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)); tD$lNh^
} ~svO*o Wa
for(int i=0;i<nEndPos.length-1;i++) smQVWs>
{ s:y ^_W)d
nEndPos = nStartPos[i+1]; V84*0&qOW
} 4FMAz^
nEndPos[nEndPos.length-1] = nFileLength; 3_5XHOdE
} ]=F8p2w?
} A 699FQ
x6'^4y])
T{vR,
//启动子线程 D';eTy Y
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; cyd~2\Kv~
for(int i=0;i<nStartPos.length;i++) PKq-@F%X
{ &GWkq>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f*xpE`&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Z%gx%$
nStartPos,nEndPos,i); xU9@$am
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;9uRO*H?T
fileSplitterFetch.start(); sNU}n<J-
} F:37MUQi
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;Pb8YvG1$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \.s`n2.w
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 84&XW
nEndPos = " + nFileLength); 8)0L2KL'
// fileSplitterFetch[nPos.length-1].start(); G{ mC7@
$GF]/;\m
]y1fM0
//等待子线程结束 `Xo4q3
//int count = 0; vH?9\3
//是否结束while循环 RB3 zHk%
boolean breakWhile = false; pvXcLR)L+3
5^)_B;.f
"<l<& qp
while(!bStop) B/eaqJ
{ )fh0&Y; R
write_nPos(); E,*&BDW
Utility.sleep(500); LAZVW</
breakWhile = true; IjZ@U%g@;
PJ 9%/Nrh
#o[\Dwu
for(int i=0;i<nStartPos.length;i++) >#N[GrJAE
{ ^b53}f8H
if(!fileSplitterFetch.bDownOver) y@apJ;_R-
{ p#H]\P'
breakWhile = false; VO`"<
break; `Q9+k<
} 5()Fvae{k
} d\Jji 6W
if(breakWhile) |f NMs
break; aR:<<IF\
8B@JFpg^
lfy7w|
//count++; ndOfbu;mf
//if(count>4) \p6 }
// siteStop(); 2a[9h#
} .s};F/(diD
xv0M
#AncOo
System.err.println("文件下载结束！"); oCJbkt=
} Fp:3#Bh
catch(Exception e){e.printStackTrace ();} +"L$ed(=nJ
} *ro.mQ_
c)3O/`
.Z5[_'T
//获得文件长度 5<N~3 1z
public long getFileSize() fq Y1ggL
{ NW De-<fQ
int nFileLength = -1; eU~?p|Np
try{ t F/nah
URL url = new URL(siteInfoBean.getSSiteURL()); e\~l!f'z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,o)4p\nV
httpConnection.setRequestProperty("User-Agent","NetFox"); U_*3>Q
6z]`7`G
#HDesen
int responseCode=httpConnection.getResponseCode(); qC.i6IL
if(responseCode>=400) 6UI>GQ
{ %Qd3BZ
processErrorCode(responseCode); qT0_L
return -2; //-2 represent access is error uRGB/ju^E
} ._ih$=
X X&K=<,Ja
HPTHF
String sHeader; xSOoIsL[
p5`ZyD]+
Yhk6Uog{4
for(int i=1;;i++) D1! {S7
{ 4ac1m,Jlt
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); z'e1"Y.
//Utility.log(in.readLine()); ] ?9t-
sHeader=httpConnection.getHeaderFieldKey(i); r_=p,#}#
if(sHeader!=null) QqjTLuN
{ <THUsY`3P&
if(sHeader.equals("Content-Length")) R ^^1/%
{ xBt<Yt"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); b_l.QKk
break; &*ZC0V3
} HIrEv
} FSVS4mtiX\
else v0u\xX[H;
break; >eu `!8
} tPzM7 n|
} .&L^J&V
catch(IOException e){e.printStackTrace ();} |zb`&tv}
catch(Exception e){e.printStackTrace ();} fX""xTNPi
{ $X X
*<?XTs<
Utility.log(nFileLength); *seu&
sD.6"w7}
+RdI;QmM
return nFileLength; 4%%B0[Wo_O
} (}6wAfGo
b%<164i
G u6[{u
//保存下载信息（文件指针位置） o\:$V
private void write_nPos() n~9 i^
{ (UXv,_"nU
try{ *WD;C0?z
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~DK F%}E
output.writeInt(nStartPos.length); N JXa_&_
for(int i=0;i<nStartPos.length;i++) JUmw$u
{ QZ?O;K1|y
// output.writeLong(nPos); S\}?zlV
output.writeLong(fileSplitterFetch.nStartPos); 9N<*S'Z
output.writeLong(fileSplitterFetch.nEndPos); +tPx0>p;
} )K8P+zn~
output.close(); tx gvVQ
} _F3KFQ4,S-
catch(IOException e){e.printStackTrace ();} r+SEw ;
catch(Exception e){e.printStackTrace ();} a4Ls^
} umqLKf=x!
>7"$}5d
Q%+}
//读取保存的下载信息（文件指针位置） e21E_exM0
private void read_nPos() ~:2&/MOP?
{ !-F^VGD(8
try{ +SO2M|ru&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); h=!M6yap<
int nCount = input.readInt(); <>SR4
nStartPos = new long[nCount]; |)m*EME
nEndPos = new long[nCount]; m*\B2\2gJ
for(int i=0;i<nStartPos.length;i++) \I'f3
{ >0kmRVd
nStartPos = input.readLong(); ]jZiW1C*a
nEndPos = input.readLong(); Y>xi|TWN
} MV% :ES?
input.close(); iTj"lA
} y;zt_O/
catch(IOException e){e.printStackTrace ();} NG!>7$@RV
catch(Exception e){e.printStackTrace ();} hTlnw[I
} 8f /T!5
^fFtI?.6jI
:D<:N*9i
private void processErrorCode(int nErrorCode) x:!C(Ep)
{ (~q#\
System.err.println("Error Code : " + nErrorCode); z0\;m{TH
} x>U1t!'
JRHf.?
`Ev A\f
//停止文件下载 fO[Rf_
public void siteStop() 5%2ef{T[
{ %KbBH:z05
bStop = true; $ /}:P
for(int i=0;i<nStartPos.length;i++) 3*CzXK>`M&
fileSplitterFetch.splitterStop(); V}vl2o
E}xz7u
~C}(\8g
} 0ClX
} >k$[hk*~
//负责部分文件的抓取 fo/ D3
**FileSplitterFetch.java FBR$,j;Y
*/ se<i5JsSV
package NetFox; Paae-EmC
2(+RIu0d
)![f\!'PI
import java.io.*; 5W?yj>JR
import java.net.*; Y|hzF:ll
<7vIh0
fK)ZJ_?w,@
public class FileSplitterFetch extends Thread { ]%NO"HzF~
G=r(SJq
u#zP>!
String sURL; //File URL W _PM!>8`
long nStartPos; //File Snippet Start Position n4ds;N3Hd
long nEndPos; //File Snippet End Position BxSk%$J
int nThreadID; //Thread's ID . 1{vpX
boolean bDownOver = false; //Downing is over 9pVf2|5hj
boolean bStop = false; //Stop identical r6O7&Me<
FileAccessI fileAccessI = null; //File Access interface @&~OB/7B:
m~= ]^e
]>VJ--fH
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1jZDw~
{ 8>%jZ%`a
this.sURL = sURL; d&[M8(
this.nStartPos = nStart; o*O"\/pmF
this.nEndPos = nEnd; 9E->;0-
nThreadID = id; C:tSCNH[
fileAccessI = new FileAccessI(sName,nStartPos);//定位 [[*0MA2Y
} ?1-n\ka
1cHSgpoJ
=`7#^7Q9
public void run() Ov~S2?E8
{ '-nuH;r
while(nStartPos < nEndPos && !bStop) zJy 89ib'
{ UtW"U0A
94qHY1rp
0%A(dJA6
try{ JT.\f,z&
URL url = new URL(sURL); 7=QC+XSO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (8@hF#N1
httpConnection.setRequestProperty("User-Agent","NetFox"); @T,H.#bL
String sProperty = "bytes="+nStartPos+"-"; S}v{^vR
httpConnection.setRequestProperty("RANGE",sProperty); R>e3@DQ~
Utility.log(sProperty); ~-`BSR
(4{@oM#H6
WDH[kJ
InputStream input = httpConnection.getInputStream(); &,Zz
//logResponseHead(httpConnection); +EiUAs~H
?ck^? p7
FkxhEat8
byte[] b = new byte[1024]; >QZt)<[
int nRead; @]ptY*
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) o trTrh
{ zZ+LisSs&
nStartPos += fileAccessI.write(b,0,nRead); |bG[TOa
//if(nThreadID == 1) xXY)KI N[
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %:be{Y6
} 6ImV5^l
7AtXG^lK
{^$"/hj
Utility.log("Thread " + nThreadID + " is over!"); Vg [5bJ5
bDownOver = true; 0JZq:hUd
//nPos = fileAccessI.write (b,0,nRead); RP@idz
} xU\:Vid+A
catch(Exception e){e.printStackTrace ();} d$?n6|4
} MlC-Aad(
} l&^[cR
WfjUJw5x"s
c;~Llj P
//打印回应的头信息 RY/ Z~]
public void logResponseHead(HttpURLConnection con) %`T^qh_dE
{ LN6JH!
for(int i=1;;i++) #u=O 5%.
{ z5*O@_r+.b
String header=con.getHeaderFieldKey(i); o2e h)rtB
if(header!=null) !{~7)iq
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1'U%7#;E
Utility.log(header+" : "+con.getHeaderField(header)); Y)j,(9
else f?<M3P
break; (zLIv9$
} $5"-s]
} O"-PNF,J
2|NyAtPb5
qyBK\WqaP
public void splitterStop() VX>t!JP p
{ AO7qs:+
bStop = true; T#^6u)
} <ZvPtW
!RUo:b+
gMK3o8B/
} FivaCNA
=cKk3kJC
{)[g
/* yExyx?j.
**FileAccess.java .-26 N6S
*//文件访问(定位，写) Vq7 kA "
package NetFox; @k #y-/~?
import java.io.*; eD1MP<>h
np>!lF:
*U^I`j[u
public class FileAccessI implements Serializable{ ! tPK"k
zr9Pm6Rl
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !skWe~/
RandomAccessFile oSavedFile; ^t%M
long nPos; n *0F
tJ_@AcF
.MPOUo/e
public FileAccessI() throws IOException 43Uy<%yb>}
{ K:50?r_-6
this("",0); ;S27m]Q?
} 3:Egqw
9U1!"/F
;RZa<2
public FileAccessI(String sName,long nPos) throws IOException 7IW7'klkvD
{ I}0-
oSavedFile = new RandomAccessFile(sName,"rw"); a#GqJ?nY
this.nPos = nPos; 2m}]z.w#
oSavedFile.seek(nPos); Yy~Dg
} 9JeGjkG,
/38Pp%
)tg*dE
public synchronized int write(byte[] b,int nStart,int nLen) ;.m[&h 0
{ 8>+eGz|
int n = -1; ]@]"bF!Dn
try{ 8k% :w0H
oSavedFile.write(b,nStart,nLen); E0Xu9IW/A
n = nLen; zMg^2{0L
} Dp'af4+%$
catch(IOException e) IN*Z__l8j`
{ iU|C<A%Hh
e.printStackTrace (); t?&ajh
} .qP zd(<T7
[vJosbU;
Nq1RAM
return n; x6P^IkL:
} >CA1Ub&ls
$>`8'I
p`C5jfI
} Q'LU?>N)/
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HM x9M$
/* sbb{VV`I
**SiteInfoBean.java <m\TZQBD
*/ 8;bOw
package NetFox; \Bf{/r5x
!"">'}E1
Va:jMN
public class SiteInfoBean { -#hl&^u$
#7)6X:/O
+%^xz 1m
private String sSiteURL; //Site's URL V!4E(sX
private String sFilePath; //Saved File's Path #]a0 51Y
private String sFileName; //Saved File's Name Z r*ytbt
private int nSplitter; //Count of Splited Downloading File |9@;Muq;
IrK )N
ng\S%nA&J
public SiteInfoBean() Iu]P^8
{//nSplitter的缺省值为5 L(iWFy1& T
//default value of nSplitter is 5 { Uh/ ~zu
this("","","",5); VE!h!`<k
} 6HyQm?c>a
,oR}0(^"\<
E[ ,Ur`>:
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &BP%~
{ /.vB /{2
sSiteURL= sURL; WVKzh
sFilePath = sPath; mZmwCS8
sFileName = sName; 6B&':N98
this.nSplitter = nSpiltter; v~j21`
f"S^:F0
l%U{Unwu
} Rc @p!Xi
%1S;y
Y~,N,>nITu
public String getSSiteURL() ^+I{*0{/[
{ E`BL3+kQ
return sSiteURL; R'He(x
} PXWBc\
)D Y?Y-n
0I1bY]*
public void setSSiteURL(String value) d(<[$3.
{ W2s6!_AN
sSiteURL = value; <a; <|Fm.
} G7b>r
J'W6NitMr
ZJ1%
public String getSFilePath() Enyx+]9
{ ,iV|^]X3$/
return sFilePath; a%cCR=s=
} #A+ dj| b
e2~&I`ct
@-)jU!
public void setSFilePath(String value) l!5fuB8
{ P`0}( '"U
sFilePath = value; R^4JM,v9x`
} eh`n?C
!/2uO5
R1)v;^B|)
public String getSFileName() %v5IR
{ u[k0z!p_ c
return sFileName; e'Njl?>3
} 9l<f?OzAO
>|IUjv2L
(= #EJB1(
public void setSFileName(String value) A%(t'z
{ EdR1W~JZ
sFileName = value; ,ELbm
} |1!RvW:[!
UaG })
@'P\c
public int getNSplitter() P3Ocfpf Bp
{ ;d5d$Np@m&
return nSplitter; l1 Nr5PT
} !X5n'1&
@~1}n/
20h+^R3{Z
public void setNSplitter(int nCount) v@n0ma=
{ IHC {2 ^
nSplitter = nCount; mQwP-s
} PLoD^3uG)
} Oc A;+}>
3;v%78[&P
{_[\k^98>
/* df9jT?l
**Utility.java ebv"`0K$
*/ 2":{3=oW~
package NetFox; {zhajY7
QTe>EJ12
`!- w^~c
public class Utility { ?OD43y1rzd
jc0Trs{Jf
;cpQ[+$nKp
public Utility() KdN+$fe*g
{ pA?kv]l(
MeCHn2zwB
R-[t4BHn
} o!$O+%4
@3g$H[}
//线程睡眠 BU;o$"L
public static void sleep(int nSecond) A*x3O%zH
{ iup "P
try{ caH!(V}6
Thread.sleep(nSecond); {)KH%
} 4s_|6{ANS
catch(Exception e) sR;^7(f!m
{ ?j:U<TY)
e.printStackTrace (); VV'*3/I
} 8slOB>2#Y
} 3{/[gX9
Z)qts=
//日志 {BI5lvx:
public static void log(String sMsg) |i~Ab!*8n
{ F4X0DRC,G
System.err.println(sMsg); ,'}qLor
} )}3!iDA
$v \@mW*R
42B_8SK
public static void log(int sMsg) Bk44 wz2X
{ Or:a\qQ1
System.err.println(sMsg); #Y>os3]
} ] -}Zd\Rs
} b~Q8&z2
xtq='s8e
P(|+1$#[
/* {];8jdg/?
**TestMethod.java _$vAitUe4S
*/ q-<t'uhs[
package NetFox; azKiXr#_(
3v?R"2\qS
|,)=-21&;
public class TestMethod { &:@)roCR
&)Z!A*w]
duT'$}2@>
public TestMethod() >JUOS2
{ ///xx/weblogic60b2_win.exe Yb?L:,a(I
try{ 2^f6@;=M
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); JK=0juv<E
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 79MF;>=tV
SiteFileFetch fileFetch = new SiteFileFetch(bean); }Y`D^z~
fileFetch.start(); b2vCr F;
} \&#IK9x{
catch(Exception e){e.printStackTrace ();} .tQeOZW'
*w,C5 f
qC:QY6g$N
} ~|kSQ7O^
C(!A% >
W^"C|4G}
public static void main(String[] args) L<H zPg
{ <yg!D21Y
new TestMethod(); 3z~d7J
} -)E nr6
} NDYm7X*et
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