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)); DXc3u^ L
} OAd}#R\U
for(int i=0;i<nEndPos.length-1;i++) }='1<~0
{ tP]-u3
nEndPos = nStartPos[i+1]; l[Rl:k!
} =r1@?x
nEndPos[nEndPos.length-1] = nFileLength; KI~M.2pk
} pv){R;f
} Q R<q[@)F
9#ZR0t.cY
kPg| o3H
//启动子线程 C6cEt5
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6;vfl*
for(int i=0;i<nStartPos.length;i++) \oc*
{ @h";gN
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @O Rk
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Rw#4 |&
nStartPos,nEndPos,i); [ #1<W`95
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); tf_<w?~
fileSplitterFetch.start(); @ob4y
} tp3]?@0
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j65qIw_Z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); U5x&?n<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", M5>cYVG
nEndPos = " + nFileLength); BT8L'qEj
// fileSplitterFetch[nPos.length-1].start(); v"N%w1`.e
U";8zplU
ofIw7D*h
//等待子线程结束 )S2GPn7
//int count = 0; Uc<j{U ,
//是否结束while循环 (np60mX<
boolean breakWhile = false; z),@YJU"z
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while(!bStop) _BP!{~&;
{ 236,o {9e
write_nPos(); Tz{f5c&
Utility.sleep(500); z.%K5vrO>
breakWhile = true; |E#+X
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:kz"Wya.
for(int i=0;i<nStartPos.length;i++) G34fxhh
{ >^5UXQr
if(!fileSplitterFetch.bDownOver) m^M sp:T,
{ LWp#i8,
breakWhile = false; qe{:9
break; PBo;lg`
} jj$D6f/mOG
} Kk?C
if(breakWhile) ZIo%(IT!c
break; "Smek#l
mOQN$d[
PUJkC
//count++; dNg5#?mzT5
//if(count>4) _)U[c;^6
// siteStop(); n?=d)[]
} U.,_zEbx,
7)U08"
8pZGu8
System.err.println("文件下载结束！"); \p%,g&^ x
} q{:]D(
catch(Exception e){e.printStackTrace ();} uKL4cr@
} `1fNB1c
f0d*%
-m"9v%>Y
//获得文件长度 e[ 9
public long getFileSize() }Jr!aM'
{ rOyKugHe
int nFileLength = -1; <T|?`;K
try{ a\@k5?
URL url = new URL(siteInfoBean.getSSiteURL()); '1r<g\l
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A`nw(f_/
httpConnection.setRequestProperty("User-Agent","NetFox"); {I:nza
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int responseCode=httpConnection.getResponseCode(); &4R-5i2a
if(responseCode>=400) dPmtU{E<M
{ n&N>$c,T27
processErrorCode(responseCode); WnkIi,<
return -2; //-2 represent access is error X<*-d6?gD`
} 1>IA9]D7
OKO+(>AQ
8uD%
String sHeader; #P)(/>nF
A]_5O8<buW
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for(int i=1;;i++) "t!_bma
{ +{dJGPoY]p
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); La9:qpj
//Utility.log(in.readLine()); _>=QZ`!r
sHeader=httpConnection.getHeaderFieldKey(i); k0^t$J W
if(sHeader!=null) XRx^4]c
{ :)g}x&A^$
if(sHeader.equals("Content-Length")) r0L' mf$
{ tB/'3#o
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2Cgq&\wS
break; >tQ$V<YB
} fB"It~ p
} 4E0 Y=
else {wwkbc*
break; c)B <d#
} 25wvB@0&
} +txHj(Y`
catch(IOException e){e.printStackTrace ();} FL?Ndy"I
catch(Exception e){e.printStackTrace ();} x$+g/7*
t=BXuFiu
v~`'!N8
Utility.log(nFileLength); Zv^n
rOA{8)jIa*
"^&Te%x_b
return nFileLength; </-aG[Fi
} ibL
"R %3v.Z
Uxb>)36I
//保存下载信息（文件指针位置） gq~6jf>
private void write_nPos() ("txj[v-/
{ :/~TV
try{ "*JyNwf
output = new DataOutputStream(new FileOutputStream(tmpFile)); .F^372hH3
output.writeInt(nStartPos.length); 3\E G
for(int i=0;i<nStartPos.length;i++) fZ[uNe[|
{ ,]H2F']4Z
// output.writeLong(nPos); {No Y`j5S
output.writeLong(fileSplitterFetch.nStartPos); ?CSv;:
output.writeLong(fileSplitterFetch.nEndPos); hyVBQhk
} 9`Zwa_Tni
output.close(); ;:Q&Rf"@%
} NGL,j\(~7
catch(IOException e){e.printStackTrace ();} =.\PG[
catch(Exception e){e.printStackTrace ();} $ )orXe|
} 2!Sl!x+i\'
Cu`ty] -'
&[qJ=HMm I
//读取保存的下载信息（文件指针位置） }[b3$WZ
private void read_nPos() "fOxS\er
{ B*&HQW *u
try{ I'e`?H t
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); E:ti]$$
int nCount = input.readInt(); 5h@5.-}
nStartPos = new long[nCount]; aU?HIIA
nEndPos = new long[nCount]; %[WOQ.Sh
for(int i=0;i<nStartPos.length;i++) v]c+|nRs
{ Jm[_X
nStartPos = input.readLong(); <Wa7$hF
nEndPos = input.readLong(); JN>h:
} LtVIvZie
input.close(); iCNJ%AZH
} 8Bwm+LYr-
catch(IOException e){e.printStackTrace ();} mIah[~G
catch(Exception e){e.printStackTrace ();} e_3($pj
} BXa.XZ<n(
O\q-Ai
5nS}h76mZ
private void processErrorCode(int nErrorCode) Qv;q*4_
{ bmI6OIWl
System.err.println("Error Code : " + nErrorCode); \%Lj !\
} %6cbHH
>TG#
3_N1y
//停止文件下载 DyM<aT
public void siteStop() -muP.h/
{ EFzPt?l
bStop = true; ]6@6g>f?
for(int i=0;i<nStartPos.length;i++) $ 9 k5a
fileSplitterFetch.splitterStop(); d:JP935
X6so)1jJ
U$Od)
} )*nZ6Cg'
} d-'BT(@:
//负责部分文件的抓取 Tl L\&n.$
**FileSplitterFetch.java K96N{"{iI%
*/ :Ny^-4-N
package NetFox; Ib2n Bg>j
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`*y%[J,I#
import java.io.*; MN[D)RKh;
import java.net.*; vf?Xt
to(lE2`.da
_71&".A
public class FileSplitterFetch extends Thread { 0.0r?T
|>Pz#DCy
9gac7(2`)
String sURL; //File URL @YbZ"Jb
long nStartPos; //File Snippet Start Position $J=`fx
long nEndPos; //File Snippet End Position =}'7}0M_=
int nThreadID; //Thread's ID *3rp g
boolean bDownOver = false; //Downing is over 6f)7*j~
boolean bStop = false; //Stop identical OlX#1W]
FileAccessI fileAccessI = null; //File Access interface WXd#`f%
vDCbD#.6
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException C=(~[Y
{ 't+'rG6x
this.sURL = sURL; &neB$m3y
this.nStartPos = nStart; ^+x,211f
this.nEndPos = nEnd; ubQr[/
nThreadID = id; >%A~ :
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "rHPcp"m
} ?;GXFKy
R~BFZF>:
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public void run() ?MOjtAG0_~
{ aB{OXU}#
while(nStartPos < nEndPos && !bStop) m@"p#pt(_
{ zvwv7JtB
q+ka}@
jQ['f\R
try{ |8fdhqy_
URL url = new URL(sURL); _ygdv\^Tet
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [a7S?%>Bh
httpConnection.setRequestProperty("User-Agent","NetFox"); 7pM&))R
String sProperty = "bytes="+nStartPos+"-"; x\pygzQ/
httpConnection.setRequestProperty("RANGE",sProperty); WnhH]WY
Utility.log(sProperty); mh35S!I3I^
|-xKH.'n
.}Hs'co
InputStream input = httpConnection.getInputStream(); wsgT`M'J[
//logResponseHead(httpConnection); o(D6
= Q"(9[Az
L#fSP
byte[] b = new byte[1024]; vH@$?b3VP
int nRead; n1)].`
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !L)yI#i4C
{ orhzeOi\
nStartPos += fileAccessI.write(b,0,nRead); mxICQ>s b
//if(nThreadID == 1) 4"eeEs h
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v1$}JX
} ~>$z1o&}.
aZ}z/.b]
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Utility.log("Thread " + nThreadID + " is over!"); /Q'O]h0a
bDownOver = true; <Ys7`e6eY
//nPos = fileAccessI.write (b,0,nRead); XlJ+:st
} *2Q x69`
catch(Exception e){e.printStackTrace ();} ,&jjpeZP
} >HRLL\u9
} q,]57s
sNJ?Z"5k1h
`!.c_%m2
//打印回应的头信息 !%QbE[Kl>
public void logResponseHead(HttpURLConnection con) f0g&=k{OD
{ Co`:D
for(int i=1;;i++) ~HXZ-*
{ cd$,,
String header=con.getHeaderFieldKey(i); [Rzn>
if(header!=null) Dm`gzGl
//responseHeaders.put(header,httpConnection.getHeaderField(header)); a2H_8iQ!
Utility.log(header+" : "+con.getHeaderField(header)); EiWd =jDm
else tfjbG;R
break; 5S4`.'
} [bd?$qi
} nG"Ae8r
E9j(%kQ2
CxVrnb[`q
public void splitterStop() bc\?y2 3
{ bfA9aT
bStop = true; Wl3fR[@3Q
} +ID%(:
BF]+fs`
IO?6F@(
} *JVJKqed
jce2lXMm
}fz;La:b
/* \fL:Ie
**FileAccess.java m`8tHHF
*//文件访问(定位，写) {4b8s%:!4
package NetFox; 6}PoBhgSg-
import java.io.*; ,YmTx
kk3G~o+
#:/-8Z(0
public class FileAccessI implements Serializable{ F6)/Iiv
;EfREfk
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Mhg_z.Z
RandomAccessFile oSavedFile; Y ptP_R:2p
long nPos; -Tr*G4
sxQMfbN
5K?%Eo72!=
public FileAccessI() throws IOException M \3Zj(E/
{ PiwI.c
this("",0); #[Vk#BIiv8
} ZNG{:5u,
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9$P*fx&m
public FileAccessI(String sName,long nPos) throws IOException *7 >K"j
{ d!]_n|B@9
oSavedFile = new RandomAccessFile(sName,"rw"); &(HIBF'O
this.nPos = nPos; kc70HrG
oSavedFile.seek(nPos); {V~Gr
} NI?YUhg>
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=qVD"Z]z
public synchronized int write(byte[] b,int nStart,int nLen) `=cOTn52
{ &c1zEgl
int n = -1; Smlf9h&
try{ "+:IA|1wD
oSavedFile.write(b,nStart,nLen); 6,;7iA]
n = nLen; 6H}8^'/u
} l@ W?qw
catch(IOException e) 5 MD=o7O^
{ I<ta2<h
e.printStackTrace (); Ro|%pT
} ~!{y3thZ
YE\s<$
rfS kQT
return n; ON<X1eU
} s4{WPU9
Bys_8x}
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} +_LWN8F
y6S:[Z{~A
jh&WL
/* x#_0 6
**SiteInfoBean.java G(1y_t
*/ :F`yAB3
package NetFox; 0*Is#73rjY
d]6#pSE
kX^Y{73
public class SiteInfoBean { >'X[*:Cx
J< U,~ra\
&p2fMVWJ7
private String sSiteURL; //Site's URL +kK6G#c
private String sFilePath; //Saved File's Path c={bunnz#
private String sFileName; //Saved File's Name VU[4 W8f
private int nSplitter; //Count of Splited Downloading File z;VabOr^
APA:K9jD
$m-rn'Q
public SiteInfoBean() u\zP`Y
{//nSplitter的缺省值为5 $M=W`E[g
//default value of nSplitter is 5 7#BUd/
this("","","",5); psZAO,p
} $h( B2
:"oQ _bLT
w_hGWpm
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) E5J2=xVW#
{ BcvCm+.S:
sSiteURL= sURL; Cg!]x o
sFilePath = sPath; igD,|YSK`z
sFileName = sName; Dqw?3 KB
this.nSplitter = nSpiltter; 3 O)^Hq+9
{yPiBu
*uq}jlD`!
} DJmT]Q]o)
9a*}&fL[
fv",4L
public String getSSiteURL() UpU2H4
{ XJ`!d\WL/!
return sSiteURL; H?(I-vO
} rIE m
AGe\PCn-
dSkW[r9Z%l
public void setSSiteURL(String value) n^Uu6
{ mXH\z
sSiteURL = value; / ao|v
} J}9 I5O
[JY1|N
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public String getSFilePath() EC4RA'Bg1k
{ kyFq
return sFilePath; : ;nvqbd
} 1$*ZN4
%`cP|k
)r)3.|wJm
public void setSFilePath(String value) z|o7k;raH
{ [LQD]#
sFilePath = value; ?J<V-,i
} f+/AD
7ktSj}7W]
r{V=)h
public String getSFileName() JFyw,p&xB
{ ]>33sb S6
return sFileName; <@DF0x!
} ^4WNP
g/o@,_
&X^ -|7~N
public void setSFileName(String value) 6z6\-45
{ xH\#:DLY
sFileName = value; Rd?8LLz
} < )dqv0=
-A?6)ggf.
d-zNvbU"
public int getNSplitter() Z#O )0ou
{ =i4%KF9x
return nSplitter; ~]MACG:'
} S~~G0GiW
p#?1l/f"
"16==tLFE
public void setNSplitter(int nCount) R1SEv$
{ 6=& wY
nSplitter = nCount; { ~Cqb7
} q/Gy&8 K
} auO^v;s
jf})"fz-*
n3)g{K^
/* lP@9%L
**Utility.java r)b`3=
*/ eF2<L[9
package NetFox; +J^}"dG
"+rX*~
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public class Utility { ?W#! S
_h.[I8xgYG
1LE8,Gm&
public Utility() N7jAPI@a\i
{ GWhb@K
]];7ozS)X
C4n5U^
} N.VzA 6C
)ei+ewVZ
//线程睡眠 PvA%c<z
public static void sleep(int nSecond) Kj-`ru
{ ."h;H^5
try{ u]oS91
Thread.sleep(nSecond); ?$o8=h
} =|jOio=s:
catch(Exception e) HDC`g
{ jm*v0kNy
e.printStackTrace (); HL_MuyE
} VR_1cwKBM
} u{\`*dNx
k|BEAdQ%M
//日志 _o`'b80;
public static void log(String sMsg) 5[;^Em)C
{ SR\#>Qwx_
System.err.println(sMsg); #_H=pNWe
} t=U[ ;?
2 OGg`1XX
O,DA{> *m
public static void log(int sMsg) .!Z.1:YR
{ ~JBQjb]
System.err.println(sMsg); >u6kT\|^C
} 45_zO#
} {wd.aUB
sSvQatwS
#$#{QEh0}
/* *BSL=8G{
**TestMethod.java n /rQ*hr
*/ lZb1kq%9g
package NetFox; ~C[R%%Gu
m,8A2;&,8
k:af
public class TestMethod { zQ7SiRt7*
U^Hymgb%
l&E-H@Pe
public TestMethod() PN<Y&/fB
{ ///xx/weblogic60b2_win.exe U4Qc$&j>
try{ )LnHm
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); "bC8/^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "j~=YW+l
SiteFileFetch fileFetch = new SiteFileFetch(bean); haB$W 4x
fileFetch.start(); gpO@xk$
} IDcu#Nz`
catch(Exception e){e.printStackTrace ();} L(}T-.,Slr
~!Onz wmO
v!40>[?|p
} -rU *)0PR
e8P |eK
{Uu7@1@n
public static void main(String[] args) ~)WE
{ Lv#DIQ8y
new TestMethod(); d(R3![:
} H@OYtPHGR
} KXYq|w
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