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)); gCb+hQq\
} 2URGd#{VQ
for(int i=0;i<nEndPos.length-1;i++) &Mk!qE<:N
{ ]=qauf>3
nEndPos = nStartPos[i+1]; oCaYmi=:
} &sWr)>vs
nEndPos[nEndPos.length-1] = nFileLength; + U5Q/g
} wW@e#:
} )N&SrzqTK
LJGpa)(
9kH~=`:?
//启动子线程 $u!(F]^
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1+;bd'Ie
for(int i=0;i<nStartPos.length;i++) }}=n]_f
{ E]OexRJ^i
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /'rj L<M
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), p2Ep(0w,R5
nStartPos,nEndPos,i); qY#*LqV
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); UhDQl%&He
fileSplitterFetch.start(); ]- 1(r,
} Xb%q9Z
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WMf / S"=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (@+pz/
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", t<p#u=jOa
nEndPos = " + nFileLength); z3tx]Ade
// fileSplitterFetch[nPos.length-1].start(); 6(bN*.
Fvl\.
K$,Zg
//等待子线程结束 5wx_ol}2
//int count = 0; JY#vq'dl|
//是否结束while循环 X3:z=X&Zd
boolean breakWhile = false; _-_iw&F
wf\"&xwh?
qPq]%G*{
while(!bStop) [<RhaZz
{ x|~8?i$%
write_nPos(); /grTOf&
Utility.sleep(500); $vegU]-R
breakWhile = true; sN[}B{+
Ay?<~)H
^Spu/55_
for(int i=0;i<nStartPos.length;i++) F?Lt-a+
{ c| ^I}
if(!fileSplitterFetch.bDownOver) SsZC g#i
{ ?Ij(B}D
breakWhile = false; lFBpNUnzU
break; 2?t@<M]
} ttsR`R1.k
} lvke!~#
if(breakWhile) V!He2<
break; 2LtDS?)@
%} ``:
yW|J`\`^T
//count++; eJ?oz^
//if(count>4) PXMd=,}
// siteStop(); w.?4}'DK
} vhfjZ
]].~/kC^3k
t`Z'TqP R
System.err.println("文件下载结束！"); %GhI0F #
} 1Toiqb/
catch(Exception e){e.printStackTrace ();} P8z%*/ 3NF
} ,eyh%k*hz
8_('[89m
u9hd%}9Qd?
//获得文件长度 Ou_H&R
public long getFileSize() q5(t2nNb
{ M&V'*.xz
int nFileLength = -1; xS,24{-HJ
try{ 'Lrn<
URL url = new URL(siteInfoBean.getSSiteURL()); 6m:$mhA5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %10ONe}
httpConnection.setRequestProperty("User-Agent","NetFox"); b)d;eS
BDI|z/~&
>@2<^&K`
int responseCode=httpConnection.getResponseCode(); zZ=SAjT QP
if(responseCode>=400) :<J7g`f
{ ^9Pr`\
processErrorCode(responseCode); :V'99Esv`
return -2; //-2 represent access is error "v1{
} 5kiW@{m
<w2h@ea
1rm\u%
String sHeader; =tOB fRM
FiUQ2w4
~[ufL25K
for(int i=1;;i++) B0@ Tz39=
{ e|]e\Or>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); a^%iAe
//Utility.log(in.readLine()); pm6#azQ
sHeader=httpConnection.getHeaderFieldKey(i); p) 8S]p]
if(sHeader!=null) s;VW %e
{ r2=@1=?8
if(sHeader.equals("Content-Length")) )5}<@Ql
{ V`I4"}M1
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 7}kJp%-
break; ! ?g+'OM
} VQ9A/DH/
} FzInIif
else *fg2bz<~[B
break; 28!C#.(h
} AP&//b,^M
} CP7dn/
catch(IOException e){e.printStackTrace ();} C"I jr=w
catch(Exception e){e.printStackTrace ();} b@Oq}^a&o
gNCS*a
=D`8,n [
Utility.log(nFileLength); Scrj%h%[
xo[o^go
E 2nz
return nFileLength; ?o" Vkc:
} W"NI^OX
K[z)ts-
*Al@|5
//保存下载信息（文件指针位置） jWrU'X
private void write_nPos() X)b$CG
{ P[3i!"O>
try{ =~1EpZ
output = new DataOutputStream(new FileOutputStream(tmpFile)); eAy,T<#
output.writeInt(nStartPos.length); c{M ,K
for(int i=0;i<nStartPos.length;i++) >#]A2,
{ bU=Utniq
// output.writeLong(nPos); !d72f8@9
output.writeLong(fileSplitterFetch.nStartPos); enQ*uMKd^
output.writeLong(fileSplitterFetch.nEndPos); =QqH`.3
} kXz~ez 7
output.close(); z<%P"
} Nr4}x7
catch(IOException e){e.printStackTrace ();} #V>R#Oh}
catch(Exception e){e.printStackTrace ();} P 9?cp{*
} y[_k/.1
(]]hSkE
!xsfhLZK
//读取保存的下载信息（文件指针位置） *vb"mB
private void read_nPos() CRb*sfKDL
{ mnpk9x}m
try{ X-["{
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $bTtD<a
int nCount = input.readInt(); [IYVrT&C'
nStartPos = new long[nCount]; *&_*G~>D
nEndPos = new long[nCount]; 0 +=sBk (
for(int i=0;i<nStartPos.length;i++) NqD]p{>Y
{ $k~TVm Yex
nStartPos = input.readLong(); CFbNv9GZj
nEndPos = input.readLong(); c-+NWC
} 'z$N{p40m
input.close(); 7+HK_wNi
} $TIeeTB
catch(IOException e){e.printStackTrace ();} v=llg ^
catch(Exception e){e.printStackTrace ();} ~o'1PAW7
} xUdF.c
YSD G!
y7HFmGM
private void processErrorCode(int nErrorCode) x%mRDm~-
{ ~gI%lORqN
System.err.println("Error Code : " + nErrorCode); dFz"wvu` o
} 9?l a5
dtTn]}J
3TwjC:Yhv2
//停止文件下载 p2STy\CS
public void siteStop() h@%Xy(/m'
{ 6 >kULp
bStop = true; "^]gIQc
for(int i=0;i<nStartPos.length;i++) xi (@\A
fileSplitterFetch.splitterStop(); -xtT,^<B
Df6i*Ko|
OUBGbld
} D3Q+K
} {)" 3
//负责部分文件的抓取 (|QJ[@?q
**FileSplitterFetch.java ~` tuPk~l
*/ 0Ui.nz j
package NetFox; $TUYxf0q
GHv6UIe&
5 ^{~xOM5
import java.io.*; *Soi
import java.net.*; Tz,-~mc
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;<+efYmyc
public class FileSplitterFetch extends Thread { zx#Gm=H4
{5dVK
m\>gOTpA4
String sURL; //File URL 07LyB\l~
long nStartPos; //File Snippet Start Position ~5HkDtI)
long nEndPos; //File Snippet End Position -@N-i$!;J
int nThreadID; //Thread's ID 'va[)~!
boolean bDownOver = false; //Downing is over f{9+,z
boolean bStop = false; //Stop identical #T)Gkc"{
FileAccessI fileAccessI = null; //File Access interface Wb}-H-O
T@W:@,34
owNwj
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException k(ouE|B
{ ^>|ZN2
this.sURL = sURL; (5$Ge$
this.nStartPos = nStart; /M2in]oH
this.nEndPos = nEnd; K=f4<tP_
nThreadID = id; Clf$EX;~
fileAccessI = new FileAccessI(sName,nStartPos);//定位 b**vUt\
} iK}p#"si
KsULQJ#,
C*Q7@+&
public void run() :C5w5 Vnj
{ Cv#aBH'N
while(nStartPos < nEndPos && !bStop) T~UDD3
{ +5y^c|L0
";/]rwHa)
}c,b]!:
try{ ZKi&f,:
URL url = new URL(sURL); 'w:ugb9]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lelmX
httpConnection.setRequestProperty("User-Agent","NetFox"); T}Tv}~!f
String sProperty = "bytes="+nStartPos+"-"; ucl001EK
httpConnection.setRequestProperty("RANGE",sProperty); U%vTmdOY
Utility.log(sProperty); <'=!f6Wh
971=OEyq*
\,;glY=M!
InputStream input = httpConnection.getInputStream(); NO5k1/-
//logResponseHead(httpConnection); W2{w<<\$3}
`EKf1U\FI
+`>7cy%cZ
byte[] b = new byte[1024]; ,M.C]6YMr
int nRead; ~ 5}t;
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) W|<c[S
{ KM&P5}
nStartPos += fileAccessI.write(b,0,nRead); 8^_:9&)i
//if(nThreadID == 1) -ssb|r
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'o&d!
} S*l/ Sa@
lT[,w9$
YnpN -Y%g
Utility.log("Thread " + nThreadID + " is over!"); vP{i+s18B
bDownOver = true; eU"yF >6'
//nPos = fileAccessI.write (b,0,nRead); ?+}Su'pv}
} 9a_P 9s3w
catch(Exception e){e.printStackTrace ();} Yc#Uu8f-
} 9R=avfI
} ZA=J`->k
h2Q'5G
I"&cr>\
//打印回应的头信息 {\>4)TA
public void logResponseHead(HttpURLConnection con) -VohU-6 |
{ YdD; Qx#O
for(int i=1;;i++) $:u*)&"t|
{ YKe&Ph.
String header=con.getHeaderFieldKey(i); -mJs0E*g
if(header!=null) QFnuu-82"
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ld(60?z>FH
Utility.log(header+" : "+con.getHeaderField(header)); i9 aR#
else !Yc:yF
break; b`e_}^,c
} Ug*B[q/
} M7BpOmK'
P#TPI*qw
QGNKQ`~
public void splitterStop() .vHHw@
{ 0YoKSo
bStop = true; _qB ._
} ZvyZ5UA
B~:yM1f@u4
4j3q69TZR
} #ed|0
sm18u-
jwwRejNV
/* C).\ J !
**FileAccess.java @Z/jaAjUC
*//文件访问(定位，写) F w{:shC
package NetFox; ]v<8l4p;
import java.io.*; YI0l&'7
NLZ5 5yo$
7c_2.T@4
public class FileAccessI implements Serializable{ LB@<Q.b,U
N+.Nu= +i2
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 cK|Uwzifd
RandomAccessFile oSavedFile; 7"|Qmyb
long nPos; ]O;*Y{:Y
Wl3S]4A
FKL4`GEm
public FileAccessI() throws IOException /US%s
{ &_3#W.w~Z
this("",0); ;8[VCU:
} aH;AGbp
e\~nqKCb
N:|``n>
public FileAccessI(String sName,long nPos) throws IOException \(LD<-a
{ fDYTupKXH
oSavedFile = new RandomAccessFile(sName,"rw"); ]DnAW'm
this.nPos = nPos; O#.YTTj
oSavedFile.seek(nPos); =?|$}vDO[
} o;c"-^>
(pH)QG
{n>.Y-=
public synchronized int write(byte[] b,int nStart,int nLen) 8`S1E0s
{ 38sLyoG=i
int n = -1; =b66H]h?
try{ XrUI[ryE
oSavedFile.write(b,nStart,nLen); .?:#<=1
n = nLen; qBF|' .$^
} 9ug4p']
catch(IOException e) hV $Zr4'
{ ";dS~(~
e.printStackTrace (); \asn^V@"zz
} XR]bd
;):;H?WS|A
`Ku:%~$/
return n; NtGJpT4YX
} KxErWP%
>}wFePl
_'!qOt7D
} p7AsNqEp
]ovtH.y
OM.-apzC
/* j![1
**SiteInfoBean.java ~5Fx[q
*/ wYe;xk`>
package NetFox; }alq~jY
N?c~AEk9U
}bihlyB&Q
public class SiteInfoBean { st??CX2
n^1BtP0!
p+Q9?9
private String sSiteURL; //Site's URL ##By!FTP
private String sFilePath; //Saved File's Path T0A=vh;S
private String sFileName; //Saved File's Name CH `Kpt
private int nSplitter; //Count of Splited Downloading File `i|!wD,=\
")9^
<:AA R2=
public SiteInfoBean() w nBvJb]4l
{//nSplitter的缺省值为5 #[i3cn
//default value of nSplitter is 5 h>>~Bi
this("","","",5); -5v{p
} @u$NB3
R{[v#sF >#
pj7al;
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +PBl3
{ p+ReQ.5|
sSiteURL= sURL; HJb^l 4Q
sFilePath = sPath; 5(2 C
sFileName = sName; :CqR1_n%
this.nSplitter = nSpiltter; E<D^j^T
w15a~\Qu
J:)ml
} HjzAFXRG
qsEFf(9G
C/ VHzV%q
public String getSSiteURL() ^fN/
{ ?*UWg[
return sSiteURL; R`o Xkj
} kbvF 9#
[g`4$_9S
%<+Ku11
public void setSSiteURL(String value) oR%cG"y
{ HoX={^aG%
sSiteURL = value; S -,$ (
} djoP`r
'w1ll9O
'k}w|gNB
public String getSFilePath() IR3+BDE)>
{ %qqCpg4
return sFilePath; ts@w9|
} /F^ Jn_
8LF=l1=~
%x;~o:
public void setSFilePath(String value) zrA3bWs
{ yD$d^/:
sFilePath = value; _J2?B?S/j
} Z6M qcAJ3j
+t-_FbFh3D
%jx<<hW
public String getSFileName() ci+ajON
{ >`[+24e
return sFileName; #zgO_H
} Migl
DD
CX2qtI8N?
public void setSFileName(String value) 3=?,Dv0P
{ 7k%!D"6_R
sFileName = value; ;FuST
} (QojIdHt
9Y:.v@:}0
Ll%}nti
public int getNSplitter() 6uUzky
{ } gwfe H
return nSplitter; E:uTjXt
} yW*,Llb5
vV=rBO0a?
[5!{>L`
public void setNSplitter(int nCount) pKLNBR|
{ ru/{s3
nSplitter = nCount; KRR)pT
} [ns==gDD
} A!^r9?<
JbitRV@a
xFIzq
/* 'ahZ*@kr
**Utility.java `H9+]TWj<
*/ hW~UJ/$
package NetFox; <eS+3,
Z:<wB#G
n``9H91
public class Utility { JSylQ201
x&JD~,Y
q-@&n6PEOZ
public Utility() p Djt\R<f
{ vxi_Y\r=T
!?J-Y
5-H"{29
} PQ;9iv
B>I:KGkV
//线程睡眠 _d^d1Q}V
public static void sleep(int nSecond) I(k(p\l%
{ $tc1te
try{ |#BN!kc
Thread.sleep(nSecond); ^xScVOdP
} L&=r-\.ev
catch(Exception e) l+wfP76w
{ 0N]\f.=`
e.printStackTrace (); GjN6Af~}
} 92C; a5s
} 7hLh}
g HxRw
//日志 E{^W-
public static void log(String sMsg) a3A3mBw
{ e7-IqQA{3C
System.err.println(sMsg); tv~Y5e&8
} oxUBlye
t.\Pn4
eR`Q7]j] -
public static void log(int sMsg) 48 0M|^
{ c4Q9foE
System.err.println(sMsg); &sYxe:H
} xTH3g^E
} z6,E}Y
[#G*GAa6*
~J#Z7y]p!j
/* M} ri>o
**TestMethod.java d.Ccc/1-
*/ Wi,)a{
package NetFox; @CxgoX^
s +qodb+
0r i
public class TestMethod { !)`*e>]x
yc`3)
(c"!&&S^ =
public TestMethod() q \fyp\z
{ ///xx/weblogic60b2_win.exe =[Z3]#h
try{ \L}7.fkb8
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~6O~Fth
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9KJ}Ai
SiteFileFetch fileFetch = new SiteFileFetch(bean); 62Tel4u
fileFetch.start(); h qhX
} q\gbjci
catch(Exception e){e.printStackTrace ();} 5')]Y1J
xsy45az<ip
IDpx_
} > sQ&5-i
L.JL4;U P
\D]9:BNJ
public static void main(String[] args) x;/dSfv_
{ >Y+m54EE
new TestMethod(); gNDMJ^`
} t. (6tL]
} =8rNOi
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