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)); 4!$s}V=6
} >Wh}f3C
for(int i=0;i<nEndPos.length-1;i++) U QE qX
{ vQ<90ZxqB
nEndPos = nStartPos[i+1]; %509\;el
} zs%Hb48V
nEndPos[nEndPos.length-1] = nFileLength; vesJEaw7
} &-s'BT[PGq
} ?P4w]a
Pa(^}n|
.tkT<o-u<J
//启动子线程 pnMEB,)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; MzPzqm<
for(int i=0;i<nStartPos.length;i++) hbU+Usx
{ r~+\ Y"rM
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |\_^B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [qdRUV'
nStartPos,nEndPos,i); ;g6M%;1-
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *eIJwXE
fileSplitterFetch.start(); .R)PJc5^
} x??pBhJH
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 79nG|Yj|\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~UyV<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }YjX3|8zL=
nEndPos = " + nFileLength); J%V-Q>L
// fileSplitterFetch[nPos.length-1].start(); dp++%:j
qZ]pq2G
"~=mG--I
//等待子线程结束 IC6gU$e
//int count = 0; u583_k%
//是否结束while循环 KQcs3F@t
boolean breakWhile = false; ,B08i o-
SaC d0. h
7uT:b!^f[
while(!bStop) !l_lo`)
{ Kh(ZU^{n
write_nPos(); .U"8mP=&
Utility.sleep(500); 7~9S 9
breakWhile = true; ygeDcnvR]
U`,0]"Qk
FW) x:2BG
for(int i=0;i<nStartPos.length;i++) m.px>v-
{ 9m|kgY# 4
if(!fileSplitterFetch.bDownOver) p`nPhk,:b
{ <WjF*x p
breakWhile = false; Vm5c+;
break; <cZGxff01
} k4,BNJt'Z
} ?6(I V]
if(breakWhile) UJ0<%^f
break; Dw=gs{8D
wUiys/OVM
3= DNb+D!
//count++; Au{<hQ=
//if(count>4) ^M%uV
// siteStop(); %@;6^=
} d}LRl"_n
w$H^q !(
H~GQ;PhRx
System.err.println("文件下载结束！"); A 6OGs/:&
} Na$Is'F&p
catch(Exception e){e.printStackTrace ();} b8$gx:aJ>$
} CSGz3uC2D
^Y u6w\QM
nt;haeJ
//获得文件长度 S{FROC~1R
public long getFileSize() af#pR&4}
{ #Y0-BYa^
int nFileLength = -1; %uJ<M-@r=u
try{ !lxTX
URL url = new URL(siteInfoBean.getSSiteURL()); \%/#x V
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0VckocF
httpConnection.setRequestProperty("User-Agent","NetFox"); pWPIJ>2G:
A,V\"KU
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int responseCode=httpConnection.getResponseCode(); TpmwD{c[\
if(responseCode>=400) $={:r/R`i
{ T21ky>8E
processErrorCode(responseCode); e%4:) IV!;
return -2; //-2 represent access is error CNr/U*+
} vo\fUT@k
}"|"Q7H
e{X6i^% m_
String sHeader; c1$ngH0
u5 {JQO
>H(i^z/c
for(int i=1;;i++) nB%;S
{ D?C)BcN
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); aO@7O*
//Utility.log(in.readLine()); %FS$zOsgGK
sHeader=httpConnection.getHeaderFieldKey(i); eh4gQ^l
if(sHeader!=null) 28/ ADZ
{ Zm"{Viv]
if(sHeader.equals("Content-Length")) %honO@$
{ 5Xl/L
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); NE/m-ILw
break; "Fy7K#n
} 0O\SU"bP
} {r>.G7P6
else {%VV\qaC
break; [zL7Q^~
} f6_];]yP
} Xcrk;!IB?
catch(IOException e){e.printStackTrace ();} |J+(:{}~
catch(Exception e){e.printStackTrace ();} f;&]:2.j
bHhtd_}
V?P,&c?84
Utility.log(nFileLength); ~by]xE1Eg
a 4=N9X
<+^6}8-
return nFileLength; 1iX)d)(b
} Nru7(ag1~
?gO8kPg/D
za:a)U^n
//保存下载信息（文件指针位置） yC3yij<oR
private void write_nPos() 2:BF[c`
{ 9Ro6fjjE
try{ \k]x;S<a
output = new DataOutputStream(new FileOutputStream(tmpFile)); %'xb%`t
output.writeInt(nStartPos.length); :9R=]#uD
for(int i=0;i<nStartPos.length;i++) *?z0$Kz<,[
{ 21ppSN>
// output.writeLong(nPos); cooUE<a
output.writeLong(fileSplitterFetch.nStartPos); 6\u!E~zy
output.writeLong(fileSplitterFetch.nEndPos); h)6GaJ=
} *\wp?s>-t
output.close(); d{3@h+zL
} oT{@_U{*J
catch(IOException e){e.printStackTrace ();} QJ F=UB
catch(Exception e){e.printStackTrace ();} 1=|7mehL%
} {^m(,K_
YAL=!~6
277ASCWLkU
//读取保存的下载信息（文件指针位置） UWZa|I~:J
private void read_nPos() e/*$^i+S
{ |.F
try{ V~T@6S
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); J0 k
int nCount = input.readInt(); :-iMdtm
nStartPos = new long[nCount]; Ja]?&j
nEndPos = new long[nCount]; Z1ALq5
for(int i=0;i<nStartPos.length;i++) kW`r=u
{ OFGsjYLw
nStartPos = input.readLong(); 6 4D]Ypx
nEndPos = input.readLong(); 7_wJpTz
} T"p(]@Ng
input.close(); ?\U!huu
} yJsH=5A
catch(IOException e){e.printStackTrace ();} &f>eQS=(
catch(Exception e){e.printStackTrace ();} l{:a1^[>y
} 8K;Y2 #
GyW.2
3;7q`
private void processErrorCode(int nErrorCode) dLvJh#`o
{ < AI;6/
System.err.println("Error Code : " + nErrorCode); [k[u*5hP|F
} X53mzs
4"@GNk~e
x lsqj`=
//停止文件下载 6AvHavA^Y
public void siteStop() R#n%cXc|
{ R*zO dxY
bStop = true; !j1[$% =#
for(int i=0;i<nStartPos.length;i++) ygSL
fileSplitterFetch.splitterStop(); M wab!Ya
(f_g7B2&y
PSRzrv$l
} !ph" mf$-
} li] 6Pj,
//负责部分文件的抓取 =39 ?:VoD
**FileSplitterFetch.java EQIUSh)M
*/ `p0ypi3hn
package NetFox; 2$ !D* <
wNNB;n`l
2b=)6H1
import java.io.*; B51kV0
import java.net.*; LhzMAW<L4
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>r)X:K+I
public class FileSplitterFetch extends Thread { QC0!p"
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~P-*}q2J
String sURL; //File URL B/J&l
long nStartPos; //File Snippet Start Position b@t5`Y-+K
long nEndPos; //File Snippet End Position IN7<@OS7
int nThreadID; //Thread's ID xU S]P)R
boolean bDownOver = false; //Downing is over (X+s-4%
boolean bStop = false; //Stop identical m,>
FileAccessI fileAccessI = null; //File Access interface m7=1%6FN3
#FYAV%pi
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?$z.K>S5
{ !r+IXuqV,!
this.sURL = sURL; S2C]?6cTq
this.nStartPos = nStart; p T[gdhc
this.nEndPos = nEnd; "PH6e bm
nThreadID = id; -6=<#9R
fileAccessI = new FileAccessI(sName,nStartPos);//定位 )9=(|Lp
} `@`1pOb
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public void run() ~%#mK:+
{ | A:@&|
while(nStartPos < nEndPos && !bStop) ]lS@}W\
{ Q0_>'sEM
p|XAlia
8I+d)(:
try{ K3mAXC,d
URL url = new URL(sURL); K(T\9J.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'GJVWpvUU
httpConnection.setRequestProperty("User-Agent","NetFox"); Ep~wWQh
String sProperty = "bytes="+nStartPos+"-"; ~2uh'e3
httpConnection.setRequestProperty("RANGE",sProperty); U5/qf8)yO
Utility.log(sProperty); >qn/<??
7ODaX.t->
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InputStream input = httpConnection.getInputStream(); wH"kk4^
//logResponseHead(httpConnection); XTqm]
RbQ <m!A
LH]CUfUrUE
byte[] b = new byte[1024]; 49 }{R/:
int nRead; DFe;4BdC
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) TSL9ax4j
{ 7\/5r.
nStartPos += fileAccessI.write(b,0,nRead); znZ7*S >6\
//if(nThreadID == 1) ~# 7wdP
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); uCzii o`S
} Y:x/!-
V*65b(q)
AxCI 0
Utility.log("Thread " + nThreadID + " is over!"); PI|`vC|yy&
bDownOver = true; VY'Q|[
//nPos = fileAccessI.write (b,0,nRead); ';RI7)<
} dEp/dd~(&
catch(Exception e){e.printStackTrace ();} Jm(ixekp
} =qoRS0Qa
} A8?[6^%O|
~U}Mv{y
noA-)
//打印回应的头信息 .Gb+\E{M
public void logResponseHead(HttpURLConnection con) *j*Du+
{ 0jB X5
for(int i=1;;i++) +nZRi3yu=
{ iRV;Fks
String header=con.getHeaderFieldKey(i); &1)xoZ'\
if(header!=null) *M~.3$NN
//responseHeaders.put(header,httpConnection.getHeaderField(header)); FWPW/oC
Utility.log(header+" : "+con.getHeaderField(header)); IlLn4Iw
else <>4!XPo%J
break; ;R[&pDx
} zp=!8Av
} }++5_Z_
PDw{R]V+
BSXdvI1y
public void splitterStop() C?H{CP
{ @?2n]n6
bStop = true; g0#q"v55
} )&Z>@S^
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dc^Vc{26Z
} }.%s xw
;;LuU<,$
aIGn9:\
/* _J"mR]I+
**FileAccess.java &?a.mh/8[[
*//文件访问(定位，写) boQ)fV"
package NetFox; rB]W,8~%
import java.io.*; R "E<8w
0#|7U_n
kEK[\f VE
public class FileAccessI implements Serializable{ INLf# N
kfpm=dKL
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %yw=[]Vjze
RandomAccessFile oSavedFile; 8[\79|
long nPos; O@`J_9
c2b6B.4
_:,.yRez
public FileAccessI() throws IOException 4%bTj,H#
{ Hptq,~_t
this("",0); [y{E
} ~PUsgL^
+>E5X4JC
q0|ZoP
public FileAccessI(String sName,long nPos) throws IOException z<QIuq
{ SL*DK.
oSavedFile = new RandomAccessFile(sName,"rw"); A c:\c7M;
this.nPos = nPos; *98Ti|
oSavedFile.seek(nPos); di_gWE
} lV7IHX1P
y''0PSfb#
<lx^aakk!
public synchronized int write(byte[] b,int nStart,int nLen) 3Wj,}
{ ~x+Ykq0
int n = -1; Hs<n^fyf
try{ e 2*F;.)
oSavedFile.write(b,nStart,nLen); LV=^jsQ5
n = nLen; -R@JIe_28f
} ]S]"`;Wh
catch(IOException e) q6)p*}-
{ b3^R,6]x&
e.printStackTrace (); (6#M9XL
} -,@bA @&
=|#w.(3y
-y<x!61
return n; rIp'vy S\p
} gN\*Y
s;>VeD)*)
:xN8R^(
} ;Bnr='[
x?>!UqgkY
(.oaMA"B
/* [,\i[[<
**SiteInfoBean.java ?7rD42\8H
*/ D3]@i&^B
package NetFox; )T<D6l Lt
_3KZME
z qO$
public class SiteInfoBean { Lkp&;+
0i_
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private String sSiteURL; //Site's URL Ix4jof6(
private String sFilePath; //Saved File's Path sVlZNj9i"
private String sFileName; //Saved File's Name Ku&*`dME
private int nSplitter; //Count of Splited Downloading File {SHqW5VX
/9TL&_A-T
IE@ z@+\(
public SiteInfoBean() G#g{3}dcK
{//nSplitter的缺省值为5 rkP4<E-M
//default value of nSplitter is 5 '@S,V/jy0z
this("","","",5); HD~jU>}}
} J,`_,T
j`+0.Zlq
1O- E],
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) u,!4vKx
{ be_C>v
sSiteURL= sURL; @?j@yRe
sFilePath = sPath; )MMhlcNC
sFileName = sName; <Q\H
this.nSplitter = nSpiltter; g!.Ut:8L9
sOjF?bCdO
SkriX\p
} j& <tdORT
d{iL?>'?^
+H?<}N*T
public String getSSiteURL() QQSH +
{ &s2#1
return sSiteURL; 0K`ZX&K?W
} B>ge, }{
Sn+FV+D
u% r!?-z
public void setSSiteURL(String value) nh?9R&
{ 4*YOFU}l
sSiteURL = value; L;4[ k;5
} @\S]]oLn
@yCW8]
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public String getSFilePath() % i%ew4
{ %f>X-*}NI-
return sFilePath; 2z[r@}3
} n=;';(wR[
`X3Xz!
rO5u~"v]
public void setSFilePath(String value) 1mY+0
{ 0I(uddG3
sFilePath = value; ntDRlX
} %GNUnr$
5#yJK>a7
p6B .s_G4
public String getSFileName() l@~1CMyN
{ (QA-"9v#i,
return sFileName; .jLMl*6%:
} &S9f#Ui
0zlM.rjEZ
r.Y*{!t
public void setSFileName(String value) T$#FAEz
{ =I+l=;05Rd
sFileName = value; l7!U),x%/U
} (ra:?B
3"HGEUqA
HKq2Js
public int getNSplitter() 97['VOh0
{ J(3gT}z-
return nSplitter; T_(qN;_
} }C_G0'"F
}R7sj
\.K\YAM<
public void setNSplitter(int nCount) eL]{#WL
{ RPz!UMQSD
nSplitter = nCount; ;"d?_{>7
} ~uP r]#
} 2U=/<3;u
^#<:<X6
g,A.Y,})
/* [K"U_b}w
**Utility.java e6tH/`Uln
*/ N*_/@qM> a
package NetFox; z Y$X|=f
+Q@/F~1@6@
EX+={U|ua$
public class Utility { x`};{oz;
'd|Q4RE+W
[0mFy)6
public Utility() ;zfQ3$@9
{ < fojX\}3
2LhfXBWf
pDLu+}@
} c n\k`8
f_Wkg)g
//线程睡眠 +YGw4{\EL
public static void sleep(int nSecond) GnSgO-$"
{ { r<(t#
try{ W\ 1bE(AwZ
Thread.sleep(nSecond); o<C]+Nt,@
} |_hioMVz
catch(Exception e) ]7XkijNb
{ lpM>}0v
e.printStackTrace (); w^:V."}-$
} oTplxF1
} ``2QOu 1
_IQU<Za
//日志 fPh}l
public static void log(String sMsg) F20wf1^
{ h"RP>fZt
System.err.println(sMsg); zIAu3
} EI?d(K
X/- W8
fD3jwPL
public static void log(int sMsg) ,ZzB#\
{ t%]^5<+X58
System.err.println(sMsg); rL!_&|
} 78^UgO/
} []2$rJZD9
l0:e=q2Ax
EPE!V>
/* E3FW*UNg[y
**TestMethod.java L|C1C cP
*/ gL[1wM%?
package NetFox; XEvGhy#
<WQ<<s@#pb
avHD'zU}N
public class TestMethod { 2yEO=SN,(
Vid{6?7kh
tdw\Di#m
public TestMethod() hX>VVeIZ
{ ///xx/weblogic60b2_win.exe 4."o.:8x
try{ !i~x"1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); g~ppPAH
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 3$96+A^M*
SiteFileFetch fileFetch = new SiteFileFetch(bean); )JY_eG&2Dx
fileFetch.start(); (dLE<\E
} Cu ['&_@
catch(Exception e){e.printStackTrace ();} +qh< Fj>
!BvTJ-e)F
,E/Y@sajn+
} uK4'n+_>\
JA SR
ABq{<2iYN
public static void main(String[] args) T/WmS?
{ 7 BnenHD
new TestMethod(); 0]h8)EW
} $p}~,Kp/
} $$bTd3N+
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