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)); \]Dt4o*yZ
} I<=Df5M
for(int i=0;i<nEndPos.length-1;i++) &48_2Q"{
{ 7dX/bzUVz8
nEndPos = nStartPos[i+1]; rxO2js
} o+?rI p
nEndPos[nEndPos.length-1] = nFileLength; f&hwi:t
} C*I(|.i@
} #Y93y\
w# *1/N
%@R~DBS
//启动子线程 XMRNuEU
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Z?^"\u-
for(int i=0;i<nStartPos.length;i++) @ 2_<,;$
{ aj~bt-cE
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]bgY6@M
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), #*c F8NV-
nStartPos,nEndPos,i); 'ZQWYr9R
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); tVqmn
fileSplitterFetch.start(); X8<2L2:
} #)`A7 $/,
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6<5Jq\-h
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); &,i~cG?
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", oh#> 5cA8
nEndPos = " + nFileLength); &kQ!KA28
// fileSplitterFetch[nPos.length-1].start(); =ZsGT
R<zG^m
CiL94Nkd9
//等待子线程结束 !RlC~^ -
//int count = 0; M8@_Uj
//是否结束while循环 *OdX u&5
boolean breakWhile = false; g6sjc,`
bQaoMZB
P|^$kK
while(!bStop) fj4^VXD
{ 4S L_-Hm.
write_nPos(); }~o ikN:
Utility.sleep(500); z8Q"%@
breakWhile = true; ]v5-~E!
Y'Z+, CNf
~]8p_;\
for(int i=0;i<nStartPos.length;i++) ^ft]b2i
{ l[/q%Ca'>
if(!fileSplitterFetch.bDownOver) fw{,bJ(U
{ .h;Se
breakWhile = false; >&H~nGP.
break; t#<KxwhcN
} hN(L@0)
} '5};M)w
if(breakWhile) 3D)b*fPc
break; .dI)R40L/\
g-yi xU
}.:d#]g8
//count++; qi+&|80T.
//if(count>4) Cj&$%sO1
// siteStop(); r(}nhUQ%E
} K@@9:T$
9b6!CNe!
=Mhg
System.err.println("文件下载结束！"); PaVO"y]C
} b4 hIeBI\
catch(Exception e){e.printStackTrace ();} yty`2$O
} =J@`0H"
4R+P
@+^c"=d1S
//获得文件长度 Lm.`+W5
public long getFileSize() x.EgTvA&d
{ h)E|?b_
int nFileLength = -1; eO{@@?/y
try{ 67J*&5? |
URL url = new URL(siteInfoBean.getSSiteURL()); w{'2q^>6*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D{AFL.r{
httpConnection.setRequestProperty("User-Agent","NetFox"); 4YJ=q% G
jNy?[ )
/#yA%0=w
int responseCode=httpConnection.getResponseCode(); ):bu;3E
if(responseCode>=400) wO"GtVd
{ ">6&+^BN'
processErrorCode(responseCode); *?8RXer
return -2; //-2 represent access is error )&.!3y 660
} abZdGnc
(5;D7zdA
w3#`1T`N
String sHeader; V:\]cGA{
8Inx/>eOI
0yHjrxc$
for(int i=1;;i++) 5 R*lVUix
{ h#{T}[
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 93I'cWN
//Utility.log(in.readLine()); ypA: P
sHeader=httpConnection.getHeaderFieldKey(i); EDN(eh(_
if(sHeader!=null) +{6`F1MO
{ nC~fvyd<P
if(sHeader.equals("Content-Length")) :l~EE!
{ 797X71>
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5.k}{{+
break; >38 Lt\
} G&o64W;-s
} z{6YC~
else y~p4">]
break; Dq`~XS*
} <bdyAUeFw
} 9d"5wx
catch(IOException e){e.printStackTrace ();} l^,qO3ES
catch(Exception e){e.printStackTrace ();} ZT9IMihV
Qcgu`]7}
Wy(pLBmb
Utility.log(nFileLength); g9qC{xd
_j 5N=I{U
sPpS~wk*
return nFileLength; nx;$dxx_Ws
} 9-G b"hr
aQmfrx
=xBT>h;
//保存下载信息（文件指针位置） hwDXm9
private void write_nPos() Yzd2G,kZ=
{ Y*\6o7
try{ =yh3Nd:u
output = new DataOutputStream(new FileOutputStream(tmpFile)); ( 2zeG`
output.writeInt(nStartPos.length); ~@YQ,\Y
for(int i=0;i<nStartPos.length;i++) \[T{M!s
{ ! o^Ic`FhS
// output.writeLong(nPos); cno;>[$
output.writeLong(fileSplitterFetch.nStartPos); u0BMyH
output.writeLong(fileSplitterFetch.nEndPos); -,/3"}<^78
} 9>{t}Id
output.close(); "!a`ygqpT
} \c68n
catch(IOException e){e.printStackTrace ();} >i`8R
catch(Exception e){e.printStackTrace ();} !a4cjc(
} qwP$~Bj
&>V/X{>$`K
8{@`kyy|
//读取保存的下载信息（文件指针位置） IM$0#2\
private void read_nPos() _-6e0srZ
{ hpjUkGm5
try{ V{FE[v_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ?C~X@sq
int nCount = input.readInt(); #|ddyCg2
nStartPos = new long[nCount]; xDLMPo&
nEndPos = new long[nCount]; !Y|8z\Q
for(int i=0;i<nStartPos.length;i++) *pK lA&_
{ Oh-Fp-v87
nStartPos = input.readLong(); #~1wv^
nEndPos = input.readLong(); $vqU|]J`
} 2R] XH 0
input.close(); 0T1ko,C!,e
} *) } :l
catch(IOException e){e.printStackTrace ();} '&)D>@g
catch(Exception e){e.printStackTrace ();} QnP{$rT
} I)rGOda{
yP%o0n/"x
55,=[
private void processErrorCode(int nErrorCode) 2x6<8J8v*
{ shy
System.err.println("Error Code : " + nErrorCode); mw Z'=H
} 1wbTqc
($:y\,5(9I
0IpST
//停止文件下载 WT?bBf
public void siteStop() XW^8A77H
{ 0&Qsk!-B
bStop = true; i[8NO$tN1)
for(int i=0;i<nStartPos.length;i++) b^%?S8]h
fileSplitterFetch.splitterStop(); lc"qqt
6I5o2i
Ny B&uf
} y]J3hKs
} RE*WM3QK~
//负责部分文件的抓取 o|+E+l9\
**FileSplitterFetch.java FXeV6zfrE
*/ =Iy/cHK
package NetFox; Dw*Arc+3V
PlF!cr7:4
ZXh~79
import java.io.*; A<2I!
import java.net.*; R|$[U
xHm/^C&px
0FTRm2(
public class FileSplitterFetch extends Thread { (GnVwJ<v9V
[\88@B=jXP
w/O<.8+
String sURL; //File URL erXy>H[;
long nStartPos; //File Snippet Start Position Esb?U|F4
long nEndPos; //File Snippet End Position y%2%^wF
int nThreadID; //Thread's ID a6k(9ZF
boolean bDownOver = false; //Downing is over ^t`f1rGR
boolean bStop = false; //Stop identical )&XnM69~b
FileAccessI fileAccessI = null; //File Access interface q%DVDq( z
Q5hb0O%a
0n\^$WY
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException w[e0wh`.
{ >/8ru*Oc
this.sURL = sURL; I'xC+nL@
this.nStartPos = nStart; /z..5r^,ZZ
this.nEndPos = nEnd; .r7D)xNa@
nThreadID = id; Is<x31R
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >1m)%zt
} xnT3^ #-h
lD9%xCo9(
g)X7FxS,z
public void run() &3WkH W
{ Mp^^!AP9
while(nStartPos < nEndPos && !bStop) 4|FRg
{ NP$e-" 1
*&(2`#C;
`}[VwQ
try{ 1 pa*T!
URL url = new URL(sURL); +g)_4fV0|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); AS`2=w
httpConnection.setRequestProperty("User-Agent","NetFox"); %A8Pkr<&E
String sProperty = "bytes="+nStartPos+"-"; -QN1oK@\mE
httpConnection.setRequestProperty("RANGE",sProperty); Ft)t`E'%j
Utility.log(sProperty); *Yj~]E0`1
,Y$F7&
} /[_
InputStream input = httpConnection.getInputStream(); Qk+=znJ
//logResponseHead(httpConnection); W]Y@WKeT
MRjH40"2
+{5JDyh0
byte[] b = new byte[1024]; 1XqIPiXJ
int nRead; A<mj8qz
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) o`b$^hv{A
{ Hde]DK,d
nStartPos += fileAccessI.write(b,0,nRead); bK!,Pc<
//if(nThreadID == 1) W\&WS"=~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }Q!h ov
} Q^*G`&w,
*^X#Eb
d&NCFx
Utility.log("Thread " + nThreadID + " is over!"); P4hZB_.=
bDownOver = true; Tld1P69(
//nPos = fileAccessI.write (b,0,nRead); s.VUdR"
} fEHh]%GT`
catch(Exception e){e.printStackTrace ();} gCg4;b6g
} @YEw^J~
} g&{gD^9)4
: :F!
8$2l^
//打印回应的头信息 kX@bv"i
public void logResponseHead(HttpURLConnection con) K~`n}_:
{ #DQX<:u
for(int i=1;;i++) ?(fQ<i n
{ >]:N?[Y_~}
String header=con.getHeaderFieldKey(i); _Wm(/ +G_|
if(header!=null) ls[Ls
//responseHeaders.put(header,httpConnection.getHeaderField(header)); yB0jL:|a
Utility.log(header+" : "+con.getHeaderField(header)); 's$A+8;L
else NE$VeW+@
break; #=`FM:WH
} '9IP;
} zY]Bu-S3
b^uP^](J
`%FIgE^
public void splitterStop() di8W2cwz
{ IUluJ.sXIf
bStop = true; 0$n8b/%.
} ^^n+
=#OHxM
jz{(q;
} xP8iz?6"V
(:_%kmu
M3DxapG
/* l4iuu
**FileAccess.java W2}%zux
*//文件访问(定位，写) 08zi/g2 3
package NetFox; @/CRIei
import java.io.*; C_;HaQiu
<{$ev&bQ
s$f+/Hs
public class FileAccessI implements Serializable{ >E//pr)_Km
zkjPLeX
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 hknwis%y
RandomAccessFile oSavedFile; fl} rz
long nPos; E9yFREvQc
6'RZ
Z-N-9E
public FileAccessI() throws IOException $w|o@ Ml)
{ :SpG&\+
this("",0); 0MwG}|RC
} *4(/t$)pEl
03X<x|
"\VW.S
public FileAccessI(String sName,long nPos) throws IOException GOv92$e
{ y+K7WUwhq
oSavedFile = new RandomAccessFile(sName,"rw"); AzHIp^
this.nPos = nPos; P`\m9"7
oSavedFile.seek(nPos); ke3HK9P;
} - XE79 fQ
/2g)Z!&+L
%k/ k]:s
public synchronized int write(byte[] b,int nStart,int nLen) /Nj:!! AN
{ L eG7x7n
int n = -1; r[.zLXgK
try{ qPFG+~\c
oSavedFile.write(b,nStart,nLen); *k3 d^9o#
n = nLen; B(4:_j\2
} Z]mM
catch(IOException e) #,f}lV,&
{ *kX3sG$8
e.printStackTrace (); |@o]X?^
} AJ;u&&c4C\
rK(x4]I l"
8w{#R{w
return n; $\YLmG
} cCo07R
GW>7R6i
`-72>F;T
} W (=Wg|cr
]wkSAi5z*
'8r8 ^g[
/* XEf&Yd
**SiteInfoBean.java 5XSxQG@k^z
*/ Sb:zN'U
package NetFox; :$SRG^7md
; McIxvj
0j a
public class SiteInfoBean { ?z)y%`}
e'/
`_J^g&y~
private String sSiteURL; //Site's URL b2/N H1A
private String sFilePath; //Saved File's Path :f?,]|]+-
private String sFileName; //Saved File's Name SQ~N X)
private int nSplitter; //Count of Splited Downloading File a`EGx{q(
:|n>H+Y
X%4uShM
public SiteInfoBean() `5k6s,
{//nSplitter的缺省值为5 o@<6TlZM
//default value of nSplitter is 5 c:h.J4mv
this("","","",5); Ac5o K
} 5oT2)yz
=E{{/%u{{S
o-Q]Dk1W
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) lJ2|jFY9
{ xu%! b0
sSiteURL= sURL; [}9XHhY1O=
sFilePath = sPath; +2;#9aa I
sFileName = sName; YmO"EWb
this.nSplitter = nSpiltter; 7U{b+=,wK
i">z8?qF
G!e}j @@
} }l]3m=)
pU:C=hq4
x;ICV%g/
public String getSSiteURL() K+h9bI/Sf
{ (2O} B.6
return sSiteURL; 2vh!pez_
} JL.ydH79
(:fE _H2z
|L.~Amd
public void setSSiteURL(String value) 9h3~;Q
{ Cdt,//xrz
sSiteURL = value; qOcG|UgF
} aV?}+Y{#
skR,M=F~
9aF..
public String getSFilePath() g6@NPQ
{ ~/|unV
return sFilePath; +]S;U&vQ
} H4y1Hpa,
So)KI_M
(v'lb!j^#
public void setSFilePath(String value) _Y ><ih
{ XZep7d}
sFilePath = value; [KimY
} PO%yWns30o
g<hv7?"[
p+`*~6Jj/
public String getSFileName() '.h/Y/oz
{ ir@N>_
return sFileName; f1]AfH#
} {M)3GsP?
A=qW]Im
3'sWlhf;
public void setSFileName(String value) Ghq'k:K,
{ 2=Y_Qrhi
sFileName = value; \6`%NhkM_
} ?2<6#>(7a
Ltic_cjYd?
$Va]vC8?
public int getNSplitter() }lNufu
{ 1)/T.q<D"
return nSplitter; ktw!T{
} tZNad
Yyo9{4v+p{
B yy-Cc
public void setNSplitter(int nCount) j3rv2W\
{ -EkDG]my
nSplitter = nCount; u6qi
} #H|j-RM2
} r;%zGFp
K&D}!.~/
e@2Vn? 5
/* LHHDt<+B
**Utility.java vq0M[Vy
*/ Za:BJ:
package NetFox; S!I <m&Cgc
vU$O{|J
qs c-e,rl
public class Utility { >nIcFm
L1Cn
~g4rGz
public Utility() Q5Ghki
{ "PX3%II
XM@-Y&c$A
!iitx U
} EkjK92cF
/<?X-IDz.{
//线程睡眠 m"|(w`n]E+
public static void sleep(int nSecond) 2`FsG/o\T~
{ dT,m{[+
try{ (fGJP*YO
Thread.sleep(nSecond); P"PeLB9K
} K_lL\
catch(Exception e) 6dS1\Y
{ ZnhuIAAG
e.printStackTrace (); KEVy%AP=*h
} rd 35)
} qiKtR
n"d)
//日志 N>6yacTB
public static void log(String sMsg) u.L8tR:(
{ ! ^*;c#
System.err.println(sMsg); Zz)oMw
} \I,Dje/:w
NX{-D}1X=
}Mb'tGW
public static void log(int sMsg) ZhbY,wJ,
{ KGE-RK
System.err.println(sMsg); -TU{r_!Z(
} mKFHT
} 7E75s)KH
!qGx(D{\
Lc:SqF
/* p:Ld)U*
**TestMethod.java =|5bhwU]
*/ |3T|F3uEX
package NetFox; <#x%A0
uuK]<h*
d>"$^${
public class TestMethod { f_P+qm
GwpBDMk
,Qi|g'a
public TestMethod() teS0F
{ ///xx/weblogic60b2_win.exe h,6S$,UI
try{ }Ka.bZS
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); vb ^!(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); s)DNLx
SiteFileFetch fileFetch = new SiteFileFetch(bean); BM$tywC
fileFetch.start(); $*)(8Cl
} [U7,\o4w
catch(Exception e){e.printStackTrace ();} _BLSI8!N@
D%Jc?6/I#3
U*fj5
} tG^?fc
yb.|7U?/x
>Hzb0N!VJ
public static void main(String[] args) |&RX>UW$W
{ aU8Ti8A>
new TestMethod(); 7 }MJK)
} f`]E]5?
} *2C79hi1
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