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)); =Z2U
} en!cu_]t
for(int i=0;i<nEndPos.length-1;i++) 6 )0$UW
{ WXNJc
nEndPos = nStartPos[i+1]; nfy"M),et
} 8_U*_I7(
nEndPos[nEndPos.length-1] = nFileLength; -}2q-
} CeR4's7
} #E5#{bra
\`{ YqOT
>~TLgq*
//启动子线程 XIJ>\ RF
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -:pLlN-f
for(int i=0;i<nStartPos.length;i++) itX<!
{ Mz40([{
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D!J ("~[3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9g J`H'
nStartPos,nEndPos,i); mY(~94{d
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); PPDm*,T.
fileSplitterFetch.start(); .pu]21m=
} y M , hF
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |w6:mtaS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +H/^RvUjF
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", !s\-i6S>
nEndPos = " + nFileLength); @`$8rck`
// fileSplitterFetch[nPos.length-1].start(); Eo)Q> AM
~8`r.1aUO
e_g7E+6
//等待子线程结束 0u QqPF t
//int count = 0; b,D+1'
//是否结束while循环 & @^|=>L
boolean breakWhile = false; DDN#w<#
5Tb93Q@c
}OI;M^5L
while(!bStop) Jnb>u*7,
{ N#C,_ k
write_nPos(); l *yml
Utility.sleep(500); bvUjH5.7
breakWhile = true; bsmZR(EnU
Cz+`C9#
@v2_gjRe
for(int i=0;i<nStartPos.length;i++) N*f?A$u/I
{ {<v?Z_!68
if(!fileSplitterFetch.bDownOver) `&LPqb
{ l <Tkg9
breakWhile = false; Y#=0C*FS
break; O8wR#(/
} G yvEc3|@
} 2!QJa=
if(breakWhile) XPBKQm_}
break; ?R(fxx
e4fh<0gX
ve49m%NQ
//count++; bJ4})P&
//if(count>4) *P7 H=Yf&
// siteStop(); h64<F3}
} !i,Eo-[Z
vO`~rUA
v-B{7 ~=#Z
System.err.println("文件下载结束！"); mSm:>hBd
} 8oK*NB29
catch(Exception e){e.printStackTrace ();} ?1T)cd*
} j^;f {0f
CBN,~wzP*
uD0T()J.P5
//获得文件长度 y-6k<RN
public long getFileSize() A=JPmsj.
{ J~Uq'1?
int nFileLength = -1; D_]4]&QYT
try{ BCMQ^hP}t
URL url = new URL(siteInfoBean.getSSiteURL()); uH="l.u
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $9YAq/#Q
httpConnection.setRequestProperty("User-Agent","NetFox"); H(Pzo+k*
d0``:
w%~UuJ#i
int responseCode=httpConnection.getResponseCode(); \e+h">`WgX
if(responseCode>=400) iY?J3nxD-:
{ $ha,DlN
processErrorCode(responseCode); )-VpDW!%_
return -2; //-2 represent access is error h*d1G9%Q1
} *lyy|3z
S9RH&/^H
!xcLJ5^W
String sHeader; 0h/bC)z
D=1:-aLP7
#0$fZ
for(int i=1;;i++) CGw,RNV
{ mO<1&{qMZ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); RwKnNIp
//Utility.log(in.readLine()); ;$,b w5
sHeader=httpConnection.getHeaderFieldKey(i); RGEgYOO
if(sHeader!=null) USd7gOq(
{ )hG4,0hv&
if(sHeader.equals("Content-Length")) W%@r
{ Z<D8{&AjS
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); tE'^O< K
break; tVQq,_9C
} "`Q&s
} f[}(E
else Gb!R>WY
break; sg`
} J4?i\wD:
} boS=
catch(IOException e){e.printStackTrace ();} :'`y}'
catch(Exception e){e.printStackTrace ();} 6}l[%8
hXnfZx%
B/O0 ~y!n
Utility.log(nFileLength); %>'Zy6C<j
|xawguJ
j%+>y;).
return nFileLength; uwl_TDc>%
} JAx0(MZO
8+i=u"<
fHK.q({Qc
//保存下载信息（文件指针位置） &R5zt]4d&
private void write_nPos() A=W:}szt]
{ _mWVZ1P
try{ ]*?lgwE
output = new DataOutputStream(new FileOutputStream(tmpFile)); {x{~%)-
output.writeInt(nStartPos.length); 7F2 WmMS
for(int i=0;i<nStartPos.length;i++) XEegUTs
{ ~+ kfb^<-
// output.writeLong(nPos); 3iM7c.f*/
output.writeLong(fileSplitterFetch.nStartPos); Vxz`
output.writeLong(fileSplitterFetch.nEndPos); hT`fAn_
} tm&,u*6$W?
output.close(); J6J">
} `L LS|S]
catch(IOException e){e.printStackTrace ();} v]Fw~Y7l!
catch(Exception e){e.printStackTrace ();} %rlMjF'tG
} 60e{]}Z
'dzbeTJD5
K$:btWSm
//读取保存的下载信息（文件指针位置） /M3;~sx
private void read_nPos() v"%>ms"n
{ r9b(d]
try{ k!$$ *a*
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Yy`A0v
int nCount = input.readInt(); `jhbKgR[
nStartPos = new long[nCount]; ~+Cl9:4T
nEndPos = new long[nCount]; rTJqw@]#WH
for(int i=0;i<nStartPos.length;i++) H+gB|
{ T-7(3#&
nStartPos = input.readLong(); k{lXK\zN
nEndPos = input.readLong(); 3KkJQ5a
} R `ob;>[Q
input.close(); <Zfh5AM
} |\| v%`r2
catch(IOException e){e.printStackTrace ();} R{aqn0M
catch(Exception e){e.printStackTrace ();} 0A8G8^T
} $DnJ/hg;qD
!B9Yw/Ba
_PwPLSg
private void processErrorCode(int nErrorCode) @ IDY7x27
{ rG[2.\&
System.err.println("Error Code : " + nErrorCode); Q4S:/"*v8
} +R{~%ZTK
w6lx&K-
^Mhh2v
//停止文件下载 vJ 28A
public void siteStop() XMxm2-%olP
{ !Bg^-F:N
bStop = true; 5UK}AkEe&x
for(int i=0;i<nStartPos.length;i++) GGZ9DC\{
fileSplitterFetch.splitterStop(); #BH]`A J
30sA\TZ
{S@, ,
} oGbh*
} :qShP3^
//负责部分文件的抓取 W!=ur,F+
**FileSplitterFetch.java 5RY-.c4}
*/ KxFA@3
package NetFox; >,)U46
fNyXDCl
ICG:4n(,
import java.io.*; x%W~@_
import java.net.*; {aopGu?i
.~^A!t
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public class FileSplitterFetch extends Thread { /P/0\3TCi
=*6H!bzX
*N6sxFs
String sURL; //File URL 3YUF\L]yyw
long nStartPos; //File Snippet Start Position .H&XPW
long nEndPos; //File Snippet End Position u:wf:^
int nThreadID; //Thread's ID G%}k_vi&q
boolean bDownOver = false; //Downing is over 2@N-#x'
boolean bStop = false; //Stop identical Q } 0_}W
FileAccessI fileAccessI = null; //File Access interface Udjn.D
.i#'IS0c
rTST_$"_6
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException dn_l#$ U
{ eG.s|0`
this.sURL = sURL; mMCd
this.nStartPos = nStart; .^ba*qb`{
this.nEndPos = nEnd; br?pfs$U
nThreadID = id; ,~Lx7 5{
fileAccessI = new FileAccessI(sName,nStartPos);//定位 52'6wwv6?
} T*(mi{[T
QUz4 Kt
j5~~%
public void run() * COC&
{ }+)q/]%
while(nStartPos < nEndPos && !bStop) R|*Eg,1g -
{ w,<n5dMv
\@{TF((Y
b<E78B+Aax
try{ 5ne&6
URL url = new URL(sURL); 1V,DcolRY
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P_.AqEH
httpConnection.setRequestProperty("User-Agent","NetFox"); 2LCOB&-Ww
String sProperty = "bytes="+nStartPos+"-"; [[ll4|
httpConnection.setRequestProperty("RANGE",sProperty); m,rkKhXP
Utility.log(sProperty); +h1X-K:I
a3Xd~Qs
2=VFUR 8
InputStream input = httpConnection.getInputStream(); `"#hhKG
//logResponseHead(httpConnection); B~YOU3
wOEc~WOd
srS)"Jt
byte[] b = new byte[1024]; {=MRJg!U
int nRead; #9HX"<5
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Q-yNw0V}F
{ NjO_Y t
nStartPos += fileAccessI.write(b,0,nRead); j@/p: fk
//if(nThreadID == 1) 2~yj =D27Z
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {}H/N
} Wo5%@C#M
wZ_"@j<
CsjrQ-#9yn
Utility.log("Thread " + nThreadID + " is over!"); zNg[%{mz
bDownOver = true; }nSu7)3$B
//nPos = fileAccessI.write (b,0,nRead); alBnN<UM
} E%a&6W
catch(Exception e){e.printStackTrace ();} Zqb*-1Qw"*
} x{/-&`F
} TV`sqKW
-z%->OUu
Y' 5X4Ks|
//打印回应的头信息 n'%cO]nSx
public void logResponseHead(HttpURLConnection con) {Z178sik
{ *e:2iM)8~
for(int i=1;;i++) WC b5
{ A+FQmLS
String header=con.getHeaderFieldKey(i); D}UgC\u
if(header!=null) +fq\K]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); O'QnfpQ*9
Utility.log(header+" : "+con.getHeaderField(header)); }g:'K
else Mhc5<~?
break; Qh*}v!3Jo
} Dw y|mxlFn
} fB'Jo<C
HrT@Df
GH&5m44
public void splitterStop() Cu<' b'%;
{ U!YoZ?
bStop = true; %Z8pPH~T
} a)7&2J
muKu@nshL
++ObsWZ
} &vQ5+
5glEV`.je
ch0cFF^]
/* `S4G+j>u6
**FileAccess.java $-<yX<.
*//文件访问(定位，写) k0TQFx.A
package NetFox; fG{3S:TQq
import java.io.*; fd62m]X
"Nz"|-3Irv
6j|~oMYP
public class FileAccessI implements Serializable{ b{X.lz0
rA@|nL{
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 kV3LFPf>0
RandomAccessFile oSavedFile; jaMpi^C
long nPos; m~&>+q ^7
`M-
M. _5mZ{
public FileAccessI() throws IOException = \K/ulZo
{ |:u5R%
this("",0); G=C2l# Ae!
} R@`xS<`L/
% 3fpIzm
L3j ~Ooo
public FileAccessI(String sName,long nPos) throws IOException S(rnVsW%Ki
{ B}aW y&D
oSavedFile = new RandomAccessFile(sName,"rw"); 0rif,{"
this.nPos = nPos; D7c+/H@PF
oSavedFile.seek(nPos); n*G!=lMji
} t{B6W)q
{7v|\6@e3
zB\ 8<97C
public synchronized int write(byte[] b,int nStart,int nLen) jP<6Q|5F
{ TPY&O{q
int n = -1; u{dkUG1ia
try{ %f(4jQ0I
oSavedFile.write(b,nStart,nLen); _ -,[U{
n = nLen; e$mVA}>Ybp
} MR,A{X
catch(IOException e) YeB C6`7y
{ {yi!vw
e.printStackTrace (); ?wjk=hM2
} 0\eSiXs
Cq-99@&;
Eok8+7g0&
return n; #}8VUbJ
} OSom-?|w
P8tCzjrV
jT;'T$
} TQvjU!>
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UA#=K+2
/* `eGp.[ffT
**SiteInfoBean.java jASK!3pY
*/ `G>|g^6%i
package NetFox; ~u?rjkSFoh
vv
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public class SiteInfoBean { SO~pe$c-
Yt r*"-
MJKPpQ(,
private String sSiteURL; //Site's URL .&K?@T4l
private String sFilePath; //Saved File's Path XD[9wd5w8
private String sFileName; //Saved File's Name lHu/pSu@k
private int nSplitter; //Count of Splited Downloading File 9(bbV5}
GW9,%}l^;
'n?"f|G
public SiteInfoBean() cc"<H}g>`
{//nSplitter的缺省值为5 aQso<oK
//default value of nSplitter is 5 q@4Cw&AI+
this("","","",5); FE06,i\{
} ~0vNs2D,S
&3*r-9BZ
)F0Q2P1I
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) B\`${O(
{ cL"Ral-qB
sSiteURL= sURL; 5+)_d%v=6!
sFilePath = sPath; O /h1ew
sFileName = sName; QKoJxjR=^
this.nSplitter = nSpiltter; T$V8n_;
mrVN&.
foI:`]2"*
} V0gu0+u~R
W5&KmA
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public String getSSiteURL() <F|S<\Y.
{ _G)x\K]N
return sSiteURL; -1R7 8(1
} 2%]#rZ
`Cu9y+t
.;D'
public void setSSiteURL(String value) ^brh\M,:@
{ oK&G
sSiteURL = value; a$LoQ<f_
} TQ5kT?/{
HZ\=NDz
+H!aE}
public String getSFilePath() GU xhn
{ I#zL-RXT
return sFilePath; E7]a#
} *#'&a(hB!
>SD?MW1E
v\XO?UEJ2
public void setSFilePath(String value) Xd&oERJj
{ K%/g!t)
sFilePath = value; 3LVL5y7|
} |@)jS.Bn
{_4zm&
o7AI
public String getSFileName() `1R[J4e
{ +ZRm1q
return sFileName; o:Tpd 0F
} _^^5
6V1 Z(K
}oii|=,#^
public void setSFileName(String value) j!a&l
{ qPCI@5n3T?
sFileName = value; az Oib=3fz
} X-%91z:o58
LM".]f!,
XJ3aaMh"
public int getNSplitter() hrbeTtqi
{ yGb^kR}d
return nSplitter; "K*^%{
} c*)PS`]t
&Fch{%S>
=Flr05}m
public void setNSplitter(int nCount) ]T>YYz
{ "6iq_!#L
nSplitter = nCount; rrZ'Dz
} 8p~|i97W]!
} By0Zz
$tebNiP
v1E(K09h2
/* JRw)~Tg @
**Utility.java zZ])G
*/ 46c0;E\9
package NetFox; ?qtL*;
w{Y:p[}
rVnolA*%
public class Utility { <P c;8[
mmEe@-lE
~G~:R
public Utility() 0"`|f0}c
{ <9?`zo$y
QWK\6
}h\]0'S~J~
} 4&E&{<;
p,#**g:
//线程睡眠 e&=T`
public static void sleep(int nSecond) p87VJ}
{ ixo?o]Xb`
try{ Qx[ nR/
Thread.sleep(nSecond); 5> =Ia@I
} ZDl(q~4?z
catch(Exception e) @jH8x!5u:
{ .cg"M0
e.printStackTrace (); _gP-$&JC
} VW\~OH
} /%h<^YDBf
N>+L?C
//日志 \-)augq([
public static void log(String sMsg) [+4--#&{
{ &V7{J9
System.err.println(sMsg); Twr<MXa
} E3o J;E
<*74t%AJ%
8w4cqr4m
public static void log(int sMsg) ,W~a%8*
{ ADN
System.err.println(sMsg); RU GhhK
} npdpKd+*K"
} {!7 ^w
+"2IQme5
i^u5j\pfY*
/* _Tj`
**TestMethod.java $^4URH
*/ ?-IjaDC}
package NetFox; 'X(G><R9
geRD2`3;
.I&]G
public class TestMethod { l~V^
F2$Z4%x#
bC@9 */i
public TestMethod() ' |>
{ ///xx/weblogic60b2_win.exe {`vv-[j|
try{ (lY<\l
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Z6I^HG{:
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); SMdQ,n1]
SiteFileFetch fileFetch = new SiteFileFetch(bean); amK.H"
fileFetch.start(); Fn~?YN
} ^s&1,
catch(Exception e){e.printStackTrace ();} 2_]"9d4
XVKR}I
2nGQD{
} > %U
H,H=y},
wLf=a^c#
public static void main(String[] args) GCTf/V\#
{ ,#PeK(
new TestMethod(); f._FwD
} n-7|{1U
} ,!?&LdPt>
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