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)); NSa6\.W)
} V&*|%,q
for(int i=0;i<nEndPos.length-1;i++) ]A;.}1'
{ %pIP#y[4
nEndPos = nStartPos[i+1]; -MRX@a^1
} NbC2N)L4
nEndPos[nEndPos.length-1] = nFileLength; 5cGQ`l
} ?K+q~DzNSD
} #c!rx%8I
@9eN\b%I^H
zuu<;^/R
//启动子线程 dz?On\66
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ZIKSHC9
for(int i=0;i<nStartPos.length;i++) Jd^Lnp6?
{ ]1FLG*sB
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), MuJP.]5>`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), j7U&a}(
nStartPos,nEndPos,i); ;4U"y8PVTh
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e|?eY)_
fileSplitterFetch.start(); 8>@JW]
} ),CKuq>
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RIQ-mpg~(k
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); I_5/e>9
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", s`ZP2"`f
nEndPos = " + nFileLength); C1'y6{,@
// fileSplitterFetch[nPos.length-1].start(); #i.,+Q
ZNne 8
(H5#r2h%Y
//等待子线程结束 &<x.D]FA]
//int count = 0; q}+zNeC
//是否结束while循环 d<+hQ\BF,
boolean breakWhile = false; F^$;hMh%
;>>n#8`
Pz34a@%"
while(!bStop) 9/!1J
{ =\_gT=tZ
write_nPos(); K-~gIlbQ`
Utility.sleep(500); gyMHC{l/B
breakWhile = true; j g//I<D
V3#ms0
m";..V
for(int i=0;i<nStartPos.length;i++) 0PqI^|!
{ Q?;Tc.O"/
if(!fileSplitterFetch.bDownOver) (8aj`> y
{ }NoP(&ebz*
breakWhile = false; q8&l%-d`
break; H<[~V0=
} [al$sCD]+
} ;1[Z&Uv8
if(breakWhile) zBlv?JwG
break; gs;^SRE I
8 eK8-R$
y] c1x=x
//count++; Yb-{+H8{J
//if(count>4) @J&korU
// siteStop(); W^H3=hZ
} #gqh0 27
mM72>1~L*
w6Nnx5Ay
System.err.println("文件下载结束！"); vue^bn
} :^WF%X
catch(Exception e){e.printStackTrace ();} ;<N:!$p
} 3ZI7;Gw
QOo'Iv+EL
) jH`lY)1
//获得文件长度 n Syq}Y3
public long getFileSize() -1Dq_!i
{ @U18Dj[
int nFileLength = -1; 7M~sol[*
try{ y7M{L8{0
URL url = new URL(siteInfoBean.getSSiteURL()); e~'lWJD
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *9"x0bth
httpConnection.setRequestProperty("User-Agent","NetFox"); hK{H7Ey*
l@Vv%w9H
'"fJA/O
int responseCode=httpConnection.getResponseCode(); ]vlBYAW'
if(responseCode>=400) ;o3gR4u_L
{ N"G aQ
processErrorCode(responseCode); .Zczya
return -2; //-2 represent access is error [K.1 X=O}
} zk FX[-'O
X8Q'*
H#_Zv]
String sHeader; 8Rwk o6x
<;S$4tux
<mE`<-$
for(int i=1;;i++) bsF_.S*k@
{ \~ChbPnc
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); iCF},W+
//Utility.log(in.readLine()); x_nwD"
sHeader=httpConnection.getHeaderFieldKey(i); ![\-J$
if(sHeader!=null) W~'xJ
{ RkYn6
if(sHeader.equals("Content-Length")) Q+=pP'cV
{ b&+zAt.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ={)85N
break; Sp80xV_B
} mkn1LzE|F
} Z5>~l
else x%=CEe?6
break; }yEV&& @
} %hsCB .r>|
} x3=1/#9
catch(IOException e){e.printStackTrace ();} ,2nu*+6Y/
catch(Exception e){e.printStackTrace ();} {siOa%;*
=EP`,zqn$9
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Utility.log(nFileLength); K:a8}w>Up
TU0-L35P1
iPTQqx-m$7
return nFileLength; ,Y/B49
} Ai< beUS
=0=#M(w
sgp.;h'
//保存下载信息（文件指针位置） `F7]M
private void write_nPos() {h?pvH_>
{ 2h
try{ [Cl0Kw.LD
output = new DataOutputStream(new FileOutputStream(tmpFile)); ('5?-
output.writeInt(nStartPos.length); H2s:M
for(int i=0;i<nStartPos.length;i++) Sf*)Z3f
{ m1X7zUCy
// output.writeLong(nPos); dH^6K0J
output.writeLong(fileSplitterFetch.nStartPos); EL?(D
output.writeLong(fileSplitterFetch.nEndPos); *p}mn#ru-
} Tn}`VW~
output.close(); $N=&D_Q
} y|5s
catch(IOException e){e.printStackTrace ();} 6{y7e L3!
catch(Exception e){e.printStackTrace ();} Y@+Rb
} 1Z# $X`
r<UVO$N
>!=@TK(~
//读取保存的下载信息（文件指针位置） 1INX#qTZ
private void read_nPos() $+*nb4
{ Ay16/7h@hi
try{ nje7?Vz
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +~^S'6yB
int nCount = input.readInt(); V.GM$
nStartPos = new long[nCount]; U**8^:*y#:
nEndPos = new long[nCount]; PM\Ju]
for(int i=0;i<nStartPos.length;i++) =_dM@j
{ mTE(JZt
nStartPos = input.readLong(); ED&nrd1P
nEndPos = input.readLong(); <7^|@L 6
} !#KKJ`uB"
input.close(); =l`)b
} 68tyWd}
catch(IOException e){e.printStackTrace ();} UM7@c7B?
catch(Exception e){e.printStackTrace ();} w]wZJ/U`
} v Y[s#*+
8rsc@]W
9M96$i`P
private void processErrorCode(int nErrorCode) ,;g%/6X
{ Xh@K89`uX
System.err.println("Error Code : " + nErrorCode); %B%_[<B
} *g(d}C!
aCG rS{
]Z!Y*v
//停止文件下载 V\L;EHtc$
public void siteStop() Vq'7gJj'
{ .WF"vUp
bStop = true; P7drUiX
for(int i=0;i<nStartPos.length;i++) $J7V]c*-b
fileSplitterFetch.splitterStop(); \dk1a
YdhTjvx
51k}LH
} W:r[o%B
} )4g_S?l=
//负责部分文件的抓取 UsE\p9mCuV
**FileSplitterFetch.java R]"Zv'M(AM
*/ z$1RD)TQB
package NetFox; Z<vz%7w
;(NTzBq!1
dSGdK $XA
import java.io.*; m%|\AZBA#
import java.net.*; gT)(RS`_)
uKJ:)oyaCP
Ic/hVKYG5
public class FileSplitterFetch extends Thread { j\uZo.Ot+
9)!Ksg(h
KXPCkNIN!
String sURL; //File URL UFB|IeX?q
long nStartPos; //File Snippet Start Position )PN8HJAArh
long nEndPos; //File Snippet End Position !:+U-mb*
int nThreadID; //Thread's ID TK5$-6k
boolean bDownOver = false; //Downing is over Z518J46o
boolean bStop = false; //Stop identical ~^F]t$rz
FileAccessI fileAccessI = null; //File Access interface =D(a~8&,
a ,mgM&yD
(PpY*jKR
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ) 57'<
{ 8{4'G$6
this.sURL = sURL; uz3cho'
this.nStartPos = nStart; 0AnL]`"t.3
this.nEndPos = nEnd; +Nn >*sz
nThreadID = id; 2zj` H9
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ]5'*^rz ^
} %pZT3dcK
=]@Bc 7@
G"r{!IFL
public void run() UN?tn}`!
{ JQ+Mg&&Q
while(nStartPos < nEndPos && !bStop) 2tz4Ag
{ V FM[-
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|]kiH^Ap
try{ dz#"9i5b
URL url = new URL(sURL); lg|6~=aQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P}6#s'07~
httpConnection.setRequestProperty("User-Agent","NetFox"); KE\>T:
String sProperty = "bytes="+nStartPos+"-"; &^ERaPynd
httpConnection.setRequestProperty("RANGE",sProperty); |1wZ`wGZ:L
Utility.log(sProperty); Yyk~!G/@
uz8eS'8
1^k}GXsWmE
InputStream input = httpConnection.getInputStream(); 9^Xndo]y
//logResponseHead(httpConnection); !MSa -
&wNr2PHd#
Yte*$cJ=
byte[] b = new byte[1024]; !d##q)D f?
int nRead; t(}Y/'
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Qz`evvH
{ 0+0Y$;<
nStartPos += fileAccessI.write(b,0,nRead); yc0 1\o
//if(nThreadID == 1) X}B]5
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @Hj]yb5
} xEG:KSH
,5 8-h?B0v
:{w3l O
Utility.log("Thread " + nThreadID + " is over!"); |f}wOkl
bDownOver = true; p&}m')
//nPos = fileAccessI.write (b,0,nRead); `@Z$+
} [<+T@"y
catch(Exception e){e.printStackTrace ();} ~&/Nl_#
} pTAm}
} X>dQK4!R
c'$y_]
dhLd2WSyH
//打印回应的头信息 V xN!Ki=
public void logResponseHead(HttpURLConnection con) .WglLUJ:Z
{ ?(s9dS,7wZ
for(int i=1;;i++) .==c~>N
{ El}~3|a?
String header=con.getHeaderFieldKey(i); ,-])[u
if(header!=null) ;180ct4
//responseHeaders.put(header,httpConnection.getHeaderField(header)); d3oRan}z
Utility.log(header+" : "+con.getHeaderField(header)); p7},ymQ|YQ
else 9'X"a
break; "dG*HKrr
} ml~)7J
} $1X!Ecq_
N]BH67<
o &b\bK%E
public void splitterStop() V\Lh(zPt
{ |}l/6WHB
bStop = true; MDpx@.A,
} Kd}%%L
|r*y63\T
rl"yE=
} T+V:vuK
$SLyI$<gP
0l(G7Ju
/* PtjAu
**FileAccess.java <Rt0 V%}-
*//文件访问(定位，写) p,4S?cr>a
package NetFox; 2V @ pt
import java.io.*; TIV|7nKL
RZvRV?<bR
Dhft[mvo
public class FileAccessI implements Serializable{ Ob'[W;p)[w
pfk)_;>,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ++kVq$9@y
RandomAccessFile oSavedFile; Si;eBPFH
long nPos; ]xJ2;{JWsO
l)Cg?9
En+`ZcA\z
public FileAccessI() throws IOException uCFpH5>
{ Xp^71A?>
this("",0); R*"zLJP
} l%cE o`U
e58tf3
;>p{|^X0D
public FileAccessI(String sName,long nPos) throws IOException %Y].i/".;P
{ Yv;iduc('
oSavedFile = new RandomAccessFile(sName,"rw"); :EC[YAK+D
this.nPos = nPos; !"^//2N+,
oSavedFile.seek(nPos); m!<uY?,hf
} y#{> tC
)J|~'{z:
0o!Egq_
public synchronized int write(byte[] b,int nStart,int nLen) NSh~O!pX
{ ue6&)7:~
int n = -1; $Jy1=/W&
try{ sU?%"q
oSavedFile.write(b,nStart,nLen); fH 5/
n = nLen; 9<!Ie^o?
} wtro'r3
catch(IOException e) 9&KiG* .
{ OEgp!J
e.printStackTrace (); v+2t;PJd2
} 2G`tS=Un
>^KO5N-:4
K<w$
return n; TqXB2`7Ri
} RS[QZOoW}
n#5%{e>
}Ias7d?re
} [[0u|`T/
6M_,4> -
|Xk>a7X
/* +dSO?Y]
**SiteInfoBean.java H(j983
*/ ;l=ZW
package NetFox; .q(1
*U^7MU0
5"9!kZ(<
public class SiteInfoBean { n[`FoY
3N5b3F
A^"( VaK
private String sSiteURL; //Site's URL c'~6 1HA<
private String sFilePath; //Saved File's Path q'[q]
private String sFileName; //Saved File's Name 2i_k$-
private int nSplitter; //Count of Splited Downloading File u IGeSd5B
Z |CL:)h
J PK(S~
public SiteInfoBean() i"o %Gc
{//nSplitter的缺省值为5 j]'7"b5
//default value of nSplitter is 5 uMe]].04
this("","","",5); 1US4:6xX_
} aoVfvz2Y
K_sHZ
=Hwlo!
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) z<9wh2*M
{ \bPSy0
sSiteURL= sURL; [GqQ6\
sFilePath = sPath; NvqIYW
sFileName = sName; wz=c#}0dB
this.nSplitter = nSpiltter; 1z$K54Mj
%d#h<e|,.
@is!VzE
} %^CoWbU
NhYce>
ruQ1Cph
public String getSSiteURL() n6]8W^g
{ Gm2q`ki
return sSiteURL; HSsG0&'-Y
} ~dc~<hK
(!B1}5"
)D"E]
public void setSSiteURL(String value) &nyJ :?
{ 6_wj,7
sSiteURL = value; *kE<7
} yhSbX4Q
\&Zp/;n
2=/,9ka~
public String getSFilePath() T>2_r6;
{ [DzZ:8
return sFilePath; M4`.[P4
} e;G}T%W
&<RK=e'*x
&K.js
public void setSFilePath(String value) "|KhqV=?v
{ U8gf_R'
sFilePath = value; z+(V2?xcvt
} rCp'O\@S
iVe"iH
ZtLZW/`
public String getSFileName() U1^3 &N8
{ P")1_!
return sFileName; O-jpS?@
} jC}2>_#m(
UHT2a9rG
sm?V%NX&
public void setSFileName(String value) V|W[>/
{ d$T856
sFileName = value; J=sj+:GS
} s5cY>
/fDXO;tN
SWWeN#Q
public int getNSplitter() ews{0
{ Mj5&vs~n;
return nSplitter; eOUv#F
} )N'rYS'9
fIwG9cR
,|G~PC8
public void setNSplitter(int nCount) ]r.95|V*
{ !l5&>1?
nSplitter = nCount; ~lH_d[
} @h)Z8so
} $WICyI{$
:F`-<x/
*1`q x+1
/* Bb9/nsbE
**Utility.java w)7s]Ld
*/ ZXH{9hxd
package NetFox; 8ZL9>"%l
-ztgirU
gPqdl6#c
public class Utility { 6O\a\z
'<-F3
!}I+)@~\w
public Utility() Cr>YpWm
{ !&#5*
9gQ ]!Oq
y)uxj-G
} fb|%)A=
2qpUUo f
//线程睡眠 #,B+&SK{
public static void sleep(int nSecond) `PS^o#
{ &MJcLM]
try{ C7Ny-rj}IA
Thread.sleep(nSecond); < VrHWJo
} zTS P8Q7
catch(Exception e) |{V@t1`
{ :J;&Z{
e.printStackTrace (); BRTCo,i
} /ei(Q'pc[
} IrMxdF~c
@ebSM#F?
//日志 05s{Z.aK
public static void log(String sMsg) &e)V!o@wJV
{ ~sMEfY,p
System.err.println(sMsg); 2#)z%K6T
} RH~I/4e
V)jF]u~g
h[i@c`3/2
public static void log(int sMsg) d*R('0z{
{ s_#6^_
System.err.println(sMsg); ^u-;VoK
} "Ta"5XW
} [ XBVES8
uy rS6e0
%4^NX@1jV
/* 9CPr/q9'
**TestMethod.java 7p_B?r
*/ 3A!Qu$r9
package NetFox; ypLt6(1j%
OJT%?P%@{
K9QC$b9(
public class TestMethod { t{Wu5<F:
|Sr
g27)$0&0
public TestMethod() jL,P )TC
{ ///xx/weblogic60b2_win.exe 8iUYZF
try{ 9o+e3TXp#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); W*~[KdgC
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 4,.[B7irR
SiteFileFetch fileFetch = new SiteFileFetch(bean); Nin7AOO
fileFetch.start(); &\e8c g
} tJII-\3"
catch(Exception e){e.printStackTrace ();} ")i_{C,b^
:!L>_ f
3XcFBFE
} @n^2UJ
COH9E\ZGF
9w.ZXd
public static void main(String[] args) "R^0eNv$
{ >~*}9y0$
new TestMethod(); UId?a}J
} ->)0jZax
} cv"Bhql
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