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)); <kak9 6A
} ;2p+i/sVj
for(int i=0;i<nEndPos.length-1;i++) Yc:%2KZ"
{ =dmr,WE
nEndPos = nStartPos[i+1]; EY,jy]|#
} c0oHE8@
nEndPos[nEndPos.length-1] = nFileLength; ^"WVE["
} eU[g@Pq:Y
} 2cR[~\_9.
GJ+^t
]~({;;3o-
//启动子线程 .ZpOYhk
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; :DD<0
for(int i=0;i<nStartPos.length;i++) Cn{Hk)6
{ \|]mClj#
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2 !s&|lI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), `o[l%I\Q
nStartPos,nEndPos,i); ,_2-Op
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g.lTNQm$u
fileSplitterFetch.start(); B5b:znW2@
} %#HU~X:
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y&/IJst&aq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); L:z0cvn"
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", L, JQ\!c
nEndPos = " + nFileLength); Ql*zl
// fileSplitterFetch[nPos.length-1].start(); LG #^g6P
v pI9TG
j[>cv;h ;
//等待子线程结束 #Y'eS'lv4
//int count = 0; O$Rz/&
//是否结束while循环 -@orIwA&
boolean breakWhile = false; T$4{fhV \
8y;Rw#Dz
1U 6B$(V^i
while(!bStop) C|'DKT4M&
{ nbi7rcT
write_nPos(); ).T&fa"
Utility.sleep(500); %opBJ
breakWhile = true; Y G+|r
]%Q!%uTh
S@qp_!
for(int i=0;i<nStartPos.length;i++) &V"oJ}M/a
{ O9=/\Kc
if(!fileSplitterFetch.bDownOver) 6Rc=!_v^
{ s|[>@~gXk
breakWhile = false; 1!#85SMx
break; K/Q"Z*
} .tBlGMcN
} -yqsJGY
if(breakWhile) Fn4v/)*H
break; |3H+b,M5
7Cgi&
s#2t\}/
//count++; Oy6fl'FIt
//if(count>4) @MW@mP)#
// siteStop(); +y7z>Fwl
} &C 9hT
=ily=j"hK
^t>mdxuq
System.err.println("文件下载结束！"); 2 $>DX\h
} la!]Y-s)'4
catch(Exception e){e.printStackTrace ();} SZykG[
} 7& M-^Ev
|Uh8b %
.@1+}0
//获得文件长度 .`or^`X3
public long getFileSize() ,75)
{ Q*ITs!~Z
int nFileLength = -1; mScv7S~/s
try{ N&9o 1_}
URL url = new URL(siteInfoBean.getSSiteURL()); _Q V=3UWP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]#!uke Q
httpConnection.setRequestProperty("User-Agent","NetFox"); @]\fO)\f
nt.LiM/L
@W,jy$U
int responseCode=httpConnection.getResponseCode(); %mI0*YRma
if(responseCode>=400) %sa?/pjK
{ UwN Vvo
processErrorCode(responseCode); 6FS%9.Ws
return -2; //-2 represent access is error xR7ZqTcw
} 7qKz_O
1wSAwpz
A5l Cc b
String sHeader; &@=Jm /5
%6K7uvTq
AFLtgoXn:
for(int i=1;;i++) TnW`#.f
{ Vk5Z[w a
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); n#_B4UqW%
//Utility.log(in.readLine()); n@p]v*
sHeader=httpConnection.getHeaderFieldKey(i); mz?<t/$U
if(sHeader!=null) `/| *u
{ =H95?\}T[
if(sHeader.equals("Content-Length")) oO}g~<fYG
{ [8V;Q
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Mz+I YP`L
break; ,@$5,rNf
} VQ=
} B|`?hw@g+
else z/?* h
break; UmKE]1Yw4r
} IsXNAYj
} so))J`ca)
catch(IOException e){e.printStackTrace ();} D%>Bj>xQD
catch(Exception e){e.printStackTrace ();} `kKssU<
1(' wg!
MGdzrcF
Utility.log(nFileLength); sG g458
f\&X$g
q~`hn(S
return nFileLength; %0\@\fC41
} F`=p/IAJK
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,GOIg|51
//保存下载信息（文件指针位置） .G/Rh92
private void write_nPos() EKc<|e,F
{ <H64L*,5'7
try{ QE 4
output = new DataOutputStream(new FileOutputStream(tmpFile)); XQ1]F{?/H
output.writeInt(nStartPos.length); FgdnX2s J
for(int i=0;i<nStartPos.length;i++) /R&`]9].s
{ n6Oz[7M
// output.writeLong(nPos); u%-]-:c
output.writeLong(fileSplitterFetch.nStartPos); =By@%ioIGG
output.writeLong(fileSplitterFetch.nEndPos); |# 0'_
} HDm]njF%qQ
output.close(); Mo/R+\u+Y
} 9.)z]Gav
catch(IOException e){e.printStackTrace ();} 2EgvS!"
catch(Exception e){e.printStackTrace ();} -TD\?Q
} }L0 [Jo:
(bm^R-SbB
MqJTRBs%
//读取保存的下载信息（文件指针位置） EBhdP
private void read_nPos() # epP~J_f
{ l|q-kRRjn
try{ xMbgBx4+
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .!1[I{KU
int nCount = input.readInt(); 3f=ZNJ>
nStartPos = new long[nCount]; sY<UJlDKT
nEndPos = new long[nCount]; r8"2C#
for(int i=0;i<nStartPos.length;i++) =gF035
{ 6R :hsC$
nStartPos = input.readLong(); w!lk&7Q7Z
nEndPos = input.readLong(); zJXK:/
} 2poo@]M/
input.close(); }u#3hYa
} Jp jHbG
catch(IOException e){e.printStackTrace ();} L|1,/h 8p
catch(Exception e){e.printStackTrace ();} ,#;hI{E
} MkW=sD_
V7,dx@J-
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private void processErrorCode(int nErrorCode) 2: QT`e&
{ MKbcJZe
System.err.println("Error Code : " + nErrorCode); \.2i?<BC
} &JX<)JEB=<
X~IilGL8:
zk<V0NJIL*
//停止文件下载 -!!]1\S*Y
public void siteStop() [4?r0vO
{ ~d7t\S
bStop = true; 2l?^\9&
for(int i=0;i<nStartPos.length;i++) DE.].FD'
fileSplitterFetch.splitterStop(); R;HE{q[ f
v4e4,Nt
Z9:
} -k + jMH
} ;gBR~W
//负责部分文件的抓取 &G2&OFAr]q
**FileSplitterFetch.java 4eWv).
*/ gWgp:;Me
package NetFox; a&{Y~Og?%
ZH~bY2^;
BP..p ^EPN
import java.io.*; 75a3hPCZ
import java.net.*; x[mz`0
h: yJ
aV5M}:D
public class FileSplitterFetch extends Thread { s[GHDQ;!
?Uq"zq
bci]"uzB
String sURL; //File URL B*_K}5UO
long nStartPos; //File Snippet Start Position np2&W'C/i
long nEndPos; //File Snippet End Position N3$1f$`
int nThreadID; //Thread's ID Gd A!8
boolean bDownOver = false; //Downing is over WVD48}HF-
boolean bStop = false; //Stop identical XQ~Xls%]
FileAccessI fileAccessI = null; //File Access interface W=HvMD
\k5"&]I3
{9(0s| pr
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -ED} 6E
{ ypEMx'p
this.sURL = sURL; k.C&6*l!5;
this.nStartPos = nStart; }E ]l4N2
this.nEndPos = nEnd; #b/L~Bw[
nThreadID = id; U[MeK)*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 xO_>%F^?
} HW]?%9a
rf H1Zl
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public void run() Mf14> `<`
{ wU|@fm"
while(nStartPos < nEndPos && !bStop) #czTX%+9(e
{ A|LO!P,w
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try{ tAq0Z)
URL url = new URL(sURL); gy@=)R/~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0g30nr)
httpConnection.setRequestProperty("User-Agent","NetFox"); f I=G>[
String sProperty = "bytes="+nStartPos+"-"; dwk%!%
httpConnection.setRequestProperty("RANGE",sProperty); tC|?Kl7
Utility.log(sProperty); i.'"`pn_
U',C-56z
msxt'-$M
InputStream input = httpConnection.getInputStream(); d4ecF%R
//logResponseHead(httpConnection); w:lj4Z_
A:Wr5`FJ
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byte[] b = new byte[1024]; <Q(E {c3"
int nRead; Q>D//_TF
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >SQzE
{ "a].v 8l!
nStartPos += fileAccessI.write(b,0,nRead); N ;=zo-8
//if(nThreadID == 1) Y_Fn)(
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6 eryf?
} PwW$=M{\.
Xk.OyQ@
K ,NmDc^
Utility.log("Thread " + nThreadID + " is over!"); =s!0EwDH3
bDownOver = true; Mv%Qze,\V^
//nPos = fileAccessI.write (b,0,nRead); zc8^#D2y&
} vYm-$KQ"o
catch(Exception e){e.printStackTrace ();} fD@d.8nXd
} Xr=BxBttp
} N `:MF 9
Yw#fQFm
9vP;i= fr
//打印回应的头信息 7)QZ<fme
public void logResponseHead(HttpURLConnection con) Xuu&`U~%
{ 8OZasf
for(int i=1;;i++) =q0V%h{
{ ( 0/M?YQF
String header=con.getHeaderFieldKey(i); i=\)[;U
if(header!=null) QTBc_Z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); VOD-< "|
Utility.log(header+" : "+con.getHeaderField(header)); Awa| (]
else nBp6uNK[
break; rwJU;wy
} l,lqhq\
} \{`^Q+<
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w^Y/J4 I0
public void splitterStop() <L8|Wz
{ EtzSaB*|
bStop = true; Xgd-^
} -_nQn
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msgR"T3'
} o3hgkoF
;Tr,BfV|Bf
5e.aTW;U
/* l#enbQ`-~
**FileAccess.java peu9Bgs
*//文件访问(定位，写) />mK.FT
package NetFox; "'bl)^+?,
import java.io.*; YA,~qT|
lND2Kb
m[xl)/e
public class FileAccessI implements Serializable{ jbipNgxkr
vN^.MR+<
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 V3ht:>c9qs
RandomAccessFile oSavedFile; 1v|-+p42
long nPos; VA[EY`8
Hc'Pp{| X
yn}Dj9(q
public FileAccessI() throws IOException mq[=,,#
{ &PE%tm
this("",0); P9yMf~
} j yD3Sa3
I+H~ 5zq.
_cQ '3@
public FileAccessI(String sName,long nPos) throws IOException pZ'q_Oux
{ 0]bt}rh
oSavedFile = new RandomAccessFile(sName,"rw"); exJc[G&t(
this.nPos = nPos; ^'E^*R
oSavedFile.seek(nPos); 't`h?VvL
} }qM^J;uy
'(@q"`n
s0dP3tz>
public synchronized int write(byte[] b,int nStart,int nLen) E#+2)Q
{ nSyLt6zn\
int n = -1; Mc.{I"c@
try{ r{v3XD/
oSavedFile.write(b,nStart,nLen); N_NN0
n = nLen; %3qjgyLZ|
} r%f Q$q>
catch(IOException e) Lbrl CB+
{ /al56n
e.printStackTrace (); x9>$197
} cxs@ph&Wk
0RA#Y(IR
;/$pxD
return n; Y"bm4&'
} g7]S
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y\^zxG*]'
} 8%CznAO"?W
Ag9GYm
n{!{,s
/* k_]'?f7Z
**SiteInfoBean.java ):PN0.H8
*/ 6"G(Iq'2t3
package NetFox; &*OwoTgk+
HjA~3l7
M,JwoKyg
public class SiteInfoBean { K*j OrQf`
A^,ul>!
HDKF>S_S
private String sSiteURL; //Site's URL RL4|!HzR
private String sFilePath; //Saved File's Path J.XkdGQ
private String sFileName; //Saved File's Name 2?%*UxcO
private int nSplitter; //Count of Splited Downloading File HE+'fQ!R
t#P7'9Se8
{2q"9Ox"
public SiteInfoBean() &'12,'8
{//nSplitter的缺省值为5 Zuzwc[Z1
//default value of nSplitter is 5 L;:PeYPL
this("","","",5); +!u9_?Tp
} 1sg:8AA
uB"B{:Kz
IrYj#,xJ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) q0%QMut%
{ bJMsB|r
sSiteURL= sURL; t }4
sFilePath = sPath; b)IQa,enH
sFileName = sName; $MDmY4\
this.nSplitter = nSpiltter; GCYXDovh
|e#W;q$v
eMdP4<u
} Os[z>H?
<UO[*_,\
^E/6vG
public String getSSiteURL() OH>Gc-V
{ vUbgSI
return sSiteURL; SN"Y@y)=
} Mo3%OR
[gUD +
rOLZiET
public void setSSiteURL(String value) vW.f`J,\D'
{ JG^GEJ
sSiteURL = value; 3.dSS
} F6~ ;f;
h(kPf]0
wclj9&k
public String getSFilePath() k+[oYd
{ r ts2Jk7f
return sFilePath; <=|^\r !}&
} 1:<n(?5JI
p}==aNZK
"a;$uW@.6
public void setSFilePath(String value) 7@ONCG
{ j9c:SP5
sFilePath = value; q<.k:v&
} \h[*oeh
RU/WI<O
=g6~2p=H
public String getSFileName() yD\Kn{
{ &^&0,g?To
return sFileName; ?i0u)<H
} eptw)S-j
XC<'m{^(m
\'g7oV;>cI
public void setSFileName(String value) wG:RvgX}
{ <z60EvHg
sFileName = value; 7>zUT0SS
} [H!do$[>
@P0rNO%y
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public int getNSplitter() N4qBCBr(
{ jXmY8||w
return nSplitter; r-S%gG}~E
} v" #8^q
4#W$5_Ny
L}Sb0 o.
public void setNSplitter(int nCount) )/!HI0TU
{ hyPS 6Y'1
nSplitter = nCount; ^3vI NF
} a"4X7 D+
} 21<Sfsc$
C+!=C{@7di
Y[b08{/
/* xv>8rW(Np5
**Utility.java 9`qw,X&AK_
*/ #(}{*dR
package NetFox; FDF DB
x/]G"?Uix
6E^m*la%
public class Utility { (oCpQDab@
8rJf2zL
ORX<ZOt1
public Utility() o4a@{nt^,
{ !+Cc^{
TG?>;It&
R'F\9eyA
} -{A64gfFxT
Xeja\5zB
//线程睡眠 zGd[sjL
public static void sleep(int nSecond) !RLXB$@`
{ |jH Yf42Q
try{ EN^L.q9#
Thread.sleep(nSecond); Z *tHZ7b
} +Y+fM
catch(Exception e) YJwI@E(l$
{ .j)DE}[q>
e.printStackTrace (); Ao\OU}
} 2b\h@VJt
} ,3GB9
oKkDG|IE
//日志 wE9z@\z]
public static void log(String sMsg) R'_F9\
{ 8rBa}v9
System.err.println(sMsg); &-IkM%_A9
} S_AN.8T
rx#GrV*y
phA{jJy?
public static void log(int sMsg) OS(Ua
{ w?fq%-6f*
System.err.println(sMsg); R%t6sbsNv
} R SWw4}
} YuO!Y9iEm
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g("[wqgG
/* b,ZBol|X
**TestMethod.java FFVh~em{
*/ Xa'b@*o&
package NetFox; &F0>V o
P 2x.rukT|
xOxyz6B\
public class TestMethod { +:C.G[+
MnY}U",
Y,4?>:39J
public TestMethod() K.?S,qg
{ ///xx/weblogic60b2_win.exe %gqu7}'
try{ Ql}#mC.>/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 5@bmm]
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); d_V7w4lK
SiteFileFetch fileFetch = new SiteFileFetch(bean); v~dUH0P<>e
fileFetch.start(); F CfU=4O
} W-1Ub |8C
catch(Exception e){e.printStackTrace ();} 9-=kVmT&g
|M?VmG/6
maQDD*
} rc{F17~vX
oB!-JX9
bM W}.v!
public static void main(String[] args) *$t=Lh
{ 7W/55ZTmJ
new TestMethod(); 1OK~*=/4
} ^!(tc=sr
} Q;z'"P
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