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)); QcG-/_,'}
} }2~$"L,_
for(int i=0;i<nEndPos.length-1;i++) 7C@%1kL
{ 0GP\*Y8
nEndPos = nStartPos[i+1]; "jMSF@lr
} qA5PIEvdq
nEndPos[nEndPos.length-1] = nFileLength; Ij9ezNZT=
} %[H|3
} a\?-uJ+
s'yT}XQ;r
b1ma(8{{{
//启动子线程 qD<\U
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; wj#A#[e
for(int i=0;i<nStartPos.length;i++) S[5e,Ew
{ `hE@S |4
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^ woCwW8n
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), tunjV1 ,]
nStartPos,nEndPos,i); Z@{e\sZ)
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); P\2UIAPa\b
fileSplitterFetch.start(); IIIP<nyc
} =E10j.r
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :B"Y3~I
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "`&1"*
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 9s@$P7N5B
nEndPos = " + nFileLength); .sR=Mf7T
// fileSplitterFetch[nPos.length-1].start(); Tkf JC|6
EQ>]~
eY#_!{*Wn
//等待子线程结束 X6<%SJC
//int count = 0; *wD| eK7
//是否结束while循环 xY94v
boolean breakWhile = false; OX[pK_:`l
/yNLFL"
}hyl)?*~
while(!bStop) 0s'H(qE,_
{ voJmNH
write_nPos(); mx;1'!'fr
Utility.sleep(500); 5T- N\)@
breakWhile = true; P{gy/'PH,
C3>`e3v
=#|K-X0d=
for(int i=0;i<nStartPos.length;i++) ~s4o1^6L
{ :#&Y
if(!fileSplitterFetch.bDownOver) ;>Q.r{P
{ 8-cCWoc
breakWhile = false; ZI/Ia$O
break; 0\2#(^
} T5b*Ia
} #<EMG|&(
if(breakWhile) >0Gdxj]\
break; =!{ E!3>*D
Qq*Ks 5
C.Ty\@U
//count++; m6 @,J?X
//if(count>4) z6>Rv9f
// siteStop(); _m2p>(N|
} QdtGFY4f,
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N^;rLrm*
System.err.println("文件下载结束！"); " }oH3L
} (f `zd.
catch(Exception e){e.printStackTrace ();} {]V+C=`
} k2Y *
?|,-Bft3
~![J~CkPS
//获得文件长度 FvVR \a
public long getFileSize() 7;x}W-`iF
{ %MH!L2|
int nFileLength = -1; KKJ)BG?qZ
try{ CE;J`;
URL url = new URL(siteInfoBean.getSSiteURL()); CP"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vS'l@`Eg]
httpConnection.setRequestProperty("User-Agent","NetFox"); t`oH7)nut
q@0g KC&U
(>a8h~Na
int responseCode=httpConnection.getResponseCode(); !bg2(2z
if(responseCode>=400) |fhYft
{ .qAlPe L:
processErrorCode(responseCode); $G}!eV 6
return -2; //-2 represent access is error d:SLyFD$q
} D,sb{N
k^C^.[?
"-afHXED
String sHeader; (HD8Mm
uXkc07 r'
.Mb<.R3
for(int i=1;;i++) 3tu:Vc.:M
{ V~!lY\
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 6<qVeO&uZ
//Utility.log(in.readLine()); 9XEP:}5,
sHeader=httpConnection.getHeaderFieldKey(i); Oi-= Fp
if(sHeader!=null) A4
{ $-ICTp
if(sHeader.equals("Content-Length")) S2,tv
{ [oS4WP
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); v| Yh]y
break; {Ne5*HFV
} L2<IG)oXU
} <2,NWn.
else 8LH\a.>
break; )Lb?ZXT3
} 2vh@KnNU
} "f|xIK`c
catch(IOException e){e.printStackTrace ();} wpI_yp
catch(Exception e){e.printStackTrace ();} D8*tzu-
&@rXt!
J_eu(d[9
Utility.log(nFileLength); On*pI37(\
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.mwB'Ll
return nFileLength; +]dh`8*8>1
} H&_drxUq;L
G%FLt[
S\"#E:A
//保存下载信息（文件指针位置） Z;M th#
private void write_nPos() c]]e(
{ Yx3ivjX.>
try{ -.!+i8d>
output = new DataOutputStream(new FileOutputStream(tmpFile)); :pXY/Pa
output.writeInt(nStartPos.length); _-c1" Kl
for(int i=0;i<nStartPos.length;i++) 6haw\ *
{ Ygs:Ox"[-G
// output.writeLong(nPos); a4E{7c
output.writeLong(fileSplitterFetch.nStartPos); iRK&-wn
output.writeLong(fileSplitterFetch.nEndPos); Xt9vTCox
} &@[pJ2
output.close(); I3,0vnE@
} rm?C_
catch(IOException e){e.printStackTrace ();} r<9G}9
catch(Exception e){e.printStackTrace ();} 8_:j.(n
} Jk>!I\
)&vuT q'7'
Hzc5BC
//读取保存的下载信息（文件指针位置） 6tZ ak1=V
private void read_nPos() GJTakhj3
{ `W9~u: F
try{ f[fH1cu&`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !))!!{
int nCount = input.readInt(); HnsPXF'8g
nStartPos = new long[nCount]; K=N8O8R$y
nEndPos = new long[nCount]; %Kzu&*9Hb
for(int i=0;i<nStartPos.length;i++) Vf#g~IOI
{ ;}KT 3Q<^
nStartPos = input.readLong(); G(;R+%pu
nEndPos = input.readLong(); I#UL nSJ3
} F_.1^XM
input.close(); des.TSZ
} 9!?Ywc>0#
catch(IOException e){e.printStackTrace ();} q{CD:I:-
catch(Exception e){e.printStackTrace ();} iBh.&K{j
} AkAQ%)6qV
u2 t=*<X
RaC8Sq7hW
private void processErrorCode(int nErrorCode) 7Q0vwKC8>
{ ~+S,`8-P
System.err.println("Error Code : " + nErrorCode); A{%LL r:
} a&Z;$
Bg.
Oj8xc!d'
//停止文件下载 \5P 5N]]
public void siteStop() x T1MW
{ ]O&\Pn0q
bStop = true; 3Pgld*i7
for(int i=0;i<nStartPos.length;i++) ^y.|KA3[
fileSplitterFetch.splitterStop(); ac%x\e$
LARMZoyi
k@P?,r
} szUJh9-
} *-X`^R
//负责部分文件的抓取 ;pt.)5
**FileSplitterFetch.java hV}C.- 6h
*/ C8KV<k
package NetFox; {HbSty
'37 <+N
'OI(MuSn
import java.io.*; ib%'{?Q.
import java.net.*; k2/t~|5
w0PAtu
R5N~%Dg)3
public class FileSplitterFetch extends Thread { PwnfXsR
dR!x)oO=
1Vx>\A
String sURL; //File URL !CUM*<iV
long nStartPos; //File Snippet Start Position xV"~?vD
long nEndPos; //File Snippet End Position 8lFYk`|g
int nThreadID; //Thread's ID s1bb2R
boolean bDownOver = false; //Downing is over uaqV)H
boolean bStop = false; //Stop identical i hcSSUm
FileAccessI fileAccessI = null; //File Access interface nm,(Wdr
2$b JMx>
wGgeK,*_
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @k9n0Qe|F
{ z:oi@q
this.sURL = sURL; GG %*d]
this.nStartPos = nStart; ^G14Z5.
this.nEndPos = nEnd; <9]J/w+
nThreadID = id; [&pMU)
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1EWskmp
} #xh M&X
cb }OjM F
j[4l'8Ek
public void run() xg;vQKS6
{ ;sAe#b
while(nStartPos < nEndPos && !bStop) ?OFfU 4
{ Y^b}~t
LcTTfb+<
>{[
try{ Y-+JDrK
URL url = new URL(sURL); Z5eM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qNWSDZQ
httpConnection.setRequestProperty("User-Agent","NetFox"); 5a|{ytP
String sProperty = "bytes="+nStartPos+"-"; =klfCFwP
httpConnection.setRequestProperty("RANGE",sProperty); DD}YbuO7
Utility.log(sProperty); #xw3a<z?u
K=>j+a5$
pP%9MSCi
InputStream input = httpConnection.getInputStream(); <07]w$m/
//logResponseHead(httpConnection); Mtc-
vi]cl=S
63QF1*gPH
byte[] b = new byte[1024]; vr4{|5M
int nRead; CYYo+5x
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) yCwe:58
{ QBd4ok:R
nStartPos += fileAccessI.write(b,0,nRead); jB,VlL
//if(nThreadID == 1) _k#!^AJ}x
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); K"zRj L+
} ;Kh?iqn^
qfqL"G
8x-(7[#e<g
Utility.log("Thread " + nThreadID + " is over!"); j!"5,~
bDownOver = true; ~9#'s'
//nPos = fileAccessI.write (b,0,nRead); q4g)/x%nc
} K%UjPzPWw
catch(Exception e){e.printStackTrace ();} EUW>8kw0
} Q]<6voyy
} .:O($9^Ho
vXg^K}a#
_<'?s>(U'
//打印回应的头信息 T1%}H3
public void logResponseHead(HttpURLConnection con) xT-`dS0u
{ OHt^e7\
for(int i=1;;i++) 'n}]
{ 6?a z
String header=con.getHeaderFieldKey(i); .yHi"ss3
if(header!=null) =t %;mi,M
//responseHeaders.put(header,httpConnection.getHeaderField(header)); gHFQs](G.
Utility.log(header+" : "+con.getHeaderField(header)); 3R%yKa#
else i:Gyi([C
break; ~=9S AJr]
} Qe_C^(P
} Rm`P.;%
TW}].A_-
^fE8|/]nG9
public void splitterStop() IY|`$sHb
{ `VF_rC[?
bStop = true; yb,$UT"]
} :KqSMuKR
<sSH^J4QqX
Tj}%G
} FiSx"o
&?5me:aU
Mkr &30il[
/* +No` 89Y
**FileAccess.java {^k7}`7,
*//文件访问(定位，写) o#>Mf464I
package NetFox; l| y.6v
import java.io.*; WJk3*$=
WJ,?5#
={51fr/C%
public class FileAccessI implements Serializable{ E{}J-_oS45
#CcEI
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 r;p@T8k
RandomAccessFile oSavedFile; o#WECs>
long nPos; M(I%QD
)G-u;1rd
;@ G^eQ
public FileAccessI() throws IOException Y#+Ws0wN
{ S(/^_Y
this("",0); +VL:O]`DJ
} )l.AsfW%
ia,5=SKJ
nm_4E8&X
public FileAccessI(String sName,long nPos) throws IOException ^=8/Iw
{ wd3OuDrU
oSavedFile = new RandomAccessFile(sName,"rw"); FjMKb
this.nPos = nPos; %Y,Ru)5}
oSavedFile.seek(nPos); E!uQ>'iq.
} D&i,`j
(" +clb`
8|Ob7+
public synchronized int write(byte[] b,int nStart,int nLen) <[w5M?n8
{ hj{)6dBX%
int n = -1; bYqv)_8
try{ ;+bF4r@:+
oSavedFile.write(b,nStart,nLen); #m;o)KkH$r
n = nLen; XN{WxcZ
} u6%\ZK._ \
catch(IOException e) )&Z`SaoP|J
{ I8c:U2D
e.printStackTrace (); `\'V]9wS
} PHJHW#sv
OUFy=5(%:
G6lC[eK
return n; Xk1uCVUe5
} \<dg
"zkQu
YV} "#
} r4<As`&
!b&+2y2i[W
[Jj@A(Cz
/* H@9QEj!Y
**SiteInfoBean.java u,{R,hTDS
*/ o+)y!
package NetFox; L=fy!R
1yqsE`4f
TL)7X.1'L
public class SiteInfoBean { bZ:xH48MY
F1BXu@~e(
y4$$*oai&
private String sSiteURL; //Site's URL %nG>3.%
private String sFilePath; //Saved File's Path g4YlG"O[~
private String sFileName; //Saved File's Name HF"TS*
private int nSplitter; //Count of Splited Downloading File mSvSdKKKlI
&#KN"uPW
\)6bLB!
public SiteInfoBean() wLb:FB2
{//nSplitter的缺省值为5 4jGN:*kZ
//default value of nSplitter is 5 t0r0{:
this("","","",5); +@yU `
} oI'& &Bt
^2{6W6=
G e5Yz.Qv
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) l)~U8
{ 2`j{n\/
sSiteURL= sURL; A{M7
sFilePath = sPath; (y~%6o6
sFileName = sName; :U=3*f.{
this.nSplitter = nSpiltter; )WW*X6[k
Lusd kc7
ofw&?Sk0
} %d*0"<v
l9OpaOVfJ
6VuyKt
public String getSSiteURL() ,>za|y<n
{ }0Uh<v@
return sSiteURL; d{t@+}0.u
} 1P'A*`!K
uB3VCO.;_
12?!Z
public void setSSiteURL(String value) wa{!%qu5.R
{ m#i4_F=^b
sSiteURL = value; e|5@7~Vi
} I/!AjB8W4
t&F:C
+rA#]#hN
public String getSFilePath() q@O
{ s6Dkh}:d
return sFilePath; (5,x5l]-N
} (6NDY5h~=n
S'W,AkT
d*VvQU8C
public void setSFilePath(String value) IR$d?\O3
{ N)Q.P'`N
sFilePath = value; g5"I{ol5T~
} TJZ/lJU
t'0&n3
w4CcdpR
public String getSFileName() *OdmKVw6G
{ J\w4N",
return sFileName; 8F[ ;ma>Z8
} 4nP4F+
;|Hpg_~%>
Rm}5AJ
public void setSFileName(String value) C.":2F;-e
{ jDTG15_=
sFileName = value; 2+DK:T[
} <|.]$QSi
EJMd[hMhe
r<Z.J/a
public int getNSplitter() CTKw2`5u
{ esE!i0%
return nSplitter; kX`m( N$
} N*6~$zl&
Z 4i5,f
5Phsh
public void setNSplitter(int nCount) q }>3NCh
{ S.B?l_d^
nSplitter = nCount; nM:<l}~v{
} U`8Er48X
} WagL8BpLx
XP0;Q;WF}
rQGInzYp
/* KK1?!7
**Utility.java q :~/2<o
*/ je2"D7D
package NetFox; K]Vp! G
GnUD<P=I
[KHlApL
public class Utility { s]6;*mI2
Y?7GFkIP$
FG{,l=Z0
public Utility() vnVT0)Lel
{ MzgP@tB
"S6";G^I
n1JV)4Mv
} +se OoTKR
zv0sz])
//线程睡眠 Ii5U)"
public static void sleep(int nSecond) !sEhjJV^7
{ dlCiqY:}
try{ D29Lu(f
Thread.sleep(nSecond); `''y,{Fs
} _?cum~A@
catch(Exception e) )g^qgxnnV
{ oqysfLJ
e.printStackTrace (); q+oc^FD?@
} 8!!h6dQgI
} 6__!M
*QWOWg4w
//日志 rC!"<
public static void log(String sMsg) iu*&Jz)D>
{ =[!(s/+>L
System.err.println(sMsg); vzbGLap#
} M|h B[
j$XaO%y)
v=hn# U
public static void log(int sMsg) .K(9=yh
{ vY|YqWt
System.err.println(sMsg); H lM7^3(&
} ~Js kA5h|&
} mVYfyLZ,(
*c=vEQn-
f(blqO.@l
/* u^|cG{i5"
**TestMethod.java 4vN:Kj
*/ _izjvg
package NetFox; g]}!
0%[IG$u)|
kh=<M{-t
public class TestMethod { kRwUR34yc
hDSf>X_*_G
Cd=$XJ-b
public TestMethod() 7}~w9jK"F
{ ///xx/weblogic60b2_win.exe [ 't.x=
try{ yhbU;qEG9
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 7%? bl
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); FvPWS!H
SiteFileFetch fileFetch = new SiteFileFetch(bean); +swTMR
fileFetch.start(); pg7~%E4
} JrLh=0i9
catch(Exception e){e.printStackTrace ();} |te=DCO
_6,\;"it?8
w|S b`eR
} 3<M yb
(7b9irL&cn
{'h&[f>zcQ
public static void main(String[] args) v&/H6r#E.
{ Q4LPi;{\
new TestMethod(); YG8C<g6E7
} (tVT&eO
} [:gg3Qzx
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