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)); 8Cef ]@x
} rE?Fp
for(int i=0;i<nEndPos.length-1;i++) ,LodP%%UV
{ U9(p ^
nEndPos = nStartPos[i+1]; ! _p(H
} vw)lD9-"
nEndPos[nEndPos.length-1] = nFileLength; k];NTALOG
} )cV*cDL1j
} sLze/D_M*
kCHYLv3.
tl"?AQcBR
//启动子线程 yOswqhz
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Yaix\*II
for(int i=0;i<nStartPos.length;i++) LK:Jkjp^
{ yp?a7t M
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %DhM}f
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), srQ]TYH ,
nStartPos,nEndPos,i); M37GQvo
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Nv5)A=6#AA
fileSplitterFetch.start(); ZwOX ,D
} bnZ~jOHl
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bmQ-5SE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~-2Gx HO`
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 9$*O^
nEndPos = " + nFileLength); bw8[L;~%_
// fileSplitterFetch[nPos.length-1].start(); 8;v/b3
^_c6Op<F
#p7K2
//等待子线程结束 ]$&N"&q
//int count = 0; `M[o.t
//是否结束while循环 6-Id{mx
boolean breakWhile = false; k9m9IE"9=$
\'CA:9V}
uD4j.%
while(!bStop) n5+Z|<3)
{ *W-:]t3CR
write_nPos(); brEA-xNWQ
Utility.sleep(500); u"gtv
breakWhile = true; A-f,&TO
9A,ok[J
*ry}T=
for(int i=0;i<nStartPos.length;i++) -gB9476-
{ :r4o:@N'
if(!fileSplitterFetch.bDownOver) @@V{W)rl
{ p6X-P%s
breakWhile = false; XiO~^=J
break; +SNjU"x
} g\]~H%2 ,
} Vrn+"2pdJ
if(breakWhile) ib-H jJ8
break; @! {Y9k2
e+<'=_x {
.]YTS
//count++; 7q(A&
//if(count>4) a.2Xl}2o5
// siteStop(); =/Ph]f9
} IXv9mr?H}
(v}4,'dS
i]15g@
System.err.println("文件下载结束！"); _=_<cgy1u
} txik{' :
catch(Exception e){e.printStackTrace ();} i:60|ngK
} 7 T
722:2 {
/|m0)H.>
//获得文件长度 +Ze;BKZ3
public long getFileSize() mtmTlGp6Lc
{ M(?0c}z
int nFileLength = -1; 4'5|YGQj
try{ ha?M[Vyw4Q
URL url = new URL(siteInfoBean.getSSiteURL()); dJ{q}U
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); iAo/Dnp2J
httpConnection.setRequestProperty("User-Agent","NetFox"); ]j0/.pG
$38)_{
N/78Ub
int responseCode=httpConnection.getResponseCode(); k~*%Z!V}C
if(responseCode>=400) uN4e n,
{ ]d~2WX Y
processErrorCode(responseCode); 89x;~D1
return -2; //-2 represent access is error ?$#P =VK
} UM<!bNz`
8j)*T9
_<KUa\
String sHeader; =&F~GCZ>
RPdFLC/
:%>)S
for(int i=1;;i++) ZeqsXz
{ e2yCWolmTS
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :gn&wi
//Utility.log(in.readLine()); {H*
sHeader=httpConnection.getHeaderFieldKey(i); :$*@S=8O
if(sHeader!=null) NfWL3"&X
{ bTt1yO
if(sHeader.equals("Content-Length")) F*T$n"^
{ ]\y]8v5(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); (H8JV1J
break; !/e*v>3u&
} NFyKTA6
} GOOm] ]I
else {y'4&vt<~
break; ey6ujV7!
} Zs4NN2~
} ?a-5^{{
catch(IOException e){e.printStackTrace ();} OT0IGsJ"'
catch(Exception e){e.printStackTrace ();} }T-'""*
M!aJKpf
&["e1ki
Utility.log(nFileLength); )-X/"d
6Yl+IP];i
oL~?^`cGZ
return nFileLength; Sm{> 8e}UE
} 2 w6iqLr?
&M:o(T
'&nQ~=3
//保存下载信息（文件指针位置） M@o^V(j
private void write_nPos() Cu!]-c{
{ JT&RaFX
try{ _+X-D9j(l
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1m5*MY
output.writeInt(nStartPos.length); n,d)Wwe_`y
for(int i=0;i<nStartPos.length;i++) n(`|:h"
{ b:cy(6G(
// output.writeLong(nPos); u 7:Iv
output.writeLong(fileSplitterFetch.nStartPos); bObsj]
output.writeLong(fileSplitterFetch.nEndPos); Nz}PcWF/
} d^f rKPB
output.close(); [8~P Pc^
} %lD+57=
catch(IOException e){e.printStackTrace ();} 6bPl(.(3
catch(Exception e){e.printStackTrace ();} <PiO %w{
} ^qzH(~g{M
Qj'Ik`o
9w~SzpJ%
//读取保存的下载信息（文件指针位置） F0~<p[9Nx
private void read_nPos() &B]1 VZUp
{ 9VanR ::XX
try{ `ZbFky{
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !*f$*,=^
int nCount = input.readInt(); [2Zl '+
nStartPos = new long[nCount]; skBD2V4
nEndPos = new long[nCount]; 7WwE] ^M
for(int i=0;i<nStartPos.length;i++) b;%t*?t
{ lh[?`+A
nStartPos = input.readLong(); KK6n"&TVa
nEndPos = input.readLong(); wSw> UU
} 6']HmM
input.close(); )XHn.>]nc
} U E$Ix
catch(IOException e){e.printStackTrace ();} @mmnr?_w
catch(Exception e){e.printStackTrace ();} $rlrR'[H
} y/5GY,z%aL
Rw|'LaW
v`{N0R
private void processErrorCode(int nErrorCode) .!Pg)|
{ #?V rt,n
System.err.println("Error Code : " + nErrorCode); #y[U2s Se
} TDUY&1[
#qh ,
b\"w/'XX
//停止文件下载 D$7#&2y
public void siteStop() 78Du
{ 6T4I,XrY_F
bStop = true; bK.*v4RG
for(int i=0;i<nStartPos.length;i++) X^Z!!KTH
fileSplitterFetch.splitterStop(); ![sXR
wYg!H>5
6JDaZh"=K
} n_3R Q6
} JXM]tV
//负责部分文件的抓取 Xjkg7p,HD@
**FileSplitterFetch.java DY9]$h*y
*/ IvT><8<G
package NetFox; t&:L?K)j
[:FiA?O]
a&V;^ /
import java.io.*; DU0/if9.
import java.net.*; .] sJl
^lAM /
TS#[[^!S
public class FileSplitterFetch extends Thread { nYFrp)DLK
FY ms]bv
I#&r5Q
String sURL; //File URL NC#F:M;b
long nStartPos; //File Snippet Start Position s2#Ia>5!
long nEndPos; //File Snippet End Position i'7+ ?YL
int nThreadID; //Thread's ID D:;idUO
boolean bDownOver = false; //Downing is over LP=j/qf|
boolean bStop = false; //Stop identical Ps74SoD-
FileAccessI fileAccessI = null; //File Access interface BBRL_6
Jjm#ofv
s4~[GO6>
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Vv45w#w;
{ +.Ij%S[Px5
this.sURL = sURL; e=WjFnK[x7
this.nStartPos = nStart; z -!w/Bv@
this.nEndPos = nEnd; ;Mup@)!j
nThreadID = id; -cM1]soT
fileAccessI = new FileAccessI(sName,nStartPos);//定位 b:D92pH
} 8.[F3Tk=
Fq@o_bI
B*,)@h
public void run() lI 4tW=
{ $[A\i<#
while(nStartPos < nEndPos && !bStop) tqZ+2c<W3
{ NS~;{d\
DK\XC%~m
\xj;{xc
try{ +yp:douERi
URL url = new URL(sURL); :-B+W9'5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d=PX}o^
httpConnection.setRequestProperty("User-Agent","NetFox"); N+=|WeZ
String sProperty = "bytes="+nStartPos+"-"; 80Dn!9j*
httpConnection.setRequestProperty("RANGE",sProperty); RqtBz3v
Utility.log(sProperty); eHyUY&N/
U}RBgPX!
UowvkVa
InputStream input = httpConnection.getInputStream(); y %Q.(
//logResponseHead(httpConnection); x}yl Rg`[
y%SxQA+\
~w+I2oS$
byte[] b = new byte[1024]; G aV&y
int nRead; lL:a}#qxU
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) N2v/<
{ 7C|!Wno[;
nStartPos += fileAccessI.write(b,0,nRead); IT1YF.i
//if(nThreadID == 1) (-21h0N[V
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .9rYBy
} 4|=>gdW)KN
_^r};}-}
9%"7~YCDas
Utility.log("Thread " + nThreadID + " is over!"); ]>t~Bcnm
bDownOver = true; LE\=Y;%
//nPos = fileAccessI.write (b,0,nRead); YQn<CjZ8af
} "XR=P> xk
catch(Exception e){e.printStackTrace ();} wlT8|
} STp9Gh-
} RpQeQM=
vR!+ 8sy$
JaCX}[R
//打印回应的头信息 m&:&z7^p
public void logResponseHead(HttpURLConnection con) SM2Lbfp!u
{ mGjB{Q+
for(int i=1;;i++) tWIs |n
{ 9 {&g.+
String header=con.getHeaderFieldKey(i); HIXAA?_eh=
if(header!=null) C#kE{Qw10r
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^#HaH
Utility.log(header+" : "+con.getHeaderField(header)); #ES[),+|mB
else H<(F$7Q!\
break; 68Fl/
} j uA@"SG
} \c< oVF'
fF(2bVKP:
zm"
public void splitterStop() RbAl_xKI
{ eV[{c %wN:
bStop = true; %MeAa?G-#
} jE\G_>
Alxf;[s
BNfj0e5b
} V\cbIx(Z^
HwUaaK
?woL17Gt
/* wa"0`a:`;
**FileAccess.java rwRZGd *p
*//文件访问(定位，写) {821e&r
package NetFox; CS7b3p!I
import java.io.*; u>*a@3$f
'J,UKK\5
/)ZjI W"|
public class FileAccessI implements Serializable{ (Q*q#U
1l,fK)z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 )|~&(+Q?]
RandomAccessFile oSavedFile; .z>/A/&+
long nPos; B\J[O5},
j&8YE7
6}^x#9\
public FileAccessI() throws IOException sL$sj|"S
{ p&(0e,`z/
this("",0); 74Jx\(d
} \ND]x]5d
\p4*Q}t
cNWmaCLN$
public FileAccessI(String sName,long nPos) throws IOException $*C }iJsF
{ w2s`9
oSavedFile = new RandomAccessFile(sName,"rw"); h4hAzFQ.s
this.nPos = nPos; T3wTMbZ!VK
oSavedFile.seek(nPos); :zHSy&i`
} q"VmuQ
yKML{N1D
o?baiOkH
public synchronized int write(byte[] b,int nStart,int nLen) e>MtDJ5
{ 2{ F-@}=
int n = -1; |]&3*%b@
try{ LJeq{Z
oSavedFile.write(b,nStart,nLen); #{6VdWZ
n = nLen; xWxHi6U(
} *~PB
catch(IOException e) LIDi0jbrq
{ A;co1,]gR
e.printStackTrace (); -H60T,o
} G*=HjLmZg
$DDO9
XJ7B?Zg
return n; OxJHhF
} o,i_py
fbApE
gq('8*S
} (Y~/9a4X
@/#G2<Vp1
]3v)3Wp
/* u>'0Xo9R
**SiteInfoBean.java +3))G
*/ ]xS%Er
package NetFox; ie1~QQ
WI1YP0V
]9QXQH
public class SiteInfoBean { ;6V~yB
C6>_wl]
G? SPz
private String sSiteURL; //Site's URL _{o 3y"DZ
private String sFilePath; //Saved File's Path !!.@F;]W
private String sFileName; //Saved File's Name jZ~girA
private int nSplitter; //Count of Splited Downloading File o6u^hG6~'
Mc?_2<u-
3Dr\ O_`u
public SiteInfoBean() 3cJ'tRsp<
{//nSplitter的缺省值为5 #?Ix6 {R
//default value of nSplitter is 5 ,zjz "7'
this("","","",5); "smU5 s,P
} BsA4/Bf
Bl>m`/\1i
Wps^wY
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) DcxT6[
{ 5%TSUU+<I
sSiteURL= sURL; &&;.7E
sFilePath = sPath; s(X\7Hz_nC
sFileName = sName; `C4(C4u
this.nSplitter = nSpiltter; >:.c?{%g*
^2dQVV.
H7uh"/A
} @Mya|zb
B}7j20:Z
W2<'b05
public String getSSiteURL() 'z91aNG]
{ oyiG04H&
return sSiteURL; U>n[R/~]
} V'b4wO1RV
^4IJL",
I!!cA?W
public void setSSiteURL(String value) WReHep
{ %Ja0:e
sSiteURL = value; &tUX(
} K7s[Fa6J
0<V/[$}\D
NP3 e^
public String getSFilePath() fx>QP?Z
{ 1TEKq#t;y
return sFilePath; }se3y
} |7K>`
wKJ|;o4;L
.8'c c8
public void setSFilePath(String value) -I4@6vE,
{ # ,H!<X;SS
sFilePath = value; ?yG[VW
} "Pc}-&
JV,h1/a("
8yIBx%"4MH
public String getSFileName() W2`3PEa
{ fNda&
return sFileName; C\{ KB@C\*
} |A68+(3u
0OlT^
]fDb|s48
public void setSFileName(String value) _|;d D
{ E#d~.#uH
sFileName = value; Ca5LLG
} V}`ri~
]?V:+>t=
07=I&Pum
public int getNSplitter() S5gBVGh
{ h143HXBi1+
return nSplitter; O:'qwJ#~
} $J<WFDn9
J>M9t%f@
3;jxIo$,
public void setNSplitter(int nCount) 83]m/Iz
{ ]D~Ibv{Y
nSplitter = nCount; h}tC+_"D
} {ZdF6~+H(!
} WNeBthq6
*oLDy1<
G'Wp)W;])\
/* ]>Dbta.27
**Utility.java Xn~\Vb
*/ rosD)]I7
package NetFox; gKQs:25
iW2\;}y
fVZ92Xw B
public class Utility { ^?0'\Z
W8x&:5Fc)3
Xhyn! &H5
public Utility() VcsMDa
{ Qe!3ae`Z
?v:FGO
mcidA%
} "\vQVZd-E
;,uATd|
//线程睡眠 p,f$9t4
public static void sleep(int nSecond) }%c>Hh
{ |Y6;8e`H
try{ MtF^}/0w!`
Thread.sleep(nSecond); `t9k!y!GV
} g[O
catch(Exception e) 7K&Uu3m
{ @@-TW`G7
e.printStackTrace (); ]ZP!y
} FSz<R*2
} m8 _yorz
M/lC&F(
//日志 @+~>utr
public static void log(String sMsg) y$di_)&g
{ O8>&J-+2
System.err.println(sMsg); raSga'uT;
} +84 p/B#
} 7:T? `V:
j[mII5e7g
public static void log(int sMsg) }/\`'LQ
{ \ntUxPox.
System.err.println(sMsg); [n&ES\o#(
} 2wPc yD
} \M|:EG%
G; exH$y
*"Iz)Xzc`
/* `'5vkO>
**TestMethod.java Z5F#r>>`
*/ a[z$ae7
package NetFox; LXJ;8uW2y
9@IL547V
NX8hFwR
public class TestMethod { WI*CuJU<zJ
/s+IstW
~H
public TestMethod() <}'=@a
{ ///xx/weblogic60b2_win.exe :x5O1Zn/t
try{ Ahba1\,N$
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ypGt6t(;
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); @^ti*`
SiteFileFetch fileFetch = new SiteFileFetch(bean); -I6t ^$HA
fileFetch.start(); Og@{6>
} $`%Om WW{
catch(Exception e){e.printStackTrace ();} NOkgG0Z
XjP;O,x
imzPVGCD{
} u)r:0;5
SsZSR.tD
XR[=W(m}
public static void main(String[] args) E^c*x^
{ f)a0!U 44
new TestMethod(); KZ#\ >
} @-xvdntx
} AOKC1iD%Y
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