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http断点续传简单实现(java)

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/* 6qpV53H  
**SiteFileFetch.java BK SK@OV  
*/ I.1l  
package NetFox; 5zna?(#}  
import java.io.*; J5 ( D7rp#  
import java.net.*; @rE )xco  
w{EU9C  
B?Sfcq-  
public class SiteFileFetch extends Thread { 1R9? [RE  
w{x(YVS H  
$IZZ`Z]B  
SiteInfoBean siteInfoBean = null; //文件信息Bean +Z2<spqG  
long[] nStartPos; //开始位置 X>8?p'*  
long[] nEndPos; //结束位置 fhx:EZ:~  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ){6)?[G  
long nFileLength; //文件长度 UVUO}B@[S  
boolean bFirst = true; //是否第一次取文件 })vr*[  
boolean bStop = false; //停止标志 E?U]w0g  
File tmpFile; //文件下载的临时信息 u(WQWsN  
DataOutputStream output; //输出到文件的输出流 >ImM~SR)  
1t=X: ]0j  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) dU^<7 K:S  
public SiteFileFetch(SiteInfoBean bean) throws IOException ATp  6-  
{ 4 xzJql  
siteInfoBean = bean; r ;8z"*  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); N@a'd0oTd  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); |ZlT>u  
if(tmpFile.exists ()) 166c\QO  
{ ]pTw]SK  
bFirst = false; .ASwX   
read_nPos(); m>dcb 6B+g  
} y]f^`2L!8>  
else f,inQ2f}d  
{ k|Yv8+XT  
nStartPos = new long[bean.getNSplitter()]; G2{M#H  
nEndPos = new long[bean.getNSplitter()]; RTBBb:eX  
} ;Jn0e:x`E  
-7z y  
*oX]=u&  
&dDI*v+  
} _Ge^ -7  
5=h'!|iY  
1$D`Z/N"A  
public void run() ;s. 5\YZ"k  
{ Q1\k`J  
//获得文件长度 $"{3yLg  
//分割文件 zQ %z "tQ  
//实例FileSplitterFetch 2*wO5v  
//启动FileSplitterFetch线程  >fA@tUQB  
//等待子线程返回 \"`>-v"h  
try{ UAXF64w{  
if(bFirst)  `pd   
{ Bd~cY/M  
nFileLength = getFileSize(); 4S0++Hp4  
if(nFileLength == -1) ^@*zH ?Rx{  
{ RR"W O  
System.err.println("File Length is not known!"); Y\Qxdq  
} & Yf#O*  
else if(nFileLength == -2) bZay/ Zkj  
{ Hu(flc+z"  
System.err.println("File is not access!"); A~GtK\=;  
} VFmg"^k5  
else 2*q: ^  
{ 3 [)s;e  
for(int i=0;i<nStartPos.length;i++) iVi3 :7*  
{ Xm=^\K3  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); io r [v  
} :e<`U~8m  
for(int i=0;i<nEndPos.length-1;i++) syW9Hlm  
{ Ie&b <k  
nEndPos = nStartPos[i+1]; J6( RlHS;  
} @Gn?8Ur%  
nEndPos[nEndPos.length-1] = nFileLength; jo;uRl  
} m$E^u[  
} )y/DGSd  
/q"d`!h)w  
<[y$D=n  
//启动子线程 zdjM%l);  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Q),3&4pM  
for(int i=0;i<nStartPos.length;i++) JXLWRe  
{ Y!= k  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1ntkM?  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Vy% :\p+  
nStartPos,nEndPos,i); aq0iNbv@  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b%[ nB  
fileSplitterFetch.start(); 7edPH3  
} \>Ga-gv6/  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (,Ja  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]/o12pI  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", T}t E/  
nEndPos = " + nFileLength); KZrMf77=  
// fileSplitterFetch[nPos.length-1].start(); oEQ{m5O9  
i+)}aA  
(zs4#ja2,  
//等待子线程结束 p2Dh3)&  
//int count = 0; YA"Ti9-EV  
//是否结束while循环 +^4BO`   
boolean breakWhile = false; b.R!2]T]i^  
*gd?>P7\0  
{K45~ha9!m  
while(!bStop) n^iNo  
{ M[YTk=IM#  
write_nPos(); Q%& _On  
Utility.sleep(500); /ojO>Y[<   
breakWhile = true; '?"t<$b  
1p7cv~#95  
Pt6hGSo.  
for(int i=0;i<nStartPos.length;i++) ]6t]m2~\  
{ n#+%!HTh  
if(!fileSplitterFetch.bDownOver) 'yPCZ`5H(  
{  <+AIt  
breakWhile = false; .M9d*qp`S  
break; Pz]bZPHn  
} Hp)X^O"  
} w]>"'o{{  
if(breakWhile) 4M @ oj  
break; -}{%Q?rYj  
,vPe}OKj  
=\~E n5  
//count++; r]A" Og_U  
//if(count>4) ~ X-)_zH  
// siteStop(); ;^R A!Nj  
} aO8c h  
x9&-(kBU  
:tRf@bD#  
System.err.println("文件下载结束!"); 4. 1rJa  
} r<;l{7lY_  
catch(Exception e){e.printStackTrace ();} slU  
} }JRP,YNh  
m7$8k@r  
Jy \2I{I'  
//获得文件长度 iO!27y  
public long getFileSize() Ho 3dsh)  
{ iM:yX=>a  
int nFileLength = -1; CF]i}xpWV  
try{ kf<c, 3A  
URL url = new URL(siteInfoBean.getSSiteURL()); Lltc 4Mzw  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A0G)imsW:_  
httpConnection.setRequestProperty("User-Agent","NetFox"); YiD-F7hf.*  
(2UW_l  
?2{bKIV_  
int responseCode=httpConnection.getResponseCode(); !7}IqSs  
if(responseCode>=400) 'eD J@4Xm  
{ _eGT2,D5r  
processErrorCode(responseCode); $:Rn;  
return -2; //-2 represent access is error 2ck 4C/ h  
} BR+nL6sU  
(=1)y'.  
))!Bg?t-  
String sHeader; {J (R  
[`d$X^<y;  
O7%2v@j|8  
for(int i=1;;i++) -K"4rz  
{ P` #QGZ>  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); gw"~RV0  
//Utility.log(in.readLine()); dm6~  
sHeader=httpConnection.getHeaderFieldKey(i); - a y5  
if(sHeader!=null) S=' wJ@?;  
{ *I0Tbc O  
if(sHeader.equals("Content-Length")) d{f@K71*  
{ U[R@x`  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \i!Son.<  
break; 6R`Oh uN.>  
} f/,tgA  
} tAjx\7IX  
else 4[TR0bM%  
break; D==Mb~  
} SVagT'BB  
} IS BV%^la|  
catch(IOException e){e.printStackTrace ();} w1r$='*I  
catch(Exception e){e.printStackTrace ();} YzAFC11,  
XF|WCZUnY%  
q_ %cbAcD  
Utility.log(nFileLength); \?DR s  
f6!D L<  
*XbI#L%>  
return nFileLength; =oX>Ph+ P  
} 'xnnLCm.  
\hlR]m!C  
n,j$D62[  
//保存下载信息(文件指针位置) 3xNMPm  
private void write_nPos() |%1?3Mpn  
{ 1tB[_$s  
try{ <*|?x86~  
output = new DataOutputStream(new FileOutputStream(tmpFile)); -kpswP  
output.writeInt(nStartPos.length); fQ 7vL~E  
for(int i=0;i<nStartPos.length;i++) @*MC/fe  
{ ~GJN@ka4%  
// output.writeLong(nPos); |.P/:e9  
output.writeLong(fileSplitterFetch.nStartPos);  Fl3#D7K  
output.writeLong(fileSplitterFetch.nEndPos); WKmbNvN^  
} K>2#UzW  
output.close(); AW,OH SXh6  
} K-eY|n  
catch(IOException e){e.printStackTrace ();} w!SkWS b,~  
catch(Exception e){e.printStackTrace ();} J:j<"uPm  
} 4v'A\~ZU  
M2@b1;  
9bJQT'<R  
//读取保存的下载信息(文件指针位置) (\a6H2z8l  
private void read_nPos() tNIlzR-  
{ s%pfkoOY%  
try{ ] asBd"  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); dQb.BOI)h  
int nCount = input.readInt(); 1tMQqI`N  
nStartPos = new long[nCount]; !k&Q 5s:  
nEndPos = new long[nCount]; @}s$]i$|-  
for(int i=0;i<nStartPos.length;i++) 6rN(_Oi-  
{ B[5r|d'  
nStartPos = input.readLong(); xJZ@DR,#  
nEndPos = input.readLong(); X|DO~{-au  
} ;WU<CKYG*  
input.close(); >dzsQ^Nj  
} E7zm{BX]  
catch(IOException e){e.printStackTrace ();} Bi3+)k>u7  
catch(Exception e){e.printStackTrace ();} Pw0Ci  
} x3p ND  
aqU' T  
|=a}iU8  
private void processErrorCode(int nErrorCode) J#2!ZQE 3  
{ ? 1*m,;Z  
System.err.println("Error Code : " + nErrorCode); :-`7Q\c}  
} r\`+R"  
Jb["4X;h  
<?Wti_ /M  
//停止文件下载 o*g|m.SjL  
public void siteStop() $2~\eG=u H  
{ vhuw &.\  
bStop = true; ULH0'@BJ  
for(int i=0;i<nStartPos.length;i++) TBrGA E  
fileSplitterFetch.splitterStop(); }MbH3ufC  
Q,h7Sk*  
C1EtoOv K  
} %wptZ"2M  
} JRMM?y  
//负责部分文件的抓取 Wu6<\^A  
**FileSplitterFetch.java A'&n5)tb  
*/ Mwp$  
package NetFox; 4*.K'(S5fx  
3jH\yXj  
k n[Y   
import java.io.*; ;a{:%t  
import java.net.*; WY:&ugGx  
llV3ka^!  
Z?Hs@j  
public class FileSplitterFetch extends Thread { G~7 i@Zs  
J[~5U~F  
<"D=6jqZ  
String sURL; //File URL P^`duZ{T  
long nStartPos; //File Snippet Start Position -u!FOD/  
long nEndPos; //File Snippet End Position `1OgYs  
int nThreadID; //Thread's ID 2lKV#9"  
boolean bDownOver = false; //Downing is over A5'NGt  
boolean bStop = false; //Stop identical r7]zQIE  
FileAccessI fileAccessI = null; //File Access interface c#IYFTz  
b1XRC`Gy  
r|e-<t4.9L  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException D]a<4a 18  
{ !\8  ;d8  
this.sURL = sURL; VQ5nq'{v  
this.nStartPos = nStart; D?yG+%&9  
this.nEndPos = nEnd; %ek'~  
nThreadID = id; z@Q@^ &0Mr  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 NLPkh,T:  
}  Uo12gIX  
65h @}9,U  
+ Q=1AXe  
public void run() ]ul$*  
{ `@[c8j7  
while(nStartPos < nEndPos && !bStop) h_1T,f (  
{ gBh;=vOD  
Ghl'nqPlm  
AcI,N~~  
try{ :l7U>~ o  
URL url = new URL(sURL); VhjM>(  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~_s?k3cd  
httpConnection.setRequestProperty("User-Agent","NetFox"); 8d*/HF)h  
String sProperty = "bytes="+nStartPos+"-"; [gy*`@w  
httpConnection.setRequestProperty("RANGE",sProperty); P0H6 mn*  
Utility.log(sProperty); "YdEE\  
>9RD_QG7  
;S0Kh"A  
InputStream input = httpConnection.getInputStream(); [V'QrcCF  
//logResponseHead(httpConnection); 8Og_W8  
Xc"&0v%;#  
322jR4QGr  
byte[] b = new byte[1024]; B+^(ktZp@  
int nRead; J psPNa  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \#o2\!@`  
{ Mu'8;9_6  
nStartPos += fileAccessI.write(b,0,nRead); (b'B%rFO  
//if(nThreadID == 1) VJ ^dY;  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mUS_(0q  
} "qc6=:y}  
8-y{a.,u.  
={LMdC~5X  
Utility.log("Thread " + nThreadID + " is over!"); >.dWjb6t  
bDownOver = true; ^c:Fy+fb  
//nPos = fileAccessI.write (b,0,nRead); K\XH4kic  
} }y9mNT  
catch(Exception e){e.printStackTrace ();} #2r}?hP/m  
} kP/M< X"  
} aK`@6F,]j  
ui(^k $  
%tG*C,l]  
//打印回应的头信息 ^v.,y3  
public void logResponseHead(HttpURLConnection con) .U T@p  
{ J'N!Omz  
for(int i=1;;i++) +cD!1IT:  
{ j"AU z)x  
String header=con.getHeaderFieldKey(i); J|&JD?  
if(header!=null) !"8fdSfg w  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); wdUBg*X8  
Utility.log(header+" : "+con.getHeaderField(header)); l}$ U])an#  
else 2tal  
break; lFTF ,G  
} 5|jw^s7  
} 0P\$ 2lk  
6252N]*  
TDd{.8qf  
public void splitterStop() rj6#1kt  
{ 2Ry1b+\  
bStop = true; H,N)4;F<c  
} kWdi59 5  
NJNJjdD>  
SJIOI@\b  
} JPGzrEaZ  
Q>n|^y6  
Qx[t /~  
/* %;.;>Y(-  
**FileAccess.java P;k0W>~k  
*//文件访问(定位,写) yRo- EP  
package NetFox; QR1{ w'c  
import java.io.*; {J^lX/D  
wC5ee:u C%  
C`5  
public class FileAccessI implements Serializable{ ?(R]9.5S  
cK 06]-Y  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .l@xsJn  
RandomAccessFile oSavedFile; ^a#X9  
long nPos; Uh][@35 p  
;pnD0bH  
[H=)  
public FileAccessI() throws IOException S{Er?0wm.R  
{ o`Ta("9^  
this("",0); &LbJT$}V  
} %Qj;,#z  
)KP5Wud X  
4fe7U=#;Y  
public FileAccessI(String sName,long nPos) throws IOException p1vp 8p  
{ gCxAG  
oSavedFile = new RandomAccessFile(sName,"rw"); |O"lNUW   
this.nPos = nPos; 1bH;!J  
oSavedFile.seek(nPos); p ZZc:\fJ  
} s M+WkN}{  
a<@N-Exr  
{c (!;U  
public synchronized int write(byte[] b,int nStart,int nLen) uV=Qp1~  
{ NOp609\^  
int n = -1; FXs*vg`  
try{ 7PkJ-JBA  
oSavedFile.write(b,nStart,nLen); 0@EwM  
n = nLen; &o<F7U'R  
} kV3 8`s>+  
catch(IOException e) 3YZs+d.;ib  
{ Yh>]-SCw  
e.printStackTrace (); IV)<5'v  
} K3=3~uY  
Jej` ;I  
ldp%{"ZZ  
return n; t 89!Ihk  
} DoeiW=  
Jm42b4  
0A( +ZMd  
} u{*SX k  
R~ZFy0  
mL4]l(U  
/* J2^'Xj_V  
**SiteInfoBean.java x l#LrvxI  
*/ }oNhl^JC  
package NetFox; f{FDuIl n  
ObiT-D?)g  
g]c6& Y,#  
public class SiteInfoBean { {\(L%\sV@  
]GRWnif  
EbdfV-E  
private String sSiteURL; //Site's URL TsGE cxIg  
private String sFilePath; //Saved File's Path }6@pJ G  
private String sFileName; //Saved File's Name $k2*[sn,  
private int nSplitter; //Count of Splited Downloading File tuhA 9}E  
M`l.t -ut  
*q1%IJ  
public SiteInfoBean() ;dzL}@we  
{//nSplitter的缺省值为5 /jRRf"B  
//default value of nSplitter is 5 kbMYMx.[  
this("","","",5); Oj^,m.R  
} Q_Gi]M9  
r3\cp0P;s  
DuOG {  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )'4k|@8|  
{ #/Eb*2C`b  
sSiteURL= sURL; W]5USFan  
sFilePath = sPath; P<f5*L#HD  
sFileName = sName; 6C+"`(u%V  
this.nSplitter = nSpiltter; ) lZp9O  
dx+hhg\L  
$]/Zxd  
} jb^N|zb  
oDU ;E  
g2T -TG'd  
public String getSSiteURL() [!U?}1YQ  
{ .;*s`t  
return sSiteURL; )kkhJI*v  
} R@`y>XGNJ  
.Fa4shNV  
f?'JAC*  
public void setSSiteURL(String value) %,k] [V  
{ ^)W[l!!<)  
sSiteURL = value; ()3O=!  
} iX4Iu3  
 z~>pVs  
|K|h+fgG6*  
public String getSFilePath() g'|MA~4yB  
{ 3dRr/Ilc  
return sFilePath; gw}Mw  
} T.qNCJmB  
d:i;z9b@to  
MKWyP+6`  
public void setSFilePath(String value) [/BE8]M ~  
{ Y>&Ew*Y  
sFilePath = value; `8Lo{P  
} W<E47  
\R3H+W  
V@\%)J'g  
public String getSFileName() E_bO9nRHV  
{ +fnK /%b  
return sFileName; V.{H9n]IO  
} ;jipe3LU  
P';?YV0  
xu'yVt9RC  
public void setSFileName(String value) R%c SJ8O#  
{ -^ C=]Medl  
sFileName = value; g{P%s'%*  
} FSRj4e1y1  
G2^et$<{uU  
@S 7sr-  
public int getNSplitter() NMi45y(Y  
{ bcZf>:gVf  
return nSplitter; jr`Ess  
} wX*K]VMn  
:,DM*zBV p  
Q pmsOp|  
public void setNSplitter(int nCount) E=#0I]v[  
{ %bdjBa}  
nSplitter = nCount; "1-}A(X  
} _IdRF5<4  
} zH*KYB  
fks)+L'  
bN3#{l-`  
/* vC5n[0  
**Utility.java i}~SDY  
*/ nYJTKU  
package NetFox; l#}.^71+  
SC- $B  
UDL RCS8i  
public class Utility { fhCc! \  
KW7UUXL  
P06R JE  
public Utility() ?]4>rl}  
{ "XT"|KF|D  
1\r|g2Z :  
9Fr3pRIJ  
} >X51$wBL  
%b^OeWip  
//线程睡眠 MW+b;0U`#  
public static void sleep(int nSecond) A3ZY~s#Iv  
{ YQS5P#  
try{ i>joT><B  
Thread.sleep(nSecond); z-c}NdW  
} RAp=s  
catch(Exception e) /P 2[:[w  
{ )<xypDQ  
e.printStackTrace (); a:_I  
} M5trNSL&u  
} Tdc3_<1  
^7.h%lSg  
//日志 \fjMc }'  
public static void log(String sMsg) dqX;#H}h  
{ X~xd/M=9^  
System.err.println(sMsg); Jx=hJ-FY  
} 2mq$H_  
AZ{^o4<q  
#"49fMi/  
public static void log(int sMsg) 1U,1)<z~u  
{ 8L1ohj  
System.err.println(sMsg); 9Mgq1Z  
} d|iy#hy"_  
} Q*XE h  
${8?N:>t  
bTSL<"(]N  
/* L.=w?%:H=  
**TestMethod.java wlPx,UqZ  
*/ |0,vQv  
package NetFox; dHk{.n^p  
v-! u\  
c   c  
public class TestMethod { =-o'gL  
Ea( ,aVlj  
@K:N,@yq  
public TestMethod() 1>Q'R  
{ ///xx/weblogic60b2_win.exe <vUVP\u~$  
try{ lW 81q2n  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :ah 5`nmPO  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [Ym   
SiteFileFetch fileFetch = new SiteFileFetch(bean); Rl6\#C*  
fileFetch.start(); P6Mhbmt9*  
} 7FF-*2@  
catch(Exception e){e.printStackTrace ();} _qWliw:0#  
Gc$gJnQio  
WX4;l(P L=  
} y4Er @8I`  
vs j3  
RJeSi`19T)  
public static void main(String[] args) T,_(?YJW  
{ /(8a~f&%r  
new TestMethod(); Krs2Gre}  
} Y+qQIMZ  
} tW;:-  
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