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)); u):%5F/
} mC{!8WC@k
for(int i=0;i<nEndPos.length-1;i++) wS F!Xx0
{ #K<=xP
nEndPos = nStartPos[i+1]; uZqu xu.
} qHC*$v#.V?
nEndPos[nEndPos.length-1] = nFileLength; SHXa{-
} 0,vj,ic*WX
} :|3"H&FWK
C1#o<pv
t?%}hs\!
//启动子线程 ;3.T* ?|o
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >+A1 V[
for(int i=0;i<nStartPos.length;i++) +,vJ7
{ F?RCaj
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {Gk}3u/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), uNPD~TYN
nStartPos,nEndPos,i); $+!}Vtb
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Azq#}Oe)u
fileSplitterFetch.start(); |k7ts&2
} Q^1#xBd
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), eu}:Wg2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); i h`y0(<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Pjj;.c 7_j
nEndPos = " + nFileLength); OVQxZ~uQ
// fileSplitterFetch[nPos.length-1].start(); {jx#^n&5R
;H m-,W
0btmao-
//等待子线程结束 T0*TTB&b
//int count = 0; @ 2%.>0s.
//是否结束while循环 6S! lD=
boolean breakWhile = false; m5'__<
2kp|zX(
:uT fhr
while(!bStop) %4r!7X|O<
{ =XRgT1>e
write_nPos(); .^9/ 0.g8t
Utility.sleep(500); XDrlJvrPL
breakWhile = true; )'K!)?&d
d 40'3]/{
vZ_DG}n11
for(int i=0;i<nStartPos.length;i++) W)$|Hm:H
{ 5x1%oC
if(!fileSplitterFetch.bDownOver) 5Re`D|8
{ R uFu,H-
breakWhile = false; U47k5s(J
break; %T,\xZ
} %`s9yRk9>E
} ,h wf
if(breakWhile) ',J%Mv>Yf
break; {*ko=77$*
V%{9o
*xZQG9`kt
//count++; &t.>^7ELF
//if(count>4) 8&2gM
// siteStop(); _,K>u6N&
} Ro3I/NI>
HhQPgjZ/
x w?9W4<
System.err.println("文件下载结束！"); Op$J"R
} *]>OCGsr
catch(Exception e){e.printStackTrace ();} [hv3o0".
} n_xQSVI0F
#r:Kg&W2FO
:hl}Zn~jt
//获得文件长度 qRP8dH
public long getFileSize() 9TXm Z
{ +}G>M=t::
int nFileLength = -1; k.? T.9
try{ 8tFyNl`c
URL url = new URL(siteInfoBean.getSSiteURL()); d~z<,_r5c
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7zP
httpConnection.setRequestProperty("User-Agent","NetFox"); /xrq'|r?C
/J9T=N
c J"]yG)=
int responseCode=httpConnection.getResponseCode(); d,Dg"Z
if(responseCode>=400) Z#cU#)`y1
{ 7"CH\*%
processErrorCode(responseCode); ~RR_[t2Z
return -2; //-2 represent access is error EH!EyNNb
} Med"dHo7
*V@MAt
k`4\.m"&
String sHeader; E*T84Jh6
KbuGf$Bv
h>5~ (n8
for(int i=1;;i++) B|q3;P
{ !,(bXa\^
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); GE3U0w6WbK
//Utility.log(in.readLine()); Y;/=3T7An
sHeader=httpConnection.getHeaderFieldKey(i); >G3J3P(
if(sHeader!=null) OTFu4"]M
{ Ci#5@Q9#w
if(sHeader.equals("Content-Length")) I3E8vi%B.
{ iDkWW
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); `bi_)i6Low
break; ~3-YxCn%
} oj4)7{
} }HQT@&=
else ,IVr4#w0=
break; +KwF U
} e[k;SSs
} oWaIjU0
catch(IOException e){e.printStackTrace ();} HS&uQc a
catch(Exception e){e.printStackTrace ();} u%IKM\
~PAbLSL*u
JU%yqXO
Utility.log(nFileLength); 5tCq}]q#P
m{yNnJ3O
,"MUfZ
return nFileLength; buM>^A"
} 3v3Va~fm`
eS# 0-
6~Oje>w;
//保存下载信息（文件指针位置） v=Bh A9[
private void write_nPos() Sdu@!<?B
{ uxJiec`&
try{ Y X{
output = new DataOutputStream(new FileOutputStream(tmpFile)); [Oy2&C
output.writeInt(nStartPos.length); xY}j8~k
for(int i=0;i<nStartPos.length;i++) ^5@"|m1
{ +&zuI
// output.writeLong(nPos); 7Caap/L:
output.writeLong(fileSplitterFetch.nStartPos); o >4>7
output.writeLong(fileSplitterFetch.nEndPos); Zz*mf+
} [6gHi.`p'
output.close(); .j<B5/+
} Hr,lA(
catch(IOException e){e.printStackTrace ();} ZxeE6&#M^w
catch(Exception e){e.printStackTrace ();} ?bYQZJ>&
} gl\{QcI8<
d=OO(sf
om39;nk!}
//读取保存的下载信息（文件指针位置） N*oJ$:#
private void read_nPos() 4y}a,
{ Y&Vbf>Hi+
try{ U &k3
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Pc ?G^ Xol
int nCount = input.readInt(); o?hw2-mH
nStartPos = new long[nCount]; VKfHN_m*
nEndPos = new long[nCount]; \C\y'H5
for(int i=0;i<nStartPos.length;i++) A)a+LW'=u
{ cz~11j#
nStartPos = input.readLong(); Ecl7=-y
nEndPos = input.readLong(); "7g8 d
} [Ik B/Xbw|
input.close(); .;v'oR1x5
} PaI63 !
catch(IOException e){e.printStackTrace ();} o|n0?bThS-
catch(Exception e){e.printStackTrace ();} hahD.P<
} >Vm
eS%6hUb
:;u]Y7
private void processErrorCode(int nErrorCode) UlZ)|Ya<M
{ ;}9Ws6#XQs
System.err.println("Error Code : " + nErrorCode); ^p%+rB.j[
} q9z!g/,d/
{[y"]_B4
w3|.4hS
//停止文件下载 !Kqj&y5
public void siteStop() E1Aa2
{ _~&vs<
bStop = true; 1`JN
for(int i=0;i<nStartPos.length;i++) soK_l|z:J
fileSplitterFetch.splitterStop(); \J g#X:d
L#MxB|fcr
n8D;6#P^
} |N.q[>^R
} Bq=](<>>
//负责部分文件的抓取 bN%MT#X
**FileSplitterFetch.java ;8Q?`=a
*/ e7AI&5Eg{
package NetFox; JV{!Ukuyp+
" yl"A4p S
`X03Q[:q"[
import java.io.*; uXa}<=O
import java.net.*; r<H^%##,w
j`M<M[C*4N
%pKs- n`
public class FileSplitterFetch extends Thread { h0QQP
AQGE(%X
& b2(Y4
String sURL; //File URL 5fv6RQD
long nStartPos; //File Snippet Start Position %Ne>'252y
long nEndPos; //File Snippet End Position XE%6c3s
int nThreadID; //Thread's ID *njB fH'
boolean bDownOver = false; //Downing is over bv"({:x
boolean bStop = false; //Stop identical Bm>(m{sX>
FileAccessI fileAccessI = null; //File Access interface iEO2Bil]
EB<tX`Wp
f3|=T8"t
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Q#bo!]H{t
{ *3oQS"8
this.sURL = sURL; oQB1fs
this.nStartPos = nStart; 'B:De"_(N
this.nEndPos = nEnd; Q%d[U4@
nThreadID = id; E*"E{E7
fileAccessI = new FileAccessI(sName,nStartPos);//定位 v^E2!X
} +a@SdWf
X2kLbe
bTKxv<
public void run() g{{SY5qDj
{ U^S:2
while(nStartPos < nEndPos && !bStop) nrhpId
{ 4tKf
$\H46Ji
I#e*,#'S
try{ QNBzc {XB
URL url = new URL(sURL); %?wE/LU>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); EU~'n-
httpConnection.setRequestProperty("User-Agent","NetFox"); @&> +`kgU-
String sProperty = "bytes="+nStartPos+"-"; Ki\jiflc7
httpConnection.setRequestProperty("RANGE",sProperty); zOp"n\
Utility.log(sProperty); S(xA}0]
i<![i5uAI
]c+'SJQ
InputStream input = httpConnection.getInputStream(); >u[ln@ l
//logResponseHead(httpConnection); </Lqk3S-!
hZG{"O!2s
P3>2=qK"E(
byte[] b = new byte[1024]; 8\_,Y ji
int nRead; AG=1TZI"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >qZRIDE5$
{ %uMsXa
nStartPos += fileAccessI.write(b,0,nRead); y[eNM6p
//if(nThreadID == 1) Y^f|}YO%y
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); K|!)<6ZsG7
} P1jkoJ
c3mlO[(
{$.{VE+v5
Utility.log("Thread " + nThreadID + " is over!"); sNTfRPC
bDownOver = true; |9JYg7<
//nPos = fileAccessI.write (b,0,nRead); +fmZ&9hFNJ
} '1*MiFxKq
catch(Exception e){e.printStackTrace ();} Dne&YVF9V
} rbWFq|(_
} !qq@F%tv
1Pc'wfj
7%WI
//打印回应的头信息 O;tn5
public void logResponseHead(HttpURLConnection con) Vt>E\{@[t
{ ]t<%>Z$
for(int i=1;;i++) / nRaxzf'
{ '?4[w]0J<
String header=con.getHeaderFieldKey(i); O#k+.LU
if(header!=null) :oQaN[3>_
//responseHeaders.put(header,httpConnection.getHeaderField(header)); G_RK3E[FK
Utility.log(header+" : "+con.getHeaderField(header)); T[J_/DE@
else yK;I<8+>_
break; X} 8U-N6)
} $S/8T
} =="SW"vNi
uEY5&wX`
,;}RIcvQV
public void splitterStop() "b;?2_w:E
{ bSzb! hT`
bStop = true; `WL*Jb
} a WC sLH
F!'"mU<f
mZ%\`H+
} SuSZ,>
d?qz7#kc
XO>Y*7rO
/* *QJ/DC$
**FileAccess.java <z PyID`
*//文件访问(定位，写) FUqiP(A
package NetFox; 8iB}a\]B
import java.io.*; uR[i9%=8L(
R7>@-EG
JKGZ0yn
public class FileAccessI implements Serializable{ 9:>vl0
yo=d"*E4^
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 mbK$Wp#
RandomAccessFile oSavedFile; %G*D0pE
long nPos; qK pU.rP
oj,
$6[]c)(
public FileAccessI() throws IOException X;0@41t'
{ `Hqu2 '`
this("",0); %|~UNP$
} Y,r2m nq
SQ[}]Tm;n
}#1{GhsS
public FileAccessI(String sName,long nPos) throws IOException Q*5d~Yr]R
{ |k0VJi
oSavedFile = new RandomAccessFile(sName,"rw"); V^D#i(5
this.nPos = nPos; Gy5W;,$q
oSavedFile.seek(nPos); qn .
} g$qh(Z_s
nK[$ID
-=Hr|AhE
public synchronized int write(byte[] b,int nStart,int nLen) +( d2hSIF
{ Phczf
int n = -1; f.{0P-Np
try{ ( KrIMZ
oSavedFile.write(b,nStart,nLen); ~kga+H
n = nLen; = zSrre
} Ra5cfkH;
catch(IOException e) WF]:?WE%
{ \`^jl
e.printStackTrace (); +y2*[
} @QofsWC
Q]HRg4r
?bEYvHAzg
return n; L r,$98Dy
} w@4+&v>O
@9L9c
k dqH36&<
} @NF8?>!
f{J7a1 `_
"(5}=T@,
/* >;Bhl|r~z
**SiteInfoBean.java F&\o1g-L
*/ {XAKf_Cg
package NetFox; H0S7k`.
VQCPgs
x+&&[>-P
public class SiteInfoBean { Jg:'gF]jt
q&.!*rPD
xFJ>s-g*
private String sSiteURL; //Site's URL />?d 2?
private String sFilePath; //Saved File's Path a;(:iMCi
private String sFileName; //Saved File's Name >3JOQ;:d8
private int nSplitter; //Count of Splited Downloading File DI\^+P
9f "*Oj
CfAqMH*ip
public SiteInfoBean() 6\bbP>ql
{//nSplitter的缺省值为5 s}.nh>Q
//default value of nSplitter is 5 Hi9]M3Ub
this("","","",5); >/>a++19
} hN.#ui5 $
aCanDMcBnq
,/KHKLY7
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =F`h2A;a
{ gm8H)y,
sSiteURL= sURL; _R]1J0
sFilePath = sPath; nL$tXm-x
sFileName = sName; Au {`oxD
this.nSplitter = nSpiltter; zAH+{4lC+
k $);<= ZI
`>V.}K^4
} ZE9*i}r
/swTn1<Y
P _ SJK
public String getSSiteURL() myYe~f4=HQ
{ 9'tM65K
return sSiteURL; mb#)w`<
} Yv{AoL~
6l=n&YO
{Hb _o)S
public void setSSiteURL(String value) &I70veNY
{ jq[>PvR
sSiteURL = value; =($qiL'h
} c/s'&gG33z
k`?n("j
au8)G_A
public String getSFilePath() 6@d( <Z
{ HdGy$m`
return sFilePath; }>j$Wr_h
} Bg3^BOT
@=9QV3D
W&"FejD
public void setSFilePath(String value) f; 22viE
{ ~6OdPD
sFilePath = value; NENbr$,G
} {\%x{
.VI2V-Q
Un<~P@T%
public String getSFileName() 'HC4Q{b`
{ 4fN<pG,
return sFileName; jQc0_F\
} ?O_;{(F_
H1X6f7`
Y-Z.AA,
public void setSFileName(String value) l-mUc1.S
{ q3;HfZ
sFileName = value; GUK/Xiu
} qvT9d7x
cgU7)`0j
Gf"/fpeQx
public int getNSplitter() ''V:+@Toh
{ ak'RV*>mT
return nSplitter; ThHK1{87X}
} M]&9Kg3
<mpkkCl,
EZ$m4:{e
public void setNSplitter(int nCount) 4g6d6~098;
{ eX=W+&lj
nSplitter = nCount; AttDD{Ta
} Q%85,L^U
} fQv^=DI#
4WNWn#M
$,R|$0B7
/* mtHw!*
**Utility.java l<gg5 Zea
*/ * @oAM,@
package NetFox; iR_X,&p
3c6#?<%0`
\}cEHLq
public class Utility { |=SaI%%Be
ua2SW(C@
1X=}
public Utility() Jo2:0<VL
{ s]}P jh8
fHM<6i<C
)O_Y(^+ $
} D@!#79:)
0"ZRJl<)[I
//线程睡眠 W#ev
public static void sleep(int nSecond) VPf=LSxJe
{ HQ]g{JVld\
try{ "6.kZ$`%
Thread.sleep(nSecond); dfk=%lZYd9
} :sJVklK
catch(Exception e) )4DF9JpD
{ xvb5-tK -
e.printStackTrace (); oas}8A)
} A9[l5E
} 32dR`qb
3]V"9+
//日志 Uc6P@O*,
public static void log(String sMsg) <zrGPwk
{ UE*M\r<
System.err.println(sMsg); hH%@8'1v
} 2jA-y!(e
6VIi nuOW
d':c
public static void log(int sMsg) <D=U=5
{ uP<tP:
System.err.println(sMsg); ZMoN
} ^xFZ;Yf
} 8nNRn[oS
W*N^Gp@
=`u4xa#m
/* 06L/i,
**TestMethod.java S)p1[&" M
*/ 3s"x{mtH
package NetFox; A=Dzd/CUO
HPT$)NeNc
LLCMp3qBz
public class TestMethod { z^@98:x
c?IFI
v, 9MAZ,
public TestMethod() F`+}p-
{ ///xx/weblogic60b2_win.exe <$/'iRtRzW
try{ !5&% P b
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); h9$Ov`N(%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >}Fe9Y.o
SiteFileFetch fileFetch = new SiteFileFetch(bean); X)x$h{ OE
fileFetch.start(); HOBM?|37CU
} EN'}+E 8
catch(Exception e){e.printStackTrace ();} qE!.C}L+
9F@Q
!3E33
} }GRZCX>
[O7:<co
tWT@%(2~0
public static void main(String[] args) } U\n:@:2B
{ (w`9*1NO
new TestMethod(); cl/}PmYIZ
} G?v]p~6
} >+LFu?y
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