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)); )(ma
} 3BSeZ:j7
for(int i=0;i<nEndPos.length-1;i++) s-C.+9
{ p}Gk|Kjlq,
nEndPos = nStartPos[i+1]; "3^6
} '[juPI(!
nEndPos[nEndPos.length-1] = nFileLength; eq@ v2o7
} a"EQldm|d
} Eui;2P~
71A{"
d&ZwVF!
//启动子线程 4\$Ze0tv
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; {(tE pr
for(int i=0;i<nStartPos.length;i++) $PTedJ}*Y
{ 7H[+iS0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )0GnTB;5Z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), O]PfQ
nStartPos,nEndPos,i); tlcA\+%)
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }6S4yepl
fileSplitterFetch.start(); >`NM?KP s
} w"BTu-I
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 96PVn
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1L9^N
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 4p-$5Fk8}
nEndPos = " + nFileLength); -p;oe}|
// fileSplitterFetch[nPos.length-1].start(); X,q=JS
pGcc6q1
{jc~s~<#
//等待子线程结束 We4 FR4`
//int count = 0; vc!S{4bN
//是否结束while循环 YT3QwN9
boolean breakWhile = false; _Ng*K]0/E
rxz3Mqg
ad~ qr n\
while(!bStop) GqAedz;.
{ z`Q5J9_<cV
write_nPos(); (dT!u8Oe
Utility.sleep(500); lZua"Ju
breakWhile = true; pIrAGA;
*K98z ?
CX:^]wY
for(int i=0;i<nStartPos.length;i++) &t8_J3?Z
{ $yc,D=*Isi
if(!fileSplitterFetch.bDownOver) s<dD>SU
{ iwVra"y
breakWhile = false; 7]^ }
break; FU[,,a0<<
} GS$k
} e7?W VV,
if(breakWhile) U-? ^B*<
break; g:6yvEu$ -
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,C&>mv xA
//count++; 2%<jYm#'z-
//if(count>4) $ i&$ZdX
// siteStop(); %zD-gw>
} R] [M_ r
q7]WR(e
/j)VES
System.err.println("文件下载结束！"); $`Xx5Ts7
} ?.A|Fy^
catch(Exception e){e.printStackTrace ();} E5t+;vL~
} =5/;h+bk+3
PVU"oz&T
_Ry.Wth
//获得文件长度 Z+dR(9otH3
public long getFileSize() Fp6Y Y
{ h]MVFn{
int nFileLength = -1; G}-.xj]
try{ L@_">'pR
URL url = new URL(siteInfoBean.getSSiteURL()); ,1[??Y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9aU:[]w
httpConnection.setRequestProperty("User-Agent","NetFox"); by U\I5
],YYFU}
N Sh.g#
int responseCode=httpConnection.getResponseCode(); r^E]GDz
if(responseCode>=400) q-G|@6O
{ y9L#@
processErrorCode(responseCode); ;F""}wzn
return -2; //-2 represent access is error yUW&Wgc=:
} 1(i>Vt.+
6XAr8mw9
9xQ8`7
String sHeader; ij i.3-
B-~&6D,
)h0E$*
for(int i=1;;i++) Di'u%r
{ e^NEj1
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); o$ce1LO?|N
//Utility.log(in.readLine()); /plUzy2Yu
sHeader=httpConnection.getHeaderFieldKey(i); &7w>K6p
if(sHeader!=null) n+qVT4o
{ b!X"2'
if(sHeader.equals("Content-Length")) b_jZL'en
{ FMdLkyK;
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); (Q5@MfK`
break; UB$`;'|i
} (bx\4Ws
} ^dnz=FB
else "q^#39i?
break; [-t> G!)
} .W :
} 0O#B'Uu
catch(IOException e){e.printStackTrace ();} N 2"3~ #
catch(Exception e){e.printStackTrace ();} 2d2@J{
nheU~jb
P$3=i`X!nw
Utility.log(nFileLength); hY}/Y
AM[jL'r|
M7DLs;sD
return nFileLength; 6%.
} 4`6c28K0?
c',:@2R
|[Ie.&)
//保存下载信息（文件指针位置） lU$4NUwM
private void write_nPos() 3kiE3*H
{ Q)Iv_N/
try{ ;T.s!B$Uu
output = new DataOutputStream(new FileOutputStream(tmpFile)); aZj J]~bO
output.writeInt(nStartPos.length); )Ig+uDGk
for(int i=0;i<nStartPos.length;i++) b0YiQjS6>
{ E69:bQ94u
// output.writeLong(nPos); i Y*o;z,~
output.writeLong(fileSplitterFetch.nStartPos); u m:0y,
output.writeLong(fileSplitterFetch.nEndPos); GsIwY {d
} KQ4kZN
output.close(); *BLe3dok(
} ({%oih
catch(IOException e){e.printStackTrace ();} %j'G.*TD
catch(Exception e){e.printStackTrace ();} rGnI(m.
} !%c{+]g
RpO@pd m
b4Z`y8=
//读取保存的下载信息（文件指针位置） &yxNvyA[u
private void read_nPos() v2hZq-q
{ yo\N[h7
try{ *Y85DEA
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); iHAU|`'N)
int nCount = input.readInt(); gjj 93
nStartPos = new long[nCount]; #NvQmz?J?
nEndPos = new long[nCount]; hv+|s(
for(int i=0;i<nStartPos.length;i++) Go>wo/Sb
{ &5\^f?'b7
nStartPos = input.readLong(); 6'xomRpYN
nEndPos = input.readLong(); sl/=g
} XE_ir Et
input.close(); X E|B)Q(
} *cbeyB{E
catch(IOException e){e.printStackTrace ();} `|$'g^eCL
catch(Exception e){e.printStackTrace ();} Y3-gUX*w0
} ]N*L7AVl
fUC9-?(K
AXwaVLEBQ
private void processErrorCode(int nErrorCode) lT8#bA
{ & _; y.!
System.err.println("Error Code : " + nErrorCode); *7ZGq(O
} L7'%;?Z
sI_7U^"[
_7U]&Nh99
//停止文件下载 dsJm>U)
public void siteStop() TZ[Zm
{ *G9sy_
bStop = true; bEm7QgV{X
for(int i=0;i<nStartPos.length;i++) s~*}0-lS
fileSplitterFetch.splitterStop(); 0ZMJ(C
/F.Wigv
RK[D_SmS
} !b8uLjd;
} rQ/,XH
//负责部分文件的抓取 $B;_Jo\|
**FileSplitterFetch.java hoa7
*/ OS-sk!
package NetFox; #B8*gFZB
1B|8ZmFJj
Z$p0&~
import java.io.*; ,apNwkY
import java.net.*; 8)N@qUV
.N,&Uv-
"-31'R-
public class FileSplitterFetch extends Thread { T.REq4<
M|q~6oM
#]CFA9z
String sURL; //File URL +Y}V3(w9X
long nStartPos; //File Snippet Start Position ;}qhc l+
long nEndPos; //File Snippet End Position `lO(s%HC
int nThreadID; //Thread's ID =<c#owe:m
boolean bDownOver = false; //Downing is over Xa," 'r
boolean bStop = false; //Stop identical ~. YWV
FileAccessI fileAccessI = null; //File Access interface Z:*@5
#sTEQjJ,J
8"%RCE
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException CS 8jA\
{ <[Q3rJ
this.sURL = sURL; *)<B0SjT
this.nStartPos = nStart; Kv37s0|g
this.nEndPos = nEnd; g:7,~}_}^
nThreadID = id; j~E",7Q'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 K<4Kk3
} }lP;U$
ljC(L/I
eSEq{?>
public void run() FdzNE
{ n(1')?"mA
while(nStartPos < nEndPos && !bStop) 08s_v=cF
{ QzOkpewf
mj&57D\fq
0p(L'
try{ ,HB2hHD
URL url = new URL(sURL); |l0Ea
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b>\?yL/%+?
httpConnection.setRequestProperty("User-Agent","NetFox"); >(r{7Qg
String sProperty = "bytes="+nStartPos+"-"; sa1h%<
httpConnection.setRequestProperty("RANGE",sProperty); {D`'0Z1"
Utility.log(sProperty); )w h%|
|&3x#1A
P`$!@T0=
InputStream input = httpConnection.getInputStream(); JhHWu<
//logResponseHead(httpConnection); 7 <9yH:1
lDc-W =X=
6"/WZmOp
byte[] b = new byte[1024]; $P z`$~
int nRead; ,CvG 20>
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <eN_1NTH_
{ 'sh~,+g
nStartPos += fileAccessI.write(b,0,nRead); o:S0*
//if(nThreadID == 1) C NsNZJ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m8R9{LC
} JL=U,Mr6
H 3@Z.D
lg:
Utility.log("Thread " + nThreadID + " is over!"); t?c}L7ht
bDownOver = true; Rk6deI]
//nPos = fileAccessI.write (b,0,nRead); ({s6eqMhDd
} S4UM|`
catch(Exception e){e.printStackTrace ();} t5B7I59
} g{IF_ 1
} NVKC'==0
6%,C_7j
d}'U?6ob
//打印回应的头信息 h `}}
public void logResponseHead(HttpURLConnection con) *&BnF\?m
{ V7d)S&*V
for(int i=1;;i++) *NFg;<:j
{ )s_n
String header=con.getHeaderFieldKey(i); 7hP<f}xL
if(header!=null) ({r*=wAP
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #LlUxHv #
Utility.log(header+" : "+con.getHeaderField(header)); 3_Cp%~Gi-_
else !Ucjax~
break; b[9&l|y^
} /X"/ha!=&D
} te|?)j
d^03"t0O]
N`@NiJ(O;
public void splitterStop() :W#rhuzC
{ +4;uF]T
bStop = true; 5|3e&
} M_v?9L
j9Ybx#
^G&3sF}
} ^d}gpin
}KUd7[s
GSclK|#tE
/* q6Rr.A
**FileAccess.java ,.iRnR
*//文件访问(定位，写) W1fW}0
package NetFox; ~5Pb&+<$
import java.io.*; 6E(Qx~iL
Y8M]Lwj
=4V&*go*\
public class FileAccessI implements Serializable{ *B`Zq)
:B3[:MpL}
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 j',W 64
RandomAccessFile oSavedFile; k@zy
long nPos; *eI)Z=8
[Wd-Zn%
]Chj T}
public FileAccessI() throws IOException `&\Q +W
{ theZ]5_C
this("",0); ojYbR<jn9
} 'z76Sa
sn7AR88M;
f}g\D#`]/
public FileAccessI(String sName,long nPos) throws IOException R_M?dEtE>
{ ^`un'5Vk
oSavedFile = new RandomAccessFile(sName,"rw"); S$KFf=0
this.nPos = nPos; >U F
oSavedFile.seek(nPos); f#+el y
} EY*(Bw
V5+SWXZ
HhO".GA
public synchronized int write(byte[] b,int nStart,int nLen) A-:O`RK
{ 5F`;yh+e
int n = -1; KiGp[eb
try{ c/c$D;T
oSavedFile.write(b,nStart,nLen); }Zl&]e
n = nLen; 21k5I #U
} NM ]bgpP
catch(IOException e) d%l{V6
{ ^u3V E
e.printStackTrace (); OL4z%mDZi
} oIUy-|
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&-(463
return n; Gt9&)/#
} IV\J3N^
*~w[eH!!
]HpA5q1ck
} ~?B;!Csk
'SQG>F Uy
hiNEJ_f
/* y:v,j42%
**SiteInfoBean.java 9UvXC)R1
*/ aF03a-qw<
package NetFox; cuOvN"nuNj
MZmb`%BZ
2^?:&1:
public class SiteInfoBean { v4@Z(M
}fp-5
cwGbSW$t
private String sSiteURL; //Site's URL t&?im<
private String sFilePath; //Saved File's Path ^>"z@$|\:
private String sFileName; //Saved File's Name qzb<J=FAU
private int nSplitter; //Count of Splited Downloading File R8.CC1Ix
K~ ;45Z2
1S@vGq}
public SiteInfoBean() JxyB(
{//nSplitter的缺省值为5 %YOndIS:
//default value of nSplitter is 5 T|tOTk
this("","","",5); r|,i'T
} )7_"wD` z
GR\5WypoJ
DY[$"8Kxcp
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) YM5fyv?
{ y"Nsh>h
sSiteURL= sURL; a#c6[!
sFilePath = sPath; ^ns@O+Fk
sFileName = sName; mrX^2SR
this.nSplitter = nSpiltter; EbqcV\Kb
ayAo^q
j <o3JV
} p!s}=wI`
! !PYP'e
znJ'iVf
public String getSSiteURL() {d?$m*YR3`
{ Qt|c1@J
return sSiteURL; EUIIr4]
} .!JVr"8
4 B*0M
&w=3^
public void setSSiteURL(String value) xLx]_R()
{ ([xo9FP;
sSiteURL = value; p ;|jI1
} < y*x]}
m*mm\wN5
|ae975
public String getSFilePath() EM\'GW
{ Q,80Hor#J
return sFilePath; IgC}&
} ^{8Gt@
ZY:[ekm%4Z
.Lfo)?zG
public void setSFilePath(String value) Mg^e3D1_
{ o=nsy]'&
sFilePath = value; umdG(osR
} T~b>B`_
29reG,>
Q[#vTB$f
public String getSFileName() 7w3CXY
{ s@fTj$h
return sFileName; Ko^c|}mh*!
} Vx @|O%
<x!GE>sf+
UUMtyf
public void setSFileName(String value) >CkjUZu]&
{ J!DF^fLe
sFileName = value; IJ/sX_k
} e${)w-R/e
}W ^: cp
~b:Rd{
public int getNSplitter() )Z %T27r,^
{ JAI)Eqqv]
return nSplitter; aH#l9kCb
} bMU(?hb
Rar"B*b;$
7==f\%,
public void setNSplitter(int nCount) N~F RM& x
{ Zk[&IBE_
nSplitter = nCount; ;>mCalwj
} 2}W0 F2*
} 8#Q$zLK42N
r#6_]ep}<'
2ZQ}7`Y
/* C{d7J'Avk
**Utility.java u!:z.RH8n
*/ Reu*Pe
package NetFox; owPm/F
z.}[m,oTF
vp.ZK[/`
public class Utility { +Y+Y6Ac[}
){Ob,LEU&
"kc/J*u-3
public Utility() M|] "W
{ Ka`=WeJ|
Yf[Qtmh]I
M5x U9]B
} [{X^c.8G)
5pn)yk~
//线程睡眠 @'=Uq
public static void sleep(int nSecond) }Nb8}(6
{ 72,rFYvpK
try{ EKp@9\XBC
Thread.sleep(nSecond); \.g\Zib )
} 4WB-Ec
catch(Exception e) AdWq Q
{ $k$4% 7
e.printStackTrace (); 6eokCc"o
} 5K?}}Frrt`
} 5#QXR+ T
4npqJ1
//日志 V"!G2&
public static void log(String sMsg) Y{*u&^0{
{ r `eU~7
System.err.println(sMsg); l (3bW1{n
} Xj*vh m%i
U!m@DJj
n k2om$nN
public static void log(int sMsg) q5L51KP2
{ vaon{2/I
System.err.println(sMsg); W}|'#nR
} <?D\+khlq
} @ps1Dr4s
1 tR_8lC
C^)*Dsp
/* (os$B
**TestMethod.java zuJtpMn
*/ YA&g$!
package NetFox; > 0<)=
CZbYAxNl
:EHJ\+kejX
public class TestMethod { ;Q+xKh%
y?SyInt
nQGQWg`
public TestMethod() FV,4pi
{ ///xx/weblogic60b2_win.exe ,y%3mR_~
try{ 4l&g6YneX
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /W<>G7%.
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); d`1I".y
SiteFileFetch fileFetch = new SiteFileFetch(bean); =LTmr1?
fileFetch.start(); *kIc9}
} =f(cH152T
catch(Exception e){e.printStackTrace ();} ,<:!NF9
3R&lqxhg
_`#3f1F@[
} 1xc~`~
yObuWDA9
al`3Lu0
public static void main(String[] args) kapC%/6"
{ 2c/Ys4/H4]
new TestMethod(); 4ikdM/
} "YB**Y
} ?3O9eZY@
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