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)); c?3F9w#
} 19YJ`(L`x
for(int i=0;i<nEndPos.length-1;i++) VgC9'"|
{ ;29XvhS8
nEndPos = nStartPos[i+1]; [gg7Z|Hu
} 51FK~5
nEndPos[nEndPos.length-1] = nFileLength; -+S~1`0
} aaa#/OWQZ
} /9vMGef@
59%f|.Z)
VQW)qOR9
//启动子线程 \Kzt*C-ZH
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; T\b";+!W
for(int i=0;i<nStartPos.length;i++) si"mM>e
{ 4'4s EjyA
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'zD;:wT
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), w|UKMbRMU]
nStartPos,nEndPos,i); Kt&$Si
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0Ts_"p
fileSplitterFetch.start(); FO3eg"{N
} Wp~4[f`,
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #I{Yf(2Z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); tRrY)eElS
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", w _6Y+
nEndPos = " + nFileLength); I5<#SW\a?
// fileSplitterFetch[nPos.length-1].start(); piM11W}|/
p6k'Q
Xk9r"RmiOb
//等待子线程结束 77bZ
//int count = 0; w]P7!t
//是否结束while循环 ]F)-}
boolean breakWhile = false; k`J..f9
\kJt@ [w%
Gv2./<{#
while(!bStop) x2IU PM
{ JI#Enh!Lv
write_nPos(); L|xen*O
Utility.sleep(500); &.bR1wX
breakWhile = true; :tS>D5dz(
zZjLt1
u g$\&rM>
for(int i=0;i<nStartPos.length;i++) Z=5}17kA
{ YPJx/@Z`
if(!fileSplitterFetch.bDownOver) uP'w.nA&2
{ -~GJ; Uw
breakWhile = false; %K f. F
break; Hn'2'Vu
} t-gNG!B
} hq[gj?P
if(breakWhile) nJ0eZBgB]
break; z o))x(
QRG)~
:8!3*C-=
//count++; E1 gTrMo
//if(count>4) qYiK bzy
// siteStop(); :g:h 0'G
} Pge}xKT
YM/3VD
rOf
System.err.println("文件下载结束！"); )Ai%wCzw*
} F p=Q$J|
catch(Exception e){e.printStackTrace ();} YKxA2`3v%
} tVh4v#@+
Y>!W&Gtu
R~c vml
//获得文件长度 oHFDg?Z`
public long getFileSize() Z.OrHg1
{ i}{Q\#=#
int nFileLength = -1; -3%)nV
try{ <|.! Px86
URL url = new URL(siteInfoBean.getSSiteURL()); +jZg%$Q!#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); N#!1@!2BN
httpConnection.setRequestProperty("User-Agent","NetFox"); 9^*YYK}%
='||BxB
GyM%vGl 3
int responseCode=httpConnection.getResponseCode(); v.&*z48
if(responseCode>=400) NHVx!Kc
{ *RE-K36m|u
processErrorCode(responseCode); |[7$) $
return -2; //-2 represent access is error nZ+5@( *
} l7y`$8Co
)0V]G{QN
6@*;Wk~
String sHeader; `Ta(P30
KGwL09)
?D 9#dGK
for(int i=1;;i++) ph (k2cb
{ 8GRrf2
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !*. nR(>d
//Utility.log(in.readLine()); 0aoHv
sHeader=httpConnection.getHeaderFieldKey(i); v5ddb)
if(sHeader!=null) f<:SdtG5
{ w*kFtNBfU
if(sHeader.equals("Content-Length")) h_"/@6
{ {%~Ec4r
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); f]65iE?x
break; ewPdhCK
} Bo(l!G
} 9NXiCP9A
else d?X6x
break; {h+E&u[zL
} RKb3=} *C
} m)2hl~o_
catch(IOException e){e.printStackTrace ();} wyEgm:Vt
catch(Exception e){e.printStackTrace ();} [!efQap
-"fq34v
CKw)J}z
Utility.log(nFileLength); <Y'YpH`l
w3UJw
_ShJ3\,K
return nFileLength; /4BXF4ksi,
} s(LqhF[N2]
qinQ5t
r>@/XYK&\
//保存下载信息（文件指针位置） O*CX@Ne
private void write_nPos() uKzz/Y{
{ 717m.t,x
try{ T0)y5
output = new DataOutputStream(new FileOutputStream(tmpFile)); ? NK}q\$
output.writeInt(nStartPos.length); /s_$CSiB
for(int i=0;i<nStartPos.length;i++) )F2tV ]k\
{ =+\oL!^
// output.writeLong(nPos); KTJ$#1q
output.writeLong(fileSplitterFetch.nStartPos); +6-!o,(
output.writeLong(fileSplitterFetch.nEndPos); lhODNWi
} KA2B3\
output.close(); )yAPYC
} zXPj7K*
catch(IOException e){e.printStackTrace ();} w'>v@`y
catch(Exception e){e.printStackTrace ();} 5E(P,!-.
} WX"M_=lc-@
nQVBHL>
&y+*3,!n8
//读取保存的下载信息（文件指针位置） yKhzymS}T
private void read_nPos() FJiP>S[]
{ N Uml"
try{ BJrNbo;T
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +'4dP#
int nCount = input.readInt(); d0,F'?.0|
nStartPos = new long[nCount]; )q-!5^ak
nEndPos = new long[nCount]; jd'R2e
for(int i=0;i<nStartPos.length;i++) He23<hd!
{ Y)RikF >
nStartPos = input.readLong(); O:R{4Q*5
nEndPos = input.readLong(); $QnfpM%+=
} 0P >dXd)T
input.close(); yln.E vJjD
} g5\B-3{
catch(IOException e){e.printStackTrace ();} \H12~=p`B
catch(Exception e){e.printStackTrace ();} en":
} Lj,%pzJ
@SB+u+mOS
r\`m[Q
private void processErrorCode(int nErrorCode) s``L?9
{ oI/ThM`=q
System.err.println("Error Code : " + nErrorCode); LvdMx]*SSr
} @h3)!#\N
'm:B(N@+
|sAg@kM
//停止文件下载 {`
public void siteStop() PdnK@a
{ 8~>3&jX
bStop = true; e/Y+S;a
for(int i=0;i<nStartPos.length;i++) x{5*%}lX8
fileSplitterFetch.splitterStop(); i i Y[
Yw `VL)v(y
$sJfxh r
} ?K#$81;[
} w5\)di
//负责部分文件的抓取 \}W.RQ^3
**FileSplitterFetch.java 2uEu,YC
*/ N*W.V,6yH
package NetFox; #1k,t
ocUu
w:v:znQrW
import java.io.*; .ji%%f
import java.net.*; j=4>In?x
,Fiiw
M?lr#}d
public class FileSplitterFetch extends Thread { B\yid@e
Yd'ke,Je
TXv#/@
String sURL; //File URL !y.7"G*
long nStartPos; //File Snippet Start Position 3\ed4D
long nEndPos; //File Snippet End Position &|eQLY #l
int nThreadID; //Thread's ID 3.Kdz}
boolean bDownOver = false; //Downing is over }X-ggO,
boolean bStop = false; //Stop identical qMOD TM~+
FileAccessI fileAccessI = null; //File Access interface `!N?#N:b)
zZ-*/THB@R
n9DFa3
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Tr)[q>
{ RqR X
this.sURL = sURL; ^`THV
this.nStartPos = nStart; cyyFIJj]
this.nEndPos = nEnd; [E1I?hfJ
nThreadID = id; g^FH[(P[G
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2t<CAKBB
} )1le-SC
j*}xe'#
|Sm/Uq(c
public void run() 8qveKS]vZ
{ zT8K})#
while(nStartPos < nEndPos && !bStop) T8LwDqio
{ F_`Gs8-VH
hrK^oa_[W
IT|CfQ [D
try{ pP&~S<[
URL url = new URL(sURL); Lq.k?!D3uh
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |n;7fqK
httpConnection.setRequestProperty("User-Agent","NetFox"); 4<|]k?@
String sProperty = "bytes="+nStartPos+"-"; 2z:9^a/]Na
httpConnection.setRequestProperty("RANGE",sProperty); qS>el3G
Utility.log(sProperty); A\>qoR!Y
f{0PLFj
[PT}!X7h
InputStream input = httpConnection.getInputStream(); gqd#rjtfz
//logResponseHead(httpConnection); vSh)r 9
::6@mFLR
NG ~sE&,7
byte[] b = new byte[1024]; XOMWqQr|
int nRead; *RhdoD|a
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .E(Ucnz/
{ q=U=Y n
nStartPos += fileAccessI.write(b,0,nRead); hE${eJQ| U
//if(nThreadID == 1) fqxMTTg@
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ryPzq}#
} p{Uro!J,K
XQ>m8K?\d
utv.uwfat
Utility.log("Thread " + nThreadID + " is over!"); %-D2I
bDownOver = true; eo!{rs@f
//nPos = fileAccessI.write (b,0,nRead); umk[\}Ip+P
} PYGHN T
catch(Exception e){e.printStackTrace ();} *P>F# ~X
} u56cT/J1
} c{[WOrA~#
H`sV\'`!}
TD'1L:mv
//打印回应的头信息 oT OMqR{"
public void logResponseHead(HttpURLConnection con) %0 S0"t
{ v2NzPzzyb
for(int i=1;;i++) S"*wP[d.9
{ zKo,B/Ke4
String header=con.getHeaderFieldKey(i); Pg7/g=Va
if(header!=null) _F3:j9^
//responseHeaders.put(header,httpConnection.getHeaderField(header)); G9;WO*
Utility.log(header+" : "+con.getHeaderField(header)); kN)P-![
else 8Pq|jK "
break; c;VW>&,B
} Onao'sjY
} $P$OWp?b
B4%W,F:@
\RJ428sxn
public void splitterStop() w5p+Yx=q
{ UWz<~Vy
bStop = true; F{v+z8nW
} L]Uy+[gg
`J;_!~:
x(A.^Yz
} GKX#-zsh79
IIzdCa{l
n=`UhC
/* EG,RlmcPp
**FileAccess.java z[th@!3
*//文件访问(定位，写) RaR$lcG+iY
package NetFox; (c;$^xZK
import java.io.*; ;tO(,^
IsI\T8yfc
ffdyDUzQ
public class FileAccessI implements Serializable{ ^vUdf.n9
9!tRM-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 WK-WA$7\
RandomAccessFile oSavedFile; 6H@=O1W
long nPos; ]O^!P,l)"
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DF<_Ns!
public FileAccessI() throws IOException YkTEAI|i
{ _95V"h
this("",0); xRb-m$B}L
} E=7~\7TE
J^U#dYd
*g7dB2{
public FileAccessI(String sName,long nPos) throws IOException >>p3#~/
{ tcfUhSz,I
oSavedFile = new RandomAccessFile(sName,"rw"); RDZl@ps8
this.nPos = nPos; koFY7;_<?
oSavedFile.seek(nPos); k@^)>J^
} R4{2+q=0
)]'?yS"
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public synchronized int write(byte[] b,int nStart,int nLen) Lf3:' n
{ cJ&%XN
int n = -1; {{j?3O//
try{ Wcbb3N$+
oSavedFile.write(b,nStart,nLen); +PjH2
n = nLen; Eg>MG87
} _jp8;M~Z
catch(IOException e) F9N)UW:w
{ M%Ov6u<I8
e.printStackTrace (); tT'+3
} 7cH[}v`pn
G0^NkH,k
0GEK xV\F
return n; jvA]EN6$;~
} HKV]Rn
lCDXFy(E
nI&Tr_"tm
} ;a2TONW
42mdak}\
C*=#=.~~{
/* p "u5wJ_
**SiteInfoBean.java |oa9 g2
*/ IWX%6*Zz
package NetFox; !ce5pA
ZdfIe~Oni
lIz"mk
public class SiteInfoBean { IZ"d s=w
vn7<>k>dx
>O?5mfMK
private String sSiteURL; //Site's URL ex1bjM7
private String sFilePath; //Saved File's Path |\J8:b>}
private String sFileName; //Saved File's Name __OD^?qa
private int nSplitter; //Count of Splited Downloading File WOiw 0
1jpcoJ@s
"*a^_tsT?i
public SiteInfoBean() /2 ')u|
{//nSplitter的缺省值为5 gq!|0
//default value of nSplitter is 5 1d,;e:=j
this("","","",5); hT]\*},
} s%GhjWZS
CNQ>J`4
yc?+L;fN
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) C[z5& x2
{ t[|^[%i
sSiteURL= sURL; q3n(Z
sFilePath = sPath; 1)U%p
sFileName = sName; n]jZ2{g+
this.nSplitter = nSpiltter; >d%;+2
\hoYQK j
;b-Y$<
} ^^1rjh1I
QE1DTU
#**vIwX-Q
public String getSSiteURL() l.Iov?e1S
{ |hk?'WGc`0
return sSiteURL; gq\ulLyOeZ
} $n.oY5=\
XDRw![H,~
gmd-$%"
public void setSSiteURL(String value) fO|oV0Rw
{ )5Mf,
sSiteURL = value; [9Q}e;T
} v2][gn+58
WW\t<O;z
S3l$\X;6X
public String getSFilePath() }&M$
{ +zn&DG0\X
return sFilePath; U=QfInB
} Z:j6AF3;
b=(?\
QpbyC_:;$4
public void setSFilePath(String value) c0h:Vqk-
{ dz3chy,3
sFilePath = value; 9Kf# jZ
} {]ie|>'=C
J=Q?_$xb}
u2}zRC=
public String getSFileName() =wE1j
{ '[V}]Z>-
return sFileName; x=s=~cu4,
} 5F&xU$$a-
8$4@U;Vh;
Y=94<e[f"
public void setSFileName(String value) no).70K
{ M@%$9N)gd
sFileName = value; KElzYZl8
} &iYy
jg%HaA<zO
\qk+cK;+
public int getNSplitter() apFY//(yu
{ Uskz~~}G
return nSplitter; :.u[^_
} tgz
ksb.]P d.
*c<0cHv*
public void setNSplitter(int nCount) *PEk+e
{ 0@ccXFE
nSplitter = nCount; " b?1Yc-
} w&VMb&<
} ti%uyXfja
#ub!
OZ2YflT
/* NWx.l8G
**Utility.java y{{7)G
*/ Tp-<!^o4
package NetFox; KPW2e2{4@
j6@5"wx
bUJ5jkZ)
public class Utility { 5^:N]Mp"
fZ8at
z;fi
public Utility() ii,/omn:
{ (?[^##03MN
E6 glR
-`knSR
} `GGACH3#s
hqr V {c
//线程睡眠 t.f#_C\
public static void sleep(int nSecond) mV\QZfoF
{ YhpNeP{A
try{ gpt98:w:
Thread.sleep(nSecond); +T\c<lJ9
} B{`4"uEb$G
catch(Exception e) ea7l:(C
{ <S/`-/=2
e.printStackTrace (); LY>-kz]
} 8~q%H1[I\N
} o'uv5asdb
-^a?]`3_v
//日志 60*;a*cy
public static void log(String sMsg) #A&(b}#:o
{ Nw74T
System.err.println(sMsg); YSQB*FBz
} tp4/c'w;)J
~k}>CNTr
(+_i^SqK
public static void log(int sMsg) ah1DuTT/G
{ 8+gti*C?\
System.err.println(sMsg); Yr7%C
} iPnu *29
} EUxkYl
4O~E4" ]
)}{V#,xz@
/* l,(Mm,3
**TestMethod.java eJh4hp;x
*/ _4H}OGZI
package NetFox; <X5'uve
3)5Gzn
6L`{oSX!
public class TestMethod { Q $wa<`
$8kQM
Mwm=r//
public TestMethod() _9@D o6
{ ///xx/weblogic60b2_win.exe ,VtrQb)Yf
try{ ~Z ,bd$
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); <M//zXa
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); O^tH43C
SiteFileFetch fileFetch = new SiteFileFetch(bean); }digw(
fileFetch.start(); .Fdqn?c|+
} Q"2t:
catch(Exception e){e.printStackTrace ();} GoVB1)
G'*_7HD
zP[_ccW@
} _3G;-iNX;
W`$D*X0*o
|(mr&7O
public static void main(String[] args) -]!m4xvK
{ v7;zce/~
new TestMethod(); J|ni'Hb
} ubq4Zv7'
} hN~]$"@2
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