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http断点续传简单实现(java)

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/* zTc*1(^  
**SiteFileFetch.java n 4y]h  
*/ }1W@  
package NetFox; [c;#>UQMf  
import java.io.*; is~2{:  
import java.net.*; x0WinLQ  
gY8$Rk %  
.ws86stFSb  
public class SiteFileFetch extends Thread { /(.:l +[w[  
Rc &m4|cw7  
C511 hbF  
SiteInfoBean siteInfoBean = null; //文件信息Bean G? XS-oSv  
long[] nStartPos; //开始位置 O1bW, n(  
long[] nEndPos; //结束位置 ;lvcg)}l  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 cv G*p||  
long nFileLength; //文件长度 Id&e'  
boolean bFirst = true; //是否第一次取文件 B(ktIy  
boolean bStop = false; //停止标志 @&Bh!_TWc  
File tmpFile; //文件下载的临时信息 E&eY79  
DataOutputStream output; //输出到文件的输出流 0^sY>N"  
f 9Kt>2IN  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) aU^6FI  
public SiteFileFetch(SiteInfoBean bean) throws IOException b?c/J {me  
{ 6uT*Fg-G  
siteInfoBean = bean; *mbzK*  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); /R&h#;l  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); O1S7t)ag  
if(tmpFile.exists ()) CH&{x7$he  
{ o +7)cI  
bFirst = false; -*z7`]5J  
read_nPos(); oeB'{bG  
} Fxc_s/^=t  
else D}LM(s3li7  
{ OF+4Mq  
nStartPos = new long[bean.getNSplitter()]; R TpNxr{[  
nEndPos = new long[bean.getNSplitter()]; P^Owgr=Y  
} -0x Q'1I  
8-Y*b89  
L!lmy&1  
28`s+sH  
} 3%5a&b  
&Jc atI  
-5 D<zP/  
public void run() %1.F;-GdsW  
{ "ayV8{m^3  
//获得文件长度 %9a3$OGZX  
//分割文件 mfN'+`r  
//实例FileSplitterFetch 5af0- hj  
//启动FileSplitterFetch线程 pCA`OP);=  
//等待子线程返回 IEMa/[n/  
try{ . ump? M  
if(bFirst) ?5J#  
{  dC{dw^  
nFileLength = getFileSize(); _io'8X2K%  
if(nFileLength == -1) *LU/3H|}  
{ q]I aRho  
System.err.println("File Length is not known!"); 6Eu(C]nC(  
} PXkpttIE]M  
else if(nFileLength == -2) )38%E;T{X  
{ ?VmgM"'md  
System.err.println("File is not access!"); DZtpY {=Z  
}  2Y23!hw  
else |w}j!}u  
{ dN)8r  
for(int i=0;i<nStartPos.length;i++) J\Pb/9M/  
{ oDMPYkpTu  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); <Q\KS  
} vxj:Y'}  
for(int i=0;i<nEndPos.length-1;i++) h_[{-WC  
{ VMRfDaO9  
nEndPos = nStartPos[i+1]; !>n!Q*\(Ov  
} b4i=%]v8  
nEndPos[nEndPos.length-1] = nFileLength; XPO-u]<W  
} 6]Hwr_/tk  
} {tUe(  
TZ5TkE;1  
j<*7p:L7_>  
//启动子线程 }7[]d7  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ={sjoMW  
for(int i=0;i<nStartPos.length;i++) uR5+")r@S  
{ 3NLn}  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), g"1V ]  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Lo{wTYt:J  
nStartPos,nEndPos,i); ,"(G  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )>:~XA|?  
fileSplitterFetch.start(); A}(]J!rc  
} A-T-4I  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _&hM6N  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); mi7?t/D1Z  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", u9OY Jo  
nEndPos = " + nFileLength); AX8~w(sv  
// fileSplitterFetch[nPos.length-1].start(); <VKJ+  
-je} PwT  
L AasmQ  
//等待子线程结束 b;UBvwY_  
//int count = 0; tfGs| x  
//是否结束while循环 j'z#V_S  
boolean breakWhile = false; AAlc %d/9  
|p&EP2?T  
BZ?3=S1*  
while(!bStop) S3ooG14Ls  
{ eV|N@  
write_nPos(); ]EX6Y  
Utility.sleep(500); DOKe.k  
breakWhile = true; {x_.QWe5  
Y:ly x-lj  
e=OHO,74z"  
for(int i=0;i<nStartPos.length;i++) Hyy b0c^=  
{ QIGUi,R  
if(!fileSplitterFetch.bDownOver) ey DV911  
{ OR+qi*)  
breakWhile = false; TjTG+uQ  
break; sip4,>,E  
} G|rE\h 2w  
} BqNeY<zB*  
if(breakWhile) f47]gtB-  
break; dgkS5Q$/  
k56Qas+3=  
 n?EgC8b9  
//count++; KUUA>'=  
//if(count>4) =#V^t$  
// siteStop(); &< BBP n@\  
}  4@  
\dtiv&x  
-<s Gu9  
System.err.println("文件下载结束!"); t^~vi'bB  
}  @./h$]6  
catch(Exception e){e.printStackTrace ();} H~+A6g]T  
} >o?v[:u*  
4f[%Bb  
u;_h%z5K  
//获得文件长度 S\).0goOW  
public long getFileSize() fZo#:"{/K  
{ T?pS2I~  
int nFileLength = -1; )y,^M3$?C  
try{ 5)!g.8-!  
URL url = new URL(siteInfoBean.getSSiteURL()); q,,  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \0b}Z#'0  
httpConnection.setRequestProperty("User-Agent","NetFox"); $9,&BW_*  
 LgNIb  
GEWjQ;g  
int responseCode=httpConnection.getResponseCode(); v745F Iy<  
if(responseCode>=400) {|?^@  
{ ZZT #V%Q=u  
processErrorCode(responseCode); ,0W^"f.g{m  
return -2; //-2 represent access is error ^HC 6v;K  
} 6eV#x%z@v'  
EnM  
'E_~ |C  
String sHeader; N y'\Q"Y]  
.T'@P7Hdx  
@L3XBV2  
for(int i=1;;i++) q Q\j  
{ ' k,2*.A  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); p'K`K\X  
//Utility.log(in.readLine()); jz bq{#  
sHeader=httpConnection.getHeaderFieldKey(i); R@o&c%K"  
if(sHeader!=null) (I >Ch)'  
{ D@bGJc0  
if(sHeader.equals("Content-Length")) ~lw9sm*2v2  
{ *S.U8;*Xj  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &zEQbHK6  
break; Du+W7]yCl  
} puC91  
} ;,&cWz  
else ==dKC;  
break; YaC%69C'  
} FH~:&;  
} 4@ PA+(kvS  
catch(IOException e){e.printStackTrace ();} Xqf,_I=V  
catch(Exception e){e.printStackTrace ();} N[e,){v  
yajdRU  
` =>}*GS  
Utility.log(nFileLength); u:l-qD9=(  
entU+Or  
)E}v~GW.+  
return nFileLength; =>$)F 4LW  
} 3Qy@^"  
CvoFt=c$jE  
npdljLN  
//保存下载信息(文件指针位置) 3z8i0  
private void write_nPos() U) J5K  
{ o:Fq|?/e  
try{ FnO@\{M"A  
output = new DataOutputStream(new FileOutputStream(tmpFile)); UkL1h7}a\  
output.writeInt(nStartPos.length); f<YYo  
for(int i=0;i<nStartPos.length;i++) Q\$3l'W  
{ %2\Hj0JQQ  
// output.writeLong(nPos); <3;p>4gN  
output.writeLong(fileSplitterFetch.nStartPos); n Nt28n@  
output.writeLong(fileSplitterFetch.nEndPos); .IeO+RDQ  
} bKQho31a'  
output.close(); 2e`}O  
} jxog8 E  
catch(IOException e){e.printStackTrace ();} 23}` e  
catch(Exception e){e.printStackTrace ();} jf9+H!?^N  
} bv+u7B6,  
k#].nQG  
QZzamT)"  
//读取保存的下载信息(文件指针位置) [l23b{  
private void read_nPos() q(KjhM  
{ 0fsVbC  
try{ n4K!Wv&u  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); \Vyys[MMY8  
int nCount = input.readInt(); l(t&<O(m9  
nStartPos = new long[nCount]; ~t6q-P  
nEndPos = new long[nCount]; 3!CUJs/W  
for(int i=0;i<nStartPos.length;i++) I1Q!3P  
{ XiW1X6  
nStartPos = input.readLong(); <tr]bCu}  
nEndPos = input.readLong(); 76nH)^%l<  
} ~YYnn7)  
input.close(); '75T2Ud  
} i>m%hbAk  
catch(IOException e){e.printStackTrace ();} SMN.AJ J  
catch(Exception e){e.printStackTrace ();} KgL!~J  
} q/i2o[f'n  
QNNURf\[(  
gEh/m.L7  
private void processErrorCode(int nErrorCode) da$FY7  
{ I3t5S;_8  
System.err.println("Error Code : " + nErrorCode); #D`@G8~(  
} +?_!8N8  
>US*7m }  
@62T:Vl  
//停止文件下载 '}.Yf_  
public void siteStop() 5ya9VZ5#  
{ IG^@VQ%  
bStop = true; iGyetFqKw  
for(int i=0;i<nStartPos.length;i++) jP+yN|  
fileSplitterFetch.splitterStop(); 28MMH Q  
qN!oN*  
t-\+t<;  
} Q0U~s\<  
} wI%M3XaBws  
//负责部分文件的抓取 1h,iWHC  
**FileSplitterFetch.java /5@YZ?|#2  
*/ l1+l@r\  
package NetFox; Uj!3MF  
o@:"3s  
cn'>dz3v  
import java.io.*; m:H^m/g  
import java.net.*; SQodk:1)  
 384n1?  
QYH-"-)  
public class FileSplitterFetch extends Thread { ].d2CJ'  
@^,q/%;  
vm [lMx  
String sURL; //File URL `^M]|7  
long nStartPos; //File Snippet Start Position 8U{D)KgS  
long nEndPos; //File Snippet End Position 5zl+M`  
int nThreadID; //Thread's ID ? x)^f+:9|  
boolean bDownOver = false; //Downing is over !]4u"e  
boolean bStop = false; //Stop identical M:+CW;||!  
FileAccessI fileAccessI = null; //File Access interface ,-UF5U  
,Z`}!%?  
H/,KY/>i  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ":]X r!e  
{ g3^s_*A  
this.sURL = sURL; 6!<I'M'[e  
this.nStartPos = nStart; "Y&I#&$b\  
this.nEndPos = nEnd; [&lK.?V)  
nThreadID = id; h@,ja  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 sy&[Q{,4  
} =KE7NXu]-  
SuE~Wb 5&  
:qzg?\(  
public void run() VPMu)1={:p  
{ q<YM,%mgj  
while(nStartPos < nEndPos && !bStop) B%F]K<  
{ bLc5$U$!I  
CoN[Yf3\  
-]N2V'QB  
try{ %>|FJ  
URL url = new URL(sURL); 0z8(9DlTc  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); MB]E[&Q!  
httpConnection.setRequestProperty("User-Agent","NetFox"); AWO)]rM  
String sProperty = "bytes="+nStartPos+"-"; [txOh!sxD  
httpConnection.setRequestProperty("RANGE",sProperty); 5y#,z`S  
Utility.log(sProperty); E_,/)U8  
*^?tr?e%I<  
T7[@ lMa?  
InputStream input = httpConnection.getInputStream(); O NabL.CV  
//logResponseHead(httpConnection); N ,~O+  
{cK<iQJ  
u0C:q`;z  
byte[] b = new byte[1024]; 5KC Qvv\  
int nRead;  s*u A3}j  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) yD9enYM  
{ Liqo)m  
nStartPos += fileAccessI.write(b,0,nRead); 3",gjXmBu  
//if(nThreadID == 1) >* -I Io  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ni;_Un~  
} K~(RV4oF8B  
DUOoTl p  
~k*]Z8Z  
Utility.log("Thread " + nThreadID + " is over!"); [ 8Ohg  
bDownOver = true; /!6'K  
//nPos = fileAccessI.write (b,0,nRead); 66=[6U9 *  
} %4~"$kE  
catch(Exception e){e.printStackTrace ();} Jqoo&T")  
} Yh<F-WOo2  
} )nm+_U  
LU3pCM{  
h&"9v~  
//打印回应的头信息 V)$!WPL@  
public void logResponseHead(HttpURLConnection con) EP>u%]#  
{ t{k:H4  
for(int i=1;;i++) !I7$e&Uz@  
{ j\}.GM'8  
String header=con.getHeaderFieldKey(i); Y\ [|k-6  
if(header!=null) Aztrq  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $|$@?H>K  
Utility.log(header+" : "+con.getHeaderField(header)); J8'"vc}=  
else z "@^'{.l  
break; 4.9qB  
} d4y#n=HnnV  
} EC?5GNGT,  
mWviWHK  
VG5+u,U6>  
public void splitterStop() ;,{ _=n>  
{ o/AG9|()4  
bStop = true; ~j!n`#.\  
} i"Jy>'  
(4H\ho8+mp  
T?3Q<[SmI  
} J=A)]YE  
[S6u:;7  
fUw:jE xz  
/* }?[];FB  
**FileAccess.java gM96RY  
*//文件访问(定位,写) NaR} 0  
package NetFox; |MNSIb&,W  
import java.io.*; rto?*^N?  
HUKrp*Hv  
C[FHqo9M?H  
public class FileAccessI implements Serializable{ 8h] TI_  
f&-`+V}U  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 1]xmOx[mb  
RandomAccessFile oSavedFile; n_kwtWX(  
long nPos; \8CCa(H  
>}SEU-7&\  
pGie!2T E  
public FileAccessI() throws IOException '54\!yQ<{  
{ /-M:6  
this("",0); Dk  `&tr  
} Ejk;(rxI  
/&gg].&2?  
~WA@YjQ]  
public FileAccessI(String sName,long nPos) throws IOException tZ]gVgZg  
{ rPk|2l,E,3  
oSavedFile = new RandomAccessFile(sName,"rw"); }Rh\JDiQ  
this.nPos = nPos; QK_5gD`$a,  
oSavedFile.seek(nPos); VEps|d3,,  
} |\(uO|)ju  
a`wjZ"}'[  
[ycX)iM  
public synchronized int write(byte[] b,int nStart,int nLen) |/,S NE  
{ "uH>S+%|b  
int n = -1; (~~m8VJ>  
try{ J|W E&5'  
oSavedFile.write(b,nStart,nLen); n/9afIN  
n = nLen; (T1< (YZ  
} &2ED<%hH`  
catch(IOException e) J v}  
{ .`D'eS6b  
e.printStackTrace (); ItVN,sVJb  
} mSYjc)z  
M`Y^hDl6  
Nj9A-*0g6N  
return n; H-_gd.VD  
} !Fl'?Kz  
::Zo` vP  
)+ <w>pc  
} ztVTXI%Kz  
5=o^/Vkc  
2@ S}x@^  
/* (Yewd/T  
**SiteInfoBean.java 1T|f<ChIF<  
*/ eB0exPz%  
package NetFox; <8WFaP3,  
(3n "a'  
snaAn?I4  
public class SiteInfoBean { "0eX/ rY%  
oc1BOW z  
|~Dl<#58  
private String sSiteURL; //Site's URL ' i+L  
private String sFilePath; //Saved File's Path tpWGmj fo>  
private String sFileName; //Saved File's Name xQsxc  
private int nSplitter; //Count of Splited Downloading File 3=enk0$  
;!<}oZp{  
OnTe_JML  
public SiteInfoBean() 5dj" UxH  
{//nSplitter的缺省值为5 ]\*^G@HA2  
//default value of nSplitter is 5 3d}v?q78  
this("","","",5);  7)2K6<q  
} F`g(vD >  
H07\z1?.K  
#eW T-m  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) yGR{-YwU!  
{ *OLqr/ yb  
sSiteURL= sURL; 1Q@]b_"Xh  
sFilePath = sPath; .UP h  
sFileName = sName; /8GdCac  
this.nSplitter = nSpiltter; /1OCK=  
c~<;}ve^z  
J&8KIOz14Z  
} lu.]R>w  
+a5F:3$  
,AnD%#o  
public String getSSiteURL() 6b|<$Je9  
{ R`(2Fy%0\k  
return sSiteURL; 9KVJk</:n  
} C|ZPnm>f30  
G)am ng/  
 sS-dHa  
public void setSSiteURL(String value)  9q"kM  
{ 4l 67B]o  
sSiteURL = value; x9YQd69  
} $toTMah w  
qFmw9\Fn  
^_]ZZin  
public String getSFilePath() J*;RL`  
{ GD4S/fn3  
return sFilePath; NW1Jr/  
} Y-ao yoNS  
UGAV"0  
t6"%u3W8M  
public void setSFilePath(String value) (%6fMVp  
{ |nNcV~%~  
sFilePath = value; S f?;j{?G  
} Vuz.b.,i`  
=F+v+zP7P  
v~mVf.j1  
public String getSFileName() ?+]=|hN  
{ ZDW9H6ux  
return sFileName; i<Z%  
} M@ U >@x;  
OjGI !  
:8`A  
public void setSFileName(String value) KQr+VQdq>  
{ 03~ ADj  
sFileName = value; RqA>"[L  
} W %*#rcdq  
O,r;-t4vYU  
g<Z :`00|  
public int getNSplitter() R /=rNUe  
{ Ll]5u~  
return nSplitter; CXq[VYM&X  
} 81Z;hO"~  
>ai,6!  
*L^W[o  
public void setNSplitter(int nCount) L$5,RUy  
{ 6q^$}eOt  
nSplitter = nCount; A|ZT ;\  
} @1*^ttC  
} 3L&:  
3m>YR-n$  
7${<u0((!  
/* 7DAP_C  
**Utility.java w5>[hQR\  
*/ ||:> &  
package NetFox; %0GwO%h},  
\OW:-  
8 W  
public class Utility { gKh*q.  
NsB]f{7>8+  
 W9?* ~!  
public Utility() FOF@@C~aH  
{ L"b&O<N o  
Bt<)1_  
S)U*1t7[  
} kp*v:*  
I# tlaz#  
//线程睡眠 -DkD*64wu  
public static void sleep(int nSecond)  ;+~5XLk  
{ .`IhxE~mN  
try{ Em!- W5*s  
Thread.sleep(nSecond); E&8Nh J  
} )Q=u[ p  
catch(Exception e) _*AI1/>`  
{ %Xh}{o$G  
e.printStackTrace (); VukbvBWPN  
} cy^=!EfA  
} }2]|*?1,  
e* [wF}))  
//日志 w-Ph-L/  
public static void log(String sMsg) xeF>"6\  
{ Zv@qdY<:  
System.err.println(sMsg); `PARZ|  
} P&Ke slk  
Ll|-CY $  
.?u<|4jE6  
public static void log(int sMsg) iYr)Ao5X  
{ "AagTFs(i  
System.err.println(sMsg); =NY;#Jjn  
} RiTL(Yx  
} K$Bv4_|x  
!Q>xVlPVu  
{ { \oC$  
/* $UzSPhv[  
**TestMethod.java KPToyCyR1  
*/ A}lxJ5h0  
package NetFox; % mQ&pk  
DWU=qD+  
Ur+U#}  
public class TestMethod { Ae7FtJO  
]zYIblpde  
<,:{Q75  
public TestMethod() eay|>xa2  
{ ///xx/weblogic60b2_win.exe y7+@ v'  
try{ ! t!4CY  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); DQ8/]Z{H  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0h1u W26^  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Y*BmBRN  
fileFetch.start(); Jh.~]\u  
} k@7#8(3  
catch(Exception e){e.printStackTrace ();} w>B}w  
|Y Lja87  
wS=vm}}u  
} Gor 9 &aJ1  
$2W#'_K+  
;87PP7~  
public static void main(String[] args) 6'r;6T *  
{ -Mr_Ao`E  
new TestMethod(); B=OzP+  
} WD%(RC"Q  
} &-*l{"7p+%  
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