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)); "aJfW
} Q;0g
for(int i=0;i<nEndPos.length-1;i++) 3\0,>L9ET@
{ }BJR/r
nEndPos = nStartPos[i+1]; D;+sStZK3
} P8n |MN
nEndPos[nEndPos.length-1] = nFileLength; K)s{D]B
} p\ _&
} o ^Ro 54i
,HtXD~N
Q> J9M`a
//启动子线程 }C<$q
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; yp"h$
for(int i=0;i<nStartPos.length;i++) _j}jh[M
{ rqz`F\A;%
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n1;zml:7_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), O7# 8g$ZIv
nStartPos,nEndPos,i); ,V.Bzf%=O
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =RjseTS
fileSplitterFetch.start(); 2dJP|T9H
} 7L$\S[E
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *`~]XM@H
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); pMLTXqL
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .1A/hAdU
nEndPos = " + nFileLength); =a!_H=+4
// fileSplitterFetch[nPos.length-1].start(); \<W/Z.}/
F6gU9=F1<
y4j\y ? T8
//等待子线程结束 H_d^Xk QZ
//int count = 0; -DL"Yw}
//是否结束while循环 dd:vQOF;
boolean breakWhile = false; ZXC_kmBN/
}}gtz-w
4{CeV7
while(!bStop) 0Q!/A5z
{ uXo?
write_nPos(); cN%@ nW0i
Utility.sleep(500); nUf0TkA
breakWhile = true; |wGmu&fY
^:Fj+d
F-%Hw
for(int i=0;i<nStartPos.length;i++) *IWWD\U
{ FqXE6^
if(!fileSplitterFetch.bDownOver) ;2[o>73F
{ kV@?Oj.&I,
breakWhile = false; rBZ0Fx$/[
break; W}'l8z]
} Mew,g:m:
} %Z+FX,AK
if(breakWhile) 3#N`n |UgC
break; g+3_ $qIQ+
UM:]QbaIn
tX~*.W:
//count++; *NCkC ~4
//if(count>4) R^&.:;Wi>
// siteStop(); 2"IDz01ne
} \Sv8c}8
@Io@1[kj
'9@AhiNV
System.err.println("文件下载结束！"); #T++5G
} K8RV=3MBLD
catch(Exception e){e.printStackTrace ();} l-$5CO
} U<I]_]
t 09-y
?.^n,[2
//获得文件长度 _0"s6D$
public long getFileSize() c'SjH".[
{ @ )Nw>/;o
int nFileLength = -1; `wKd##v'@
try{ Af Y]i
URL url = new URL(siteInfoBean.getSSiteURL()); U3~rtc*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); y 'Ah*h
httpConnection.setRequestProperty("User-Agent","NetFox"); A$70!5*
bMB*9<c~
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int responseCode=httpConnection.getResponseCode(); {'sp8:$a
if(responseCode>=400) %\T#Ik~3
{ m\G45%m
processErrorCode(responseCode); *R3^:Y&
return -2; //-2 represent access is error <b-OdOg
} |cgc^S/~H
{$Z S 27
Tly*i"[&
String sHeader; SvQ!n4 $
*yYeqm
8(g}/%1mt3
for(int i=1;;i++) p# JPLCs
{ _6-N+FI
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); HT7I~]W
//Utility.log(in.readLine()); -f["1-A
sHeader=httpConnection.getHeaderFieldKey(i); )zkr[;j~`
if(sHeader!=null) r-o+NV
{ @cc}[Uw4B
if(sHeader.equals("Content-Length")) lJdrrR)wg
{ ai"N;1/1O|
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 8Y [4JXUK
break; v^aI+p6
} 9XmbHS[0V
} pgBIYeY,
else YRQ?:a{H
break; %OOy90b2
} i,,mt_/,
} P"+R:O\!g
catch(IOException e){e.printStackTrace ();} XZT|ID_u"
catch(Exception e){e.printStackTrace ();} O Ke 9/._
JqV}$E"M2
ogqKM_
Utility.log(nFileLength); :9f 9Z7M
AjJ/t4<
kn+@)3W:*
return nFileLength; |E&|6h1
} v%7Gh-P
W@RD bsc
Z-3("%_$/
//保存下载信息（文件指针位置） gfiFRwC`v
private void write_nPos() w|f@sB>j
{ Hi^Z`97c
try{ rJ(AO'=
output = new DataOutputStream(new FileOutputStream(tmpFile)); Vi#[kn'
output.writeInt(nStartPos.length); wb ^>/
for(int i=0;i<nStartPos.length;i++) 6Ev+!!znu
{ Tnas$=J
// output.writeLong(nPos); WO$8j2!~#
output.writeLong(fileSplitterFetch.nStartPos); F`>qg2wO
output.writeLong(fileSplitterFetch.nEndPos); x"A\Z-xxz
} = u&dU'@q
output.close(); f9t+x+ Z
} I#;.;%u
catch(IOException e){e.printStackTrace ();} 3gYtu-1
catch(Exception e){e.printStackTrace ();} <?h(Dchq
} r`i.h ^2De
8X/SNRk6p
G 2uM6
//读取保存的下载信息（文件指针位置） Z/q'^PB p
private void read_nPos() yji>vJHu
{ ?*6Q;.f<
try{ ni6zo~+W]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }(oWXwFb&W
int nCount = input.readInt(); xeKm} MN]S
nStartPos = new long[nCount]; \H 5t-w=
nEndPos = new long[nCount]; 8%p+:6kP5
for(int i=0;i<nStartPos.length;i++) pZ]&M@Ijp
{ <) -]'@*c
nStartPos = input.readLong(); 5=V29
nEndPos = input.readLong(); t ?05
} 5"bg8hL
input.close(); [LrO"9q(
} zb s7G
catch(IOException e){e.printStackTrace ();} VVfTFi<
catch(Exception e){e.printStackTrace ();} O^8=Xj#}
} (yoF
7!;zkou
V P(JV
private void processErrorCode(int nErrorCode) 7Kpv fyL{
{ G?!8T91;
System.err.println("Error Code : " + nErrorCode); *+(eH#_2/
} AC!yc(^<
nI] zRduC
S5r.so
//停止文件下载 ^S 45!mSb
public void siteStop() n8JM 0 U-
{ aSI%!Vg.
bStop = true; MRT<hB
for(int i=0;i<nStartPos.length;i++) ]Bs{9=2
fileSplitterFetch.splitterStop(); FGeKhA 8jT
"whs?^/
fcy4?SQ.<i
} /N,\st
} ,eSpt#M
//负责部分文件的抓取 7jGfQ
**FileSplitterFetch.java 0}po74x*r
*/ CZ>Ujw=&k
package NetFox; qRz /$|.
nRT]oAi
])q,mH
import java.io.*; uX%$3k
import java.net.*; w-C%,1F,/
TaF;PGjVw
QB !%
public class FileSplitterFetch extends Thread { <U8w#dc
T7o7t5*
q s:TR
String sURL; //File URL C=2DxdZG
long nStartPos; //File Snippet Start Position bf.yA:~U
long nEndPos; //File Snippet End Position nWhf
int nThreadID; //Thread's ID hZWkw{c
boolean bDownOver = false; //Downing is over \7IT[<Se
boolean bStop = false; //Stop identical (iIzoEpb8W
FileAccessI fileAccessI = null; //File Access interface x:h)\%Dg<
)`6OSB
[.6bxK
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #o,FVYYj
{ cucT|y
this.sURL = sURL; PDLps[a
this.nStartPos = nStart; =5:S"WNj
this.nEndPos = nEnd; 74&{GCL
nThreadID = id; -9Ygn_M
fileAccessI = new FileAccessI(sName,nStartPos);//定位 aj=-^iGG
} /1uGsE+[
h iK}&
;=1[D
public void run() 4UK>Vzn
{ fPstSez
while(nStartPos < nEndPos && !bStop) F!w|5,)
{ KTwP.!<v
?{xD{f$
cob??|,\m
try{ |?hsMN
URL url = new URL(sURL); 8k+k\V{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [ $"
httpConnection.setRequestProperty("User-Agent","NetFox"); #K iqV6E
String sProperty = "bytes="+nStartPos+"-"; K@Xj)
httpConnection.setRequestProperty("RANGE",sProperty); @VyNe(U
Utility.log(sProperty); l}k'ZX4
mx#)iHY
sCp)o,;
InputStream input = httpConnection.getInputStream(); DghqSL^s
//logResponseHead(httpConnection); =NSunW!
Zv*uUe
AYfe_Dj
byte[] b = new byte[1024]; nc1?c1s,f
int nRead; vZs~=nfi#|
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3+q-yP#X
{ j8]M}Q$
nStartPos += fileAccessI.write(b,0,nRead); P>$+XrTE
//if(nThreadID == 1) |;^$IZSsz
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); lR mVeq:
} }SyK)W5Y
THB[(3q
e@S\7Ks
Utility.log("Thread " + nThreadID + " is over!"); q8,,[R_
bDownOver = true; k~F,n
//nPos = fileAccessI.write (b,0,nRead); *I}_g4
} hS>=pO+y
catch(Exception e){e.printStackTrace ();} Qstd;qE~
} wDW/?lT&
} M(uJ'Ud/!
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de[NIDA;`
//打印回应的头信息 0-57_";%Q
public void logResponseHead(HttpURLConnection con) zQUNvPYM
{ 25r3[gX9`
for(int i=1;;i++) '@IReMl
{ 2=%]Ax"R
String header=con.getHeaderFieldKey(i); fhNJB0
if(header!=null) !89hO4 0r
//responseHeaders.put(header,httpConnection.getHeaderField(header)); gvL*]U7
Utility.log(header+" : "+con.getHeaderField(header)); madbl0[y.
else woF{O)~X
break; )J2UNIgN
} ~=<uYv?0s
} Cv4nl7A'
$iA:3DM07
,]y_[]636
public void splitterStop() J aJ/|N
{ e AaS }g 0
bStop = true; ~-uDN)
} '(ZT}N
OYb:);o,iE
JNP6qM
} ^t$uDQ[hA
;Cjj_9e,:
dxH.
/* y(E<MRd8V
**FileAccess.java Z|)1ftcC
*//文件访问(定位，写) {~G~=sC$
package NetFox; 4r86@^c*
import java.io.*; _'^_9u G
g_?Q3
0kw)-)=
public class FileAccessI implements Serializable{ 6$zd2N?
,DEcCHr,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 563ExibH
RandomAccessFile oSavedFile; N^k& 8
long nPos; 7{9M ^.}
ic l]H
=EU;%f
public FileAccessI() throws IOException zZey
{ d#W^S[[
this("",0); Lf%}\0:
} ,4B8?0sH|
}r;=<mc,O
YN7`18u
public FileAccessI(String sName,long nPos) throws IOException &5G@YQD1e
{ q]*jTb
oSavedFile = new RandomAccessFile(sName,"rw"); cmq4w&x/
this.nPos = nPos; e-1G\}E
oSavedFile.seek(nPos); 'q RQO(9&m
} +oHbAPs8
ou`KkY||
qG9j}[d'
public synchronized int write(byte[] b,int nStart,int nLen) $D D esy3
{ /s+S\ djk
int n = -1; -"^xg"
try{ rhly.f7N=A
oSavedFile.write(b,nStart,nLen); ug;~dhe~
n = nLen; ~&+a.@T
} eZ0-O /_i
catch(IOException e) EB6X Yr
{ 7@m+y
e.printStackTrace (); }OTJ{eG
} z2!4w +2
%%)y4>I
x3.,zfWs
return n; j*;.>akY7
} \~t!M~H
TmM~uc7mj
%az6\"n
} xO,;4uE
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?{5}3abB`
/* X|QokAR{$>
**SiteInfoBean.java .])X.7@x
*/ X\i;j!;d
package NetFox; S/RChg_L5
(Jk[%_b>_
Gvvw:]WgF
public class SiteInfoBean { wfcR[
1?.NJ<)F
{vZAOz7#
private String sSiteURL; //Site's URL u`Y~r<?P(
private String sFilePath; //Saved File's Path 4x@W]*i
private String sFileName; //Saved File's Name obPG]*3
private int nSplitter; //Count of Splited Downloading File }7P[%(T5
p{``a=
GCv1x->
public SiteInfoBean() _>?.MUPB
{//nSplitter的缺省值为5 Q:T9&_|
//default value of nSplitter is 5 n.R"n9v`
this("","","",5); cRNVqMpg
} GdrVH,j
S2W@;XvV
^\Q%VTM
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) M=SrZ,W
{ >J_P[v
sSiteURL= sURL; {))Cb9'
sFilePath = sPath; |YfJ#Agm+
sFileName = sName; ?[Ma" l>
this.nSplitter = nSpiltter; 6:`[Fi
&2O~BIRE
>m{>0k(^`
} [nrD4
QXl~a%lB
jpTk@
public String getSSiteURL() oL<5hN*D
{ _#{qDG=
return sSiteURL; 4mpcI
} G|"m-.9F
UISsiiG(
.3cD.']%
public void setSSiteURL(String value) % I2JS
{ gFfKK`)}D'
sSiteURL = value; \ Z5160
} peOoZdJd
5P 5Tgk
cR*~JwC:
public String getSFilePath() AEElaq.B
{ ,068IEs
return sFilePath; +ef>ek
} nNnfcA&W
=En1?3?
_9Rj,
public void setSFilePath(String value) R\/tKZJjb
{ _5$L`&
sFilePath = value; crSqbL
} Y4X`(\A
@e$EwCV,
jR@>~t[}o
public String getSFileName() $d,{I8d
{ s'IB{lJ9
return sFileName; l m(mY$B*_
} >$=l;jO`n
xh!T,|IR
Gm0}KU
public void setSFileName(String value) C',uY7}<
{ pr,1pqiAf
sFileName = value; AI9922}*
} TgJ6O,0
\$F#bIjC
HMmVfGp]
public int getNSplitter() y-gXGvZ
{ Pj{I}4P`
return nSplitter; =U8+1b
} )a`kL,
g@Y]$ey%A
kVG+Wr7l0F
public void setNSplitter(int nCount) HnsLYY\
{ BqdpJIr
nSplitter = nCount; e+>$4Jq
} n1PvZ~^3
} yw89*:A6
bMv[.Z@v(
\%V !& !'
/* S?OCy4dk:
**Utility.java Z/4bxO=m
*/ "s(|pQh;
package NetFox; ~lqNWL^l
Ap|g[J
OIjG`~Rx
public class Utility { DNyt_5j&:
:2:%
C#3&,G W
public Utility() 0V`~z-#
{ ZjrBOb
x;LO{S4Z
b5f+q:?{
} -mLu!32I<
'UZ i>Ta
//线程睡眠 $*Wa A`(U
public static void sleep(int nSecond) &h=f
{ fGe"1MfU
try{ W2M[w_~QE
Thread.sleep(nSecond); %dhrXK5
} 1'dZ?`O
catch(Exception e) ;sz_W%-;@
{ +OtD@lD`!
e.printStackTrace (); ((^vsKT
} `Ao"fRv#
} +$/NTUOP
#yEkd2Vy{
//日志 vu*9(t)EC
public static void log(String sMsg) Q7/Jyx|
{ bBGg4{
System.err.println(sMsg); lEb H4 g
} $~?)E;S
e:_[0#
mmCGIX
public static void log(int sMsg) lTtc#
{ C+mPl+}w
System.err.println(sMsg); D}-HWJQA3
} P*hYh5a
} !FB2\hiM
1CV?
9[`\ZGWD
/* f2v~: u
**TestMethod.java (#>Q#Izr
*/ x`'s
package NetFox; v3kT~uv
47A[-&y*X
j)juvat
public class TestMethod { 57;( P
s!Iinc^p
h///
public TestMethod() Mt%Q5^
{ ///xx/weblogic60b2_win.exe I7t}$S6
try{ Qkw_9
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); V|{~9^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); gI@nE:(m
SiteFileFetch fileFetch = new SiteFileFetch(bean); &b2@+/ F
fileFetch.start(); .v9i|E=<~
} BrZ17
catch(Exception e){e.printStackTrace ();} Q^?$2ck=
{?X +Yw
;CV'
} RtDTcaW/
g|4>S<uC
^?0?*
public static void main(String[] args) %(s2{$3
{ ma"M?aM
new TestMethod(); A v;NQt8ut
} 1 7iw`@
} %uo#<Ny/ I
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