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)); Jb|dpu/e
} k7nke^,|
for(int i=0;i<nEndPos.length-1;i++) ?{1& J9H
{ $L72%T
nEndPos = nStartPos[i+1]; C5TC@w1*
} LP>GM=S#"
nEndPos[nEndPos.length-1] = nFileLength; 4@jX{{^6%
} Upc_"mkI.
} q3u:Tpn4%
k P=~L=cK
gZL,xX
//启动子线程 DLoH.Fd
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; VP }To
for(int i=0;i<nStartPos.length;i++) A ?[Wfq|
{ [n$6T
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &3 x [0DV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), K*tomy
nStartPos,nEndPos,i); xE6hE'rh.O
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *3(mNpi{_
fileSplitterFetch.start(); T?*f}J
} riSgb=7q9
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M ~6$kT
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /b."d\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 3oPyh $*
nEndPos = " + nFileLength); `dgZ`#
// fileSplitterFetch[nPos.length-1].start(); fjqd16{Q
O]?PC^GGY
N LSJ D
//等待子线程结束 x.q"FXu
//int count = 0; L1MG("R
//是否结束while循环 3#{Al[jq
boolean breakWhile = false; XJA];9^
Z1U@xQj
rotu#?B
while(!bStop) CE|rn8MB
{ acow
write_nPos(); YN7JJJ/~T
Utility.sleep(500); 8)YDUE%VH
breakWhile = true; Eg_ram`\R
8M7Bw[Q1
Wfsd$kN6{
for(int i=0;i<nStartPos.length;i++) |u#7@&N1
{ d_Z?i#r0l
if(!fileSplitterFetch.bDownOver) =F46v{la
{ lB
breakWhile = false; RVh{wg
break; \$xj>b;
} AK&=/[U>
} lPg?Fk7AP
if(breakWhile) -o@L"C>
break; =tc!"{
)< p ~
wAc;{60s]
//count++; bg^<e}{<H
//if(count>4) rw[Ioyr-
// siteStop(); pzeCdHF
} JD]uDuE
a" L9jrVrw
sY&Z/Y
System.err.println("文件下载结束！"); G BM8:IG \
} IJDE{)
catch(Exception e){e.printStackTrace ();} vU9:`@beu
} +77B656
b[~-b
NJg )S2]7
//获得文件长度 4-oaq'//BT
public long getFileSize() x!n8Wx
{ )Cd.1X8
int nFileLength = -1; /z: mi
try{ H'&[kgnQ@
URL url = new URL(siteInfoBean.getSSiteURL()); /25Ay
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); s133N?
httpConnection.setRequestProperty("User-Agent","NetFox"); 0xfF
m"wP]OQH*+
^p3W}D
int responseCode=httpConnection.getResponseCode(); .Gb!mG
if(responseCode>=400) Y;kiU
{ Yw_!40`
processErrorCode(responseCode); ^95njE`>t`
return -2; //-2 represent access is error E[<*Al+N
} @]Lu"h#u=
LX#gc.c
1o?uf,H7O
String sHeader; ;*WG9Y(W
>+):eBL
T@a|*.V
for(int i=1;;i++) z#2n+hwE
{ |^"0bu"
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )T^xDx
//Utility.log(in.readLine()); i:1 @ vo
sHeader=httpConnection.getHeaderFieldKey(i); ?@;#|^k9
if(sHeader!=null) PJ^qE|X
{ U_WO<uhC
if(sHeader.equals("Content-Length")) IRTD(7"oyp
{ ygQe'S{!S\
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); pj7v{H+
break; .aR9ulS
} z7TyS.z
} q}W})
else HEw&'
break; ~ 7<M6F
} I+ Y{_yw"f
} oXUb_/
catch(IOException e){e.printStackTrace ();} L+}<gQJ(
catch(Exception e){e.printStackTrace ();} 13+.>
^!gq_x
a4pewg'
Utility.log(nFileLength); /i#";~sO
uaZHM@D
5]n\E?V'L
return nFileLength; U>DCra;
} uF<?y0t
KtGbpcS$f
!;0K=~(Y^
//保存下载信息（文件指针位置） rR 86D
private void write_nPos() 1xInU_SPf
{ cQm4q19
try{ mi[8O$^iJ
output = new DataOutputStream(new FileOutputStream(tmpFile)); !s:e
output.writeInt(nStartPos.length); c=X+uO-
for(int i=0;i<nStartPos.length;i++) mhB2l/
{ Xt +9z
// output.writeLong(nPos); ILqBa:J
output.writeLong(fileSplitterFetch.nStartPos); (>NZYPw^3
output.writeLong(fileSplitterFetch.nEndPos); aemi;61T\
} +}PN+:yV
output.close(); Je}0KW3G9L
} @_1cY#!
catch(IOException e){e.printStackTrace ();} m.<u!MI
catch(Exception e){e.printStackTrace ();} 7Gy:T47T\@
} 'u~0rMe4})
J_?v=dW`
u1=K#5^
//读取保存的下载信息（文件指针位置） 7*"Jx}eM
private void read_nPos() [2h.5.af
{ MdmN7>
try{ 8:>V'j
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); X-#&]^d
int nCount = input.readInt(); SMzq,?-`
nStartPos = new long[nCount]; m xqY
nEndPos = new long[nCount]; Hq!|r8@6
for(int i=0;i<nStartPos.length;i++) *ifz@8C }
{ [FLR&=.(
nStartPos = input.readLong(); jFUpf.v2
nEndPos = input.readLong(); MpBdke$
} >##Z}auY
input.close(); D:/q<<|
} 3&nN;4~Zx6
catch(IOException e){e.printStackTrace ();} niKfat?
catch(Exception e){e.printStackTrace ();} N$x&k$w R
} kw E2V+2
} `5k^J$x
tym:C7v%~
private void processErrorCode(int nErrorCode) ?)186dp
{ ,[)l>!0\H
System.err.println("Error Code : " + nErrorCode); ~?FhQd\Q
} =4l @A>
)BvMFwQG
Hf\sF(, (
//停止文件下载 kguZAO6
public void siteStop() gu+zfvkcY
{ 6su~SPh
bStop = true; <fM}Kk
for(int i=0;i<nStartPos.length;i++) Fm,` ]CO
fileSplitterFetch.splitterStop(); b $JS|
@Z2np{X:
Gx6%Z$2n
} Od)y4nr3~
} X%3?sH
//负责部分文件的抓取 H!&_Tv[
**FileSplitterFetch.java uYWD.]X;[
*/ (zsv!U
package NetFox; oQObr
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m\X\Xp~A
import java.io.*; J=k=cFUX
import java.net.*; _+'!l'`
-Ep#q&\
E6ZkO/
public class FileSplitterFetch extends Thread { \2e^x
23WrJM!2N
.7 0
String sURL; //File URL 8B:y46
long nStartPos; //File Snippet Start Position &9fQW?Czs
long nEndPos; //File Snippet End Position ?_i>Kx
int nThreadID; //Thread's ID doOuc4
boolean bDownOver = false; //Downing is over *=.~PR6W{
boolean bStop = false; //Stop identical )*>wa%[-q
FileAccessI fileAccessI = null; //File Access interface cw{TS
y<E];ub
W(R~K -
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %l!?d`?
{ { ]_j)R
this.sURL = sURL; [&PF ;)i
this.nStartPos = nStart; kM{8zpn
this.nEndPos = nEnd; #Pp:H/b
nThreadID = id; Rd5_{F
fileAccessI = new FileAccessI(sName,nStartPos);//定位 RYjK4xT?Y/
} }b&lHr'Uw
eNK[P=-
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public void run() M{{kO@P"9
{ Z)M "`2Ur
while(nStartPos < nEndPos && !bStop) kuD$]A Q`&
{ ,1#? 0q
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@,TIw[p
try{ jD6HCIjd'
URL url = new URL(sURL); Q_|}~4_+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wlJi_)!
httpConnection.setRequestProperty("User-Agent","NetFox"); }o*A>le
String sProperty = "bytes="+nStartPos+"-"; )q-NE)
httpConnection.setRequestProperty("RANGE",sProperty); Syy{ ^Ae}
Utility.log(sProperty); rZJJ\ , |
e,/]]E/o
ZK+F<}
InputStream input = httpConnection.getInputStream(); jDpA>{O[
//logResponseHead(httpConnection); 94BH{9b5
\&hq$
z3K$gEve
byte[] b = new byte[1024]; 3NLn}
int nRead; g"1V]
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Lo{wTYt:J
{ ,"(G
nStartPos += fileAccessI.write(b,0,nRead); )>:~XA|?
//if(nThreadID == 1) A}(]J!rc
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); A-T-4I
} _&hM6N
mi7?t/D1Z
2c 0;P #ol
Utility.log("Thread " + nThreadID + " is over!"); 5MaN {*)l
bDownOver = true; 6/mz.,g2
//nPos = fileAccessI.write (b,0,nRead); ,<t.Iz%
} fq6Obh=A#
catch(Exception e){e.printStackTrace ();} KtL?,zi
} E6TeZ%g
} 5 ix*wu`,
!q\=e@j-i
S F*C'
//打印回应的头信息 <v|"eq}
public void logResponseHead(HttpURLConnection con) ,bl }@0A
{ ]yf?i350
for(int i=1;;i++) kk-<+R2
{ RTcxZ/\"#
String header=con.getHeaderFieldKey(i); E(4c&
if(header!=null) P\7*ql`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); FT-.gi0
Utility.log(header+" : "+con.getHeaderField(header)); )bOfs*S
else z/1$G"
break; m6ge %
} |NZi2Bu
} $:F+Nf 8
OX]$Xdb2:
_M%S
public void splitterStop() ~4{q
{ "kyCY9)%
bStop = true; wS*r<zj
} #XDgvX >
=#V^t$
&<BBPn@\
} 4@
(w hl1
`|ie#L(:7/
/* <#C,66k
**FileAccess.java <bzzbR[F
*//文件访问(定位，写) lLTqk\8g
package NetFox; e c&Y2
import java.io.*; kL*P 3 0
#uhUZq
Ds">eNq
public class FileAccessI implements Serializable{ kP ]Up&'
f$xXR$mjf
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 mQ:{>`
RandomAccessFile oSavedFile; q,,
long nPos; \0b}Z#'0
f,cd=vGj
P }sr
public FileAccessI() throws IOException *H QcI-
{ u1%URen[x
this("",0); ^9[Q;=R
} 13X}pnW
7y'uZAF
^<CVQ8R7
public FileAccessI(String sName,long nPos) throws IOException <=*f
{ Gaix6@X6'
oSavedFile = new RandomAccessFile(sName,"rw"); 4b2d(x)0X
this.nPos = nPos; kXSX<b<%
oSavedFile.seek(nPos); uAn}qrqE9
} 5daq}hsQs
@L3XBV2
T$%|=gq
public synchronized int write(byte[] b,int nStart,int nLen) p\w<~pN[
{ t%lat./yT
int n = -1; rm[C{Pn
try{ >$4#G)s
oSavedFile.write(b,nStart,nLen); $d?W1D<A
n = nLen; G\@pg;0|y
} ljKIxSvCFp
catch(IOException e) +X=*>^G(-
{ Y,}_LS$f
e.printStackTrace (); Jl/wP
} WoEK #,I;
nq M7Is
p~$cwbQ!
return n; O(T5
} $H)^o!
4@PA+(kvS
Xqf,_I=V
} |THpkfW
:o'x?]
o!M8V ^vW
/* 4Z)s8sDKW
**SiteInfoBean.java ~bLx2=-"
*/ \R#SoOd
package NetFox; )'djqpM.
%k!CjW3
a`!Jq'
public class SiteInfoBean { "n%s>@$
Oidf\%!mvR
Qm%PpQ^Lz3
private String sSiteURL; //Site's URL m{/7)2.
private String sFilePath; //Saved File's Path C-&ymJC|
private String sFileName; //Saved File's Name f<YYo
private int nSplitter; //Count of Splited Downloading File Q\$3l'W
<`}P
Pxlc RF
public SiteInfoBean() %O"8|ZG9{
{//nSplitter的缺省值为5 mO>L]<O
//default value of nSplitter is 5 Pyo|Sgk
this("","","",5); b:dN )m
} 6_j |@
1MN!
U2 *ORd
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) en<~_|J
{ [l23b{
sSiteURL= sURL; c[h~=0UtJ
sFilePath = sPath; ]S6Gz/4aV+
sFileName = sName; HlGSt$woX
this.nSplitter = nSpiltter; 3!CUJs/W
7UfNz60+~
M8/a laoT
} /(dP)ysc
2JfSi2T
./YR8#,
public String getSSiteURL() 9d5$cV
{ cQU/z"?+
return sSiteURL; gEh/m.L7
} 6nx\|F
#D`@G8~(
={BD*=i
public void setSSiteURL(String value) @62T:Vl
{ (80m'.X
sSiteURL = value; IG^@VQ%
} rAenxZ,tF
28MMH Q
J@3,
public String getSFilePath() 7N$2N!I(
{ wI.aV>
return sFilePath; I ]m
} y'R}
;ArwEzo(
CFtQPTw
public void setSFilePath(String value) }%wd1`l7
{ ZEqW*piI
sFilePath = value; 'a~@q~!
} QYH-"-)
\nl(tU#j
SI7rTJ]/
public String getSFileName() 3c<aI=$^
{ 78&|^sq
return sFileName; Y ;Ym=n'
} Xaq;d'
hkMeUxS
l]*RiK2AC
public void setSFileName(String value) 7)Toj
{ QS#@xhH
sFileName = value; eM7@!CdA9q
} f|d~=\0y
\""^'pP@
;:;E|{e
public int getNSplitter() UK=ELvt]
{ y=3 dGOFB
return nSplitter; P>/:dt'GJ}
} j\y;~ V
Ymut]`dX
@C;1e7
public void setNSplitter(int nCount) !cW rB9
{ vrs
nSplitter = nCount; v:O{"s
} @r"\bBi
} mqSVd^
}lZEdF9GhG
%|-N{>wKy
/* |XyX%5p*
**Utility.java C=?S
*/ X4;U4pU#
package NetFox; `4"8@>D
]!hjKu"
]S2rqKB
public class Utility { )2f#@0SVL
SB62(#YR
oF%m
public Utility() kg/B<w'
{ i VSNara
U8_{MY-9}
hRkCB
} .D*Qu}
-^p{J TB+
//线程睡眠 qt8Y3:=8l
public static void sleep(int nSecond) *!5CL'
{ )_#V>cvNG
try{ }\a#e^-xQ+
Thread.sleep(nSecond); 'Ru(`" 1|
} M.}9)ho
catch(Exception e) =G-OIu+H!U
{ sW>%mnx
e.printStackTrace (); fc#9e9R
} {lI}a8DP
} U:7h>Z0W
+){^HC\7h
//日志 l+ }=D@l
public static void log(String sMsg) -E-#@s
{ N_Us6X
System.err.println(sMsg); G]lGoa}]`u
} &PMQ]B
[gWeD
a&s34Pd
public static void log(int sMsg) kWzp*<lWe
{ ~ 'ZwD/!e
System.err.println(sMsg); iI GK"}
} *|rdR2R!
} F^dJ{<yX
2BccE
.f~9IAXP`
/* =*UK!y?n
**TestMethod.java ;dIk$_FN
*/ g]~vZj
package NetFox; /T _M't@j
%i9S"
;,{_=n>
public class TestMethod { E$"NOR
@@Ib^sB%
?9 huuJs7
public TestMethod() (4H\ho8+mp
{ ///xx/weblogic60b2_win.exe SioeIXU
try{ J=A)]YE
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [S6u:;7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); fUw:jExz
SiteFileFetch fileFetch = new SiteFileFetch(bean); "Q:Gd6?h;
fileFetch.start(); x^s,<G
} f;E#CjlTL
catch(Exception e){e.printStackTrace ();} t{})6
,,H5zmgA
VDxm|7
} k1Y\g'1
Ez1eGPVr
9<mMU:
public static void main(String[] args) Wn<?_}sa|z
{ A7 RI&g v5
new TestMethod(); ,TBOEu."4
} _c>iux;
} BM :x`JY
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