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)); [!-gb+L
} G0Qw& mqF
for(int i=0;i<nEndPos.length-1;i++) Vm>EF~r
{ >MYDwH
nEndPos = nStartPos[i+1]; 9;?u%
} ~"CGur P
nEndPos[nEndPos.length-1] = nFileLength; }Mt1C~{(
} 7K:V<vX5
} HP1QI/*v
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bAGKi.
//启动子线程 G9 O6Fi
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ow.!4kx{d
for(int i=0;i<nStartPos.length;i++) wz*iwd-
{ (Y@T5-!D
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $?G@ijk,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |f#hGk6
nStartPos,nEndPos,i); pX?3inQP%(
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v/.'st2%
fileSplitterFetch.start(); f,KB BBbG
} cN8Fn4gq
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'in%Gii
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); v#d\YV{I
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %gh#gH
nEndPos = " + nFileLength); N}K [Q=
// fileSplitterFetch[nPos.length-1].start(); ?YLq iAA
~<m^
r~j [Qm"CJ
//等待子线程结束 DylO;+
//int count = 0; C;N6",s!
//是否结束while循环 YAOfuas]j
boolean breakWhile = false; [49Cvde^
7RL J
MQ-u9=ys
while(!bStop) {;c'@U
{ nQjpJ /=
write_nPos(); '\tI|
Utility.sleep(500); cR/Nl pX
breakWhile = true; jTvcKm|q
%+N]$Q
Pc`d]*BYi
for(int i=0;i<nStartPos.length;i++) )Y7H@e\1
{ VAz4@r7hkq
if(!fileSplitterFetch.bDownOver) ApXf<MAy
{ 'z(Y9%+a
breakWhile = false; f +{=##'0
break; gwRB6m$
} <46&R[17M
} FklR!*oL,)
if(breakWhile) G?1GkR
break; ,X4+i8Yc
[-])$~WfW
w={q@. g%
//count++; z'EQdQ)
//if(count>4) %N*[{j= ^
// siteStop(); i[!|0U`p
} J rx^
)8@-
j Q5F}
System.err.println("文件下载结束！"); zjQ746<&)i
} r ;RYGLx
catch(Exception e){e.printStackTrace ();} 4,I,f>V
} H9/!oI1P?
rx1u*L
9&n9J^3L
//获得文件长度 ub-3/T
public long getFileSize() [a2]_]E%
{ ]#)(D-i
int nFileLength = -1; $r/$aq=K
try{ }qn>#ETi
URL url = new URL(siteInfoBean.getSSiteURL()); .N X9Ab
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G% tlV&In
httpConnection.setRequestProperty("User-Agent","NetFox"); $[>{s9E
NPT-d
@7twe;07r
int responseCode=httpConnection.getResponseCode(); -tj#BEC[H(
if(responseCode>=400) k$3pmy*
{ JU?;Kq9R
processErrorCode(responseCode); .9nqJ7]
return -2; //-2 represent access is error yE8D^M|g
} u}@N Qeg
ba|xf@=&
K81X32Lm'
String sHeader; d`^3fr'.4A
J:@gmo`M;V
)D+BvJ Y"
for(int i=1;;i++) $ZM'dIk?
{ #n>U7j9`O
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .G{cx=;
//Utility.log(in.readLine()); .l1x~(
sHeader=httpConnection.getHeaderFieldKey(i); ?+t;\
if(sHeader!=null) ys9:";X;}
{ >dl5^
if(sHeader.equals("Content-Length")) 4YfM.~ 6
{ T+Z[&|
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4$xVm,n|
break; (U:-z=E#1
} cRLw)"|
} ,HZ%q]*:~
else |?T=4~b
break; u cpU$+
} w2 Y%yjCV
} DBAyc#&#
catch(IOException e){e.printStackTrace ();} Hr?lRaV
catch(Exception e){e.printStackTrace ();} A8'RM F1
sFpg
4/_jrZO
Utility.log(nFileLength); ET}Z>vU}+
1K Fd ~U
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return nFileLength; 4 Ej->T.
} TKB8%/_p
\3JCFor/
1/M^7Vb.
//保存下载信息（文件指针位置） Tbi?AJa}
private void write_nPos() YV.' L
{ *yhA8fJ
try{ 1>Sfv|ZP,
output = new DataOutputStream(new FileOutputStream(tmpFile)); )'+[,z ;s
output.writeInt(nStartPos.length); 2;v:Z^&
for(int i=0;i<nStartPos.length;i++) xX<f4H\'
{ "\o#YC
// output.writeLong(nPos); w6vbYPCN
output.writeLong(fileSplitterFetch.nStartPos); KuJ)alD;1
output.writeLong(fileSplitterFetch.nEndPos); h4`8C]
} S_P&Fv
output.close(); <=.6Z*x+
} <2pp6je\0s
catch(IOException e){e.printStackTrace ();} 6Z_V,LD9L
catch(Exception e){e.printStackTrace ();} a|t~&\@
} /a1uG]Mt
w%])
RTmp$lV
//读取保存的下载信息（文件指针位置） NXOXN]=c<
private void read_nPos() %~Yo{4mHs
{ ;Nn(
try{ v9f+ {Y%-
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); jEBn"]\D
int nCount = input.readInt(); dmF=8nff
nStartPos = new long[nCount]; q;eb
nEndPos = new long[nCount]; #/YS
for(int i=0;i<nStartPos.length;i++) kLgkUck8]
{ T?1BcY
nStartPos = input.readLong(); c(Dp`f,
nEndPos = input.readLong(); n#X~"|U`
} 4/(#masIL
input.close(); eo]nkyYDP
} A%D'Z85 -
catch(IOException e){e.printStackTrace ();} !aT:0m$:9c
catch(Exception e){e.printStackTrace ();} "@G[:(BoB<
} {)qr3-EM#
-}6ew@GE
IW\^-LI.
private void processErrorCode(int nErrorCode) _[6sr7H!
{ 3yx[*'e$
System.err.println("Error Code : " + nErrorCode); sC3Vj(d!i
} $ar^U
m,HE4`g
dj0%?g>
//停止文件下载 9`f@"%h
public void siteStop() $FPq8$V
{ {"]!zL
bStop = true; 2^'Ec:|f
for(int i=0;i<nStartPos.length;i++) irlFB#..
fileSplitterFetch.splitterStop(); D\Ez~.H
XM\\Imw
>w.;A%|N
} Vlx.C~WYn
} }TTghE!
//负责部分文件的抓取 "l&SRX?g
**FileSplitterFetch.java `rn/H;r!Z
*/ 89M'klZ
package NetFox; Q/|.=:~FO
FAM{p=t]HT
Au2?f~#Fv
import java.io.*; qx#M6\L!
import java.net.*; YrL(4Nt8
UBL{3s^"
`4K|L6
public class FileSplitterFetch extends Thread { F~Dof({:
,b5'<3\
t'2A)S
String sURL; //File URL BH'*I yv
long nStartPos; //File Snippet Start Position qm=U<'b^
long nEndPos; //File Snippet End Position h3`}{ w
int nThreadID; //Thread's ID !=YEhQ-
boolean bDownOver = false; //Downing is over ?|ZbQz(bL
boolean bStop = false; //Stop identical Ck/44Wfej
FileAccessI fileAccessI = null; //File Access interface GFFwk4n1
7^i7U-A<A
'HWl_M
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $NR[U+
{ xb\EJ1M>
this.sURL = sURL; ]T)N{"&N/
this.nStartPos = nStart; HO<|EH~lu
this.nEndPos = nEnd; I(M/X/
nThreadID = id; uX-^9t
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =dQ[I6
} ,=+t2Bn
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`t/j6e]
public void run() _*H Hdd5I
{ r|l?2 eO~
while(nStartPos < nEndPos && !bStop) \ ITd\)F%N
{ 1%_RXQVG
i bzY&f
Phi5;U!
try{ QD7KE6KP'
URL url = new URL(sURL); =DdPwr 0Op
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M0$MK>
httpConnection.setRequestProperty("User-Agent","NetFox"); %np(z&@wi
String sProperty = "bytes="+nStartPos+"-"; "s|P,*Xf
httpConnection.setRequestProperty("RANGE",sProperty); 3VLwY!2:
Utility.log(sProperty); ?kR1T0lKkE
3zB'AG3b
WVR/0l&bU
InputStream input = httpConnection.getInputStream(); ~HIj+kN
//logResponseHead(httpConnection); [7}3k?42X
gnH{_
VzXVy)d
byte[] b = new byte[1024]; 9]v,3'QI
int nRead; <eXGtD
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) vb[0H{TT2
{ '9!_:3[d\]
nStartPos += fileAccessI.write(b,0,nRead); jSpj6:@B
//if(nThreadID == 1) V.{HMeE4
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s?HK2b^;D
} =0?5hxMd
lo!pslqsn
}Nr6oUn
Utility.log("Thread " + nThreadID + " is over!"); XncX2E4E
bDownOver = true; Z}t;:yhR
//nPos = fileAccessI.write (b,0,nRead); *+*W# de.
} ND1hZ3(^
catch(Exception e){e.printStackTrace ();} x\'3UKQP+^
} :6o%x0l
} g?80>-!bF
D_dv8
,a&,R*r@&
//打印回应的头信息 +(=-95qZ
public void logResponseHead(HttpURLConnection con) ZP~H!
{ ZV--d'YiEm
for(int i=1;;i++) m}z6Bbis0
{ Y$>NsgQn6
String header=con.getHeaderFieldKey(i); {> ,M
if(header!=null) :h(RS;
//responseHeaders.put(header,httpConnection.getHeaderField(header)); [\3ZMH *
Utility.log(header+" : "+con.getHeaderField(header)); QcrhgR
else /)kJ iV
break; f_)#
} EPJ>@A>;D
} Ub\^3f
.#~!w!T
wb9(aS4
public void splitterStop() 4 xqzdR_
{ SZTn=\
bStop = true; ~IYR&GEaUG
} SZXSVz0j
Ye]K 74M.
?5CE<[
} d;<'28A
=COQv=GT
qeFaY74S
/* gbYM1guiD
**FileAccess.java eyh}O
*//文件访问(定位，写) ,y'6vW`%g9
package NetFox; aAe`o2Xs
import java.io.*; 'Z#_"s#L
f/c&Ya(D~
IuP~Vt{m
public class FileAccessI implements Serializable{ z2{y<a9;?
8H-yT1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 k={1zl ;
RandomAccessFile oSavedFile; c*B< - l<5
long nPos; q)9n%- YgP
KDb j C'3
L4B/ g)K
public FileAccessI() throws IOException I!?Xq
{ 31c*^ZE.
this("",0); ;Q,t65+Am
} %\-E R!b
"f 89
?\8
public FileAccessI(String sName,long nPos) throws IOException s<"|'~<n
{ X+sKG5nS
oSavedFile = new RandomAccessFile(sName,"rw"); ,9d]-CuP;
this.nPos = nPos; g_{N^wS
oSavedFile.seek(nPos); ]B;`Jf
} 5,p;b
OQfFS+6
x#3*C|A
public synchronized int write(byte[] b,int nStart,int nLen) !AJkd.
{ {H(l"KuL
int n = -1; RtR@wZ2\s
try{ ;8XRs?xyd
oSavedFile.write(b,nStart,nLen); `1P|<VbZ
n = nLen; 8#JX#<HEo
} [u!n=ev
catch(IOException e) zMA;1Na
{ \~A qA!)6
e.printStackTrace (); \8$~ i
} g(tVghHxt$
8Yk*$RR9
TaD;_)(
return n; 1xEOYM)
} NW5OLa")J<
Jn=;gtD-*
Ur]$@N
} uarfH]T{
.,z6a
b9X*2pnWJ
/* 8>[g/%W
**SiteInfoBean.java =MQ/z#:-P
*/ +Mijio
package NetFox; \X&8EW
tgG*k$8z
Q*T'tkp
public class SiteInfoBean { 3E*m.jX
g=4^u*
sq`Xz8u
private String sSiteURL; //Site's URL Sj~SG
private String sFilePath; //Saved File's Path =W3 K6w
private String sFileName; //Saved File's Name T%)E!:}v
private int nSplitter; //Count of Splited Downloading File 7xeqs q
L>~Tc
#}y8hzS$
public SiteInfoBean() VSY p
{//nSplitter的缺省值为5 :+Ukwno?/
//default value of nSplitter is 5 A811VL^
this("","","",5); ` 'Qb?F6
} ?p@J7{a
c$ZVvu
{7goYzQsi%
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4Wiy2
{ <v0`r2^S{-
sSiteURL= sURL; RX>P-vp
sFilePath = sPath; 0uDDaFS
sFileName = sName; #gV n7wq
this.nSplitter = nSpiltter; I2*rtVAP'j
zw+aZDcV(
>E+g.5 ,:W
} W#<1504ip
7m-%
_aPAn|.
public String getSSiteURL() =lJ ?yuc
{ /jGBQ-X
return sSiteURL; @M"gEeI9
} ).5X
)6)bI.BY
!}TsFa
public void setSSiteURL(String value) kh0cJE\_^
{ 4uIYX
sSiteURL = value; :_R:>n9 p
} 12n:)yQy
Y}c/wF7o
:82h GU
public String getSFilePath() *z0d~j*W;
{ Lg7A[\c ~
return sFilePath; EhHxB fAQ
} m]2xOR_
{=[>N>"
e NIzI]~
public void setSFilePath(String value) ]X>yZec
{ l\s!A&L
sFilePath = value; 0ae8Xm3J@R
} Q>%n&;:
[ /o'l:
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public String getSFileName() 5X!-Hj
{ kMQ /9~
return sFileName; yc](
} >Wr%usNxc
d<a|dwAeh
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public void setSFileName(String value) '}_r/l]K
{ -x//@8"
sFileName = value; /WTEz\k
} O]u'7nO{{
"Q.*
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public int getNSplitter() s/D)X=P1
{ .hat!Tt9
return nSplitter; "@UQSf,
} vamZKm~p
q\6(_U#Tl
D`LBv,n
public void setNSplitter(int nCount) B3#G
{ !K>iSF<
nSplitter = nCount; KMRPleF
} sT\:**
} 7<yc:}9nx
LCHMh6
(wDE!H7
/* GI%&.Vd
**Utility.java F_ F"3'[
*/ cszvt2BIg
package NetFox; WUYI1Ij;
5}#wp4U
,S-h~x
public class Utility { w"^h<]b
9"P|Csj
dVQ[@u1,
public Utility() X06Lr!-%
{ I_J&>}V'
[*',pG
BR2Gb~#T
} po*G`b;v
I^?tF'E
//线程睡眠 kU<t~+
public static void sleep(int nSecond) l[}4 X/
{ c2npma]DZ
try{ tq3_az ~1
Thread.sleep(nSecond); ;m(iKwDt
} C ^Y\?2h1
catch(Exception e) 8-2`S*
{ 4_R|3L
e.printStackTrace (); w_(3{P[Iz
} THYw_]K
} -R`{]7V
YFO{i-*q
//日志 YT\@fgBt
public static void log(String sMsg) Z?axrGmg0
{ hS]w A"\87
System.err.println(sMsg); ~G!JqdKJ0
} YlHP:ZW-cu
$coO~qvU
X,QsE{
public static void log(int sMsg) ,;)ZF
{ -#|D>
System.err.println(sMsg); qA)OkR'm
} cr1x CPJj
} ?%,NOX
*G19fJ[5
m@4Dz|
/* 6\4-I^=B
**TestMethod.java \|;\
*/ V ;T :Q%
package NetFox; A6&*VD
d#ir=+o{h
!J`lA
public class TestMethod { ZaFt4#
O*EV~{K
6%v9o?:~l
public TestMethod() Y=Vbs x
{ ///xx/weblogic60b2_win.exe %Y^J''
try{ oUv26t~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); </h^%mnd
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %$!3Pbui
SiteFileFetch fileFetch = new SiteFileFetch(bean); ag=d6q
fileFetch.start(); t'qYM5
} :D.0\.p
catch(Exception e){e.printStackTrace ();} GtA`0B
.Mt3ec<
TktH28tK
} R@vcS=m7
kBu{ bxL
oaoTd$/5
public static void main(String[] args) /R)wM#&
{ >[}oH2oi
new TestMethod(); hx;f/EPx
} OrY[
} ^Co-!jM
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