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)); v-42_}
} |K aXek
for(int i=0;i<nEndPos.length-1;i++) s-k~_C>Fw
{ #s(B,`?N
nEndPos = nStartPos[i+1]; ]rZ"5y
} rTDx|pvYx
nEndPos[nEndPos.length-1] = nFileLength; s:jr/ j!
} u;h9Ra1
} =Ky1v$<
P.&,nFIg3
g3e\'B'
//启动子线程 3ZC to[Y
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; (^eE8j/K
for(int i=0;i<nStartPos.length;i++) oopTo51,a
{ %DgU
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ib/&8)Y+J
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), VskyRxfdW3
nStartPos,nEndPos,i); e9k}n\t3
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); rM=Q.By+\
fileSplitterFetch.start(); sDA&U9;
} EUZ#o\6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), p2s*'dab7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <RH2G
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", h8OmO5/H
nEndPos = " + nFileLength); jI:5[. Y
// fileSplitterFetch[nPos.length-1].start(); uf4C+ci
s @\UZC
'}3@D$YiM%
//等待子线程结束 y^pzqv
//int count = 0; qXC>DGy
//是否结束while循环 iv@ey-,<
boolean breakWhile = false; VA{2a7]
xaiA2
+ q@kRQY;n
while(!bStop) ~Iw7Xq E2
{ GR6BpV7
write_nPos(); h^QicvZ
Utility.sleep(500); {Yp>h5nwM_
breakWhile = true; ^W}(]jL
B+W 4r9#
}s i{
for(int i=0;i<nStartPos.length;i++) 'Bul_D4B
{ x%<oeM3U
if(!fileSplitterFetch.bDownOver) `>.^/SGu>?
{ rGNYu\\
breakWhile = false; Nn`l+WA3
break; 6bv~E.
} G[;GP0\N
} _zuaImJ0o
if(breakWhile) ](^$5Am
break; U%<E9G594
?W6qwm,?L
!xqy6%p
//count++; 5uo?KSX%
//if(count>4) q?&Ap*
// siteStop(); c8@zpkMj/
} D'Fj"&LK
\3WF-!xe
nM=5L:d
System.err.println("文件下载结束！"); w)nFH)f
} @pV~Q2%
catch(Exception e){e.printStackTrace ();} vZ&{
} *6C ]CS
?j'Nx_RoX
%ZKP d8
//获得文件长度 [Yi;k,F:
public long getFileSize() &d%0[Ui`
{ fV "gL(7
int nFileLength = -1; y TbOBl
try{ [|5gw3y
URL url = new URL(siteInfoBean.getSSiteURL()); Ro2Ab^rQ|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6bE~m<B\`
httpConnection.setRequestProperty("User-Agent","NetFox"); O4+a[82
uQ(C,f[6p
dcn/|"jr
int responseCode=httpConnection.getResponseCode(); g"KH~bN
if(responseCode>=400) :l;SG=scx
{ 0%W0vTvL
processErrorCode(responseCode); @5=2+ M
return -2; //-2 represent access is error WDF;`o*3
} |/YwMBi
e`7dRnx&0
E!s?amM4
String sHeader; qr<+@Q
`[(.Q
dlf nhf
for(int i=1;;i++) ;_nV*G.y#^
{ xQ]^wT.Q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); N!Q~?/!d
//Utility.log(in.readLine()); !vY5X2?tr,
sHeader=httpConnection.getHeaderFieldKey(i); myvn@OsEw
if(sHeader!=null) m"|AD/2;(
{ (Qp53g
if(sHeader.equals("Content-Length")) (+x!wX( x
{ ExW3LM9(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .1q4Q\B<
break; |PaVb4j
} .S6u{B
} Cvgk67C=$
else +gh*n,:|
break; V|q`KOF
} F8*zG 4/&
} + 2j]
catch(IOException e){e.printStackTrace ();} Be4n\c.
catch(Exception e){e.printStackTrace ();} x3C^S~
V.?Oly
&f"kWOe$X
Utility.log(nFileLength); ';J><z{>
fEYo<@5c]
k0>]7t$L
return nFileLength; Z&MfE0F/B
} {{+woL'C
iqAME%m
VYAz0H1-_
//保存下载信息（文件指针位置） 92pl#Igt
private void write_nPos() F8En)#
{ +=JJ=F)
try{ t$k$Hd';
output = new DataOutputStream(new FileOutputStream(tmpFile)); z'rB_l
output.writeInt(nStartPos.length); =L F9im
for(int i=0;i<nStartPos.length;i++) ]4 q6N
{ p J#<e
// output.writeLong(nPos); # ZcFxB6)
output.writeLong(fileSplitterFetch.nStartPos); >SSRwYIN
output.writeLong(fileSplitterFetch.nEndPos); 9?i~4&EY
} meM61ue_2
output.close(); )m4O7'2G
} 9+"\7MHw
catch(IOException e){e.printStackTrace ();} W%&'EJ)62
catch(Exception e){e.printStackTrace ();} 5IfyD ]<
} Xb/^n.>
qR>"r"Fq
h}@)oSX }
//读取保存的下载信息（文件指针位置） nApkK1?
private void read_nPos() ^a?H"
{ \UR/tlw+/
try{ cUPC8k.1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .V'=z|
int nCount = input.readInt(); LI/;`Y=
nStartPos = new long[nCount]; #nS[]UbwZ
nEndPos = new long[nCount]; xZpGSlA
for(int i=0;i<nStartPos.length;i++) { kF"<W
{ fD:>cje
nStartPos = input.readLong(); SPEDN}/^
nEndPos = input.readLong(); gyx4='Q
} D/7hVwMw:
input.close(); ,U?W
} @w]z"UCwV@
catch(IOException e){e.printStackTrace ();} Y^(Sc4 W
catch(Exception e){e.printStackTrace ();} /0J1_g
} j$K[QSn
~GWn>
$YM6}D@
private void processErrorCode(int nErrorCode) Jf,)Y>EI
{ D3>;X=1
System.err.println("Error Code : " + nErrorCode); ]-D;t~
} J}035
0H6^2T<
/<Doe SDJ|
//停止文件下载 nv9kl Q@
public void siteStop() J"x M[c2
{ N1LZXXY{
bStop = true; 7D;g\{>M
for(int i=0;i<nStartPos.length;i++) ET&Q}UOE
fileSplitterFetch.splitterStop(); Me[T=Tt`@w
^EE3E'
zr%lBHuW
} W'6~`t
} B\1F
//负责部分文件的抓取 9VdVom|e
**FileSplitterFetch.java d paZ6g
*/ GEXT8f(7
package NetFox; x(h(a#,r
|U%S<X
lq=|=
import java.io.*; w}^z1n
import java.net.*; $+)2CXQe5
-}|GkTM
|gEA.} pY
public class FileSplitterFetch extends Thread { I7b(fc-r
_l]`Og@Y
3N6U6.Tqb
String sURL; //File URL q:sDNj)R\
long nStartPos; //File Snippet Start Position l=*^FK]L`
long nEndPos; //File Snippet End Position v<bq1QG
int nThreadID; //Thread's ID X&DuX %x0
boolean bDownOver = false; //Downing is over ^57[&{MuBF
boolean bStop = false; //Stop identical j{N;2#.u
FileAccessI fileAccessI = null; //File Access interface p.i$[6M
Y'"2s~_ Z
@OAX#iQl
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException U~Aw=h5SD
{ awuUaE
this.sURL = sURL; _H@s^g
this.nStartPos = nStart; ~J!a?]
this.nEndPos = nEnd; ,pir,Eozg
nThreadID = id; %lNWaA
fileAccessI = new FileAccessI(sName,nStartPos);//定位 mtuq
} W+PAlsOC
ZV}BDwOFI
V[,/Hw~d%
public void run() XP5q4BM
{ @8C^[fDL
while(nStartPos < nEndPos && !bStop) (u85$_C
{ _v4TyJ
^ cN-
Q_/{TE/sO5
try{ =wK3\rG
URL url = new URL(sURL); ;&e5.K+.Z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); kac@yQD
httpConnection.setRequestProperty("User-Agent","NetFox"); tp$NT.z
String sProperty = "bytes="+nStartPos+"-"; 3?Y%|ZVM
httpConnection.setRequestProperty("RANGE",sProperty); _6THyj$f
Utility.log(sProperty); C.@R#a'
1JgnuBX"
VY<v?Of i-
InputStream input = httpConnection.getInputStream(); CU6rw+Vax
//logResponseHead(httpConnection); C]*9:lK
&9PzBc
]tH/87qJ
byte[] b = new byte[1024]; gqNd@tYI
int nRead; }txHuq1Q.
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #!h:w
{ 'mpY2|]\$
nStartPos += fileAccessI.write(b,0,nRead); #^<7VS!x
//if(nThreadID == 1) kxoJL6IC
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); EiI3$y3;
} K>Fo+f
Lcplc"C
UBpYR> <\
Utility.log("Thread " + nThreadID + " is over!"); ywmx6q4MFL
bDownOver = true; eznw05U
//nPos = fileAccessI.write (b,0,nRead); V!c{%zd
} vuuID24:
catch(Exception e){e.printStackTrace ();} 1mL--m'r
} ?A(=%c|,g
} z1f~:AdL
tbAN{pX
go6Hb>
//打印回应的头信息 N_$ X4.7p
public void logResponseHead(HttpURLConnection con) Sl^HMO
{ Y1{6lhxgE
for(int i=1;;i++) 6 )0$UW
{ g Gg8O? Z
String header=con.getHeaderFieldKey(i); ^O#,%>1J
if(header!=null) x_v pds
//responseHeaders.put(header,httpConnection.getHeaderField(header)); eN>=x40
Utility.log(header+" : "+con.getHeaderField(header)); N-3w)23*:
else %whPTc0P
break; 7\JRHw
} 9g J`H'
} PAH; +
kbN2dL
4@u*#Bp`|
public void splitterStop() 7ykpDl^@
{ yS0!#AG
bStop = true; U,gg@!1GJo
} ey_3ah3x
K63OjR>H
Ovxs+mQ
} J2f}{!b+I
C?fd.2#U
t3}>5cAxy
/* o+*YX!]#L
**FileAccess.java H{x'I@+
*//文件访问(定位，写) 5V':3o;D__
package NetFox; }R=n!Y$F
import java.io.*; -,)&?S
jdiH9]&U
0Dv r:]R
public class FileAccessI implements Serializable{ uZL,+Ce|
6!sC
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 CBN,~wzP*
RandomAccessFile oSavedFile; ~2PD%+e7]
long nPos; wj!YYBH
wW EnAW~
rE$0a-d2B
public FileAccessI() throws IOException & Xm!i(i
{ }$iKz*nx|
this("",0); \f\CK@
} O_OgTa
w%~UuJ#i
v7gs $'Q
public FileAccessI(String sName,long nPos) throws IOException !k@(}CN_*
{ I!1|);li
oSavedFile = new RandomAccessFile(sName,"rw"); +-~8t^
this.nPos = nPos; KG<. s<
oSavedFile.seek(nPos); /|Z_Dy
} !xcLJ5^W
'tvX.aX2
gr1NcHu
public synchronized int write(byte[] b,int nStart,int nLen) q>|&u
{ uJ-Q]yQ
int n = -1; g?B4b7II
try{ V3D`pt\[x
oSavedFile.write(b,nStart,nLen); [GQn1ZLc
n = nLen; lldNIL6B%
} Gk:tT1
catch(IOException e) Hq$&rNnq\
{ wtM1gYl^
e.printStackTrace (); 8]h~jNku
} tVQq,_9C
"`Q&s
W_.WMbT
return n; 4j|IG/m
} IC"Z.'Ph
.n[;H;
Th_PmkvC
} }fO+b5U
s!<RWy+
QL]e<2oPJ
/* (^pIB~.z
**SiteInfoBean.java 9$k0
*/ j%+>y;).
package NetFox; {ty)2
5(5:5q.A/D
&R5zt]4d&
public class SiteInfoBean { Gr-~&pm
'uC=xG.*}
@U+#@6
private String sSiteURL; //Site's URL | |"W=E
private String sFilePath; //Saved File's Path j)ME%17
private String sFileName; //Saved File's Name 4mjlat(d
private int nSplitter; //Count of Splited Downloading File @AtJO>w
`G0k)eW
%rlMjF'tG
public SiteInfoBean() brCXimG&jo
{//nSplitter的缺省值为5 *8r^!(Kj
//default value of nSplitter is 5 &V|kv"Wwj
this("","","",5); cO$xT;kK
} %oB0@&!mS
dGgltY
e"y-A&|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) G2<$to~{
{ -Ew>3Q
sSiteURL= sURL; >AFQm
sFilePath = sPath; C$p012D1
sFileName = sName; qt(4?_J
this.nSplitter = nSpiltter; in K]+H]{
9a[1s|>w-
A9lw^.
} yAAV,?:o[
!Q WNHL
ClY`2
public String getSSiteURL() _TLspqi
{ _aYhW{wW
return sSiteURL; 6cd!;Ca
} -oUGmV_
{yv_Ni*6!
F?$Vx)HI
public void setSSiteURL(String value) j,Mbl"P
{ Qo:vAv
sSiteURL = value; ]0&X[?
} gg.]\#3g
<THwl/a
43E)ltR=]
public String getSFilePath() aGBd~y@e
{ Ypl;jkHP
return sFilePath; ]isq}Qv~
} K\wu9z8M
8o[gzW:Q)U
De>e`./56
public void setSFilePath(String value) :-O$rm
{ u(FOSmNkN
sFilePath = value; :1Nc6G
} ZBR^$?nj
pj<aMh
qSlo)aP
public String getSFileName() K>vl o/#!
{ c]Gs{V]\
return sFileName; |{(JUXo6K
} z:Tj0<A'
)^BZ,e
1X2|jj
public void setSFileName(String value) ZB|s/
{ ZV:df 6S
sFileName = value; P>u2""c
} MM]0}65KG
50dN~(;p
JBA{i45x
public int getNSplitter() :%33m'EV}
{ "!(@MfjT
return nSplitter; n|?sNM<J3
} ~CHcbEWk)W
-fV\JJ
P`O`MwEAf
public void setNSplitter(int nCount) pGD-K41O]
{ f+ZOE?"
nSplitter = nCount; L~e0^X?
} *g %bdO
} 'v^shGI%Ht
_.R]K$U
aCH;l~+U
/* a * CXg.i
**Utility.java k%u fgHl!
*/ 6HJsIeQ
package NetFox; o3\^9-jmp
>Ik%_:CC`
O"|d~VQ
public class Utility { j~S=kYrGM
>);M\,1\I
B5+Q%)52
public Utility() bC"h7$3
{ BMQ4i&kF|
6AdUlPM
#@w/S:KbJt
} oiR9NB&<
K:qc "Q=C
//线程睡眠 G;#xcld
public static void sleep(int nSecond) 3!cenyE
{ G9xO>Xp^Al
try{ 8-H:5E 4Y
Thread.sleep(nSecond); yxT}hMa
} /qwY/^
catch(Exception e) Q(Q?L5
{ v5e*R8/
e.printStackTrace (); |;(P+Q4lB
} hT_Q_1,
} uit.r^8l
Wi5Dl=
//日志 X{i>Q_8>
public static void log(String sMsg) A.7lo
{ ?IS[2 v$
System.err.println(sMsg); =_3rc\0
} z19%!k
F4"bMN
thX4-'i
public static void log(int sMsg) bQ 0Ab"+D
{ #PPHxh*S
System.err.println(sMsg); _I3"35a
} O[L#|_BnEO
} m~W[,7NE0&
xe(7q1
l O*
/* -vc$I=b;
**TestMethod.java Hi$N"16A5z
*/ 9M1DE
package NetFox; .q:6F*,1M
8yDsl
Qi=0[
public class TestMethod { i|,}y`C#
Pk(%=P,
(Uu5$q(
public TestMethod() .!lLj1?p
{ ///xx/weblogic60b2_win.exe aR@+Qf
try{ CK|AXz+EN
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 'Ox "YE
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); n_Y7*3/b-o
SiteFileFetch fileFetch = new SiteFileFetch(bean); }.WO=IZ
fileFetch.start(); o /1+ }f
} {]0T
catch(Exception e){e.printStackTrace ();} R-,L"Vv
2 w! 0$
" ;T a8
} :9x]5;ma
}y J,&N'p
9jx>&MnWs
public static void main(String[] args) 3fZoF`<a
{ pEN`6*
new TestMethod(); d1t_o2
} >zw@!1{1
} saQo]6#
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