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)); B_tQeM
} kp; &cQu!
for(int i=0;i<nEndPos.length-1;i++) Nm"<!a<F
{ C9pnU,[
nEndPos = nStartPos[i+1]; N(BiOLZL6
} j%5a+(H,z;
nEndPos[nEndPos.length-1] = nFileLength; x~Cz?ljbn
} HTN$ >QTI
} 3W'FcE)|E
o}W;Co
',#
//启动子线程 "ZqEP R)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ZM 8U]0[X
for(int i=0;i<nStartPos.length;i++) BPiiexTV9
{ E[*0Bo]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7vq DZg
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Dt|fDw$]D
nStartPos,nEndPos,i); yDuq6`R*
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Pl?}>G
fileSplitterFetch.start(); vG3M5G
} ki4Xp'IK
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), uAT/6@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); `x*/UCy\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", KcnjF^k
nEndPos = " + nFileLength); 94YA2_f;
// fileSplitterFetch[nPos.length-1].start(); 369Zu4|u
FH[#yq.Pr
kz_M;h>
//等待子线程结束 ]Y=S
//int count = 0; lfgtcR{l5
//是否结束while循环 :ovt?q8">
boolean breakWhile = false; Kk>DYHZ6y
sy=dY@W^
U\?+s2I)v
while(!bStop) ,0,Oe=d
{ ?#i|>MRR>
write_nPos(); jf8w7T
Utility.sleep(500); kAt RY4p
breakWhile = true; GqMB^Ad
L^x5&CCwk
X7b!;%3@
for(int i=0;i<nStartPos.length;i++) | F8]Xnds
{ L, #Byao
if(!fileSplitterFetch.bDownOver) S<9gyW
{ hWm0$v1p
breakWhile = false; $i -zMa
break; df yrn%^Ia
} #XfT1
} 3jS7 uU
if(breakWhile) &rcdr+'
break; s4N,^_j
xlk5Gob*
;8uHRcdQ
//count++; E;$$+rA
//if(count>4) ]y}Zi/zh
// siteStop(); :k\}Ik
} <oQ6ZX
!x6IV25
Wy!uRzbBv
System.err.println("文件下载结束！"); 03C .Xh=!
} Z"]xdOre
catch(Exception e){e.printStackTrace ();} c{ 7<H
} !;jgzi?z
5Vm Eyb
4NJVW+:2
//获得文件长度 ePi Z
public long getFileSize() Agz=8=S%
{ IE|,~M2
int nFileLength = -1; fmBkB8
try{ >r~|1kQ.
URL url = new URL(siteInfoBean.getSSiteURL()); y=wdR|b
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); E~}[+X@
httpConnection.setRequestProperty("User-Agent","NetFox"); 16L"^EYq
K1<k+t/V
pA*i!.E/b
int responseCode=httpConnection.getResponseCode(); |K6nOX!i
if(responseCode>=400) ["<5?!bU
{ *XHj)DC;
processErrorCode(responseCode); \6Xn]S
return -2; //-2 represent access is error M`(;>Kp7
} {rz>^
raSF3b/0
K[n<+e;G
String sHeader; \Ec X!aC
~R)1nN|
=1eV
for(int i=1;;i++) ,=yOek}
{ z_'dRw
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \G]K,TG
//Utility.log(in.readLine()); bKTqX[=
sHeader=httpConnection.getHeaderFieldKey(i); Sio1Q0
if(sHeader!=null) ykJ+%gla
{ zI(xSX@
if(sHeader.equals("Content-Length")) 5[1@`6j
{ ixg\[5.Q+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); n<=y"*
break; x,}ez
} w' .'Yu6
} 2m|Eoc&M_
else hjw4Xzju
break; t2~"B&7My
} /nwxuy
} uwmoM>I W^
catch(IOException e){e.printStackTrace ();} 6Q?BwD+>
catch(Exception e){e.printStackTrace ();} :vw0r`
cn@03&dAl
c]S+70!n
Utility.log(nFileLength); U<K|jsFo
tWcizj;?wK
^ sS>Mts
return nFileLength; S_a :ML<
} 8moUK3w
?0? x+
7ZL,p:f
//保存下载信息（文件指针位置） !Jk(&.
private void write_nPos() MiRibHXI,
{ fLLnf].O
try{ E {I)LdAqK
output = new DataOutputStream(new FileOutputStream(tmpFile)); D1oaG0
output.writeInt(nStartPos.length); od;Bb
for(int i=0;i<nStartPos.length;i++) d&O'r[S
{ 0~Um^q*'3
// output.writeLong(nPos); [8{_i?wY
output.writeLong(fileSplitterFetch.nStartPos); Z83q-
output.writeLong(fileSplitterFetch.nEndPos); 1'(_>S5CG
} <)r,CiS
output.close(); 0*/mc96
} (xI)"{
catch(IOException e){e.printStackTrace ();} <\B],M1=s=
catch(Exception e){e.printStackTrace ();} z4 GN8:~x
} AN|jFSQ'
4he v ;
Z&AHM &,yj
//读取保存的下载信息（文件指针位置） Np|:dP9#}
private void read_nPos() =>gyc;{2K<
{ }IxY(`:qs
try{ 7}.#Z
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ho?|j"/7
int nCount = input.readInt(); yBpW#1=
nStartPos = new long[nCount]; $q4XcIX 7
nEndPos = new long[nCount]; sURUQ H
for(int i=0;i<nStartPos.length;i++) c#]'#+aH
{ j<`I\Pmv
nStartPos = input.readLong(); p.6$w:eV
nEndPos = input.readLong(); Y\ #.EVz
} ;u4@iN}p
input.close(); )^*9oqQ
} .6lY*LI
catch(IOException e){e.printStackTrace ();} $O;N/N:m
catch(Exception e){e.printStackTrace ();} 0X] ekq
} T4%i`<i
Xq=!"E
1puEP*P
private void processErrorCode(int nErrorCode) ;oN{I@}k
{ jKY Aid{-
System.err.println("Error Code : " + nErrorCode); L%c]%3A
} 8:3oH!n
9,Crmbw8
@lb=-oR!~
//停止文件下载 rCnV5Yb0O
public void siteStop() d/ 'A\"o+
{ D=5t=4^H(
bStop = true; 3&drof\{
for(int i=0;i<nStartPos.length;i++) g]EQ2g_N1
fileSplitterFetch.splitterStop(); 6xDl=*&%
EOd.Tyb!/
*IMF4x5M
} >oM9~7f
} a"v"n$
//负责部分文件的抓取 y]~+`9
**FileSplitterFetch.java |!jYv'%
*/ HJ2]Nz:
package NetFox; 'O\d<F.c$2
H{Y5YTg]
O+{pF.P#V
import java.io.*; {2'74
import java.net.*; j. ks UJ
ims=-1,
&vJ(P!2f<
public class FileSplitterFetch extends Thread { fl5UY$a2-
YW4bm
_{2Fx[m%
String sURL; //File URL 3isXgp8
long nStartPos; //File Snippet Start Position wB1-|=K1
long nEndPos; //File Snippet End Position bJG!)3cx
int nThreadID; //Thread's ID b]tA2~e
boolean bDownOver = false; //Downing is over n]6}yJJo
boolean bStop = false; //Stop identical i5>J
FileAccessI fileAccessI = null; //File Access interface E7Gi6w~\
%>I?'y^
c'TiWZP~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Y*5@|Q
{ 8;+Hou
this.sURL = sURL; _!$Up
this.nStartPos = nStart; Z;"4$@|qE
this.nEndPos = nEnd; (DELxE
nThreadID = id; Pi"tQyw39$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \@ WsF$
} NbQMWU~7
rH2tC=%
, $D&WH
public void run() BRSgB-Rr7
{ XEgx#F ;F
while(nStartPos < nEndPos && !bStop) Im' :sJ31
{ Z CQt1;
J^F(]
ga2Q3mV
try{ %1 VNP(E
URL url = new URL(sURL); >zfZw"mEP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xi1N? pP
httpConnection.setRequestProperty("User-Agent","NetFox"); -!bLMLIg
String sProperty = "bytes="+nStartPos+"-"; b*6c.o
httpConnection.setRequestProperty("RANGE",sProperty); 0Z1H6qn
Utility.log(sProperty); "M5ro$qZ}
U~){$kpI#
c=jI.=mi3
InputStream input = httpConnection.getInputStream(); 6b+ WlIb
//logResponseHead(httpConnection); Vgru, '
_/z)&0DO
_]?Dt%MkD
byte[] b = new byte[1024]; G\,A> mT/P
int nRead; uz#eO|z@o
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;*37ta
{ q_T?G e
nStartPos += fileAccessI.write(b,0,nRead); {Y@-*pL]
//if(nThreadID == 1) tmY-m,U
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .1[2 CjQ
} hklO:,`
nX.sh
z7.C\l
Utility.log("Thread " + nThreadID + " is over!"); v{rK_jq
bDownOver = true; MLv.v&@S
//nPos = fileAccessI.write (b,0,nRead); VT.{[Kl
} 8H%I|fm
catch(Exception e){e.printStackTrace ();} d6d(?"
} HA3SQ
} C}8e<[})
Vf,~MG
WT ~dA95
//打印回应的头信息 hOrk^iYN=
public void logResponseHead(HttpURLConnection con) +k(3+b$S-
{ )R a/
for(int i=1;;i++) RwE*0 T
{ OL ]T+6X
String header=con.getHeaderFieldKey(i); )zL"r8si
if(header!=null) XB!`*vZ/<
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }r<@o3t
Utility.log(header+" : "+con.getHeaderField(header)); [;V1y`/K1
else Er)_[^) HG
break; yY@s(:
} ,0<F3h
} X?}GPA4 W
$vbAcWj
BqEubP(si
public void splitterStop() <cfH'~
{ J!K/7uS
bStop = true; W1vAK
} XpAq=p0;
"TH-A6v1
O"s`-OM;n
} ^* /v,+01f
3W0E6H"
1~xn[acy
/* { d2f)ra.
**FileAccess.java |>o0d~s
*//文件访问(定位，写) 6L6~IXL>
package NetFox; -JQg ~1
import java.io.*; }A'<?d8
Hb AMoow!
M_.,c Vk
public class FileAccessI implements Serializable{ tU2toV
8|-mzb&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ,,H$>r_;
RandomAccessFile oSavedFile; I}W-5%
long nPos; KutgW#+40
: $52Ds!i
I9G*iu=U
public FileAccessI() throws IOException /&!d
{ ZEyGqCf3
this("",0); R#Nd|f<
} oQjB&0k4
&_^*rD~
@Jn:!8U0
public FileAccessI(String sName,long nPos) throws IOException % x*Ec[l
{ vyx\N{
oSavedFile = new RandomAccessFile(sName,"rw"); 0qd;'r<
this.nPos = nPos; $I6eHjYT
oSavedFile.seek(nPos); io33+/
} GqD!W8+
Lvj5<4h;
m<'xlF
public synchronized int write(byte[] b,int nStart,int nLen) Md?bAMnG+}
{ _kY[8e5
int n = -1; dV=5_wXZ$
try{ *I1W+W`G
oSavedFile.write(b,nStart,nLen); e%v4,8
n = nLen; UV8r&O
} 8W<)c
catch(IOException e) &'ETx"
{ QKaj4?p$|S
e.printStackTrace (); ut5!2t$c
} 6ewOZ,"j"4
a&c#* 9t{
[11-`v0
return n; A%w]~ chC9
} }:D~yEP
Z a1|fB
gsR9M%mv
} y=qo-v59'
n]fbV/x
]XafFr6pe
/* DUliU8B}\
**SiteInfoBean.java -r'seb5
*/ ~S_IU">E
package NetFox; &?Z)V-1H
2GKU9cV*`
-hR\Y2?
public class SiteInfoBean { ~q|e];tA
<W%Z_d&Xv
xv%USm
private String sSiteURL; //Site's URL 95 .'t}
private String sFilePath; //Saved File's Path 3XlnI:w=
private String sFileName; //Saved File's Name MMr7,?,$
private int nSplitter; //Count of Splited Downloading File hYv 6-5_
<J}9.k
yGG\[I;7
public SiteInfoBean() v*fc5"3eO
{//nSplitter的缺省值为5 ~_j%nJ &2
//default value of nSplitter is 5 59Q Q_#>
this("","","",5); 32|L $o
} o3=S<|V
N3c)ce7[
}=m?gF%3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) jMWwu+w
{ +U)|&1oa
sSiteURL= sURL; ]9< 9F ?
sFilePath = sPath; UpseU8Wo
sFileName = sName; FRQ("6(
this.nSplitter = nSpiltter; K}/`YDu
WJ8vHPSM
+Y]*>afG
} g+r{>x
BCZnF /Zo
PZg]zz=V4
public String getSSiteURL() Z*aU2Kr`;
{ `"":
return sSiteURL; St&HE:
} _v=WjN
|b~g^4
}J'wz;t1
public void setSSiteURL(String value) y*Q-4_%,
{ m1o65FsY08
sSiteURL = value; ?[/,*Q%
} ];~[Olc
(0m$W<
&`Z)5Ww
public String getSFilePath() 8PjhvU
{ UuC"-$:
return sFilePath; 2OlC7X{
} {!Z_&i5
5N+(Gv[`"
/~huTKA}
public void setSFilePath(String value) LF.~rmPa
{ HtYR 0J
sFilePath = value; 4m!3P"$
} cE>/iZc
}e=GvWGa
Pc4cSw#5
public String getSFileName() HFWm}vA:
{ &:f'{>3z
return sFileName; o? "@9O?
} PlRs-%d
Sz@?%PnU|
H>X1(sh#}
public void setSFileName(String value) 7tKft
{ sZBO_](S
sFileName = value; g}r5ohqC#
} 3^yWpSC
Mf13@XEo
K2`WcEe
public int getNSplitter() <U`Nb) &
{ tS|zf,7
return nSplitter; ^l9 *h
} jV&W[xKa
E?D{/k,zZ
FGhrf
public void setNSplitter(int nCount) 0M2+?aKif
{ ]!o,S{a&
nSplitter = nCount; 5<?$/H|7T
} <f{`}drp/
} Cy'W!qH
[7w_.(f#
&YP>"<
/* k\Tm?^L)
**Utility.java `9{C/qB
*/ .h^Ld,Chj
package NetFox; I19F\ L`4
2czL 1Ci
usf(U>
public class Utility { -vAG5x/,
!O_^Rn+<2
>8t[EsW/
public Utility() vg1s5Yqk
{ _!1c.[\T
y+R$pzX
#N}}8RL
} z4:09!o_
pvxqeC9`
//线程睡眠 W?Abx
public static void sleep(int nSecond) g c=|<(
{ -3U} (cZ*
try{ 7B"aFnK;[J
Thread.sleep(nSecond); )WJI=jl
} )3">%1R
catch(Exception e) lfd{O7L0b
{ Ap18qp
e.printStackTrace (); [/j-d
} |]b/5s;>
} 8so}^2hTlT
_Fy:3,(
//日志 wb"t:(>&
public static void log(String sMsg) {z ~ '
{ Gfch|Q^INy
System.err.println(sMsg); ~36XJ
} uoc-qmm
e}w!]
fltcdA
public static void log(int sMsg) ,1h(k<-
{ c{(%+
System.err.println(sMsg); rn*VL(Yd(
} <WkLwP3^
} 4yy yXj
MRu+:Y=K
S@-X?Lu
/* rVmO/Y#Hx$
**TestMethod.java s7LX
*/ P^+>QJ1
package NetFox; dU n#'<g5
( h,F{7
@},k\Is
public class TestMethod { #2,L)E\G8e
zxHfQ(
NPabM(<`
public TestMethod() X~!?t}
{ ///xx/weblogic60b2_win.exe G&Sg.<hn
try{ !\v3bOi&
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); `?m(Z6'
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `XY[HK
SiteFileFetch fileFetch = new SiteFileFetch(bean); Hb4rpAeP
fileFetch.start(); (b!DJ;(O9
} ePdzQsnVe
catch(Exception e){e.printStackTrace ();} k Er7,c
:D-vE7
u?/]"4
} %&GQ]pmcY
{.W%m
V^5 t~)#46
public static void main(String[] args) Cvy;O~)
{ '.yr8
new TestMethod(); #}?$mxME*
} F@3,>~[%I
} oaE3Aa
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