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)); rzl0*CR
} x-hr64WFK
for(int i=0;i<nEndPos.length-1;i++) /y2)<{{I
{ zc1y)s0G
nEndPos = nStartPos[i+1]; Y.7iKMp(
} !PAuMj)P
nEndPos[nEndPos.length-1] = nFileLength; d3,%Z &
} ~tw#Q
} dq6|m }g{
D]P_tJI
pUp&eH
//启动子线程 T6Oah:50EM
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; bi01]
for(int i=0;i<nStartPos.length;i++) #L3heb&9
{ F\K&$5J{p
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), t@_MWF
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5*~]=(BE
nStartPos,nEndPos,i); cN{(XmX5n
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7{"urs7 T
fileSplitterFetch.start(); 3zr95$Mt
} pbXh}YJ&
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vJ&g3ky
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); V"A*k^}
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |(evDS5
nEndPos = " + nFileLength); F]fBFDk
// fileSplitterFetch[nPos.length-1].start(); `l%)0)T
m|/q o
fV>12ici
//等待子线程结束 Z?@oe-mz
//int count = 0; `]T#uP<u
//是否结束while循环 zyHHz\{
boolean breakWhile = false; 2#y-3y<G
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[B2g{8{!
while(!bStop) CO<P$al
{ /Wx({N'h$
write_nPos(); Kw/7X[|'G
Utility.sleep(500); %}`zq8Q;
breakWhile = true; P{2ue`w[
1:.I0x!
~uUN\qx52
for(int i=0;i<nStartPos.length;i++) QTC-W2t]
{ Ra!Br6
if(!fileSplitterFetch.bDownOver) D_)i%k\
{ Yg~$1b@
breakWhile = false; A.8[FkiNmD
break; *)8!~Hs
} 4?u<i=i
} w4<n=k
if(breakWhile) >Q-"-X1
break; ]b+Nsr~
Szb#:C
h!zev~u1)`
//count++; SNUq
//if(count>4) IEP^u `}
// siteStop(); zP`&X:8
} R?Dc*,
GN=ugP 9
X+$IaLfCxD
System.err.println("文件下载结束！"); ~BbF:DS
} y~r5KB6w
catch(Exception e){e.printStackTrace ();} d#W>"Cqxqa
} .7`c(9<
S^zt>
p~evPTHnrX
//获得文件长度 \46 'j.
public long getFileSize() qX%oLa
{ Y0?<~Gf
int nFileLength = -1; U;qGUqI
try{ v>!tws5e
URL url = new URL(siteInfoBean.getSSiteURL()); {gkY:$xnrG
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9sId2py]W
httpConnection.setRequestProperty("User-Agent","NetFox"); 8-_\Q2vG
r9vO(m~
rGt/ /6
int responseCode=httpConnection.getResponseCode(); 6!|/(~
if(responseCode>=400) 71I: P|.>
{ ; `Vbl_"L
processErrorCode(responseCode); 4UISuYg'
return -2; //-2 represent access is error d95 $w8>
} NGs@z^&V
K1oSoD8c
Qw@_.I
String sHeader; u|Tg*B
bMvHAtp
j96\({;k
for(int i=1;;i++) ,?KN;~t#vz
{ D\LXjEme.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); P:QSr8K
//Utility.log(in.readLine()); <?E~Qc t
sHeader=httpConnection.getHeaderFieldKey(i); Oe_*(q&
if(sHeader!=null) Xf/qUao
{ $%"?0S
if(sHeader.equals("Content-Length")) 2t3DQ
{ (kFg2kG
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {+N7o7
break; WW[Gne
} n%&+yg
} )Zbrg~-@
else 6xT"j)h
break; g?1! /+
} wyC1M
} _!:*&{
catch(IOException e){e.printStackTrace ();} 4.&hV?Kxz
catch(Exception e){e.printStackTrace ();} SMMvRF`7
i!7|YAu
lG/h[
Utility.log(nFileLength); d>-k-X-[
KwxO%/-}S
d#Xt2
return nFileLength; (d?sFwOt\
} +hL%8CVU M
vNIQ1x5Za
YCI-p p
//保存下载信息（文件指针位置） # M18&ld,r
private void write_nPos() h3BDHz,
{ 0NFYFd-50
try{ cP,bob]
output = new DataOutputStream(new FileOutputStream(tmpFile)); gBPYGci2F
output.writeInt(nStartPos.length); Sf"]enwB
for(int i=0;i<nStartPos.length;i++) ? f>pKe
{ I?~iEO\nh
// output.writeLong(nPos); /xh/M@G3
output.writeLong(fileSplitterFetch.nStartPos); aS)Gj?Odf
output.writeLong(fileSplitterFetch.nEndPos); NB#-W4NA
} 4lsg%b6_%,
output.close(); 3?Tk[m1b
} rL3 f%L
catch(IOException e){e.printStackTrace ();} M #)@!
catch(Exception e){e.printStackTrace ();} =H)"t:xE
} X0&[cyP!
t{g7 :A
>21f%Z
//读取保存的下载信息（文件指针位置） 96]!*}
private void read_nPos() 3{FUFx
{ L>>Cx`ASi
try{ tv\_& ({
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); i&',g
int nCount = input.readInt(); `44 }kkBT
nStartPos = new long[nCount]; -j"]1JLQ
nEndPos = new long[nCount]; r{ }&* Y
for(int i=0;i<nStartPos.length;i++) 5fuB((fd(
{ |x$2-RUP
nStartPos = input.readLong(); 6ntduXeNVh
nEndPos = input.readLong(); ]zUvs6ksLG
} g|V md
input.close(); w^N3Ma
} s;!Tz)
catch(IOException e){e.printStackTrace ();} p)y'a+|7
catch(Exception e){e.printStackTrace ();} -V'h>K
} "&{sE RYY
am(jmf::
Kq4b`cn{_
private void processErrorCode(int nErrorCode) K'u66%wAL
{ )4CF*>*6V
System.err.println("Error Code : " + nErrorCode); 5rPK7Jh`B
} s!eB8lkcT
{wy#HYhv
\`N<0COP
//停止文件下载 QsC6\Gt#
public void siteStop() _7P#?:h
{ r?:xD(}Q
bStop = true; PZE{-TM?W
for(int i=0;i<nStartPos.length;i++) S{7 R6,B5
fileSplitterFetch.splitterStop(); 5FQtlB9F
[_w;=l0 ;
S*9qpes-m|
} vd]75
} e%K oecq
//负责部分文件的抓取 n"dYN3dE
**FileSplitterFetch.java H=1Jq
*/ hJkF-yW
package NetFox; YIZ+BVa
45H(.}&f
_+NM<o#A
import java.io.*; YfZ96C[a
import java.net.*; f>kW\uC
EI!e0V1!
Nub)]S>_/t
public class FileSplitterFetch extends Thread { bUS"1Tg]*6
wN^$8m5\T^
V+- ]txu|
String sURL; //File URL ON q=bI*
long nStartPos; //File Snippet Start Position eR*y<K(d
long nEndPos; //File Snippet End Position Aat-938FP6
int nThreadID; //Thread's ID #s]'2O
boolean bDownOver = false; //Downing is over G.y~*5?#
boolean bStop = false; //Stop identical .!Qo+(
FileAccessI fileAccessI = null; //File Access interface o'auCa,N
4 /Q4sE~<
ed:[^#Lj
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException e=#'rDm
{ >cYYr@S
this.sURL = sURL; 2uy<wJE>
this.nStartPos = nStart; ocDAg<wo
this.nEndPos = nEnd; DF`?D +
nThreadID = id; | l|7[
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }[c,/NH
} zd-qQ.j0
;[R#:Rk
[Z$E^QAP
public void run() 7f,!xh$
{ 2SHS!6:Rl
while(nStartPos < nEndPos && !bStop) O;m@fS2%3
{ "GY/2;
f'28s*n
QxS=W2iN
try{ Ka|, qkb
URL url = new URL(sURL); C<u<:4^H
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); u/S{^2`b
httpConnection.setRequestProperty("User-Agent","NetFox"); &>$+O>c ,
String sProperty = "bytes="+nStartPos+"-"; 3wf&,4`EX
httpConnection.setRequestProperty("RANGE",sProperty); y L|'K}
Utility.log(sProperty); <-rw>,
#yi&-9B
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InputStream input = httpConnection.getInputStream(); 5*P+c(=
//logResponseHead(httpConnection); 3rh@|fg)E
[t}\8^y
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byte[] b = new byte[1024]; v[J"/:]
int nRead; nlsif
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~]LkQQ'
{ gtVnn]Jh
nStartPos += fileAccessI.write(b,0,nRead); p81Vt
//if(nThreadID == 1) 8{ooLdpX7
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x-%4-)
} | g[iK1
~&\}qz3
/CfgxPo
Utility.log("Thread " + nThreadID + " is over!"); U2TR>0l
bDownOver = true; VsR8|Hn$
//nPos = fileAccessI.write (b,0,nRead); k3S
} I2G:jMPy
catch(Exception e){e.printStackTrace ();} k/]4L!/ T
} ] lONi
} h qT6]*
|jT^[q(z
9f U,_`r
//打印回应的头信息 l Taw6;
public void logResponseHead(HttpURLConnection con) h =E)5&Z
{ rD":Gac
for(int i=1;;i++) }{#ty uzAo
{ Lw_s'QNWR
String header=con.getHeaderFieldKey(i); !gbPxfH:6
if(header!=null) YOE!+MiO
//responseHeaders.put(header,httpConnection.getHeaderField(header)); GX-V|hLaGX
Utility.log(header+" : "+con.getHeaderField(header)); oTLA&dy@
else .m/$ku{/J
break; RW I7eC
} #ssSs]zl
} jS<(Oo
SNl% ?j| f
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public void splitterStop() noL&>G
{ .XTR HL*:
bStop = true; ]~!?(d!J/
} Al-;-t#Dc
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} :Y)jf
n4%ZR~9WH
$vjl-1x&
/* MIF`|3$,
**FileAccess.java S;L=W9=wby
*//文件访问(定位，写) bpp{Z1/4
package NetFox; K}e:zR;;^
import java.io.*; ckhU@C|=*
E8LA+dKN:
{@YY8SKb9
public class FileAccessI implements Serializable{ }fT5(+ Wo
:plN<8
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ZlG|U]mM5
RandomAccessFile oSavedFile; 2uZ4$_
long nPos; 6>=yX6U1q^
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ta+MH,
public FileAccessI() throws IOException :XFr"aSt
{ !9p;%Ny`
this("",0); AS? ESDC
} 'JK"3m}nT
kfj)`x
X"Ca
public FileAccessI(String sName,long nPos) throws IOException dgp1B\
{ ($or@lfs
oSavedFile = new RandomAccessFile(sName,"rw"); Vl\8*!OL%
this.nPos = nPos; M%(^GdI#Vf
oSavedFile.seek(nPos); Z`]r)z%f
} ms%RNxU4:
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4}xw&x
public synchronized int write(byte[] b,int nStart,int nLen) <reALC
{ 0Fc^c[
int n = -1; 0ub0[A
try{ 0aM&+j\q}
oSavedFile.write(b,nStart,nLen); ^Iy'G44
n = nLen; 6 @A'N(I=O
} dn1Fwy.
catch(IOException e) ?%A9}"q]
{ ;Y9-0W
e.printStackTrace (); ?[VL 2dP0
} #UesXv
[L ?^+p>
{16]8-pe
return n; R(AS$<p{!>
} &,8F!)[9
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Y!qn[,q8
} r7^oqEp@B
H5!e/4iz
1tIJ'#6
/* 4^(aG7
**SiteInfoBean.java N}gPf i
*/ Q&]f9j_
package NetFox; -qqI@+u+
f"RS,]
4..M *U
public class SiteInfoBean { [JVEKc ym
ORx6r=zg
qd<-{
private String sSiteURL; //Site's URL Lvd es.0|
private String sFilePath; //Saved File's Path cNl NJ
private String sFileName; //Saved File's Name cw3j&k
private int nSplitter; //Count of Splited Downloading File W7#dc89}
8vqx}2
vdIert?p
public SiteInfoBean() Bw/8-:eb
{//nSplitter的缺省值为5 %urd;h D
//default value of nSplitter is 5 x:$ xtu
this("","","",5); VjLv{f<p
} MSaOFv_Q
pv]2"|]V)
mgE r+
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ).3riR
{ J!\oH%FJp
sSiteURL= sURL; e|}B;<
sFilePath = sPath; B",;z)(%
sFileName = sName; Xti.yQx\
this.nSplitter = nSpiltter; rU9z? (
["^? vhv
$uUR@l
} b.j$Gna>Q
alH6~
}0V aZ<j
public String getSSiteURL() 4w5);x.
{ #w@V!o
return sSiteURL; Qo~|[]GE
} Ggk#>O G
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=}g-N)^
public void setSSiteURL(String value) mg]t)+PQ
{ i_(6}Y&
sSiteURL = value; 4;*jE (
} HtV8=.^
N 9W,p2
rS8}(lf
public String getSFilePath() ykYef
{ m+Kl
return sFilePath; YeS5%?Fk
} s}F.D^^G
1ixBwnp?
yV*jc`1
public void setSFilePath(String value) 0^vz /y1c
{ Lpohc4d[V
sFilePath = value; @jCMQYR
} %xrldn%
3i1TBhs6
mw&'@M_(7
public String getSFileName() {T-=&%||
{ x[=,$;o+
return sFileName; 6UI6E)g
} A0,h7<i
a<J<Oc!
]nNn"_qh
public void setSFileName(String value) 21O@yNpS$
{ 2HO2
sFileName = value; ,rV;T";r
} }9kn;rb$g
>n3ig~0d
nC(Lr,(
public int getNSplitter() 2@W`OW Njm
{ y+p"5s"
return nSplitter; dVg'v7G&V(
} Ma4eu8
R"j<C13;%
CG;+Z-"X
public void setNSplitter(int nCount) g:Q:cSg<
{ {n&GZG"f
nSplitter = nCount; Id1de>:;
} U1`pY:P
} MOPHu O{^
*cZ7?
M@JW/~p'
/* nDcH;_<;9a
**Utility.java h$mGawvZ~
*/ [dFe-2u ,$
package NetFox; \l%##7DRp]
a6@k*9D>
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public class Utility { =YIosmr
# [ +n(
#&ei
public Utility() +IMt$}7[
{ +:W/=C d(h
ht#,v5oG>f
EeHghq
} \u04m}h]
%k<+#j6ZH
//线程睡眠 39MOqVc
public static void sleep(int nSecond) bI^F(
{ -Kw7! =_ g
try{ Kn1T2WSAg
Thread.sleep(nSecond); ?9%$g?3Z
} TqSjL{l%
catch(Exception e) X#Ob^E%J
{ v,Zoy|Lu
e.printStackTrace (); [kTckZv
} nch#DE82
} f:t j
6q8PLyIp
//日志 r9*6=*J|
public static void log(String sMsg) 65nK1W`i
{ EEMRy
System.err.println(sMsg); E62_k 0q
} Ls+vWfF=#
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9R">l5u
public static void log(int sMsg) 4 L 5$=V
{ JP(0/?Q
System.err.println(sMsg); RP^vx`9h
} QyY<Zi;6
} f$5\ b[O
_8ks`O#}
nN^lY=3
/* <2fy(9y
**TestMethod.java =**Q\Sl
*/ %%#bTyF
package NetFox; ;.<HpDfG_
ZmycK:f
Jz*A!Li
public class TestMethod { cj^hwtx
xj9xUun
*K& $9fah
public TestMethod() acgx')!c
{ ///xx/weblogic60b2_win.exe dWu;F^
try{ Lxv6\3I+
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {;m|\652B
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); of GoaH*h
SiteFileFetch fileFetch = new SiteFileFetch(bean); 52NI{"
fileFetch.start(); J qmL|S)
} m=Gb<)Y
catch(Exception e){e.printStackTrace ();} ;Wa&Dg/5`
p$ETAvD
yY*(!^S
} A`Rs n\
F\v~2/J5v
=diGuIB
public static void main(String[] args) rg=Ym.
{ K`j:F>b
new TestMethod(); $~j9{*]5
} NTO.;S|2%
} ]>ndFE6kl
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