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)); -qn[HXq
} Oje|bxQ
for(int i=0;i<nEndPos.length-1;i++) a%[q |oyR
{ 5upShtC
nEndPos = nStartPos[i+1]; J%r7<y\
} h=f6~5l5
nEndPos[nEndPos.length-1] = nFileLength; b:x7)$(
} PHkDb/HIx|
} $y6rvQ 2>S
75(W(V(q
m'.T2e.u
//启动子线程 G^"H*a
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Gm@iV,F%R
for(int i=0;i<nStartPos.length;i++) xT+ ;w[s
{ -><QFJ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), q6)p*}-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 1,u{&%yL"w
nStartPos,nEndPos,i); 9L=;KtE1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); G"fdu(.@
fileSplitterFetch.start(); z[FI2jl
} `wV|q~
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :xN8R^(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); u S(@?m$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ;x RjQR
nEndPos = " + nFileLength); yr{5Rp05=
// fileSplitterFetch[nPos.length-1].start(); 5)x6Q|-u
_3KZME
zK /f$}
//等待子线程结束 6#?NL]A
//int count = 0; hqWPf
//是否结束while循环 6o9sR)c ?
boolean breakWhile = false; xrX?ZJ
x{QBMe`
lSs^A@s
while(!bStop) ~\-r
{ _H/67dcz,
write_nPos(); w1.MhA
Utility.sleep(500); tbRE/L<
breakWhile = true; sMN>wbHwh[
CElPU`J,\[
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for(int i=0;i<nStartPos.length;i++) kYmo7
{ Bd.Z+#%l"
if(!fileSplitterFetch.bDownOver) kkHTbn=!
{ hQP6@KIe)
breakWhile = false; *+NZQjl'
break; qYDj*wqf
} KWtu,~O_u
} T&mbXMN
if(breakWhile) p5D5%B/
break; giQ{Xrj
X!2.IsIS8
)Xq@v']%~9
//count++; $:PF9pY(
//if(count>4) 4LJ]l:m
// siteStop(); - a
} Ny]'RS-
1mY+0
Bmi:2} j
System.err.println("文件下载结束！"); b1eK(F
} ^l&nB.
catch(Exception e){e.printStackTrace ();} /0Rt+`
} D9e+
J2)-cY5G
[0d-CEp[
//获得文件长度 =I+l=;05Rd
public long getFileSize() o(?VX`2"
{ XKpL4]{&q4
int nFileLength = -1; 2Px$0&VN
try{ 6#OL ;Y]_
URL url = new URL(siteInfoBean.getSSiteURL()); L7i}Ga!8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4jDs0Hn"
httpConnection.setRequestProperty("User-Agent","NetFox"); HVtr,jg
=}B4I
N |OMj%Uk
int responseCode=httpConnection.getResponseCode(); KyuA5jQ7
if(responseCode>=400) :;" aUHU'
{ e{^:/WcYB
processErrorCode(responseCode); N*_/@qM> a
return -2; //-2 represent access is error _)HD4,`
} 5KL9$J9k
|@T5$Xg]5
}:,o Y<
String sHeader; < fojX\}3
NB|RZf9M
5`1(}
for(int i=1;;i++) #i`A4D
{ VEFwqB1l
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); G\'u~B/w
//Utility.log(in.readLine()); TnbGO;
sHeader=httpConnection.getHeaderFieldKey(i); ~ LJ>WA
if(sHeader!=null) wGov|[X
{ 2b6? 9FX*
if(sHeader.equals("Content-Length")) t 1Ir4
{ 4yJ*85e]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); b0~H>cnA
break; `:-@E2
} X/- W8
} ;~'cITL
else 7yqSt)/U
break; (<d&BV-"
} =Do3#Xe2V
} Yj^avO=;
catch(IOException e){e.printStackTrace ();} E3FW*UNg[y
catch(Exception e){e.printStackTrace ();} L5-T6CD
XEvGhy#
w(vE2Y ?
Utility.log(nFileLength); #f|NM7
L5V'Sr
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return nFileLength; 0gwm gc/#
} )$l9xx[
q5'yD;[hE
xnRp/I
//保存下载信息（文件指针位置） %X0NHta~@
private void write_nPos() ]@ Sc}
{ &k_wqV
try{ @qO8Jg"Q
output = new DataOutputStream(new FileOutputStream(tmpFile)); IQk#
output.writeInt(nStartPos.length); {l*&l2
for(int i=0;i<nStartPos.length;i++) D_ Bx>G9
{ qUDz(bFk/
// output.writeLong(nPos); }`<>$2b
output.writeLong(fileSplitterFetch.nStartPos); 9pl_V WrQ
output.writeLong(fileSplitterFetch.nEndPos); d=4f`q0k
} VkN[=0a,
output.close(); aCH:#|B
} /_VRO9R\V
catch(IOException e){e.printStackTrace ();} QGbD=c7
catch(Exception e){e.printStackTrace ();} S$lmEJ_
} \yX !P1
a7v[l04
u7Y'3x,`
//读取保存的下载信息（文件指针位置） VM\Z<}C
private void read_nPos() [K)1!KK,L
{ [b k&Nd[
try{ LD~uI
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); i9EMi_%
int nCount = input.readInt(); ssr)f8R#,#
nStartPos = new long[nCount]; z?t(+^
nEndPos = new long[nCount]; Fzld0p9=
for(int i=0;i<nStartPos.length;i++) Nh\8+v*+{
{ |jaY[_.@
nStartPos = input.readLong(); B[0,\>
nEndPos = input.readLong(); jC Kt;lj
} "!6 B5Oz
input.close(); 4 _U,-%/
} Q@ )rw0$
catch(IOException e){e.printStackTrace ();} NKUI! [
catch(Exception e){e.printStackTrace ();} ^; V>}08
} A3pQ?d[
V=MZOj6
j5^b~F%
private void processErrorCode(int nErrorCode) 8|Y^Jn\p5u
{ }0>/G?2Yp
System.err.println("Error Code : " + nErrorCode); EC#10.
} Bcon4
k ,(:[3J
/k"P4\P`+Q
//停止文件下载 !|c5@0Wr
public void siteStop() Hv*O9!cC
{ qW>J-,61/
bStop = true; g(H3arb&
for(int i=0;i<nStartPos.length;i++) OR8o%AxL7
fileSplitterFetch.splitterStop(); p<19 Jw<
#8OqX*/
Oh4WYDyT
} O_Q,!&*6
} ".<p R} qp
//负责部分文件的抓取 r1atyK
**FileSplitterFetch.java >GUTno$J
*/ 5xUPqW%3
package NetFox; -h`0v
?%ntO]
[rsAY&.
import java.io.*; P'~3WL4MKs
import java.net.*; Y|nTc.A
kyB]fmS
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public class FileSplitterFetch extends Thread { R&xd ic!
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String sURL; //File URL U$bM:d
long nStartPos; //File Snippet Start Position RA/yvr
long nEndPos; //File Snippet End Position xRN$cZC
int nThreadID; //Thread's ID 2fB@zF
boolean bDownOver = false; //Downing is over _P1-d`b0 a
boolean bStop = false; //Stop identical p<34}iZ
FileAccessI fileAccessI = null; //File Access interface xpwzzO*U
DYK|"@
iSlVe~ef
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ZrS!R[
{ %xz02$k
this.sURL = sURL; DmsloPB?_
this.nStartPos = nStart; WcFZRy-erc
this.nEndPos = nEnd; S:s^si2/
nThreadID = id; my6T@0R
fileAccessI = new FileAccessI(sName,nStartPos);//定位 w2L)f,X
} P_g
ta(x4fP_
[^f`D%8o
public void run() nv]64mL3
{ n3\vq3^?
while(nStartPos < nEndPos && !bStop) yK^k*)2N
{ jtwO\6t&
]\lw^.%
FC#Qtu~J
try{ $@Fj_ N
URL url = new URL(sURL); RI=B(0A
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [tN/}_]
httpConnection.setRequestProperty("User-Agent","NetFox"); x!+a,+G
String sProperty = "bytes="+nStartPos+"-"; PdZSXP4;k
httpConnection.setRequestProperty("RANGE",sProperty); P.Bk-#}$
Utility.log(sProperty); _?"J.i
X(\RA.64
",m5}mk:4
InputStream input = httpConnection.getInputStream(); bOdD:=f
//logResponseHead(httpConnection); AdNsY/Y(
3^Y-P8.zdB
mN`a]L'
byte[] b = new byte[1024]; q'q{M-U<
int nRead; K2QD&!4/T2
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) r[x7?cXsW
{ 7vFqO;
nStartPos += fileAccessI.write(b,0,nRead); ?0x;L/d])
//if(nThreadID == 1) 4/4IZfznX
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); uRIr,U^
} ;b^@o,=
7o<RvM
^&}Y>O,
Utility.log("Thread " + nThreadID + " is over!"); >Vvc55z
bDownOver = true; ~>n<b1}W
//nPos = fileAccessI.write (b,0,nRead); qA30G~S
} -vyC,A
catch(Exception e){e.printStackTrace ();} ulQE{c[
} R+\5hI@ >i
} xM:dFS
x^"OH
ZD/!C9:&.0
//打印回应的头信息 +vP1DXtj(
public void logResponseHead(HttpURLConnection con) :MVD83?4
{ c1`o3gb
for(int i=1;;i++) 7j Q`i;L}Y
{ 4{Iz\:G:{/
String header=con.getHeaderFieldKey(i); *"#>Ov>
if(header!=null) =$m|M m[a
//responseHeaders.put(header,httpConnection.getHeaderField(header)); mBNa;6w?{*
Utility.log(header+" : "+con.getHeaderField(header)); S4Rv6{r:
else i_MDLS>-
break; ]`MRH[{
} 6)TFb,
} &t4j px
'{J!5x?L^
pd|c7D!6U,
public void splitterStop() 03MB,
{ a9"Gg}h\
bStop = true; Tkd4nRo~
} !_]WUQvV?
5L4~7/kj
5!AzEB
} ?vZ&CB
*bZV4}
Gm*i='f!?
/* j"c"sF\q
**FileAccess.java K$rH{dUM
*//文件访问(定位，写) nGRF<2!
package NetFox; tnp]wZ
import java.io.*; N&=,)d~M
Jk`A}
4Jw0m#UN1
public class FileAccessI implements Serializable{ ;'nu9FU*O
H*l8,*M}
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 +('jqbV
RandomAccessFile oSavedFile; -PxA~((g5
long nPos; byd[pnI$H
[/#;u*n
s7=]!7QGS!
public FileAccessI() throws IOException rQ/S|gG
{ /VJ[1o^
this("",0); y*P[*/g
} Zr`:A$
xHI>CNC,
-[ F<u
public FileAccessI(String sName,long nPos) throws IOException [Q)lJTs
{ '*W/Bett
oSavedFile = new RandomAccessFile(sName,"rw"); o-/Xa[yC
this.nPos = nPos; RM,r0Kv17Y
oSavedFile.seek(nPos); JgEpqA12
} cp[k[7XGD
!30BZM^
g,9o'fs`x
public synchronized int write(byte[] b,int nStart,int nLen) is`le}$^y
{ #Ey!?Z
int n = -1; 3<?#*z4]_
try{ .|cQ0:B[
oSavedFile.write(b,nStart,nLen); O7:JG[tR*
n = nLen; 4K:p
} v dyu=*Y
catch(IOException e) sJ!AI n<
{ p ^T0(\1
e.printStackTrace (); jFnq{Lt
} 7 zK%CJ
)9J&M6LX
TDA+ rl
return n; d:Wh0y}
} umK~K!i
9 *Q/3|
-bduB@#2d
} L<*wzl2Go
wF[^?K '
oj[Wzeg%
/* C%0|o/Wi
**SiteInfoBean.java ,J~kwJ$L
*/ }n oI2.-#
package NetFox; !ai, \
80LKxA;5N
Fz~-m#Ts
public class SiteInfoBean { Jah~h44&
O\=3{
) j_g*<
private String sSiteURL; //Site's URL St^s"A
private String sFilePath; //Saved File's Path *dL!)+:d
private String sFileName; //Saved File's Name AMGb6enl
private int nSplitter; //Count of Splited Downloading File 3u3(BY{"\F
&AG,]#
YFL9Q<
public SiteInfoBean() b7p&EK"Hm
{//nSplitter的缺省值为5 :"#EQq]ct
//default value of nSplitter is 5 49E<`f0
this("","","",5); {Ug?k<h7|
} TG~:Cmc
" +'E
Uo#%f+t
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) RHZ5f0b4L
{ l}A8
sSiteURL= sURL; 7loIX Qw
sFilePath = sPath; E9!u|&$S
sFileName = sName; 2j+v\pjYC
this.nSplitter = nSpiltter; 3M=ym.
y2bL!Y<s9
Po#;SG#Ee
} ggR@& \
s_}T-%\
k4FxdX
public String getSSiteURL() hiZE8?0+~N
{ ,A T!:&<X
return sSiteURL; Iww.Nd2
} QqA~y$'ut
l*T>9yC
z|;7;TwA
public void setSSiteURL(String value) Sp3?I2 o
{ &=oW=g2
sSiteURL = value; 0!!b(X(
} S\RjP*H*
CZcnX8P'8
|r[yMI|VR
public String getSFilePath() r<,W{Va
{ n8n(<
return sFilePath; Rd7Xs
} 20h|e+3
Hg\+:}k&9
pCS2sq8RC
public void setSFilePath(String value) `!rH0]vy
{ ?9hw]Q6r}
sFilePath = value; {KYbsD
} o_>id^$>B
c|OIUc
gmkD'CX*A
public String getSFileName() P[6@1
{ d5mhk[p7\J
return sFileName; y1z<{'2x
} W&23M26"{
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@|kBc.(]
public void setSFileName(String value) -S5M>W.Qb{
{ <+ 0cQq=2
sFileName = value; T7`9[
} h$7rEs
wmbjL=f Ia
tr3Rn :0]
public int getNSplitter() A??(}F L
{ ej-x^G?C
return nSplitter; PF5;2
} "e.QiK
/c/t_xB
3~ITvH,`s
public void setNSplitter(int nCount) )QS4Z{)U
{ mv9k_7<
nSplitter = nCount; z*?-*6W
} C%P)_)--V
} `QC
#Ezq}F8Y
PR rf$& u
/* j/"{tMqQp
**Utility.java g}HB|$P7
*/ Sj?u^L8es}
package NetFox; X :2%U
BZAeg">3
.Y B}w
public class Utility { wcGI2aflD
~<b/%l>h1
D4 {?f<G0F
public Utility() 1n}q6oa=
{ ];BGJ5^j
Nu!(7
@j +8M
} 0ox 8_l
cI}qMc
//线程睡眠 r(sQI# P
public static void sleep(int nSecond) e.pm`%5bO
{ 1,cd[^`.
try{ kO3{2$S6
Thread.sleep(nSecond); -dX{ R_*
} biwV7<
catch(Exception e) FO"8B
{ yn&AMq ]o
e.printStackTrace (); =%u\x=u|
} QmQsNcF~z
} a[TR_uR
gucd]VH
//日志 9o-fI@9
public static void log(String sMsg) ~ou1{NS
{ k2>gnk0
System.err.println(sMsg); mKWfRx*UdG
} +rEqE/QF
u<8 f;C_
X8!=Xjl)
public static void log(int sMsg) L #'N
{ f.f5f%lO~
System.err.println(sMsg); Vp3 9`m-W
} RB]K?
} u15-|i{y7
KX*Hev'K
;K[ G]8
/* }z/;^``
**TestMethod.java Dd+ f,$
*/ RusC5\BUX
package NetFox; ]7WBoC8
}5n((7@X
y w"Tw
public class TestMethod { Qxds]5WB/
{"33 .^=
p%304oP6
public TestMethod() ; n2|pC^
{ ///xx/weblogic60b2_win.exe UN`F|~@v
try{ e2#"o{+@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); m35Blg34
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); j7;v'eA`;7
SiteFileFetch fileFetch = new SiteFileFetch(bean); bH7[6#y$
fileFetch.start(); @Z$`c{V<
} U_a)g X
catch(Exception e){e.printStackTrace ();} 0x'-\)v>3
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5,:tjn
} <YbOO{
66\0JsT?3
w>I>9O}(`
public static void main(String[] args) xG<H${ k;
{ NLDmZra
new TestMethod(); dfB#+wh
} fFXG;Q8&
} `Rj<qz^7
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