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)); T|p"0b A
} M{\I8oOg
for(int i=0;i<nEndPos.length-1;i++) *Uh!>Iv;
{ 25T18&R
nEndPos = nStartPos[i+1]; '7/)Ot(
} ;r8X.>P*
nEndPos[nEndPos.length-1] = nFileLength; Rv=YFo[B
} yr6V3],Tp
} <[phnU^ 8
%;/P&d/
%RVZD#zr
//启动子线程 pI[uUu7O
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >Q/Dk7#
for(int i=0;i<nStartPos.length;i++) pJ=#zsE0
{ n?Q|)2 2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !W\+#ez
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), C+]I@Go'Tk
nStartPos,nEndPos,i); 2/f}S?@
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s.#`&Sd>
fileSplitterFetch.start(); @co S+t
} B[}6-2<>?C
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >usL*b0%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 43w}qY1
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", S@Y39
nEndPos = " + nFileLength); lFkR=!?=
// fileSplitterFetch[nPos.length-1].start(); .d*8C,
@d_M@\r=j
.X&9Q9T=#
//等待子线程结束 &[9709 (=
//int count = 0; 0"R|..l/
//是否结束while循环 z{543~Og59
boolean breakWhile = false; _GPe<H
YR70BOxK
KoRV%@I
while(!bStop) 7^Uv7<pw
{ yu|>t4#GT
write_nPos(); JC"z&ka
Utility.sleep(500); [Pp'Ye~K@c
breakWhile = true; rOYx b }1
AX INThJ
@iiT<
for(int i=0;i<nStartPos.length;i++) )+^+sd
{ jdN`mosJ
if(!fileSplitterFetch.bDownOver) ^q&x7Kv%
{ <aw[XFg
breakWhile = false; u +hX
break; mq l Z?-
} km(Po}
} im8CmQ
if(breakWhile) S/ *E,))m
break; W_=f'yb:E
(:_$5&i7
dr(*T
//count++; VVZ'i.*_3?
//if(count>4) 4*L_)z&4;
// siteStop(); 7$b1<.WX
} K9[UB
1oS/`)
7pd$\$
System.err.println("文件下载结束！"); _$'ashF
} >z03{=sAN
catch(Exception e){e.printStackTrace ();} W!X@
} [ 3Gf2_
b 6p|q_e
7/H)Az@i45
//获得文件长度 r$1Qf}J3=
public long getFileSize() KXy6Eno
{ *hx
int nFileLength = -1; sx%[=g+<2(
try{ 2T35{Q!=F
URL url = new URL(siteInfoBean.getSSiteURL()); 8mMQ[#0:}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -@s#uA h
httpConnection.setRequestProperty("User-Agent","NetFox"); @- xjfC\d
/(cPfZZ
QY/w
int responseCode=httpConnection.getResponseCode(); pb}*\/s
if(responseCode>=400) }pYqWTG
{ \Z/@C lCm
processErrorCode(responseCode); WLT"ji0w2
return -2; //-2 represent access is error Wc#24:OKe3
} 6t$8M[0-U
y0#2m6u
"x-j~u?
String sHeader; UfGkTwoo=
= [E
3n _htgcv
for(int i=1;;i++) <YY14p
{ t# i#(H
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); QV!up^Zso
//Utility.log(in.readLine()); fVlB=8DNk&
sHeader=httpConnection.getHeaderFieldKey(i); }tz7b#
if(sHeader!=null) 0S"MC9beg
{ ;I}fBZ3
if(sHeader.equals("Content-Length")) l**X^+=$
{ se)TzI^]b@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )e{aN+
break; "sTRS*
} (>Em^(&
} d0D]Q
else rp$'L7lrX
break; @dKTx#gZ
} >7|VR:U?B
} eFgA 8kY)
catch(IOException e){e.printStackTrace ();} uT"rq:N
catch(Exception e){e.printStackTrace ();} jd:6:Fm
j%kncGS
dN q$}
Utility.log(nFileLength); ;l+Leex
L0,'mS
vP&(-a
return nFileLength; *@5@,=d
} 5! {D!
]Ze1s02(
c{|p.hd
//保存下载信息（文件指针位置） 4s-!7
private void write_nPos() Y<OFsWYY
{ lxx2H1([
try{ -n 1v3
output = new DataOutputStream(new FileOutputStream(tmpFile)); Ui~>SN>s
output.writeInt(nStartPos.length); 79gT+~z
for(int i=0;i<nStartPos.length;i++) uRvP hkqm
{ o!Zb0/AP)
// output.writeLong(nPos); pBHRa?Y5
output.writeLong(fileSplitterFetch.nStartPos); J1k>07}|
output.writeLong(fileSplitterFetch.nEndPos); ftb\0,-
} Q,g\
output.close(); 3]Ct6
} ?,z}%p
catch(IOException e){e.printStackTrace ();} oH@78D0A
catch(Exception e){e.printStackTrace ();} IGl9g_18
} KlEpzJ98
Jy)/%p~
C|bET
//读取保存的下载信息（文件指针位置） _BufO7`.
private void read_nPos() ("KF'fp&M2
{ 1MFbQs^
try{ 5P2K5,o|n~
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 81F9uM0
int nCount = input.readInt(); &oNAv-m^GD
nStartPos = new long[nCount]; \z$= K
nEndPos = new long[nCount]; E.h*g8bXe
for(int i=0;i<nStartPos.length;i++) :gv"M8AP
{ CIWO7bS
nStartPos = input.readLong(); *. t^MP
nEndPos = input.readLong(); Gv&V|7-f0
} iZmcI;?u
input.close(); PCA4k.,T
} ?,/ }`3Vw
catch(IOException e){e.printStackTrace ();} Ry&6p>-
catch(Exception e){e.printStackTrace ();} P}iE+Z3
} G@0&8
4+n\k
k6^Z~5 Sy
private void processErrorCode(int nErrorCode) (7Qo
{ y =@N|f!
System.err.println("Error Code : " + nErrorCode); , gHDx
} [g,}gyeS(
vO=fP_
)7@0[>
//停止文件下载 !-bB559Nv
public void siteStop() $G>.\t
{ HW|IILFB
bStop = true; $b\P|#A
for(int i=0;i<nStartPos.length;i++) al0L&z\
fileSplitterFetch.splitterStop(); }Z>)DN=+
~&O%N
[QTV9
} *hrd5na
} iso4]>LF
//负责部分文件的抓取 Ac6=(B
**FileSplitterFetch.java Vl]>u+YqE
*/ 'qi}|I
package NetFox; Tw% 3p=
E^PB)D(.
J,G lIv.A
import java.io.*; 6zkaOA46V
import java.net.*; $kgVa^
^8tEach
<{pz<io)
public class FileSplitterFetch extends Thread { wr4:Go`
c,22*.V/
=;k|*Ny
String sURL; //File URL -di o5a
long nStartPos; //File Snippet Start Position !wNO8;(
long nEndPos; //File Snippet End Position ]9L oZ)
int nThreadID; //Thread's ID 4 :=]<sc,
boolean bDownOver = false; //Downing is over 'yth'[
boolean bStop = false; //Stop identical *I'yH8Fcn
FileAccessI fileAccessI = null; //File Access interface 598i^z{~0%
.543N<w
zX~MC?,W1
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException yVc(`,tZ(
{ edV\-H5<
this.sURL = sURL; 4YHY7J
this.nStartPos = nStart; % nIf)/2g
this.nEndPos = nEnd; *A< 5*Db:F
nThreadID = id; b[yiq$K/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2tLJU Z1
} 5r_|yu
:EH=_"
:LTN!jj
public void run() G`zm@QL
{ zJXplvaL;
while(nStartPos < nEndPos && !bStop) C7vxw-o|&p
{ xpI wrJO
b\ PgVBf9
Y~Ifj,\
try{ ':}\4j&{E
URL url = new URL(sURL); +{>=^9%X
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fLVAKn
httpConnection.setRequestProperty("User-Agent","NetFox"); >MK98(F
String sProperty = "bytes="+nStartPos+"-"; ]{kPrey
httpConnection.setRequestProperty("RANGE",sProperty); i&k7-<
Utility.log(sProperty); L(o15
BC]?0 U
rbQR,Nf2x
InputStream input = httpConnection.getInputStream(); 4~=l}H>&
//logResponseHead(httpConnection); fQ98(+6
0Qd:`HF[
or]IZ2^n
byte[] b = new byte[1024]; _rYkis^u
int nRead; zT[!o j7
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Il.K"ll
{ vI]N^j2%
nStartPos += fileAccessI.write(b,0,nRead); 1U\z5$V
//if(nThreadID == 1) vFsLY
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ETLD$=iS
} "]iB6
.~}1+\~5
EzIGz[
Utility.log("Thread " + nThreadID + " is over!"); go"Hf_
bDownOver = true; 0;ji65
//nPos = fileAccessI.write (b,0,nRead); ;6wA"
} sC;+F*0g
catch(Exception e){e.printStackTrace ();} 5Ph4<f` L~
} ;GI&lpKK
} *4Izy14e
l+R+&b^
@o6L6Y0Naa
//打印回应的头信息 E!#WnSpnK
public void logResponseHead(HttpURLConnection con) ^H'\"9;7
{ _y3Xb`0a
for(int i=1;;i++) '=6\v!
{ 9mFE?J
String header=con.getHeaderFieldKey(i); <9%R\_@$H
if(header!=null) L:8q8i
//responseHeaders.put(header,httpConnection.getHeaderField(header)); RGU\h[
Utility.log(header+" : "+con.getHeaderField(header)); A4ygW:
else ""D 4s
break; 'eX '
} h-D}'R
} h*Pc=/p
6DWgl$[[
T n}s*<=V
public void splitterStop() 4g7)iL^#~
{ !L8#@BjU
bStop = true; !3v1bGk
} \_U$"/$4VH
U3:j'Su4H?
e*n@j
} ;Q&5,< N)j
s!e3|pGS
))i}7chc
/* -o.:P>/
**FileAccess.java Rx|;=-8zg
*//文件访问(定位，写) pO.2<
package NetFox; 6Kb1~jY
import java.io.*; +&"zU GTIc
4 N7^?
|B2+{@R
public class FileAccessI implements Serializable{ .y,0[i V N
IyPnp&_
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 f>Jr|#k
RandomAccessFile oSavedFile; SC])?h-Fw
long nPos; 7fX<511(
HOh!Xcu
d&s9t;@=
public FileAccessI() throws IOException B !=F2
{ C=4Qlt[`
this("",0); 4X(H;
} 19KQlMO.G
(/*]?Ehd
yEj^=pw
public FileAccessI(String sName,long nPos) throws IOException ~<OSYb
{ R+,u^;\
oSavedFile = new RandomAccessFile(sName,"rw"); Q&|\r
this.nPos = nPos; QW~1%`
oSavedFile.seek(nPos); QS]1daMIK<
} e01epVR;
r_;Nt
VgC2+APg
public synchronized int write(byte[] b,int nStart,int nLen) _W'-+,
{ _M5|Y@XN-
int n = -1; 3CGp`~Zf
try{ qH6>!=00
oSavedFile.write(b,nStart,nLen); l/ ;
n = nLen; x*&|0n.D
} 'D"C4;X
catch(IOException e) W#C*5@8
{ eSmLf*\G
e.printStackTrace (); f_Av3
} df#$9-
5=?\1`e1[
0f>5(ek
return n; =;&yd';k
} <)-Sj,
tWa)_y
M8b;d}XL
} r7,t";?>
*6F[t.Or
Gvqxi|
/* q,eVjtF
**SiteInfoBean.java 8j\cL'
*/ .oUTqki
package NetFox; |:<f-j7t~
!|S43i&p
I\JGs@I
public class SiteInfoBean { s^uS1
Z//+Gw<'
vf%&4\ib
private String sSiteURL; //Site's URL }\:NuTf
private String sFilePath; //Saved File's Path 0C6-GKbZ
private String sFileName; //Saved File's Name CxG#"{&
private int nSplitter; //Count of Splited Downloading File #c?j\Y9nz
4 bH^":i(
Uu(SR/R}
public SiteInfoBean() os={PQRD
{//nSplitter的缺省值为5 04l!:Tp,
//default value of nSplitter is 5 %H&@^Tt a
this("","","",5); \EtQ5T*u
} QKN+>X
5BKt1%Pg
T iiWp!mX
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) b8SHg^}
{ 4f'V8|QM{
sSiteURL= sURL; 5Qn '
sFilePath = sPath; Zk"eA'"\
sFileName = sName; CtAwBQO
this.nSplitter = nSpiltter; ~W+kiTsD?
n}G|/v<
QYjsDL><
} 9:1Q1,-i!-
K&70{r
{~sDYRX
public String getSSiteURL() t@N=kV
{ a$"Hvrj
return sSiteURL; oxkoA
} ~r`9+b[9{
V(6Z3g
e`TH91@
public void setSSiteURL(String value) #( jw!d&
{ V7P&%oz{C
sSiteURL = value; !0@Yplj
} W7\f1}]H
D.Q=]jOs
Dg?70v<a
public String getSFilePath() *q".-u!D[
{ `-l6S
return sFilePath; 4VCOKx
} OJ$]V,Z00x
?$^2Umt0
-~ Mb
public void setSFilePath(String value) Vz)`nmO}5\
{ b6F4>@gjg
sFilePath = value; Rh{zH~oZ
} 4V==7p x(
$!(pF
{{MRELipW
public String getSFileName() 7MHKeLq
{ @I/]D6 ~"
return sFileName; pxf$1
} U,q\emR
5nO% Ke=
YmgLzGk`
public void setSFileName(String value) :1^R9yWA4
{ Y2SJ7
sFileName = value; (egzH?
} #KXa&C
Mt5PaTjj
kO{s^_qR^c
public int getNSplitter() rZ^v?4Z\
{ ,o,I5>`
return nSplitter; RYl>
} uVDa^+=
oDYRQozo>
S.q].a
public void setNSplitter(int nCount) r*_ZJ*h[
{ :WL'cJ9a
nSplitter = nCount; :!b'Vk
} p>;_e(
} P2'DD 3
WT`4s
sZm$|T0
/* I=9!Rs(QF
**Utility.java (tGY%oT"
*/ -3lb@ 6I6
package NetFox; 'n$%Ls}S
}HYjA4o\A
]Ww?QhJ
public class Utility { '@CR\5 @
~\3kx]^10
ZMLg;-T.&4
public Utility() B7<Kc
{ w{90`
&0(
r~nsN*t
} z2hc.29t
S^<g_q
//线程睡眠 <u:WlaS
public static void sleep(int nSecond) ?zJOh^
{ "0k8IVwp
try{ 4bJZmUb
Thread.sleep(nSecond); VA%Un,5h
} lmSo8/%T
catch(Exception e) 4[-*~C|W5
{ >ap1"n9k
e.printStackTrace (); ?8mlZ X9C
} t 6^l`6:p
} \7 NpT}dj
:C8$Xi_i}
//日志 ?k|H3;\
public static void log(String sMsg) 'EfR|7m
{ $4T2z-
System.err.println(sMsg); eDZ8w
} Pv+5K*"7Cg
~w;]c_{.b
AkT<2H|4
public static void log(int sMsg) N#_GJSG_|
{ .ol'.t,S
System.err.println(sMsg); \Ro^*4B
} FsGlJ
} z5X~3s\dP
fn/7wO$!
?[MsQQd~
/* =@5x"MOz
**TestMethod.java Vax^8 -
*/ ?`Y\)'}
package NetFox; W Qc>
')$NfarQ.
A[YpcG'9
public class TestMethod { ACK1@eF
0G2g4DSKD
%,*G[#*&
public TestMethod() |uH%6&\
{ ///xx/weblogic60b2_win.exe vkRi5!bR
try{ xT)psM'CL
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /)rkiwp
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); B,(Heg
SiteFileFetch fileFetch = new SiteFileFetch(bean); y9|K|xO[
fileFetch.start(); 1Fi86
} !"TZ:"VZU
catch(Exception e){e.printStackTrace ();} l#wdpD a{
;*[9Q'lI*
5b6s4ZyV
} N|2y"5
4E:bp
8%~t
public static void main(String[] args) r CRgzC
{ AP\ofLmq
new TestMethod(); m!OMrZ%)}
} J:F^ #gW
} 7CB#YP?E
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