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)); /Mu@,)''
} /RC7"QzL
for(int i=0;i<nEndPos.length-1;i++) sp*v?5lW
{ NPe%F+X
nEndPos = nStartPos[i+1]; \)?HJ
} 7VFLJrt
nEndPos[nEndPos.length-1] = nFileLength; hFl^\$Re
} ITT@,
} n#OB%@]<V
<<R*2b
r|Tcfk]%
//启动子线程 r? E)obE
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; s6^>F/x
for(int i=0;i<nStartPos.length;i++) ~1vDV>dpE
{ *itUWpNhr
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }2<7%FL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ` v@m-j6
nStartPos,nEndPos,i); [e}]}t8m
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @7j AL-
fileSplitterFetch.start(); K}MK<2vU
} h|{]B,.Lh
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), JHTSUq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Q|?L*Pq2I
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", l3I:Q^x@
nEndPos = " + nFileLength); zsyIV!(
// fileSplitterFetch[nPos.length-1].start(); @8r pD"x
aH/ k Ua
j yUCH*@
//等待子线程结束 ;P%1j|7
//int count = 0; AogVF
//是否结束while循环 9H`XeQ.
boolean breakWhile = false; *]/zc1Q4M
]R f[y
'=8d?aeF
while(!bStop) ofw3S|F6
{ LR.<&m%~.
write_nPos(); CSq4x5!_7>
Utility.sleep(500); 70tH:Z)"
breakWhile = true; >rKIG~P_
j0evq+
;LSANr&
for(int i=0;i<nStartPos.length;i++) co|aC!7
{ ywm8N%]v
if(!fileSplitterFetch.bDownOver) .Una+Z
{ !1H# 6
breakWhile = false; W^LY'ypT
break; Z!zF\<r
} f=gW]x7'R+
} J({Xg?
if(breakWhile) iYm-tsER;
break; tKx~1-
Nk VK
n QZwC
//count++; FX`>J6l:X
//if(count>4) `yXg{lk
// siteStop(); e95Lo+:f
} j<jN05p
d#rf5<i
f:|1_j
System.err.println("文件下载结束！"); u^bidd6JRn
} QIvVcfM^
catch(Exception e){e.printStackTrace ();} hl(hJfp
} ju8q?Nyhs
ujq=F
0c'<3@39k|
//获得文件长度 )E@.!Ut4o
public long getFileSize() i&66Fi1
{ >j(_[z|v3
int nFileLength = -1; `nv~NLkl
try{ 7#ibN!
URL url = new URL(siteInfoBean.getSSiteURL()); #9}D4i.`}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); aweV#j(y
httpConnection.setRequestProperty("User-Agent","NetFox"); T?soJ]A
JG!mc7
z.9U}F
int responseCode=httpConnection.getResponseCode(); R_ ,UMt
if(responseCode>=400) M!A}NWF
{ kmsb hYM)
processErrorCode(responseCode); iWB=sL&p
return -2; //-2 represent access is error NI}yVV
} [.'|_l
QP^Cx=
bv9i*]
String sHeader; otl0JHt*+
UkT=W!cq
|\<`Ib4j
for(int i=1;;i++) [.8BTj1%
{ }=UHbU.n~!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); fk[-mZ
//Utility.log(in.readLine()); o"Euwh!!
sHeader=httpConnection.getHeaderFieldKey(i); c~$)UND^
if(sHeader!=null) fc%xS7&
{ *:YiimOY"
if(sHeader.equals("Content-Length")) ~xfP:[u
{ WJndoB.f[2
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Lh"<XYY
break; /vde2.|
} 3n1;G8Nf
} F/bT)QT<f
else ^f &XQQY
break; :q7Wy&ow
} =wHVsdNCN
} *_{j=sd
catch(IOException e){e.printStackTrace ();} !t%j?\f
catch(Exception e){e.printStackTrace ();} u\x}8pn
V>%rv'G8
}bpQq6ZF
Utility.log(nFileLength); }DEg-j,F
%@ODs6 R0
y$F'(b|)
return nFileLength; !/*\}\'4
} 3!Ij;$
-M~:lK]n
%lx!.G
//保存下载信息（文件指针位置） u+e{Mim
private void write_nPos() qu6D 5t
{ N1S{suic
try{ ksqQM
output = new DataOutputStream(new FileOutputStream(tmpFile)); UA0Bzoky;
output.writeInt(nStartPos.length); 2K6qY)/_
for(int i=0;i<nStartPos.length;i++) #7$ H
{ B6As,)RjD:
// output.writeLong(nPos); R)(T^V`{
output.writeLong(fileSplitterFetch.nStartPos); K5VWt)Z#
output.writeLong(fileSplitterFetch.nEndPos); >`mVY=Hi
} F>6|3bOR
output.close(); sPQQ"|wU
} $}q23
catch(IOException e){e.printStackTrace ();} \?ZB]*Fu
catch(Exception e){e.printStackTrace ();} YnS#H"
} Y%aCMP9j~9
#PW9:_BE
TG?brgW
//读取保存的下载信息（文件指针位置） $q{!5-e
private void read_nPos() f=Gg9bnm3
{ syj0.JD
try{ t?&|8SId
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); El".I?E*
int nCount = input.readInt(); KVaiugQ
nStartPos = new long[nCount]; r~8 $1"
nEndPos = new long[nCount]; dNH08q8P
for(int i=0;i<nStartPos.length;i++) ]t,BMu=%
{ (9GWbB?
nStartPos = input.readLong(); \<>ih)J@tt
nEndPos = input.readLong(); {.|CdqwY
} ^_W#+>&--
input.close(); Tc:)- z[o
} 8z`G,qh
catch(IOException e){e.printStackTrace ();} fc3{sZE2M
catch(Exception e){e.printStackTrace ();} |O+H[;TB6
} 3m)0z{n
\fdv]f
6]N;r5n
private void processErrorCode(int nErrorCode) fu ,}1Mq#
{ 1{.|+S Z!
System.err.println("Error Code : " + nErrorCode); nEy&>z
} ]Sz:|%JP1
YnMvl
yYYSeH
//停止文件下载 At>DjKx]O
public void siteStop() g%I"U>!2
{ g2ixx+`?|:
bStop = true; m,w A:o$'
for(int i=0;i<nStartPos.length;i++) h"Q8b}$^)
fileSplitterFetch.splitterStop(); #L;dI@7C
q!7ANib6O
}C?'BRX
} <2x^slx)?
} itP,\k7>d
//负责部分文件的抓取 R|, g<
**FileSplitterFetch.java >T-u~i$s
*/ ]p GL`ge5
package NetFox; b\!_cb~"@
]:-mbgW
&h)yro
import java.io.*; hWLA<wdb
import java.net.*; ZvX*t)VjTz
8/cX]J
Gj?t_Zln
public class FileSplitterFetch extends Thread { BwpqNQN
cwlRQzQ(
xm~`7~nFR
String sURL; //File URL @b%=H/5\
long nStartPos; //File Snippet Start Position !>o7a}?
long nEndPos; //File Snippet End Position lfgq=8d
int nThreadID; //Thread's ID Q&tG4f<
boolean bDownOver = false; //Downing is over o:'MpKm
boolean bStop = false; //Stop identical rZ$O?K
FileAccessI fileAccessI = null; //File Access interface v!-pSa)3
pah'>dAL
Ge@{_
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException SKN`2[ahD
{ ^z*t%<@[Q
this.sURL = sURL; Dx?,=~W9
this.nStartPos = nStart; Q3~H{)[Kq
this.nEndPos = nEnd; ,[KD,)3y
nThreadID = id; t{9GVLZ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 #zs~," dRv
} ;igIZ$&
vA{-{Q
.~;\eW[
public void run() Sz`,X0a
{ $a]`nLUa
while(nStartPos < nEndPos && !bStop) !f[_+CD
{ 'IQ0{&EI
(ZZ8L-s
tDcT%D {:
try{ ED gag
URL url = new URL(sURL); (?c"$|^J
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); T!#GW/?
httpConnection.setRequestProperty("User-Agent","NetFox"); UI0VtR]
String sProperty = "bytes="+nStartPos+"-"; 7JH6A'&
httpConnection.setRequestProperty("RANGE",sProperty); 6nvz8f3*r]
Utility.log(sProperty); ouQ T
03Ycf'W
f$$/H>MJ
InputStream input = httpConnection.getInputStream(); g!|kp?
//logResponseHead(httpConnection); 0{D'n@veP
rb.N~
!F$6-0%
byte[] b = new byte[1024]; x 9fip-
int nRead; =:pJ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) b4kgFA
{ I\ob7X'Xu!
nStartPos += fileAccessI.write(b,0,nRead); {EQOP]
//if(nThreadID == 1) W${Ue#w77
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )ez9"# MH'
} <bWG!ZG
PJH&
GD$l||8
Utility.log("Thread " + nThreadID + " is over!"); q2E_A
bDownOver = true; y<Ot)fa$
//nPos = fileAccessI.write (b,0,nRead); %h!B^{0
} zrb}_
catch(Exception e){e.printStackTrace ();} NBGH_6DROw
} {P_.~0pc*
} )SGq[B6@I
xy;;zOh`
4kx N<]
//打印回应的头信息 rey!{3U
public void logResponseHead(HttpURLConnection con) ?=Kduef
{ Km$\:Xo
for(int i=1;;i++) JWxwJex
{ NzvXN1_%
String header=con.getHeaderFieldKey(i); ww1[rCh\+
if(header!=null) -iZ`Y?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); OneY_<*a<
Utility.log(header+" : "+con.getHeaderField(header)); [4)F f
else `ERz\`d~Y;
break; S f# R0SA
} X&H"51
} ?:0Jav
8quaXVj^a
|FRg\#kf%
public void splitterStop() 8}:nGK|kx
{ -QNh
bStop = true; ]`WJOx4
} z F;K
?S=mybp
4*;MJ[|
} >vsqG=x
m1AJ{cs
mt.))#1
/* <#4h}_xA%
**FileAccess.java )4;`^]F
*//文件访问(定位，写) r3?o9D>
package NetFox; qH_Dc=~la
import java.io.*; >9J:Uo1z
BZ^}J!Q'*
veECfR;
public class FileAccessI implements Serializable{ I]q% 2ie
'|=;^Z7.K
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 A3*!"3nU
RandomAccessFile oSavedFile; 2X&qE}%k S
long nPos; hi[pVk~B)
j] [,J49L
xgtR6E^k
public FileAccessI() throws IOException I%Z
{ 3G4-^hY<
this("",0); BJ(M2|VH
} |4`{]2C
w4Z'K&d=
1h5 Akq
public FileAccessI(String sName,long nPos) throws IOException 32 =z)]FZ
{ e96k{C`j0
oSavedFile = new RandomAccessFile(sName,"rw"); ^<AwG=
this.nPos = nPos; Oow2>F%_#
oSavedFile.seek(nPos); (7*}-Uy[C
} v &+R^iLE
$ME)#(
/a o5FL
public synchronized int write(byte[] b,int nStart,int nLen) ~Cjn7
{ @lph)A Nk
int n = -1; Ga'swP=hf
try{ [ikOb8 G#
oSavedFile.write(b,nStart,nLen); >o,TZc\
n = nLen; A5w6]:f2
} 8\gjST*
catch(IOException e) sx<%2
{ 1-QS~)+
e.printStackTrace (); WuW^GC{7
} W@!S%Y9
@s^-.z
F4{IEZ
return n; @\I#^X5lv
} mj@13$=
VLN_w$iEq
`y* }lg T
} >lM l
8HdAFRw
1ZRT:N<-
/* sn>~O4"
**SiteInfoBean.java O|UC ?]6
*/ ,6W>can
package NetFox; WOf 4o
#cLBQJq
61 ~upQaR
public class SiteInfoBean { {kAc(
Dn}Jxu'(
5rUdv}.
private String sSiteURL; //Site's URL *_g$MI
private String sFilePath; //Saved File's Path T9q-,w/j;
private String sFileName; //Saved File's Name ;ovP$ vl>
private int nSplitter; //Count of Splited Downloading File /,Jqmm#s^
& "B=/-(
HE_8(Ms;8
public SiteInfoBean() .XhrCiZ
{//nSplitter的缺省值为5 0Fr?^3h
//default value of nSplitter is 5 K'I#W lg
this("","","",5); Q)z8PQl O
} e<q?e}>?
RY*U"G0#w
i(+p0:< 0
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ]]j;/TiG
{ $ o#V#
sSiteURL= sURL; xA[mm
sFilePath = sPath; HiJE}V;Vq
sFileName = sName; @!d{bQd,
this.nSplitter = nSpiltter; fa2kG&, _
$]2vvr
mU9kVx1+
} ?#Q #u|~
ib791
-+-_I*(
public String getSSiteURL() SOvF[,+
{ Lbb0_-']
return sSiteURL; Ef13Q]9|
} Hg (Gl
-1ub^feJ,
|)/aGZ+
public void setSSiteURL(String value) 4]}'Hln*U
{ )TM4R)r%)9
sSiteURL = value; NSA-}2$
} y Fq&8 x<X
2Q:+_v
Fh9h,' V"
public String getSFilePath() ^@NU}S):yN
{ g5r(>,vY
return sFilePath; _ZkI)o
} .y:U&Rw4
=kG@a(-
x;<W&s}(
public void setSFilePath(String value) 3>VL}Ui}
{ 2WYPO"q
sFilePath = value; *%@h(js
} >`ZyG5
4d;8`66O
A1zjPG&]
public String getSFileName() Hc(OI|z~
{ fPW@{~t
return sFileName; [Hh9a;.*}h
} $5Ff1{
W-zP/]Dh
_b;{_g
public void setSFileName(String value) %&t<K3&Yh
{ xe&i^+i
sFileName = value; PBkt~=j
} &H:(z4/
vn"{I&L+w0
'$zIbQ:
public int getNSplitter() R`^_(yn>
{ ,]c 1A$Sr0
return nSplitter; {o`]I>gb
} M?uC%x+S$_
(,Df^4%7
3HY9\'t6
public void setNSplitter(int nCount) :'*~uJrR
{ i9][N5\$
nSplitter = nCount; q;>7*Y&
} #';:2Nyq
} K~ehP[^
0T5L_%c
AoL2@C.C%D
/* IG9VdDj
**Utility.java ?R.j^S^
*/ M%;hB*9
package NetFox; Lrq.Ab#
a]tVd#
/,Re"!jh
public class Utility { xLH)P<^`C
L"*/:$EJL.
,0HRAmG
public Utility() ` 3K)GA
{ 2Gaa(rJ5o
u-G+ j)
pYZ6e_j1~
} % 0+j?>#X
=CVBBuVy
//线程睡眠 ]R9HyCl&a6
public static void sleep(int nSecond) _#8RSr8'y
{ !s?nJ(p
try{ o@i#|kx,
Thread.sleep(nSecond); 3Xy-r=N.l
} Z+. '>
catch(Exception e) JB]q
{ ly_HWuFJ3
e.printStackTrace (); g0Gf6o>2
} _k~KZ;l
} I5n^,@md
A='N=^Pm
//日志 8=uu8-l8g
public static void log(String sMsg) EkNunCls
{ 3e;^/kf<9
System.err.println(sMsg); .Blf5b
} kbMWGB%;
fd<:_f]v
(w/T-*
public static void log(int sMsg) k" PayyAC
{ (I{rLS!o,L
System.err.println(sMsg); # ,_u_'C*!
} +:!7L=N#
} MUREiL9L|
jun_QiU:2
,*hLFaR-
/* D"rK(
**TestMethod.java *><F'
*/ ;=; 9tX
package NetFox; .e=:RkI,
LzXmb 7A
D rHVG
public class TestMethod { p#?7w
[~#WG/!:
*|C^=*j9
public TestMethod() kG@@ot" n
{ ///xx/weblogic60b2_win.exe =Og)q$AL
try{ jW3!6*93
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *@v)d[z_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); T| V:$D'
SiteFileFetch fileFetch = new SiteFileFetch(bean); >qjq=Ege
fileFetch.start(); 9m<jcxla$
} dx&'fe*?
catch(Exception e){e.printStackTrace ();} o9%)D<4M
f~y%%+{p
iAa.}CI,zB
} Dhw(#{N
3z)Kz*xr
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public static void main(String[] args) v7jq@#-
{ D!NQ~'.a=2
new TestMethod(); ,)Ju[
} ^~@U]
} 57zSu3v4Y
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