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)); RinRQd
} N!3f1d7RQ
for(int i=0;i<nEndPos.length-1;i++) b +_E)4
{ nNKL{Hp
nEndPos = nStartPos[i+1]; S'e2~-p0F
} 3WYW])
nEndPos[nEndPos.length-1] = nFileLength; _V?Q4}7d/
} ;D7jE+
} ^b#E%Rd
9+']`=a:
=EJ"edw]%0
//启动子线程 a*8}~p,
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; {mQJ6 G'ny
for(int i=0;i<nStartPos.length;i++) #wyS?FP-
{ qGqu/$bh
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -iHhpD9"X
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), bW]+Og
nStartPos,nEndPos,i); GdU W$.
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2 *$n?
fileSplitterFetch.start(); %r"GL
} u|c+w)a
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), DvCt^O*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #`$7$Y~]
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", qg/5m;U
nEndPos = " + nFileLength); "q.uiz+1:
// fileSplitterFetch[nPos.length-1].start(); Dhoj|lc
+q$|6?
;GSJnV
//等待子线程结束 fL;p^t u3
//int count = 0; M\f0 =`g
//是否结束while循环 d#Ajb
boolean breakWhile = false; M6sDtL9l
C.-a:oQ[
jxaoQeac
while(!bStop) @UJmbD{
{ ]r6bJ2
write_nPos(); eZi<C}z
Utility.sleep(500); E6k&r}
breakWhile = true; ay4xOwcR
Uj)]nJX
<4,?lZ
for(int i=0;i<nStartPos.length;i++) *lAdS]I
{ Gu).*cU
if(!fileSplitterFetch.bDownOver) 8A.7=C' z
{ 8)8oR&(f
breakWhile = false; F.D1;,x
break; x["
} I:<R@V<~#
} !++62Lf
if(breakWhile) /g''-yT7#
break; YPnJldVn
u0b-JJ7)BQ
sEyl\GL
//count++; S45>f(!
//if(count>4) 5i#w:O\cz
// siteStop(); ^^l"brPa
} 9G+rxyWMW
D:tZiS=0
ycD.:w p\'
System.err.println("文件下载结束！"); YCO:bBmp:
} T(^8ki
catch(Exception e){e.printStackTrace ();} gq3OCA!cX
} GuvF
wtLMc
mtddLd,
//获得文件长度 e622{dfVS
public long getFileSize() v^fOT5\
{ lG>e6[Wc
int nFileLength = -1; ^\jX5)2{
try{ W%K8HAP"
URL url = new URL(siteInfoBean.getSSiteURL()); 4CT9-2UC
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z,YUguc|
httpConnection.setRequestProperty("User-Agent","NetFox"); S=SncMO nE
Cpv%s 1M
bGc|SF<V
int responseCode=httpConnection.getResponseCode(); 3>)BI(Wl
if(responseCode>=400) Lu.tRZ`$38
{ '<S:|$$
processErrorCode(responseCode); >[4|6k|\x
return -2; //-2 represent access is error .WyX/E$I^!
} y4rJ-
5G;^OI!g
3MJWCo-[
String sHeader; O \8G~V 5"
5XO'OSdYq
![ID0}MjJ
for(int i=1;;i++) n4T2'e
{ {eN{Zh5"
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); %&+R":Bw
//Utility.log(in.readLine()); Prz+kPP
sHeader=httpConnection.getHeaderFieldKey(i); Ds,"E#?
if(sHeader!=null) ef:$1VIBda
{ J*KBG2+13
if(sHeader.equals("Content-Length")) qZ_fQ@
{ PG[O?l
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); BBE1}V!u
break; o+Ti$`2<O7
} ss@}Dt^
} X8n/XG~_
else JX$NEq(
break; \ +-hn
} `=$jc4@J
} Q*&aC|b&
catch(IOException e){e.printStackTrace ();} (VPM>ndkw
catch(Exception e){e.printStackTrace ();} 1S]gD&V
n.6 0$kR`
3/IWO4?_
Utility.log(nFileLength); )P9{47
A.C278^O8
6O@ ^`T
return nFileLength; Fp6[W5>(-
} mx(%tz^t
~muIi#4
/xm#:+Sc
//保存下载信息（文件指针位置） ivUsMhx>S,
private void write_nPos() NRuG?^/}d
{ &J/4J
try{ LXu"rfp
output = new DataOutputStream(new FileOutputStream(tmpFile)); iraRB~
output.writeInt(nStartPos.length); kl3S~gE4@
for(int i=0;i<nStartPos.length;i++) MLD>"W
{ "kBqY+:Cn
// output.writeLong(nPos); P2Qyz}!wo
output.writeLong(fileSplitterFetch.nStartPos); r{B,uj"
output.writeLong(fileSplitterFetch.nEndPos); 0.BUfuuh
} &kjwIg{
output.close(); fzFvfMAU
} R4~zL!7;
catch(IOException e){e.printStackTrace ();} Wt)SdF=U/
catch(Exception e){e.printStackTrace ();} ZH$sMh<xg
} ZOrTbik
)lDIzLp
L^ #<HQ
//读取保存的下载信息（文件指针位置） ,+f0cv4
private void read_nPos() m~j\?mb{+
{ ~Riu*<
try{ 'D0X?2
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); R|)2Dg
int nCount = input.readInt(); |N=@E,33
nStartPos = new long[nCount]; [ 4Y `O
nEndPos = new long[nCount]; `k}l$ih`X
for(int i=0;i<nStartPos.length;i++) ,8xP8T~Kmv
{ kF+}.x%
nStartPos = input.readLong(); >xZhK63C/
nEndPos = input.readLong(); VM]GYz|#]
} N{hF [F
input.close(); @ Zgl>
} 4/`h@]8P
catch(IOException e){e.printStackTrace ();} Zu0;/_rN
catch(Exception e){e.printStackTrace ();} rxy{a
} Yf!*OGF
QLB1:O>
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private void processErrorCode(int nErrorCode) )p!*c,
{ Rgfc29(8
System.err.println("Error Code : " + nErrorCode); 3u?`q%Y-e
} n(Q\',C
i (%tHa37
$p0 /6c
//停止文件下载 |,1bkJt
public void siteStop() /Oggt^S
{ vhYMWfbY
bStop = true; 4j=<p@
for(int i=0;i<nStartPos.length;i++) >9.5-5"
fileSplitterFetch.splitterStop(); MS st
sw41wj
B|Fl,55
} +-H}s`
} 42V,PH6o
//负责部分文件的抓取 7>'uj7r]=
**FileSplitterFetch.java %Le:wC
*/ @q> ktE_
package NetFox; w~kHQ%A
~9JW#HHzn
"t[M'[ `C
import java.io.*; E /fw?7eQ
import java.net.*; w`c0a&7
u(pdP"
"wA0 LH_
public class FileSplitterFetch extends Thread { kAZC"qM%i
Qw24/DJK
xn(+G$m
String sURL; //File URL ?mH@`c,fM
long nStartPos; //File Snippet Start Position iD>G!\&
long nEndPos; //File Snippet End Position -"W)|oC_
int nThreadID; //Thread's ID \*f;!{P{
boolean bDownOver = false; //Downing is over t*{,Gk
boolean bStop = false; //Stop identical j~M#Ss-H8
FileAccessI fileAccessI = null; //File Access interface x}tKewdOSe
<jbj/Q )"
Wgxn`6
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /Zo~1q
{ P3'2IzNw
this.sURL = sURL; +"]oc{W!
this.nStartPos = nStart; Zxg1M
this.nEndPos = nEnd; {5T0RL{\N
nThreadID = id; 9*#$0Y=
fileAccessI = new FileAccessI(sName,nStartPos);//定位 m)s xotgXf
} <"*"1(wN
ZhH+D`9
mfXD1]<.
public void run() Q]< (bD.7
{ +"'F Be
while(nStartPos < nEndPos && !bStop) ]]>nbgGn#
{ H76E+AY
}<vvxi
Vy]A,Rn7
try{ B,3 t`
URL url = new URL(sURL); 9'1hjd3k
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l`SK*Bm~<
httpConnection.setRequestProperty("User-Agent","NetFox"); ./$ <J6-J
String sProperty = "bytes="+nStartPos+"-"; q1H=/[a
httpConnection.setRequestProperty("RANGE",sProperty); 53B.2 4Tm
Utility.log(sProperty); S[vRw]*
JW=uK$sO
Yt -W1vl
InputStream input = httpConnection.getInputStream(); @4;&hP2Z:
//logResponseHead(httpConnection); @gNpJB]V
~eDI$IO
:Df)"~/mO+
byte[] b = new byte[1024]; ^w>&?A'!
int nRead; F&xv z2G
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) aSUsyOe
{ =(%*LY!Xc
nStartPos += fileAccessI.write(b,0,nRead); cn$5:%IK
//if(nThreadID == 1) S#k{e72 *
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \I;cZ>{u"}
} B$ui:R/ t
1YFeVMc
D-6
Utility.log("Thread " + nThreadID + " is over!"); i<mevL
bDownOver = true; ozU2
//nPos = fileAccessI.write (b,0,nRead); {B3(HiC
} *|oPxQCtK
catch(Exception e){e.printStackTrace ();} d<#p %$A4
} 7{-@}j`
} _ \l HI
ZPlPN;J^1
\*uugw,\y
//打印回应的头信息 ha5e(Hj?
public void logResponseHead(HttpURLConnection con) ]oEQ4
{ p'}lN|"{O
for(int i=1;;i++) L?HF'5o
{ /_q#ah
String header=con.getHeaderFieldKey(i); e8{^f]5
if(header!=null) >60"p~t
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :W~f;k
Utility.log(header+" : "+con.getHeaderField(header)); "qS!B.rt:
else ;1@C_5C
break; ^sV|ck
} KY g3U
} OF8WDo`
088C|
^!}F%
public void splitterStop() g5}lLKT
{ D^u\l
bStop = true; wu2:'y>n
} N<liS3>
'0RRFO
f>niFPW"
} I8k
vU}: U)S
#W|!fILL
/* WYLX?x
**FileAccess.java VjB*{,
*//文件访问(定位，写) kwlC[G$j7
package NetFox; | 3giZ{
import java.io.*; C2G |?=
>S'>!w
Fg=v6j4W
public class FileAccessI implements Serializable{ TV=c,*TV
K2HvI7$-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ZoxS*Xk
RandomAccessFile oSavedFile; !BUi)mo
long nPos; BI.V0@qZ
A$@o'Q;he
:Fw?{0
public FileAccessI() throws IOException <HF-2?`
{ bMmra.x4L
this("",0); 9|=nV|R'6
} lR@& Z6lw
W2<3C
K/|
public FileAccessI(String sName,long nPos) throws IOException .&iN(Bd
{ v459},!P
oSavedFile = new RandomAccessFile(sName,"rw"); Q]#Z9H
this.nPos = nPos; 76u{!\Jo/{
oSavedFile.seek(nPos); X$V|+lTk
} -k{Jp/-D
Cs4hgb|
tOH0IE c
public synchronized int write(byte[] b,int nStart,int nLen) iyj3QLqE
{ fY_%33_I$
int n = -1; e+@xsn3
try{ 9p`r7:
oSavedFile.write(b,nStart,nLen); g1@wf
n = nLen; jNc<~{/
} o&$hYy"<.L
catch(IOException e) 2~FPw{]j
{ gS$A
e.printStackTrace (); _-%d9@x
} fxtxu?A>
G{o+R]Us
w>vH8f
return n; d#\W hRE
} WZ?!!
x?L hq2
5pJ*1pfeo
} hYb9`0G"2
d(S}NH
dJl^ADX[@
/* Dp^/gL=
**SiteInfoBean.java O&'/J8
*/ lLCdmxbT
package NetFox; w^o}E)O
-0 0}if7
4;*f1_;f~
public class SiteInfoBean { 0{R/<N
VXIQw'Cq
mP-2s;q
private String sSiteURL; //Site's URL yVS\Q,:J9
private String sFilePath; //Saved File's Path Y8ehmz|g]J
private String sFileName; //Saved File's Name ez*jjm
private int nSplitter; //Count of Splited Downloading File M!{'ED
jTSOnF}C~+
Uix{"
public SiteInfoBean() ^\wl2
{//nSplitter的缺省值为5 T=\!2gt
//default value of nSplitter is 5 r(`nt-o@
this("","","",5); I]uhi{\C
} R]QpMj%o
@ yxt($G
;[6&0!N\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )+Y&4Qu
{ d^84jf.U
sSiteURL= sURL; n`L,]dco
sFilePath = sPath; G|9B)`S
sFileName = sName; r4;Bu<PQN1
this.nSplitter = nSpiltter; }*kJ-q&0
.nZ3kT`
k dU! kj
} C6@t
X+ f9q0
o&-L0]i|
public String getSSiteURL() =B(mIx;m
{ Oif,|:
return sSiteURL; JJf<*j^G
} [7W(NeMk
n33kb/q*
s AE9<(g&@
public void setSSiteURL(String value) <_:zI r,
{ A=`*r*
sSiteURL = value; F?4Sz#
} 3Gd0E;3sk~
_#'9kx|)
+1@AGJU3
public String getSFilePath() b5 Q NEi
{ D ,M@8h,
return sFilePath; KQ)T(mIqp
} #T%zfcUj
6?SFNDQ"C
Qpu3(`d<
public void setSFilePath(String value) mJMq{6;
{ frH)_YJ%
sFilePath = value; DuNcX$%%
} <lo`q<q
h4 vm{ho
u~'OcO
public String getSFileName() tWk{1IL
{ d=F-L
return sFileName; n,nisS
} CW0UMPE5
~`Sle xK|}
detLjlE
public void setSFileName(String value) Kbas-</Si
{ `P.CNYR<J
sFileName = value; D#v?gPo4
} cyMs(21
d8:C3R
t _\MAK
public int getNSplitter() M 9"-WIG@h
{ re uYTH
return nSplitter; ;0j*>fb\q7
} Ae3,^
c]v +
h7?.2Q&S
public void setNSplitter(int nCount) r}EM4\r
{ HV\"T(89
nSplitter = nCount; FpzP#;
} EcW1;wH
} (C`@a/q
EUZq$@uWL
l* Y[^'
/* evOb
**Utility.java qGa<@ b
*/ -f.R#J$2
package NetFox; *<k&#D"m
<E}N=J'uJ
1S*P"8N}0h
public class Utility { wOcg4HlW
g7Z9F[d
Wp4K6x
public Utility() UTX](:TC
{ CB]l[hM$
pqq?*\W&[v
oCA(FQ6
} KZ3B~#oQ
4\1;A`2%0
//线程睡眠 g*c\'~f;
public static void sleep(int nSecond) HXV73rDA
{ KJJb^6P48W
try{ ST8/ ;S#c
Thread.sleep(nSecond); @]"9EW 0
} 9-iB?a7{.
catch(Exception e) E!~2\qKT
{ &b6@_C9
e.printStackTrace (); I\%Lb z
} b`|MK4M(
} Tl7:}X<?
MMr7,?,$
//日志 hYv 6-5_
public static void log(String sMsg) <J}9.k
{ K2MNaB
System.err.println(sMsg); iEgM~
} -+_aL4.
-Fc#
Y6%OV?}v!
public static void log(int sMsg) @ h`Zn1;
{ H_=[~mJ
System.err.println(sMsg); NEou2y+}
} O*/-I pM
} GJt9hDM$0
3N*C]
NE%yv,B
/* L{,7(C=
**TestMethod.java x&/Syb
*/ $,zM99
package NetFox; ;xtb2c8HT
L?C~ qS2g
uvv-lAbjw
public class TestMethod { >upUY(3&
RkP|_Bf8)
$5CY<,f
public TestMethod() [K@!JY
{ ///xx/weblogic60b2_win.exe ~)IJE+e>}
try{ WJ4UJdf'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); UkbQ'P+oS
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >37}JUG
SiteFileFetch fileFetch = new SiteFileFetch(bean); {ZEXlNPww
fileFetch.start(); Dlf=N$BL7d
} 5 ^J8<s@_
catch(Exception e){e.printStackTrace ();} $<% nt
NWwtq&pz2
#I~dv{RX
} by<@Zwtf
HtYR 0J
4m!3P"$
public static void main(String[] args) $<e .]`R
{ %vYlu%c<
new TestMethod(); #&KE_n
} Y'*h_K
} N_[ Q.HD"
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