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)); g1ytT%]
} b#A(*a_gN
for(int i=0;i<nEndPos.length-1;i++) fQP,=
{ ]H>+m 9
nEndPos = nStartPos[i+1]; VcrVaBw
} o_(0
nEndPos[nEndPos.length-1] = nFileLength; \@8*TS
} VjY<\WqbS
} =tnTdp0F
5y040 N-
^j[Ku
//启动子线程 ;$z7[+M
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ODek%0=
for(int i=0;i<nStartPos.length;i++) "ee'2O
{ 8<{;=m8cQ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^EuW( "
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), o)p[ C
nStartPos,nEndPos,i); YNk|+A.<d
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); A=y"x$%-_
fileSplitterFetch.start(); C 0>=x{,v
} /'\;8A$J`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |Q5+l.%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); BJgDo
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", F3Dt7q
nEndPos = " + nFileLength); ,z[(k"
// fileSplitterFetch[nPos.length-1].start(); .yX>.>"T|
u1N1n;#
*Q5x1!#z#
//等待子线程结束 vtZ?X';wh
//int count = 0; d/lffNS=
//是否结束while循环 -;U3w.-
boolean breakWhile = false; 6rT4iC3Q{
<6R"h-u"
9x[ U$B
while(!bStop) Z\'wm'
{ AEqq1A
write_nPos(); c.0]1
Utility.sleep(500); (AuPZ
breakWhile = true; 4w;~4#ZPp
O_AGMW/2+
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for(int i=0;i<nStartPos.length;i++) "wINBya'M
{ LipxAE?O
if(!fileSplitterFetch.bDownOver) 3q?5OL^$
{ HCazwX
breakWhile = false; ;ctU&`
break; ;'^, ,{
} "xn|zB
} !oGQ8 e
if(breakWhile) |xeE3,8
break; Sr"/-
|Euus5[
e9:P9Di(b
//count++; !W~<q{VTs
//if(count>4) bE4HDq34
// siteStop(); /WYh[XKe
} H(&Z:{L
="dDA/,$VS
>)3VbO
System.err.println("文件下载结束！"); L {qJ-ln:
} :1MMa6
catch(Exception e){e.printStackTrace ();} c{4R*|^
} `)tA YH
_Ex|f5+
%Rarr
//获得文件长度 @c]Xh:I
public long getFileSize() TY6 rwU
{ v|&s4x?D
int nFileLength = -1; 4U{m7[
try{ ~-<:+9m
URL url = new URL(siteInfoBean.getSSiteURL()); v20~^gKo=m
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FWY[=S
httpConnection.setRequestProperty("User-Agent","NetFox"); pBU]=[M0
%w:'!X><
Z Xb}R^O-
int responseCode=httpConnection.getResponseCode(); 3+9 U1:1[.
if(responseCode>=400) >qpqQ; bm
{ \O? u*
processErrorCode(responseCode); 2kJ!E@n7
return -2; //-2 represent access is error ?!7 SzLll
} yoU2AMH2D^
Pb4q`!
5#!ogKQ(i
String sHeader; 2GUupnQkD
j ug'g
liD47}+
for(int i=1;;i++) a(|xw
{ ^@"c`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !tBeuemN%
//Utility.log(in.readLine()); jsdBd2Gdc
sHeader=httpConnection.getHeaderFieldKey(i); 0'@u!m?
if(sHeader!=null) N&x:K+Zm.
{ N7pt:G2~%
if(sHeader.equals("Content-Length")) (3O1?n[n
{ 1i+FL''
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [Xh\mDU.
break; _:%U_U
} /RqhykgZ
} Qc3?}os2
else ; 8E;
break; n ,1tD
} {82rne`[
} e?=elN
catch(IOException e){e.printStackTrace ();} Rf:<-C0T
catch(Exception e){e.printStackTrace ();} 6RP+4c
5[<F_"x
|*E"G5WZM
Utility.log(nFileLength); ;dOs0/UM&
T3rn+BxF7
k9&@(G[K3
return nFileLength; %YCd%lAe,
} N5KEa]k1nw
DB~MYOX~
"&Mou
//保存下载信息（文件指针位置） G *@@K
private void write_nPos() piuKVU
{ 6V P)$h8
try{ ]738Z/)^
output = new DataOutputStream(new FileOutputStream(tmpFile)); ! ]\2A.b[
output.writeInt(nStartPos.length); LfllO
for(int i=0;i<nStartPos.length;i++) ;Z4o{(/zU
{ pZ\$50t&O
// output.writeLong(nPos); RM#fX^)=
output.writeLong(fileSplitterFetch.nStartPos); Vrg3{@$
output.writeLong(fileSplitterFetch.nEndPos); f8#*mQ
} esteFLm`6
output.close(); )Oe`s(O@[I
} )7w@E$l"
catch(IOException e){e.printStackTrace ();} .HCaXFW
catch(Exception e){e.printStackTrace ();} >[8#hSk
} O8[k_0@
5A,=vE
FW5}oD(H
//读取保存的下载信息（文件指针位置） ?~ ?Hdv
private void read_nPos() zv@bI~3~
{ 5}7ISNP;f
try{ |=u96G~N
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); W]@6=OpH
int nCount = input.readInt(); IhwN],-V
nStartPos = new long[nCount]; *(p7NYf1
nEndPos = new long[nCount]; gg(k7e
for(int i=0;i<nStartPos.length;i++) .OV-`TNWj
{ 7dHIW!OA
nStartPos = input.readLong(); .v\PilF
nEndPos = input.readLong(); :~i+tD
} M=6G:HHY
input.close(); t*s!0'Y
} NFV_+{X\
catch(IOException e){e.printStackTrace ();} CdNih8uG
catch(Exception e){e.printStackTrace ();} ^X^,>Z|
} S QSA%B$<
%!yxC
'xk1o,;
private void processErrorCode(int nErrorCode) _6LH"o3
{ _<3r'Y,
System.err.println("Error Code : " + nErrorCode); %:%MUdl6
} POY=zUQ'/
,$ mLL
);!dg\U
//停止文件下载 Z>&K&ttJ
public void siteStop() LC76Qi;|k
{ SKW;MVC
bStop = true; t%:G|n Sz
for(int i=0;i<nStartPos.length;i++) 4Lw'v:(
fileSplitterFetch.splitterStop(); LjCykk
x~nQm]@`h
YY\Rua/nG
} VD9J}bgJ
} #]igB9Cf)w
//负责部分文件的抓取 (c<f<D|
**FileSplitterFetch.java j $KM9
*/ '/dTqg*W
package NetFox; }d@LSaM
;}f6Y['z
EL"4E',
import java.io.*; tfsh!)u?
import java.net.*; uV!MW=)
VSx%8IM+X
_m" ^lo
public class FileSplitterFetch extends Thread { b6]e4DL:R
XQ4dohGCP
FRc |D
String sURL; //File URL C9GU6Ao
long nStartPos; //File Snippet Start Position [rc'/@L
long nEndPos; //File Snippet End Position ]gEu.Nth`
int nThreadID; //Thread's ID H RWZ0 '
boolean bDownOver = false; //Downing is over 'aNahzb
boolean bStop = false; //Stop identical 5=*@l
FileAccessI fileAccessI = null; //File Access interface B{^`8Htrn
< rv1IJ
~>4@;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException {7/A
{ .0?ss0~
this.sURL = sURL; W6)dUi :"
this.nStartPos = nStart; 9t.fij
this.nEndPos = nEnd; </8be=e7p
nThreadID = id; LRhP7D+A
fileAccessI = new FileAccessI(sName,nStartPos);//定位 dE+CIjW5
} _,11EeW@
M^Q&A R'F
@"jmI&hYn
public void run() ?G2qlna
{ k\Yu5)
while(nStartPos < nEndPos && !bStop) 2Zv,K-G
{ R (t!xf
Q9Q!9B@
*7)S%r,?
try{ h4J{jh.
URL url = new URL(sURL); ViCg|1c
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); h9,wiT
httpConnection.setRequestProperty("User-Agent","NetFox"); fQ2!sV
String sProperty = "bytes="+nStartPos+"-"; |`N$>9qN
httpConnection.setRequestProperty("RANGE",sProperty); #nxER
Utility.log(sProperty); u>JqFw1
@1/Q
5d)'`hACe
InputStream input = httpConnection.getInputStream(); MoC*tImWR
//logResponseHead(httpConnection); olUqBQ&ol
D?^`(X P
t;Fbt("]:
byte[] b = new byte[1024]; <=B1"'\
int nRead; vE^h}~5U
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) AH"g^ gw~T
{ ux"D ]P
nStartPos += fileAccessI.write(b,0,nRead); >$#*`6R
//if(nThreadID == 1) P_:?}h\
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8=ukS_?Vy
} U*`
Eg287B
jQH5$
Utility.log("Thread " + nThreadID + " is over!"); ~;!i)[-
bDownOver = true; t?3{s\z8+
//nPos = fileAccessI.write (b,0,nRead); *il]$i
} LaEX kb*s
catch(Exception e){e.printStackTrace ();} PVQ#>_~5
} 5~<a>>
} 7cOg(6N
3:02`;3
;f\R$u-
//打印回应的头信息 ]$XBd{\D{
public void logResponseHead(HttpURLConnection con) A~yw8v5UF
{ =/!{<^0
for(int i=1;;i++) $_I%1
{ utFcFdX
String header=con.getHeaderFieldKey(i); g:uaI
if(header!=null) IV 3@6t4k
//responseHeaders.put(header,httpConnection.getHeaderField(header)); zBrWm_R5T
Utility.log(header+" : "+con.getHeaderField(header)); Qzs\|KS
else Aoy1<8WP%
break; %$9)1"T0Y
} T9XW%/n
} w#gU1yu
!4b;>y=m
Ztpm_P6
public void splitterStop() {W:)oh>
{ TGt1d
bStop = true; j 44bF/
} 9L)&n.t1
6S+K*/w
@88z{
} E=tx.h4xG~
U d=gdsL
JK^B+.
/* 5LhJ8$W
**FileAccess.java J*q=C%}.
*//文件访问(定位，写) '#An+;x{
package NetFox; ~gLEhtW
import java.io.*; c|;|%"Mk
r{6B+3J
`Hp.%G(
public class FileAccessI implements Serializable{ #&`WMLl+8
^1FZ`2u;
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ,ovv
RandomAccessFile oSavedFile; g]PLW3
long nPos; |@Idf`N$
Xw}Y!;<IEu
|uBot#K|
public FileAccessI() throws IOException e5/DCz
{ tx&U"]
this("",0); rEpKX
} c7TWAG_+
Z :i"|;
4kY{X%9
public FileAccessI(String sName,long nPos) throws IOException &+w!'LSaD
{ 3=L1HZH
oSavedFile = new RandomAccessFile(sName,"rw"); F~@1n,[
this.nPos = nPos; M(]|}%
oSavedFile.seek(nPos); o? xR[N-J
} ~\s &]L
\,IDLXqp
yI)fu^
public synchronized int write(byte[] b,int nStart,int nLen) @j8L{FGnN
{ w!h{P38
int n = -1; /:L&uqA
try{ d?qO`- ~$
oSavedFile.write(b,nStart,nLen); =<W[dV=W
n = nLen; Ywb)h^{!
} *CD=cmdD*
catch(IOException e) h|>n3-k|p
{ jnLu|W&
e.printStackTrace (); H&Lbdu~E
} zmS-s\$,
Mn{Rg>X
j9fL0$+FI
return n; ['YRY B
} OZ]3OL,
?[fl$EG
RKZk/ly
} g_!xO2LH,8
e&7}N Za
dz.MH
/* ]CJ>iS!V
**SiteInfoBean.java DG9;6"HBX
*/ iQR})=Q
package NetFox; jQlK-U=oi
rG%_O$_dO
SmEd'YD!J
public class SiteInfoBean { lxJ.h&"P
wDTV /"Y
g wiC ,
private String sSiteURL; //Site's URL U`4Zj1y
private String sFilePath; //Saved File's Path !Yi<h/:
private String sFileName; //Saved File's Name "_}D{ws1
private int nSplitter; //Count of Splited Downloading File 8@#Y <{
ng6p#F,3
O g~"+IGp
public SiteInfoBean() S|h m
{//nSplitter的缺省值为5 Jg6[/7*m
//default value of nSplitter is 5 qk"=nAJX
this("","","",5); .Bn2;nO
} *Bz&
g2_df3Q
qUg4-Z4
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) J4^cd
{ Hx0,kOh)
sSiteURL= sURL; No|{rYYKK
sFilePath = sPath; Q9V4-MC9
sFileName = sName; WU@,1.F:
this.nSplitter = nSpiltter; a6#PZ!1
3c6)
\kO_"{7n
} Q1B!W
Jxp'.oo[
ikiy>W8
public String getSSiteURL() 7FFYSv,[:
{ C#0Wo
return sSiteURL; l.)!jWY
} =h!m/f^x
FeMu`|2
Xy<KvFy
public void setSSiteURL(String value) [: j_Y3-9
{ S5!2%-;<k
sSiteURL = value; K`<P^XJr
} p}z0(lQ*~
SQk!o{
+w5?{J
public String getSFilePath() B!anY}/U
{ V [>5
return sFilePath; U7=Z.*/62
} _v,n~a}&
8hT>)WH}wo
hn.fX:}
public void setSFilePath(String value) p,fin?nW c
{ {BU,kjv1g
sFilePath = value; VGIc|Q=F
} NKrk*I"G
'r CR8>k
%Et]w
public String getSFileName() ]CYe=m1<2Q
{ \ZH=$c*W
return sFileName; Mt`.|N;y!
} z_)$g=9$
ZW"J]"A
@P?*<b{
public void setSFileName(String value) _6(=0::x
{ 9Wn0YIc
sFileName = value; f63q
} uwJkqlUOz
\b->AXe8
hSmM OS{
public int getNSplitter() zFIbCv8
{ QHK$
return nSplitter; .755-S
} y-YYDEl
9w1)Mf}
,ic}
public void setNSplitter(int nCount) 9z#IdY$a
{ }V{, kK
nSplitter = nCount; FB""^IC?W
} u|E,Wy1
} 0#G"{M
O1A*-G:X
Vufw:}i+^
/* ocvBKsfhE`
**Utility.java U4gZW]F
*/ kI]1J
package NetFox; 0)Z7U$
pR$c<p
$[d}g
public class Utility { T!n<ya!
J0`?g6aY
pw,.*N3P
public Utility() =~)n,5
{ -v:Y\=[\
l!1bmg#]$
uQDu<@5^[
} ^0 t`EZ$
3jQ |C=
//线程睡眠 ,i}"e(f
public static void sleep(int nSecond) 0 [s1!Cm!i
{ eu~;G H
try{ 4P.ry|2
Thread.sleep(nSecond); ixp%aRRP
} GRNH!:e
catch(Exception e) B::vOg77
{ P++gR@
e.printStackTrace (); \"Np'$4eu
} \(u P{,ML
} N.fIg
Gce![<|ph
//日志 DP?gozm
public static void log(String sMsg) |i|O9^*%
{ 3[c54S+(U
System.err.println(sMsg); 4)`{ L$
} Q5Wb)
qU}[(9~Ru
u}pLO9V"`
public static void log(int sMsg) Mqna0"IYx*
{ ,Rf<6/A
System.err.println(sMsg); 0_ ;-QAd
} Y,+$vj:y8
} <h^vl-L>
?&[`=ZVn
a^,Xm(Wb}
/* \E n^Vf
**TestMethod.java 5y.kOe4vH
*/ OH&&d=~
package NetFox; Cjw|.c`
PJ);d>tz
-ohqw+D
public class TestMethod { &L_(yJ~-
?8`b
O5E\#*<K
public TestMethod() f- _~rQ
{ ///xx/weblogic60b2_win.exe 1B2>8N
try{ t)5bHVx
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); l@':mX3xd
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0DGXMO$;
SiteFileFetch fileFetch = new SiteFileFetch(bean); X'O3)Yg
fileFetch.start(); mzDbw-#
} F6yMk%
catch(Exception e){e.printStackTrace ();} 3d[fP#NY7
Y\s@'UoVN
U4Il1| M&
} @2V#bK
q5Z]Z.%3O
m#ID%[hg$
public static void main(String[] args) 7V?TLGgd$
{ | X! d*4
new TestMethod(); 2Lm.;l4YO
} rQCj^=cf;~
} |%Pd*yZA
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