NA
catch(IOException e){e.printStackTrace ();} dK}WM46$
catch(Exception e){e.printStackTrace ();} #0bO)m+NZ
} oWp}O?
ZU|6jI}
.?rbny
//读取保存的下载信息（文件指针位置） _ }E-~I>
private void read_nPos() StU 4{
{ +Y>"/i. N
try{ [eNkU">}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); :8^M5}
int nCount = input.readInt(); _8Nw D_"
nStartPos = new long[nCount]; ~h)@e\Kc
nEndPos = new long[nCount]; 6?V<BgCC
for(int i=0;i<nStartPos.length;i++) ]C16y. ~e
{ ;&Bna#~B
nStartPos = input.readLong(); U*3AM_w
nEndPos = input.readLong(); R:'Ou:Mh
} sI&i{D
input.close(); xF( bS+(o
} x&C%4Y_]
catch(IOException e){e.printStackTrace ();} 6<x~Mk'u)
catch(Exception e){e.printStackTrace ();} `DLp<_z>
} qH#r-
zoZ<)x=;
ic*->-!
private void processErrorCode(int nErrorCode) erx5j\
{ ~;M)qR?]W
System.err.println("Error Code : " + nErrorCode); 5Vp;dc
} JEWL)
3CR@' qG-
;,1=zhKU.
//停止文件下载 4_PCqEp)
public void siteStop() pOC% oj
{ f64(a\Rw!^
bStop = true; Fe!D%p Qv
for(int i=0;i<nStartPos.length;i++) ^WE4*.(
fileSplitterFetch.splitterStop(); YD&|1h
_u&>&,:q
%#~((m1
} I=K!)X$
} NO-k-
//负责部分文件的抓取 10wvfRhng
**FileSplitterFetch.java q7X}MAW
*/ r&}(9Cq&"y
package NetFox; U1ZIuDg'E
\6{krn|
qysTjGwa]
import java.io.*; iI5+P`sE&J
import java.net.*; fUC9-?(K
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&V'519vmoZ
public class FileSplitterFetch extends Thread { CuH2E>wz
!fY7"E{%%
ypx: )e"/
String sURL; //File URL 9O;cJ)tXY
long nStartPos; //File Snippet Start Position 4/S=5r}
long nEndPos; //File Snippet End Position Hd9XfU
int nThreadID; //Thread's ID Ju!(gh
boolean bDownOver = false; //Downing is over z{9=1XY
boolean bStop = false; //Stop identical M)&Io6>
FileAccessI fileAccessI = null; //File Access interface ? ^M /[@
! Tx&vtq
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException bS.s?a
{ 4&QUh+F
this.sURL = sURL; [J^
this.nStartPos = nStart; 5W/{h q8}}
this.nEndPos = nEnd; -LtK8wl^
nThreadID = id; <,"4k&0Q>V
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +`@M*kd
} q:I$EpKf?Q
HPg3`Ul
8S\RN&T$
public void run() oM!xz1kVL
{ :.kZR;
while(nStartPos < nEndPos && !bStop) 0}{'C5
{ vw2`:]Q+
{_?rh,9q
H`~;|6}]n
try{ ! QM.P t7c
URL url = new URL(sURL); j~;;l!({i
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hoa7
httpConnection.setRequestProperty("User-Agent","NetFox"); H&#{l)
String sProperty = "bytes="+nStartPos+"-"; UXT p
httpConnection.setRequestProperty("RANGE",sProperty); ~C-,G"zw&G
Utility.log(sProperty); e ^Ds
'Gx$Bj
LxLy+yC#p
InputStream input = httpConnection.getInputStream(); !\FkG8
//logResponseHead(httpConnection); B z^|SkEit
"-31'R-
T.REq4<
byte[] b = new byte[1024]; cvnB!$eji
int nRead; %Y]=1BRk}
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (D<(6?
{ #2RiLht
nStartPos += fileAccessI.write(b,0,nRead); /kgeV4]zR
//if(nThreadID == 1) )KE[!ofD
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {`(>O"_[Q
} {o0qUX>[
^Dg<Ki
sV/l5]b]
Utility.log("Thread " + nThreadID + " is over!"); O:'?n8rWL
bDownOver = true; &$'z
//nPos = fileAccessI.write (b,0,nRead); \8S~c8Z~
} Yw'NX5#)g
catch(Exception e){e.printStackTrace ();} ).5RPAP
} -`+<{NHv\
} BecPT
*>NX%by)
PRkSQ4
//打印回应的头信息 b&#DnZcf
public void logResponseHead(HttpURLConnection con) %ft &Q
{ eg/<[ A:
for(int i=1;;i++) MP^ d}FL
{ %c|UmKKi
String header=con.getHeaderFieldKey(i); b0v:12q
if(header!=null) ;{#^MD MB
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /J3ZL[o?Q
Utility.log(header+" : "+con.getHeaderField(header)); sa1h%<
else \3Pv# )
break; )w h%|
} |&3x#1A
} P`$!@T0=
|TsE-t*E}
eS+g|$cW
public void splitterStop() >&,[H:Z
{ ,](:<A)W&
bStop = true; _;1}x%4v
} >j*;vG5T
WIr2{+#
'G&{GVbXY
} r%@Lej5+
\f:z+F!6R
7ZxaPkIu&%
/* urBc=3Rz
**FileAccess.java rH8@69,B
*//文件访问(定位，写) &;i "P
package NetFox; ;G |i^
import java.io.*; ^n1%OzGK#
0AK,&nbF
"_|oWn
public class FileAccessI implements Serializable{ j.e0;! (L}
uo\ .7[1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >Dw~POMy
RandomAccessFile oSavedFile; ^3VR-u<O
long nPos; wh6yPVVF/
Q=mI9
_"@CGXu
public FileAccessI() throws IOException `x8J
{ xu5ia|gYz7
this("",0); j/`94'Y
} k%s_0 @
<BFQ:
M`YWn ;
public FileAccessI(String sName,long nPos) throws IOException ldha|s.*
{ Tm}rH]F&
oSavedFile = new RandomAccessFile(sName,"rw"); XfPFo6
this.nPos = nPos; te|?)j
oSavedFile.seek(nPos); d^03"t0O]
} N`@NiJ(O;
:W#rhuzC
>F1kR\!
public synchronized int write(byte[] b,int nStart,int nLen) (jjTK'0[
{ zGKyN@o
int n = -1; C+[%7vF1
try{ YHNR3
oSavedFile.write(b,nStart,nLen); Snp|!e
n = nLen; @"a6fn
} Y3.$G1{#0w
catch(IOException e) X cr =
{ <8,o50`B
e.printStackTrace (); >r`b_K
} dzLQI}89+k
\B F*m"lz
[B@'kwD\l
return n; j/=iMq
} CTX9zrY*T
XU!2YO)t;!
-9N@$+T
} S/|,u`g-
4[Z\ ?[
f-DL:@crU
/* Jk@]tAwoM
**SiteInfoBean.java 3LDS Z1f
*/ A.<H>=Z#O
package NetFox; H]Hv;fcC
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r/pH_@
public class SiteInfoBean { V7#v6!7A@
4BnSqwa_
EA ]+vq
private String sSiteURL; //Site's URL f}g\D#`]/
private String sFilePath; //Saved File's Path R_M?dEtE>
private String sFileName; //Saved File's Name *I}`dC[
private int nSplitter; //Count of Splited Downloading File 'iLpE7
db'/`JeK b
4XVCHs(
public SiteInfoBean() !.2<| 24
{//nSplitter的缺省值为5 8.F~k~srA
//default value of nSplitter is 5 *6HTV0jv
this("","","",5); COH<Tj
} m/#a0~dB
mF` B#
KiGp[eb
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ;&H4u)
{ z/i+EE
sSiteURL= sURL; DN4$Jva
sFilePath = sPath; R$;n)_H
sFileName = sName; y#}cC+;
this.nSplitter = nSpiltter; (&/2\0QV
}VDqj}is
s4&^D<
} zD?oXs
y% :4b@<
f~}H
public String getSSiteURL() pp9Zb.D\
{ mPq$?gdp
return sSiteURL; wAnb Di{W
} 2^?:&1:
qI^ /"k*5
n3J53| %v
public void setSSiteURL(String value) C6rg<tCH
{ NcY608C
sSiteURL = value; B"%{i-v>**
} AT5aDEb^^
%YOndIS:
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public String getSFilePath() *)+ut(x|#
{ DY[$"8Kxcp
return sFilePath; YM5fyv?
} y"Nsh>h
aL\nT XakX
#-h\.#s
public void setSFilePath(String value) znJ'iVf
{ (Vo>e =q
sFilePath = value; `5H$IP1XhA
} N/GQt\tV<
*5xJv
(%`QhH
public String getSFileName() z $MV%F
{ a ^%"7Ri
return sFileName; ^{8Gt@
} !+:ov'F
iDf,e Kk$'
u :F~K
public void setSFileName(String value) ]THPSw_y8
{ [d* ~@P
sFileName = value; _v* nlc
} j) ,,"54*
8/K!SpM*d
*28pRvY:b
public int getNSplitter() `_&Vt=7lG
{ RxQh2<?
return nSplitter; F4e:ZExJ
} TT-h;'nJ
ApjOj/
zq%D/H6J,
public void setNSplitter(int nCount) 5aa<qtUjH
{ j^`hzh3S
nSplitter = nCount; (!:cen~|[
} )Z %T27r,^
} JAI)Eqqv]
aH#l9kCb
bMU(?hb
/* z~A]9|/61v
**Utility.java ~@kU3ZGJZ
*/ H)(:8~c,p
package NetFox; ;>mCalwj
2}W0 F2*
YZ+RWu9K
public class Utility { 1 `KN]Nt
w;l<[q?_
Q3"}Hl2
public Utility() is/scv<
{ <EST?.@~+
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~/_SMPLo
} pa{re,O"e
KWWa&[ev)
//线程睡眠 1nu^F,M
public static void sleep(int nSecond) }@r{?8Ru
{ Ve 4u+0
try{ mLL340c#\
Thread.sleep(nSecond); 1LJUr"6]
} {?`al5Sz
catch(Exception e) -@ZiS^l
{ B7z -7&TE
e.printStackTrace (); ^H6<Km l/V
} V=1Bo~
} hxS 6:5Uc
R-P-i0~
//日志 ]@Sj`J[fd
public static void log(String sMsg) y7^{yS[,
{ kQ
System.err.println(sMsg); Ldn8
} CXCpqcC
5MSB dO
ce6__f5?
public static void log(int sMsg) CR|lt
{ EJ`T$JD
System.err.println(sMsg); \Y}3cE
} mZUfn%QXb(
} 3 LdQ]S
-Qn=|2Mm?
)P|[r
/* n k2om$nN
**TestMethod.java q5L51KP2
*/ vaon{2/I
package NetFox; W}|'#nR
tbO H#|
[7YPl9
public class TestMethod { IMk'#)
,[A'tUl _
CwX Z
public TestMethod() v|E"[P2e
{ ///xx/weblogic60b2_win.exe 'u` .P:u?
try{ { m|pl
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); "4%"&2L
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); *]i!fzI']
SiteFileFetch fileFetch = new SiteFileFetch(bean); 5 Qoew9rA
fileFetch.start(); b2@VxdFN
} NuU9~gSQ
catch(Exception e){e.printStackTrace ();} X(7qZ P~
(mlzg=szW
KeNL0_Pw
} oc^Br~ Th
Dk5Zh+^
0D8K=h&e
public static void main(String[] args) v<fnB
{ [NFNzwUB
new TestMethod(); wW"z
} ,<:!NF9
} 3R&lqxhg
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