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)); !9]q+XefJ
} 9FcH\2J
for(int i=0;i<nEndPos.length-1;i++) !JnxNIr&i|
{ 5XF&yYWq
nEndPos = nStartPos[i+1]; [t+qYe8
} R&@NFin
nEndPos[nEndPos.length-1] = nFileLength; 5-.{RU=
} VX,@Gp_'m
} +O?`uV
7z9[\]tt
6>F1!Q
//启动子线程 iXD=_^^o .
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 4\iy{1{E,C
for(int i=0;i<nStartPos.length;i++) O_^ uLp
{ naiy] oY"
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7f\/cS^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), m:5x"o7)ln
nStartPos,nEndPos,i); w(UZmZb}
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); y7-daek
fileSplitterFetch.start(); b0h>q$b
} 'tMS5d)4:
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), C`b)}dY
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (/gMtIw
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", VNHt ]Ewj
nEndPos = " + nFileLength); mJa8;X!r6
// fileSplitterFetch[nPos.length-1].start(); yCZ[z A
x4[ Fn3JL
9B2`FJ
//等待子线程结束 {IT;g9x
//int count = 0; r)Fd3)e
//是否结束while循环 KJCi4O&
boolean breakWhile = false; .7r$jmuFs
"J*LR
P;[>TCs ]8
while(!bStop) @h)X3X
{ K?H(jP2mpM
write_nPos(); aKk0kC
Utility.sleep(500); QI{<q<
breakWhile = true; S\W&{+3
02mu%|"
*Fz#x{zt
for(int i=0;i<nStartPos.length;i++) am#(ms
{ u%rB]a$/
if(!fileSplitterFetch.bDownOver) p^i]{"sjbU
{ <n)R?P(or
breakWhile = false; <G#z;]N
break; {6brVN.V
} gfmaO]
} 8!VFb+
if(breakWhile) $,#,yl ol
break; d&5GkD.P
>? ({
,Z p9,nf
//count++; ljRR{HOl
//if(count>4) uq_h8JH$
// siteStop(); bs_"Nn?
} )!``P?3?
I=3e@aTZ,
g)Byd\DS
System.err.println("文件下载结束！"); jW-j+WGSM
} \Ow-o0
catch(Exception e){e.printStackTrace ();} .h8%zB#|i
} 2W=( {e)$
M7(vI4V
( |1 $zF+
//获得文件长度 [[PUK{P0
public long getFileSize() eiF!yk?2
{ f*g>~!
int nFileLength = -1; Gd~Xvw,u
try{ $3!j1
URL url = new URL(siteInfoBean.getSSiteURL()); q($lL~Ls
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .Jz$)R
httpConnection.setRequestProperty("User-Agent","NetFox"); 8E/]k\
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1@Bq-2OD4
int responseCode=httpConnection.getResponseCode(); A`7uw|uO$
if(responseCode>=400) MO:##C
{ x,js}Mlw
processErrorCode(responseCode); r6Z&i^cMe
return -2; //-2 represent access is error A^JeB<, 5a
} ehXj.z
mj<(qZh
`"M=ZVk
String sHeader; vhEPk2wD,
(]>c8;o#b
:9c QK]O6
for(int i=1;;i++) 6@!<'l%z
{ WB5[!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !$St=!
//Utility.log(in.readLine()); kAf:_0?6
sHeader=httpConnection.getHeaderFieldKey(i); K|Std)6
if(sHeader!=null) Cdiu*#f
{ 6ndt1W z
if(sHeader.equals("Content-Length")) A[;R_
{ j;1X-
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); !3$Ph
break; =4/lJm``
} qbHb24I
} `>'E4z]-_
else cW26TtU(
break; 1Xt%O86
} =cM\o{ q
} -O\!IXG^
catch(IOException e){e.printStackTrace ();} S*IF/ fu
catch(Exception e){e.printStackTrace ();} }X)mZyM[
{*`qL0u]^
X&TTw/J!^
Utility.log(nFileLength); w=s:eM@
!BP/#
vR3'B3y
return nFileLength; X.}:gU-
} zdzTJiY2[Z
),mKEpf
p}.L]Y
//保存下载信息（文件指针位置） [,3o
private void write_nPos() kKr7c4q
{ #pErGz'{
try{ /9,!)/j
output = new DataOutputStream(new FileOutputStream(tmpFile)); b<P9@h~:
output.writeInt(nStartPos.length); C,P>7
for(int i=0;i<nStartPos.length;i++) |,cQJ
{ +)h*)
// output.writeLong(nPos); 2w>WS#
output.writeLong(fileSplitterFetch.nStartPos); I} m\(TS-"
output.writeLong(fileSplitterFetch.nEndPos); V##=-KZ
} qT$;ZV #
output.close(); {`2! 3= "
} (/UW}$] h
catch(IOException e){e.printStackTrace ();} D[32t0
catch(Exception e){e.printStackTrace ();} ?f f!(U
} NF8'O
5Iinen3>
6<X.]"u+E~
//读取保存的下载信息（文件指针位置） `2-6Qv
private void read_nPos() 7DZxrVw
{ }%Mj`Bh
try{ nb-]fa
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); (mbC! !>
int nCount = input.readInt(); j3>0oe!
nStartPos = new long[nCount]; 0<tce
nEndPos = new long[nCount]; `W>cA64 o
for(int i=0;i<nStartPos.length;i++) zwJB.4@
{ jB)RvvMU5
nStartPos = input.readLong(); 1<|\df.
nEndPos = input.readLong(); >wSrllmj@
} B1^9mV'O
input.close(); =;L44.,g
} #(pY~\
catch(IOException e){e.printStackTrace ();} Mo'6<"x
catch(Exception e){e.printStackTrace ();} t[e`wj+qz
} 7&`Yl[G
$y$E1A6h+
!kW~s_gUb*
private void processErrorCode(int nErrorCode) E$"`|Df
{ V$Zl]f$S
System.err.println("Error Code : " + nErrorCode); #i;y[dQ
} [AHoTlPZ
[,yYr
jR[b7s
//停止文件下载 pqF!1
public void siteStop() }PUY~ u
{ L3;cAb/
bStop = true; *";O_ :C!
for(int i=0;i<nStartPos.length;i++) #O1%k;BL
fileSplitterFetch.splitterStop(); frRO?
O77^.B
U|~IJU3-
} AA XQ+!
} nV/;yl4e{
//负责部分文件的抓取 Dqg01_O9O
**FileSplitterFetch.java 8&wN9tPYZ
*/ K''2Jfm
package NetFox; M@=VIrX,m
HhB&vi
E_H.!pr
import java.io.*; BIxjY!!"
import java.net.*; R*O<(
~o27~R ]
,56objaE
public class FileSplitterFetch extends Thread { \ZtF,`Z
o&RNpP*
M.K%;j`
String sURL; //File URL ebiOR1)sN
long nStartPos; //File Snippet Start Position MI,kKi
long nEndPos; //File Snippet End Position ;4<!vVf e
int nThreadID; //Thread's ID s&L 6C[
boolean bDownOver = false; //Downing is over }{F1Cr
boolean bStop = false; //Stop identical R]" jr
FileAccessI fileAccessI = null; //File Access interface &5n0J
J_d!` Hhe
.9!?vz]1
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException wY*tq{7
{ ]L_h3Xz\X
this.sURL = sURL; \s_`ZEB
this.nStartPos = nStart; )<vuv9=k\%
this.nEndPos = nEnd; h[oI/X
nThreadID = id; ]SG(YrF
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^ ^k]2oG
} _e$T'*q
nP#|JRn=
'?uwUBi
public void run() dZ`c
{ R?iC"s!
while(nStartPos < nEndPos && !bStop) ,dXJCX8so
{ s5J?,xu
1fqJtP6
4KB>O)YNg'
try{ =:_DXGW2H
URL url = new URL(sURL); L)X[$:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wf2v9.;X:<
httpConnection.setRequestProperty("User-Agent","NetFox"); "wnN 0 p
String sProperty = "bytes="+nStartPos+"-"; &n~v;M
httpConnection.setRequestProperty("RANGE",sProperty); ;S+]Z!5LT
Utility.log(sProperty); .qS(-7<
QE+HL8c^s
1C+d&U
InputStream input = httpConnection.getInputStream(); Wgb L9'}B
//logResponseHead(httpConnection); {'z(
/@Ec[4^=!.
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byte[] b = new byte[1024]; 1.I58(0~+
int nRead; )8%m|v#W
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0+Z?9$a1
{ \S0QZQbz/
nStartPos += fileAccessI.write(b,0,nRead); i,!tu
//if(nThreadID == 1) $7*@TMX
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cs?IzIQ
} "f:_(np,
)6{,y{5!
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Utility.log("Thread " + nThreadID + " is over!"); 2]cU:j6G
bDownOver = true; ;s?,QvE{r#
//nPos = fileAccessI.write (b,0,nRead); a+<{!+3v
} ZMGC@4^F
catch(Exception e){e.printStackTrace ();} NIG* }[}P
} K"8!
} |!L0X@>
F#a'N c9
R|[gEavFl
//打印回应的头信息 {R?VB!dR
public void logResponseHead(HttpURLConnection con) o\X|\nUk
{ ,zh_-2^X
for(int i=1;;i++) *2 ~"%"C
{ B1TWOl?d{
String header=con.getHeaderFieldKey(i); VBz G`&NG
if(header!=null) 6t3Zi:=I
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ,3W,M=j)
Utility.log(header+" : "+con.getHeaderField(header)); *hh iIiog+
else { T?1v*.[
break; c"P:p%\m&u
} \lK `
} rN'}IS@5
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czH# ~
public void splitterStop() Mg&<W#$K
{ f& Vx`oj
bStop = true; BzTzIo5
} 7V&ly{</
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_po5j;"_O
} J^zB5W,)
]Mvpec_B
u.}H)wt
/* f,Am;:\|
**FileAccess.java $Qxy@vU
*//文件访问(定位，写) 4jzjrG
package NetFox; ~VV$wU!A
import java.io.*; orAr3`AR3
BN6cu9a
24\^{3nOK
public class FileAccessI implements Serializable{ FJBB@<>:
#VsS C1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [rz5tfMp
RandomAccessFile oSavedFile; z`,dEGfh^
long nPos; ^-F#"i|Cn
7Rn 4gT
U|8?$/*\
public FileAccessI() throws IOException V7B%o:FZo
{ cH707?p/I
this("",0); l nJ
} YD0j&@.
0v``4z2Z
. HAFKB;
public FileAccessI(String sName,long nPos) throws IOException qCq?`0&#
{ L]l?_#*x
oSavedFile = new RandomAccessFile(sName,"rw"); -h=wLYl@0i
this.nPos = nPos; Ox@$ }
oSavedFile.seek(nPos); X^i3(N
} {fY(zHC
O9RnS\
E!`/XB/nA
public synchronized int write(byte[] b,int nStart,int nLen) .(s@{=
{ AjsjYThV
int n = -1; X>Z83qV5d!
try{ Y5*A,piq
oSavedFile.write(b,nStart,nLen); #IeG/t(
n = nLen; kmt+E'^]
} DLO#_t^v.
catch(IOException e) |T-Ytuy8
{ @f-rS{
e.printStackTrace (); *48LQzc
} #XNURj
m-qOyt
>f;oY9 {m
return n; R5 EC/@
} `g{eWY1l
!m9g\8tE
avqJ[R
} o/!a7>xO4
`2'*E\
RC!T1o~L
/* /|<0,ozoJ
**SiteInfoBean.java !V/p.O
*/ @'S !G"\
package NetFox; r}t%DH
|CjdmQ u
f=40_5a6
public class SiteInfoBean { u8[jD^
1)M%]I4
ivi&;
private String sSiteURL; //Site's URL )W![TIp
private String sFilePath; //Saved File's Path =+wkjTO
private String sFileName; //Saved File's Name 82z<Q*YP
private int nSplitter; //Count of Splited Downloading File 79MB_Is]s
:*lB86Ly
"8`f x
public SiteInfoBean() {2%@I~US
{//nSplitter的缺省值为5 "@E(}z'sM
//default value of nSplitter is 5 |;P9S
this("","","",5); }!RFX)T
} w.H\j9E l
uCpk1d
To19=,:
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) tr\}lfK%
{ 1PJ8O|Zt8
sSiteURL= sURL; [.`#N1-@M
sFilePath = sPath; NFcMh+qnK
sFileName = sName; kVe_2oQ_>
this.nSplitter = nSpiltter; lTpmoDa%
slMWk;fmD}
l %{$CmG\
} NEh5
.pQ4#AJ
ryp@<}A]!d
public String getSSiteURL() nAJ<@a
{ {'#^
return sSiteURL; SD^6ib/]b
} ?gMxGH:B.&
)0JXUC e
vxzOG?Xc:
public void setSSiteURL(String value) %vO b"K$X
{ sCFqz[I
sSiteURL = value; zl j%v/9
} \P_1@sH=
*@r)3
b_]14 v
public String getSFilePath() KS/1ux4x
{ MKYXYR
return sFilePath; E{*~>#+
} 3Q`F x
{<a(1#{
!tT$}?Ano
public void setSFilePath(String value) E+AEV`-
{ [}|-%4s
sFilePath = value; 1\q2;5
} jZcjiOX
5rqjqfFa
`5;O|qRq
public String getSFileName() 'g8~539{&
{ x[3kCa|4A
return sFileName; +pJ;}+
} %b2.JGBqJ
.!Kdi|a)
FS r`Y
public void setSFileName(String value) 6I(y`pJ
{ 4^VY
sFileName = value; G6xdGUM
} S=^yJ6xJ
|HJdpY>Uu
l}%!&V0
public int getNSplitter() kssS,Ogf\_
{ u#?K/sU
return nSplitter; {Q?AIp6u|
} l/`<iG%
)h,+>U@
1b E$x^P
public void setNSplitter(int nCount) gQgG_&xkC
{ KP[ax2!x
nSplitter = nCount; "8J$7g@n@
} Vp\BNq_!s
} q*TH),)J
s%>>E!Qi_
K7Kd{9-2
/* U5z^R>k
**Utility.java $[}31=0
*/ kWc%u-_
package NetFox; EQ8jxr<p
YQ g03i
[Oe$E5qv)]
public class Utility { LpeQx\
BhLYLlXPY
F(^vD_G
public Utility() ]8*g%
{ 2PE|4zG
mEv<r6qDT
vXLiYWo
} ?P,z^
f%` =>l
//线程睡眠 wAkpk&R
public static void sleep(int nSecond) }|%dN*',
{ Oj\lg2Ck
try{ ZZ?0%9
Thread.sleep(nSecond); _?M34&.X
} ^Wo/vm*]
catch(Exception e) XxcY
{ zR6,?Tzg
e.printStackTrace (); 9u^PM
} &YGd!Q
} So{/V%
^[,Q2MHCT(
//日志 'FgBYy/
public static void log(String sMsg) 9Bvi2 3
{ Wf/r@/q
System.err.println(sMsg); ?1*Ka
} kfr' P u
zsFzF`[k
ayfR{RYi
public static void log(int sMsg) z/!LC;(
{ a?S5 =
System.err.println(sMsg); G d~ v _
} nF>41 K
} mivb}cKM
k>E^FB=
7'Z-VO
/* |_."U9!Z^
**TestMethod.java ze2%#<
*/ 7irpD7P>
package NetFox; ;\j7jz^uC
B-^r0/y;
%"-bG'Yc
public class TestMethod { \4Uhc3
,w`g+ 9v
"DaE(S&
public TestMethod() -t]3 gCLb
{ ///xx/weblogic60b2_win.exe &!P' M
try{ ^h\(j*/#X
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); mtU{d^B
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $%BI8_
SiteFileFetch fileFetch = new SiteFileFetch(bean); GCf,Gfmr
fileFetch.start(); H;nEU@>"Z
} L4DT*(;!E
catch(Exception e){e.printStackTrace ();} !"2S'oQKS
{Qi J-[q
TAxu]C$P
} K| dI'TnW
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/KLkrW
public static void main(String[] args) InI>So%e|<
{ [rkw k\m*
new TestMethod(); ?g\emhG
} nb<e<>L
} HYg! <y
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