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http断点续传简单实现(java)

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/* HwuPjc#  
**SiteFileFetch.java OFbg]{ub?  
*/ *v3 |  
package NetFox; ^eRT8I  
import java.io.*; 9D w&b  
import java.net.*; iCKwd9?)  
>MrU^t  
='>UKy[=  
public class SiteFileFetch extends Thread { Cw5K*  
O3: dOL/C  
2H "iN[2A  
SiteInfoBean siteInfoBean = null; //文件信息Bean ,quTMtk~  
long[] nStartPos; //开始位置 0Wm-` ZA  
long[] nEndPos; //结束位置 S$WM&9U   
FileSplitterFetch[] fileSplitterFetch; //子线程对象 gXJ^o;R>M  
long nFileLength; //文件长度 *b_54X%3  
boolean bFirst = true; //是否第一次取文件 w5jZI|  
boolean bStop = false; //停止标志 mh]$g<*m  
File tmpFile; //文件下载的临时信息 r/2:O92E  
DataOutputStream output; //输出到文件的输出流 mkA|gM[g7  
7#3)&"j  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) D:EF@il  
public SiteFileFetch(SiteInfoBean bean) throws IOException )c !S@Hs  
{ GA}^Rh`T-  
siteInfoBean = bean; Uroj%xN  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); TMsoQ82  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");  e5]AB  
if(tmpFile.exists ()) LS;anNk@.}  
{ 1D6O=j\  
bFirst = false; \TlUC<urP  
read_nPos(); &Z!2xfQy>  
} 2&URIQg*J  
else #{,IY03  
{ 18`%WUPnT  
nStartPos = new long[bean.getNSplitter()]; E%B Gf}h  
nEndPos = new long[bean.getNSplitter()]; 3>Snd9Q  
} %/zZ~WIf  
w'XgW0j{  
efR$s{n!  
NM.B=<Aw*  
} qT @IY)e  
f tDV3If  
q:^Cw8  
public void run() >IjLFM+U  
{ <LN$[&f#  
//获得文件长度 jRAL(r|  
//分割文件 !g"9P7p  
//实例FileSplitterFetch c"1d#8J  
//启动FileSplitterFetch线程 p\ S3A(  
//等待子线程返回 K6 7? d  
try{ "mK (?U!A  
if(bFirst) SI5QdX  
{ Bx4GFCdifC  
nFileLength = getFileSize(); ]E^f8s0#V  
if(nFileLength == -1) 09 s}@C  
{ I1O?)x~  
System.err.println("File Length is not known!"); /vu!5?S  
} RiG!TTa b  
else if(nFileLength == -2) p]=;t"  
{ w}q"y+=Z:  
System.err.println("File is not access!"); =:eE!  
} caht4N{T  
else GY xI$y0:  
{ zX`RN )C  
for(int i=0;i<nStartPos.length;i++)  H>6;I  
{ J7o?h9  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); G9Tix\SpF  
} cyg>h X{U  
for(int i=0;i<nEndPos.length-1;i++) DU8LU*q'  
{ Uiw7Y\Im|  
nEndPos = nStartPos[i+1]; U{(07GNm#  
} /GGu` f  
nEndPos[nEndPos.length-1] = nFileLength; 8ZfIh   
} V}+;b bUc-  
} =lQ[%&  
 ?Nql7F4  
|3ETF|)?  
//启动子线程 ZRGZ'+hw  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [zEP|  
for(int i=0;i<nStartPos.length;i++) ?GU!ke p  
{ "\?G  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), );H[lKy  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~W{h-z%q  
nStartPos,nEndPos,i); ;tiU OixJ  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); P@`"MNS  
fileSplitterFetch.start(); ',Pk>f]AB-  
} ^I?y\:.  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), q.{/{9  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); g>P9hIl  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 4{t$M}?N  
nEndPos = " + nFileLength); *Bsmn!_cB{  
// fileSplitterFetch[nPos.length-1].start(); e/jM+%  
vK`h;  
,8nZzVo  
//等待子线程结束 9Ib(x0_  
//int count = 0; FH`&C*/F0Y  
//是否结束while循环 m-92G8'  
boolean breakWhile = false; q|l|mO  
UyKG$6F?3  
 j)6B^!  
while(!bStop) [:@?,?V\N  
{ $IZZ`Z]B  
write_nPos(); 6 <S&~q  
Utility.sleep(500); [;YBX] t  
breakWhile = true; >I~z7 JS  
^QR'yt3e  
;o459L>sW  
for(int i=0;i<nStartPos.length;i++) w1(06A}/  
{ v} ;qMceJ  
if(!fileSplitterFetch.bDownOver) X$Vz  
{ Go7hDmu  
breakWhile = false; 5?0gC&WfN  
break; aZGDtzNG5h  
} ) '`AX\  
} f<p4Pkv  
if(breakWhile) <>Ddxmw  
break; `h5eej&s(  
L#q9_-(#  
x`vs-Y:P  
//count++; : ";D.{||  
//if(count>4) ! H=k7s  
// siteStop(); .|`=mx  
} g~:(EO(w  
C-^%g [#  
Z1&GtM  
System.err.println("文件下载结束!"); [Fj+p4*N  
} M 8j(1&(:  
catch(Exception e){e.printStackTrace ();} zTT  
} AeCG2!8^0  
B00wcYM<1r  
^|i\d \  
//获得文件长度 h21(K}  
public long getFileSize() kDl4t]j  
{ Zbh]SF{3F  
int nFileLength = -1; #_\MD,(  
try{ *u;">H*BW  
URL url = new URL(siteInfoBean.getSSiteURL()); :_,]?n  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "u8o?8+q~  
httpConnection.setRequestProperty("User-Agent","NetFox"); G,|]a#w&v.  
EZumJ."  
;=\5$J9  
int responseCode=httpConnection.getResponseCode(); \"`>-v"h  
if(responseCode>=400) UAXF64w{  
{  `pd   
processErrorCode(responseCode); GKujDx+h  
return -2; //-2 represent access is error  |iUfM3  
} n!eqzr{  
p6y0W`U  
&DQ4=/Z  
String sHeader; ka)LK@p6  
eGe[sv"k  
6 #x)W  
for(int i=1;;i++) K[>@'P}y  
{ UtBlP+bE?y  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); lH@E%  
//Utility.log(in.readLine()); }A)36  
sHeader=httpConnection.getHeaderFieldKey(i); 5ZyBP~  
if(sHeader!=null) Zjic"E1  
{ UQ.D!q  
if(sHeader.equals("Content-Length")) nHA`B.:B  
{ :e<`U~8m  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Tb0;Mbr  
break; PUjoi@]  
} !Xx<~l IC  
} hp]ng!I{\u  
else +fP/|A8P  
break; 'W?v.W &  
} JQ/t, v$G  
} [[0bhmG)  
catch(IOException e){e.printStackTrace ();} ZG/8Ds  
catch(Exception e){e.printStackTrace ();} ]%<Q:+38  
&e]]F#  
Ce5w0&VlS  
Utility.log(nFileLength); hi3sOK*r;<  
O? Gl4_y  
<[y$D=n  
return nFileLength; `f 6)Q`n  
} Rw/JPC"  
f*T)*R_  
`zzKD2y  
//保存下载信息(文件指针位置) =2nn "YVP  
private void write_nPos() }6CXJ+-UR  
{ N;x<| %peL  
try{ LE<u&9I\  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~6-"i0k  
output.writeInt(nStartPos.length); si^4<$Nr%j  
for(int i=0;i<nStartPos.length;i++) Z`oaaO  
{ Od!F: <  
// output.writeLong(nPos); eN]>l  
output.writeLong(fileSplitterFetch.nStartPos); )zW%\s*'  
output.writeLong(fileSplitterFetch.nEndPos); n-hvh-ZO  
} ]/o12pI  
output.close(); Jny)uo8  
} Q$fRi[/L  
catch(IOException e){e.printStackTrace ();} *TM;trfz  
catch(Exception e){e.printStackTrace ();} ksu}+i,a  
} '6o`^u>  
hEv=T'*,K)  
CP]S-o}yd  
//读取保存的下载信息(文件指针位置) o=-Vt,2{  
private void read_nPos() b\?7?g  
{ ljYpMv.>xG  
try{ aVppOxA  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -3G 4vRIo  
int nCount = input.readInt(); 97(Xu=tX  
nStartPos = new long[nCount]; ws>WA{]gq  
nEndPos = new long[nCount]; BSfm?ku"!  
for(int i=0;i<nStartPos.length;i++) tM^;?HL]  
{ *gd?>P7\0  
nStartPos = input.readLong(); <Qcex3  
nEndPos = input.readLong(); )+n,5W  
} QY~<~<d+G  
input.close(); Xq,UV  
} ePq13!FC/  
catch(IOException e){e.printStackTrace ();} ceb s.sF:  
catch(Exception e){e.printStackTrace ();} gV"qV   
} `dv}a-Q)c  
/ojO>Y[<   
Sa;<B:|  
private void processErrorCode(int nErrorCode) t;.^K\S4  
{ @K$VV^wp  
System.err.println("Error Code : " + nErrorCode); %@lV-(5q  
} Lj&1K~U  
n5Nan  
:DdBn.  
//停止文件下载 GJ1;\:cQq  
public void siteStop() d~{jEg  
{ L$+d.=]  
bStop = true; K\{b!Cfr^  
for(int i=0;i<nStartPos.length;i++)  <+AIt  
fileSplitterFetch.splitterStop(); N5 SLF4R1  
{W5ydHXy  
bJQ5- *F  
} AT B\^;n.  
} Hp)X^O"  
//负责部分文件的抓取 n7IL7?!o  
**FileSplitterFetch.java [G{rHSK5tQ  
*/ CM%|pB/z  
package NetFox; r}/yi  
;wij}y-6  
2;r]gT~  
import java.io.*; \{c,,th  
import java.net.*; _tWJXv~;  
nG"tO'J6  
@+'c+  
public class FileSplitterFetch extends Thread { k}-yOP{  
:/C ?FHs9  
;^R A!Nj  
String sURL; //File URL .:}.b"%m  
long nStartPos; //File Snippet Start Position #ZG3|#Q=L  
long nEndPos; //File Snippet End Position };&HhBc!g  
int nThreadID; //Thread's ID kOs(?=  
boolean bDownOver = false; //Downing is over :tRf@bD#  
boolean bStop = false; //Stop identical <^lJr82  
FileAccessI fileAccessI = null; //File Access interface }3v'Cp0L  
$ A-+E\vQ@  
JDLTOLG  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &w+;N5}3  
{ t)-*.qZh  
this.sURL = sURL; (k%GY< bP  
this.nStartPos = nStart; W8w3~  
this.nEndPos = nEnd; 01U *_\  
nThreadID = id; bTZ>@~$  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 j?EskT6  
} h ?uqLsRl  
06 QU  
5Z/yhF.{  
public void run() 5]jx5!N  
{ M]}l^ m>L  
while(nStartPos < nEndPos && !bStop) yiiyqL*E  
{ vB[~pQ;Z  
<,\ `Psa)N  
W7H&R,  
try{ P @zz"~f7  
URL url = new URL(sURL);  }10\K  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,Pn-ZF  
httpConnection.setRequestProperty("User-Agent","NetFox"); (2UW_l  
String sProperty = "bytes="+nStartPos+"-"; z0#-)AeS  
httpConnection.setRequestProperty("RANGE",sProperty); mDE'<c`b4  
Utility.log(sProperty); "r u]?{v  
/:bKqAz;M  
e# t3u_  
InputStream input = httpConnection.getInputStream(); {vs 4vS6  
//logResponseHead(httpConnection); C\ tprnY  
k!5m@'f  
/\ytr%7,'  
byte[] b = new byte[1024]; @.'z* |z  
int nRead; =WC-Sj{I  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !RS9%ES_?  
{ rJ'/\Hh5P  
nStartPos += fileAccessI.write(b,0,nRead); puOC60zI  
//if(nThreadID == 1) K*~]fy  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _@Y"$V]=Vt  
} MR`:5e  
1%%'6cWWu  
WzjL-a(  
Utility.log("Thread " + nThreadID + " is over!"); yQ9ZhdQS  
bDownOver = true; Mtm/}I  
//nPos = fileAccessI.write (b,0,nRead); pe9@N9_5  
} d')-7C  
catch(Exception e){e.printStackTrace ();} sONBQ9  
} o/C(4q6d  
} g& k58{e  
$[g_=Z  
!=3Rg-'d1  
//打印回应的头信息 Guh%eR'Wt  
public void logResponseHead(HttpURLConnection con) #/|75 4]]  
{ ['z!{Ez  
for(int i=1;;i++) n|Pr/ddL   
{  ?>af'o:  
String header=con.getHeaderFieldKey(i); &-M]xo ^  
if(header!=null) f|U0s  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); baee?6  
Utility.log(header+" : "+con.getHeaderField(header)); f;gZ|a  
else b.s9p7:J  
break; Ur^j$B}  
} {Hl[C]25X  
} UfO7+_2  
<\" .L  
%a];  
public void splitterStop() H6gU?9%  
{ n 6{2]&sd  
bStop = true; MM?`voj~`p  
} Y>B P?l  
m 41t(i  
'Hw4j:pS  
} nBN&.+3t  
@wp4 |G  
Gih[i\%Q  
/* q]\X~ 9#  
**FileAccess.java &-%X:~|:X  
*//文件访问(定位,写) P}V=*g  
package NetFox; k;I  &.H  
import java.io.*; EATu KLP\  
3$VxRz)  
MAqLIf<G  
public class FileAccessI implements Serializable{ /- 4$7qd  
oE?QnH3R  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 3xNMPm  
RandomAccessFile oSavedFile; Q$ri=uB;+  
long nPos; >`'O7.R  
1tB[_$s  
BByCM Y  
public FileAccessI() throws IOException .R5y:O  
{ 99=s4*xzM  
this("",0); R^*K6Ad  
} dRI^@n  
-h#mn2U~3r  
N j4IQ<OV  
public FileAccessI(String sName,long nPos) throws IOException <YFY{VC(  
{ ]3B%8  
oSavedFile = new RandomAccessFile(sName,"rw"); 15{Y9!  
this.nPos = nPos; GKiukX$'  
oSavedFile.seek(nPos); v>A=2i*j  
} 4 o(bxs"  
Xf d*D  
,e`'4H  
public synchronized int write(byte[] b,int nStart,int nLen) ifK%6o6  
{ ~]'pY  
int n = -1; U7iuY~L  
try{ I]nHbghcW  
oSavedFile.write(b,nStart,nLen); ;n6b%,s  
n = nLen; -x`G2i  
} M+`H g_#Q  
catch(IOException e) xd-XWXc  
{ 9}29&O  
e.printStackTrace (); BVw Wj-,  
} @kFu*"  
~D[?$`x:  
re &E{  
return n; 1l8Etp&<  
} 6rN(_Oi-  
B[5r|d'  
xJZ@DR,#  
} X|DO~{-au  
fNu'((J-  
>dzsQ^Nj  
/* E7zm{BX]  
**SiteInfoBean.java Bi3+)k>u7  
*/ Pw0Ci  
package NetFox; ?=;qK{)37  
^Q+i=y{W  
zsXoBD\h  
public class SiteInfoBean { C\ZkGX  
!? 5U|  
sZ&G%o  
private String sSiteURL; //Site's URL %\$;(#h  
private String sFilePath; //Saved File's Path 1w(JEqY3h:  
private String sFileName; //Saved File's Name xI*#(!x"G  
private int nSplitter; //Count of Splited Downloading File DI|:p!Nx  
L,,*gK  
]aryV?!6  
public SiteInfoBean() nqVZqX@oE  
{//nSplitter的缺省值为5 kcie}Be  
//default value of nSplitter is 5 =*vMA#e  
this("","","",5); `Y=WMNy  
} *i{Y9f8  
f.B>&%JRZ  
6 sxffJt  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^!8P<y  
{ 9Z5D\yv?H  
sSiteURL= sURL; ]iNEw9  
sFilePath = sPath; -62'}%?A<C  
sFileName = sName; E\nv~Y?SG  
this.nSplitter = nSpiltter; X>YsQrK(ig  
JwnQ0 e  
t*<#<a  
} I zbU)ud  
eM7Bc4V  
F}GPZ=T;  
public String getSSiteURL() YC_5YY(k  
{ !QI\Fz?  
return sSiteURL; 8vSse  
} YW@#91.  
hwN?/5  
`+:.L>5([  
public void setSSiteURL(String value) !HeSOzN  
{ ^u}L;`L  
sSiteURL = value;  7R#+Le)  
} _p-t<ytnh  
jOpcV|2  
9+s.w25R  
public String getSFilePath() ml|W~-6l  
{ >odbOi+X  
return sFilePath; me6OPc;:!  
} cRd0S*QN2  
5 < wnva  
mI*[>#q>  
public void setSFilePath(String value) oh"O07  
{ 65h @}9,U  
sFilePath = value; {U<xdG  
} ~=<}\a~  
rNjn~c  
ZQ^r`W9_ +  
public String getSFileName() C98]9  
{ (/-hu[:  
return sFileName; ae"]\a\&1o  
} Ghl'nqPlm  
'0y9MXRT  
"<_0A f]  
public void setSFileName(String value) iRg7*MQu  
{ =[\s8XH,  
sFileName = value; A1P K  
} r:&` $8$  
53-v|'9'  
;z M*bWh9  
public int getNSplitter() r<F hY  
{ R8rfM?"W  
return nSplitter; Ev7J+TmXM  
} mWR4|1(  
oI)GKA_Ng7  
2aJS{[  
public void setNSplitter(int nCount) p~noM/*2r  
{ uZfnzd)c  
nSplitter = nCount; +dA,P\  
} P=3RLL<l  
} W^3uEm&l!)  
%sHF-n5P  
E9?ph D  
/* r]3'74j:  
**Utility.java J psPNa  
*/ O+ }qQNe<  
package NetFox; `wF8k{Pb  
Mu'8;9_6  
iyj+:t/  
public class Utility { ?4H i-  
it]E-^2>  
D]c`B  
public Utility() /Q~gU<  
{ A,r*%&4~  
vad12WrG<  
yG Wnod'  
} ` PYJ^I0  
f2,jh}4  
//线程睡眠 =K{\p`?  
public static void sleep(int nSecond) cUTE$/#s  
{ %QKZT=}  
try{ #2r}?hP/m  
Thread.sleep(nSecond);  /'31w9  
} +w=AJdc  
catch(Exception e) ynA|}X  
{ h3dsd  
e.printStackTrace (); &WNf M+  
} JaB<EL-9r2  
} Gmf B  
u,}{I}x_  
//日志 Q{B}ef  
public static void log(String sMsg) K&8dA0i2u2  
{ 7^w >Rj  
System.err.println(sMsg); nLV9<M Zm  
} wdUBg*X8  
l}$ U])an#  
pp7$J2s+j  
public static void log(int sMsg)  o x+ 3U  
{ hWH:wB  
System.err.println(sMsg); )T;?^kho  
} keB&Bjd&  
} =XXZ?P  
_/wV;h~R  
pZtu&R%GU  
/* SPp#f~%m  
**TestMethod.java `'V4PUe  
*/ me OMq1  
package NetFox; q$aaA`E%  
0_CN/5F  
sg+uBCGB  
public class TestMethod { -eX5z  
i+gQE!  
@xB*KyUW  
public TestMethod() $V1;la!  
{ ///xx/weblogic60b2_win.exe JA)] _H P  
try{ 2 !'A:;  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); dDF .qXq.  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); o1<_fI  
SiteFileFetch fileFetch = new SiteFileFetch(bean); `X3^fg  
fileFetch.start(); `F/Tv 5@L  
} }[M`uZ  
catch(Exception e){e.printStackTrace ();} {#)0EzV6  
nxr!`^Mne  
ATR!7i\|  
} }fKSqB]T-  
 =|9H  
9'r:~ O  
public static void main(String[] args) R9B&dvG  
{ +"1NC\<*  
new TestMethod(); &gjF4~W]  
} qbv#I;  
} q `pP$i:  
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