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)); 3 {OZdl|
} >hFg,5 _l3
for(int i=0;i<nEndPos.length-1;i++) dBeZx1Dy
{ QqdVN3#1z
nEndPos = nStartPos[i+1]; y88lkV4a
} -LnNA`-
nEndPos[nEndPos.length-1] = nFileLength; c`M ,KXott
} *ak"}s
} BXxl-x
B s{n
qJZ:\u8oO
//启动子线程 `*ml/% \
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; V.?Oly
for(int i=0;i<nStartPos.length;i++) '7ps_pz
{ h4,S/n
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), CW . O"_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), vUD>+*D
nStartPos,nEndPos,i); g+zfa.wQ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); rl0|)j
fileSplitterFetch.start(); _c@k>"_{S
} WW.amv/[a
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B.ar!*X
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); .CAcG"42
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,b!]gsds
nEndPos = " + nFileLength); k4!z;Yq
// fileSplitterFetch[nPos.length-1].start(); JZom#A. dt
4/+P7.}ea-
G8hq;W4@]/
//等待子线程结束 kfQi}D'a
//int count = 0; +}-Ecr
//是否结束while循环 iO2%$Jw9\
boolean breakWhile = false; ZL^ svGy
]R7zvcu&
7TaHE
while(!bStop) i3usZ{_r
{ ]fb3>HOTJ
write_nPos(); <7X6ULQ
Utility.sleep(500); #>[5NQ;$'
breakWhile = true; \4FKZ>1+R
k,M%"FLQ
t^KoqJ
for(int i=0;i<nStartPos.length;i++) ]$xN`O4W{
{ qFwJ%(IQ
if(!fileSplitterFetch.bDownOver) f83Tl~
{ %$3)xtS6
breakWhile = false; k2t#O%_f
break; [;*Vm0>t
} q7-.-k<dQ
} [pgld9To
if(breakWhile) tw?\bB
break; |v?*}6:a
Ej7>ywlW
,^d!K(xb
//count++; w=K!U]
//if(count>4) cPL]WI0(
// siteStop(); !5escR!\D
} RbA.%~jjx*
* U#@M3g.
),#hBB`ZA
System.err.println("文件下载结束！"); JAA{5@ST
} {24Y1ohK
catch(Exception e){e.printStackTrace ();} ocbNf'W;
} WymBjDos:
&:MfLDJ
V {H/>>k7
//获得文件长度 BMlu>,
public long getFileSize() ;;cPt44s
{ xw5LPz;B
int nFileLength = -1; ( /):
try{ ^,;AM(E
URL url = new URL(siteInfoBean.getSSiteURL()); !?%'Fy6t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R]8^ @i1
httpConnection.setRequestProperty("User-Agent","NetFox"); erQ0fW
>QJfTkD$
u>U4w68
int responseCode=httpConnection.getResponseCode(); KE k]<b=
if(responseCode>=400) FA#?+kd
{ JMa[Ulz
processErrorCode(responseCode); X8Ld\vZYn
return -2; //-2 represent access is error 'dFhZ08u}
} vs|_l!n3
oF9c>^s
LtDQgel"
String sHeader; AT6:&5_`
Gd08RW
kk*:S*,
for(int i=1;;i++) zLa3Q\T
{ Ad@Odx=o*R
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); z%pD3J?>
//Utility.log(in.readLine()); Es~|:$(N]|
sHeader=httpConnection.getHeaderFieldKey(i); 6-w'?G37
if(sHeader!=null) ZO!
{ l*+5WrOS
if(sHeader.equals("Content-Length")) J/o$\8tiMw
{ ZX Sl+k.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); V;V,G+0Re
break; =:;KYuTr
} ~il{6Z+#n
} V>2mzc
else xa?#wY b
break; 1`X- O>
} S_B $-H|
} rq.S0bzH
catch(IOException e){e.printStackTrace ();} W?B(Jsv
catch(Exception e){e.printStackTrace ();} ca!=D $
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F$QAWs
Utility.log(nFileLength); kZ0|wML8
P=j89-e
%!>~2=Q2*
return nFileLength; B:pIzCP
} u*<G20~A
K^_Mt!%
1YklPMx6
//保存下载信息（文件指针位置） /<Doe SDJ|
private void write_nPos() 8jnz;;|
{ +foyPj!%
try{ 0uf'6<fR
output = new DataOutputStream(new FileOutputStream(tmpFile)); *vss
output.writeInt(nStartPos.length); mu(EmAoenQ
for(int i=0;i<nStartPos.length;i++) 2eOde(K+
{ zgdOugmmt_
// output.writeLong(nPos); {Y%X
output.writeLong(fileSplitterFetch.nStartPos); Z{|U!tn
output.writeLong(fileSplitterFetch.nEndPos); XU}|Ud562
} #jja#PF]7
output.close(); (v\Cv)OS
} B`/cKfg
catch(IOException e){e.printStackTrace ();} a09]5>*
catch(Exception e){e.printStackTrace ();} )cMW,
} c 4<~?L
K`9ph"(Z
oM@X)6P_
//读取保存的下载信息（文件指针位置） _l`s}yC
private void read_nPos() W|PKcZ ]Uc
{ WaVP+Ap
try{ 3KF[ v{
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); k]n=7vw;
int nCount = input.readInt(); +;}XWV
nStartPos = new long[nCount]; f8Xe%"<
nEndPos = new long[nCount]; s57-<&@J9
for(int i=0;i<nStartPos.length;i++) @CSTp6{y
{ #NAlje(7
nStartPos = input.readLong(); 95,{40;X7
nEndPos = input.readLong(); *Q<%(JJ
} |$r|DX1[
input.close(); ;btH[a iV
} &DMKZMj<Q*
catch(IOException e){e.printStackTrace ();} v;9VX
catch(Exception e){e.printStackTrace ();} V8z91
} S=^a''bg
S)@95pb
M.Fu>Xi
private void processErrorCode(int nErrorCode) ?Afx{H7
{ :>Gm&w (n
System.err.println("Error Code : " + nErrorCode); axl!zu*
} $Q[>v!!X
7kBULeBn|
[8k7-}[
//停止文件下载 JZ[~3swR
public void siteStop() oJF@O:A
{ ^oFg5
bStop = true; L`yyn/2>
for(int i=0;i<nStartPos.length;i++) ("t; 2Mw
fileSplitterFetch.splitterStop(); C^@~
/"t*gN=wrF
acWm+
} W*q[f!@
} -ISI!EU$
//负责部分文件的抓取 U$J l5[`F^
**FileSplitterFetch.java N/A.1W
*/ ^X%{]b K
package NetFox; _5^p+
Tc6H%itV
T4`.rnzyRb
import java.io.*; Go}C{(4T
import java.net.*; yfS`g-j{~
GM6Y`iU
54kd>)|"ag
public class FileSplitterFetch extends Thread { S6 F28 d[j
nn@"68]g
N\IdZX%u
String sURL; //File URL )#9R()n!
long nStartPos; //File Snippet Start Position kfo, PrW`A
long nEndPos; //File Snippet End Position LI[ w?6B
int nThreadID; //Thread's ID A*BIudli
boolean bDownOver = false; //Downing is over I=VPw5"E
boolean bStop = false; //Stop identical JJ3(0 +
FileAccessI fileAccessI = null; //File Access interface }LNpr
#msXAy$N3r
f i-E_
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException r'/7kF- 5
{ !2WRxM
this.sURL = sURL; ~_P,z?
this.nStartPos = nStart; 7FMg6z8~
this.nEndPos = nEnd; '&5A*X]d
nThreadID = id; qby!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 N(v<*jn
} A]2zK?|s
^tIi;7k
"E;]?s9x
public void run() j_E$C.XU{g
{ T<\Q4Coth
while(nStartPos < nEndPos && !bStop) 2G8f4vsC[
{ o$>A;<
" 1YARGu
~S)o('
try{ B*A{@)_
URL url = new URL(sURL); 0+b1R}!2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); C8%Iol
httpConnection.setRequestProperty("User-Agent","NetFox"); 83UIH0(
String sProperty = "bytes="+nStartPos+"-"; d-g&TSGd
httpConnection.setRequestProperty("RANGE",sProperty); 2H8,&lY.p
Utility.log(sProperty); xX`P-h>V`c
X8Px
=&~*r
InputStream input = httpConnection.getInputStream(); o'@VDGS`
//logResponseHead(httpConnection); vV:eU-a
jE.U~D)2YF
9u/"bj
byte[] b = new byte[1024]; r5z_{g
int nRead; %N@454enH
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 8V%(SV
{ K oPTY^
nStartPos += fileAccessI.write(b,0,nRead); +Sk;
//if(nThreadID == 1) \+mc
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |s :b9sfA
} m M!H}|
k41lw^Jh
vW`{BWd
Utility.log("Thread " + nThreadID + " is over!"); [1@-F+
bDownOver = true; `#hdb=3
//nPos = fileAccessI.write (b,0,nRead); NrVrR80Y
} |HXI4MU"
catch(Exception e){e.printStackTrace ();} X62h7?'Pd
} 'u$e2^
} s4bLL
T_O\L[]p*
MV5'&" ,oB
//打印回应的头信息 s{#ZRmc2B
public void logResponseHead(HttpURLConnection con) |:n4t6
{ FA?xp1E
for(int i=1;;i++) w+bQpIPM
{ 8 M3Q8&
String header=con.getHeaderFieldKey(i); pS vDH-
if(header!=null) rxQn[
//responseHeaders.put(header,httpConnection.getHeaderField(header)); .WA(X5
Utility.log(header+" : "+con.getHeaderField(header)); A{lzQO
else 7nB@U$]-Sz
break; |D%i3@P&ZR
} !.mMO_4}
} .vG_\-@
L)JpMf0
.w^M?}dx
public void splitterStop() k.>*!l0
{ =NwmhV
bStop = true; Q@hx+aM
} #P$=P2o
uBw1Xud[YI
=]yJvn"
} Q4r)TR,
MCU{@\?Xf
wxEFM)zr
/* *yOpMxE
**FileAccess.java ?U:?o_w
*//文件访问(定位，写) u^SXg dj
package NetFox; TLzg*
import java.io.*; rIp84}
ET1/oG<@
*xXa4HB
public class FileAccessI implements Serializable{ ^?(A|krFg
g PogV(V
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~hPp)-A
RandomAccessFile oSavedFile; o0^'xVv
long nPos; a(s}Ec${Z
_Dl!iV05:
e~jw YImA
public FileAccessI() throws IOException 'WkDpa
{ 'n%Ac&kk
this("",0); 7(lR$,bE;=
} *;. l/
LF?83P,UJ#
Ks:~Z9r}
public FileAccessI(String sName,long nPos) throws IOException >up'`K,
{ pXPwn(
oSavedFile = new RandomAccessFile(sName,"rw"); J6/Mm7R
this.nPos = nPos; 8P.UB{QNe
oSavedFile.seek(nPos); X6%w6%su5
} [TvH7ott'1
X*VHi
R:kNAtK
public synchronized int write(byte[] b,int nStart,int nLen) Y15KaoK?
{ fw,ruROqD
int n = -1; aN{C86wx
try{ y-O# +{7
oSavedFile.write(b,nStart,nLen); 1[o] u:m9U
n = nLen; ?#ue:O1
} \9dSI
catch(IOException e) +J30OT8
{ ZvEcExA-
e.printStackTrace (); /\*,|y\<
} nw[DI%Tp
RX:wt
od!"?F
return n; |\"vHt?@G
} _;",7bT80
`W< 7.
&-W5T?Sl
} =cE:,z;g
Y%:FawR
WH2?_U-8h
/* xnWCio>M
**SiteInfoBean.java ik02Q,J
*/ eW#U<x%P
package NetFox; ]uO8
@54,I
DG}YQr.L
public class SiteInfoBean { 1xg^;3m2
jca7Cx`sm
j>X;a39|
private String sSiteURL; //Site's URL "|w..%Wc
private String sFilePath; //Saved File's Path :L<$O7
private String sFileName; //Saved File's Name w_|R.T\7
private int nSplitter; //Count of Splited Downloading File Tyt:Abym=
qG3 [5lti
&WAO.*:y
public SiteInfoBean() z:<mgp&/<
{//nSplitter的缺省值为5 K}ACZT)Wp
//default value of nSplitter is 5 k.? aq
this("","","",5); Vzf{gr?
} g{wIdV
DODo !
IQ[?ej3W
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) }LQ*vD-Jj
{ ^p(t*%LM
sSiteURL= sURL; 6dQa|ACX_
sFilePath = sPath; 6He7A@Eh
sFileName = sName; :"? boA#L
this.nSplitter = nSpiltter; +F q`I2l|
MN\/F4Io
JG&`l{c9
} 7><ne|%
2zR*`9$
Rro|P_
public String getSSiteURL() 86O"w*9
{ M$g%kqa
return sSiteURL; KpBh@S
} 1BQTvUAA
W Da;wt
epa)ctS9
public void setSSiteURL(String value) j-|YE?AA
{ JoQzf~
sSiteURL = value; l!e8=QlJ
} <$Q\vCR
eCdx(4(\a
8[5%l7's
public String getSFilePath() ,}F2l|x_
{ /G`&k{SiK
return sFilePath; ~a m]G0
} o>#<c @
=MO2M~e!
B'6^E#9
public void setSFilePath(String value) |Axg}Q|
{ vfzGRr
sFilePath = value; {;^booq
} d_#\^!9
M`\c'|i/
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public String getSFileName() d}tn/Eu?B
{ kH*l83
return sFileName; <K:?<F
} %Bmi3 =Rr
M xj
K1uN(T.Ju
public void setSFileName(String value) D.)$\Caq
{ 5)V]qV$
sFileName = value; A=|LMJMWR
} Gdnk1_D>
l)D18
K,tmh1
public int getNSplitter() R?+Eo(0q,
{ eJ)Bs20Q
return nSplitter; kac@yQD
} 6}R^L(^M
vrn IEur
3?Y%|ZVM
public void setNSplitter(int nCount) 0*VRFd4
{ wRf_IBhCd
nSplitter = nCount; oju/%ieh
} (rFY8oHD
} : Ey
~$#DB@b
KXcG;b[7n
/* {.SN
**Utility.java lE08UEk1i
*/ 1Y@6oT
package NetFox; Eag->mw/~
'mpY2|]\$
h+zJ"\
public class Utility { s`Z(f:/6*
Yg/e8Q2
S4s\tA<
public Utility() EiI3$y3;
{ 8gJ"7,}-'
/MsXw/],
~^" cNv
} ;E:ra_l
?v#t{e0eQ
//线程睡眠 MR%M[SK1
public static void sleep(int nSecond) Rb<aCX
{ Kr=DoQ."d8
try{ N:0/8jmmO
Thread.sleep(nSecond); nk1(/~`
} 9%oLv25{)
catch(Exception e) xBG&ZM4"^f
{ X"J79?5
e.printStackTrace (); Ts0.Ck
} wke$
} :::"C"Ge
wED~^[]f
//日志 s7O?)f f
public static void log(String sMsg) 9NaC7D$,
{ 9/D+6hJ]:
System.err.println(sMsg); 5'\/gvxIC
} y&lj+j
P\iw[m7O
/+2^xEIjE
public static void log(int sMsg) @`k!7? Sq
{ Ee9u7TFT
System.err.println(sMsg); s?=f,I
} NeCTEe|V
} M^r1b1tR
nE]R0|4h
$k@reN9
/* 9XF+? x
**TestMethod.java T9{94Ra
*/ "FcA:7+
package NetFox; *ky5SM(NR
qOZe\<.V<
h_?D%b~5
public class TestMethod { h\C
9g"a`a?c
\PU|<Ru.
public TestMethod() V5K`TC^
{ ///xx/weblogic60b2_win.exe KLsTgo|J
try{ 4&K~EX"^T
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); $&n!j'C:
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Mh>^~;
SiteFileFetch fileFetch = new SiteFileFetch(bean); |w6:mtaS
fileFetch.start(); $Xk1'AzB8
} 3?Bq((
catch(Exception e){e.printStackTrace ();} vwZ2kk!|i
qB3 SQ:y
U;;vNzcn
} n0O- Bxhl
0Vh|UJ'&7
t=iy40_T
public static void main(String[] args) .cQwjL
{ kxWf1hIz0
new TestMethod(); %l,p />r
} O9=vz%
} m]=|%a6
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