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http断点续传简单实现(java)

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/* %AMF6l[  
**SiteFileFetch.java gYL#} )g  
*/ j97c@  
package NetFox; RZvRV?<bR  
import java.io.*; uL-$^],  
import java.net.*; GyE5jh2  
dDe$<g5L4  
qE^u{S4Z@  
public class SiteFileFetch extends Thread { 8LtkP&Wx  
Lz- (1~o  
Or1ikI"  
SiteInfoBean siteInfoBean = null; //文件信息Bean <t*3w  
long[] nStartPos; //开始位置 yWYsN  
long[] nEndPos; //结束位置 5N>L|J2  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 5t-(MY  
long nFileLength; //文件长度 &I(3/u  
boolean bFirst = true; //是否第一次取文件 $a')i<m^g  
boolean bStop = false; //停止标志 yX\~ {%  
File tmpFile; //文件下载的临时信息 N8wA">u  
DataOutputStream output; //输出到文件的输出流 CfLPs)\ACm  
q_6 <}2m,U  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 0@!-+}i  
public SiteFileFetch(SiteInfoBean bean) throws IOException =rNI&K_<  
{ S?H qrf7<  
siteInfoBean = bean; Yu9(qRK  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); e58tf3  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); GQkI7C  
if(tmpFile.exists ()) ;;17 #T2  
{ %Y].i/".;P  
bFirst = false; h*NBSvn  
read_nPos(); e=6C0fr  
} #w[Ie+  
else \T!tUd  
{ S#D6mg$Z,  
nStartPos = new long[bean.getNSplitter()]; g<4@5OQKu  
nEndPos = new long[bean.getNSplitter()]; %?`$#*f\%  
} 9H%L;C5<  
Ut"F b  
:jWQev"/  
6$+F5T  
} NSh~O!pX  
LwCf}4u"  
{Pi]i?   
public void run() al Q:'K  
{ (d5kD#.N  
//获得文件长度 7OZjLD{ID  
//分割文件 \H?r[]*c%  
//实例FileSplitterFetch "Kn%|\YL@4  
//启动FileSplitterFetch线程 [1`&\C_E  
//等待子线程返回 H|!|fo-Tx  
try{ pL'+sW  
if(bFirst) OEgp!J  
{ "\Nn,3qp  
nFileLength = getFileSize(); )mXu{uowr  
if(nFileLength == -1) 2G`tS=Un  
{ ~LN {5zg  
System.err.println("File Length is not known!"); AtlUxFX0S  
} Rp"" &0  
else if(nFileLength == -2) ~d6zpQf7>  
{ |NWo.j>4-  
System.err.println("File is not access!"); RS[QZOoW}  
} /4 -6V d"8  
else arj?U=zy  
{ )1 !*N)$  
for(int i=0;i<nStartPos.length;i++) q6>%1~?  
{ |lf,3/*jDB  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); g)~"-uQQ  
} K@@[N17/8  
for(int i=0;i<nEndPos.length-1;i++) fnO>v/&B  
{ 1lQO`CmR6M  
nEndPos = nStartPos[i+1]; \ssqIRk  
} w97%5[-T  
nEndPos[nEndPos.length-1] = nFileLength; 2~*.X^dR  
} S_56!  
} _0e;&2')  
_ye74$#  
NXDuO_#  
//启动子线程 zH+a*R  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; CrI:TB>/ "  
for(int i=0;i<nStartPos.length;i++) },G5!3  
{ g flu!C6  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), LYyOcb[x  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &,~Oi(SX5  
nStartPos,nEndPos,i); aRF}F E,u  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]eZrb%B .  
fileSplitterFetch.start(); R<x~KJ11c  
} pbePxOG  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4XXuj  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); loFApBD=$^  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", sDnXgCcS!  
nEndPos = " + nFileLength); a@V`EEZ  
// fileSplitterFetch[nPos.length-1].start(); "_T8Km008  
Ves x$!F#  
jpek=4E  
//等待子线程结束 KI{B<S3*Z  
//int count = 0; h#rziZ(  
//是否结束while循环 6Z3L=j  
boolean breakWhile = false; u3ns-e  
$UGX vCR  
a$ FO5%o  
while(!bStop) K _sHZ  
{ V t@]  
write_nPos(); yd4\%%]  
Utility.sleep(500); m<uBRI*I  
breakWhile = true; "WE*ED  
tjTnFP/=  
pw5uH  
for(int i=0;i<nStartPos.length;i++) Dm 0Ts~  
{ +:?"P<'  
if(!fileSplitterFetch.bDownOver) wXnluE  
{ )4BLm  
breakWhile = false; -3On^Wj]  
break; Zf~Z&"C)  
} Q9h;`G 7t  
} E2~&GkU.UN  
if(breakWhile) (W4H?u@X0  
break; >")<pUQ  
Q,m1mIf  
U^.kp#x#  
//count++; 6<h ==I   
//if(count>4) n6]8W^g  
// siteStop(); %RS8zN  
} =7212('F  
oF0BBs$  
QlCs ,bT  
System.err.println("文件下载结束!"); .>Fy ]Cqoh  
} r0 fxEYze&  
catch(Exception e){e.printStackTrace ();} yO`HL'SMo  
} B LI 9(@  
6_wj,7  
[uD G;We=  
//获得文件长度 ,`O.0e4pn  
public long getFileSize() L|H:&|F  
{ $)6%LG_@  
int nFileLength = -1; Hlj_oDL  
try{ ydm2'aV  
URL url = new URL(siteInfoBean.getSSiteURL()); U+FI^Xrt#  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); kMP3PS  
httpConnection.setRequestProperty("User-Agent","NetFox"); Mo~zq.  
$"[5]{'J  
_ ^ny(zy(  
int responseCode=httpConnection.getResponseCode(); $zUHka   
if(responseCode>=400) Yg kd1uI.  
{ l" P3lKS  
processErrorCode(responseCode); oDBv5  
return -2; //-2 represent access is error +zf[Im%E  
} 7U, [Ruu  
\]=''C=J  
M\rZr3  
String sHeader; kt;uB X3  
]5Mq^@mD'  
F2:nL`]b[  
for(int i=1;;i++) ZtLZW/`  
{ K*[`s'Ip-  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $WS?/H0C  
//Utility.log(in.readLine()); P")1_!  
sHeader=httpConnection.getHeaderFieldKey(i); |.EC>D /  
if(sHeader!=null) &kp`1kv":  
{ ]oIP;J:&  
if(sHeader.equals("Content-Length")) _(%;O:i  
{ QxI^Bx  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <tx`#,  
break; *'ffMnSZ  
} r(6$.zx  
} a 0+W-#G  
else 64R~ $km  
break; ly~tB LH}  
} 1@S(v L3a  
} NwbX]pDT  
catch(IOException e){e.printStackTrace ();} EwX:^1f  
catch(Exception e){e.printStackTrace ();} bDADFitSo  
:.bBV]6q  
.Gq]Mrim9G  
Utility.log(nFileLength); +Cg[!6[#  
A$o7<Hx  
0wnC"2GUX  
return nFileLength; eOUv#F  
} ,?/AIL]_  
9T;DFUM  
fIwG9cR  
//保存下载信息(文件指针位置) *mtS\J  
private void write_nPos() 3 =-XA2zJ  
{ ]r.95|V*  
try{ {&,MkWgG  
output = new DataOutputStream(new FileOutputStream(tmpFile)); fuao*L]  
output.writeInt(nStartPos.length); Lh rU fy  
for(int i=0;i<nStartPos.length;i++) G'IRqO *]  
{ @b{I0+li"/  
// output.writeLong(nPos); uP NZ^lM  
output.writeLong(fileSplitterFetch.nStartPos); 6s(.u l  
output.writeLong(fileSplitterFetch.nEndPos); %&}gt+L(M  
} tx_h1[qi  
output.close(); h= Mmd  
} 'LW~_\  
catch(IOException e){e.printStackTrace ();} m[8?d~  
catch(Exception e){e.printStackTrace ();} $;VY`n  
} (F=q/lK$  
*pj^d><  
:xy4JRcF  
//读取保存的下载信息(文件指针位置) i!u:]14>  
private void read_nPos() mGP&NOR0^y  
{ >\4"k4d}  
try{ Bh ,GQHJ  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); X-k$6}D  
int nCount = input.readInt(); EaN1xb(DYa  
nStartPos = new long[nCount]; ag{cm'.  
nEndPos = new long[nCount]; h}&1 7M  
for(int i=0;i<nStartPos.length;i++) bSgdVP-  
{ #Pr w2u  
nStartPos = input.readLong(); ;%B:1Z  
nEndPos = input.readLong(); VbfTdRD-  
} 2C[xrZa^  
input.close(); O0RV>Ml'&  
} .{,fb  
catch(IOException e){e.printStackTrace ();} ,0\P r  
catch(Exception e){e.printStackTrace ();} d8ck].m=  
} ni~1)"U.  
/ht-]Js$G  
*Eg[@5;QA  
private void processErrorCode(int nErrorCode) _MxKfah'  
{ B:rzM:BQ  
System.err.println("Error Code : " + nErrorCode);  4"~F  
} Zg=jDPt}  
HIsB)W&%@  
@5tGI U;1  
//停止文件下载 p,K!'\  
public void siteStop() JDP/vNq  
{ D/&nEMp6  
bStop = true; T0v{qQ  
for(int i=0;i<nStartPos.length;i++) J-5E# v  
fileSplitterFetch.splitterStop(); eJ+@<+vr;x  
[Ufx=BPx3  
}UX0 eI4  
} |f{(MMlj  
} u{8:VX  
//负责部分文件的抓取 Bv{DZ?{s  
**FileSplitterFetch.java =.(~`ici~  
*/ ;Q\MH t*  
package NetFox; 6Ij'z9nJw  
;Z!x\{- L  
9^g?/8  
import java.io.*; J. $U_k  
import java.net.*; 2F#DJN#  
^?R8>97_?  
8fWk C<f}  
public class FileSplitterFetch extends Thread { 'bn$"A"{o  
A Qm!7,  
'n/L1Fn  
String sURL; //File URL D]'/5]~z<  
long nStartPos; //File Snippet Start Position BFvRU5&Sz  
long nEndPos; //File Snippet End Position Pq3m(+gf  
int nThreadID; //Thread's ID @FaK/lKK  
boolean bDownOver = false; //Downing is over k7)<3f3&S.  
boolean bStop = false; //Stop identical 'mYUAVmSC#  
FileAccessI fileAccessI = null; //File Access interface 7u<C&Z/  
P-?R\(QYtR  
U0@Qc}y  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException T7LO}(I.&  
{ {66P-4Ev(  
this.sURL = sURL; =`E{QCW  
this.nStartPos = nStart; Ft<B[bQ  
this.nEndPos = nEnd; VI k]`)#  
nThreadID = id; ^SWV!rrg  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 b*TQKYT  
} w)Z-, J  
;.{J>Q/U,  
j]'ybpMT"  
public void run() l]~mB~  
{ H:]'r5sw  
while(nStartPos < nEndPos && !bStop) fb?YDM  
{ 'cPE7uNT  
@M!nAQ8hY  
@&f~#Xe  
try{ ukc<yc].+?  
URL url = new URL(sURL); Jxsch\  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Nin7AOO  
httpConnection.setRequestProperty("User-Agent","NetFox"); 89P'WFOFK  
String sProperty = "bytes="+nStartPos+"-"; J936o3F_  
httpConnection.setRequestProperty("RANGE",sProperty); tJII-\3"  
Utility.log(sProperty); k]=lo'bF4  
=^mBj?(V7  
D9%t67s  
InputStream input = httpConnection.getInputStream(); )QW p[bV  
//logResponseHead(httpConnection); d8J(~$tXQN  
n+D93d9LP  
+o|I@7f  
byte[] b = new byte[1024]; Xk`'m[  
int nRead; MQMc=Z4d  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) bkS-[rW  
{ e/R$Sfj]  
nStartPos += fileAccessI.write(b,0,nRead); _g%,/y 9y  
//if(nThreadID == 1) _<u>? Qt  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]N{jF$  
} :&J1#% t  
,'%*z  
*:"p*qV*  
Utility.log("Thread " + nThreadID + " is over!"); 5%]O'h  
bDownOver = true; +wGFJLHJ  
//nPos = fileAccessI.write (b,0,nRead); `]4tJJy$  
} WSqo\]  
catch(Exception e){e.printStackTrace ();} }ws(:I^  
} j5!pS xOC  
} =y0h\<[  
M.``o1b  
K$c?:?wmo  
//打印回应的头信息 !|~yf3  
public void logResponseHead(HttpURLConnection con) A`nzqe#(1  
{ u?SxaGEa  
for(int i=1;;i++) =)f5JwZPG  
{ #Q/xQ`+|.  
String header=con.getHeaderFieldKey(i); yX%NFXD  
if(header!=null) Oid;s!-S6  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); O #5`mo  
Utility.log(header+" : "+con.getHeaderField(header)); /)<Xoa  
else ~(}n d  
break; +Uxt xl'  
} ?0?+~0sI  
} ^?S lM  
V|)nU sU  
& Tkl-{I  
public void splitterStop() u-R;rf5%k  
{ 1AQ3<  
bStop = true; ~\u~>mtchu  
} 9#1Jie$  
G8lTIs4u;  
=8A L>:_  
} :'Tq5kE  
R= .UbY  
%afz{a5  
/* <q:2' 4o  
**FileAccess.java 8TCbEPS@Q  
*//文件访问(定位,写) ZM_-g4[H  
package NetFox; 7T?T0x3>  
import java.io.*; MCTTm^8O  
?OC&=}  
^C~t)U  
public class FileAccessI implements Serializable{ ;aDYw [  
Q|7;Zsd:  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 mV.26D<c  
RandomAccessFile oSavedFile; \RmU6(;IQ  
long nPos; %<\tN^rP  
Id{Ix(O  
~;@\9oPpz%  
public FileAccessI() throws IOException yAQ)/u[|  
{ QeQxz1  
this("",0); z'}z4^35,  
} @+hO,WXN  
]u47]L#  
&/$3>MD2`  
public FileAccessI(String sName,long nPos) throws IOException ~vKDB$2  
{ /;WFRp.  
oSavedFile = new RandomAccessFile(sName,"rw"); $?y\3GX  
this.nPos = nPos; H(DI /"N  
oSavedFile.seek(nPos); gH/(4h  
} <*z9:jz Q  
e?<$H\  
&XB1=b5  
public synchronized int write(byte[] b,int nStart,int nLen) {CQI*\O  
{ 3^]Kd  
int n = -1; smPZ%P}P+c  
try{ h%&2M58:  
oSavedFile.write(b,nStart,nLen); bq z*90  
n = nLen; K Vnz{cx`  
} -;o0) DwZ  
catch(IOException e) -932[+  
{ ; g\r Y  
e.printStackTrace (); mV|Z5= f  
} ~Hvf"bvK|  
K QCF "  
*/j[n$K>~`  
return n; +K48c,gt?  
} BP=<TRp .  
.2SD)<}(9  
/\m>PcPa  
} nBtKSNT#Q  
te+r.(p  
gP?.io 9Oi  
/* "cGjHy\j`  
**SiteInfoBean.java m]&y&oz  
*/ uXVs<im  
package NetFox; v dPb-z4  
$|K-wN[  
j=Z;M1  
public class SiteInfoBean { R2y~+tko?  
s\.\z[1  
.`^wRpa2M  
private String sSiteURL; //Site's URL i*e'eZ;)  
private String sFilePath; //Saved File's Path Dj{=Y`Tw  
private String sFileName; //Saved File's Name 'e8O \FOf  
private int nSplitter; //Count of Splited Downloading File u(g9-O  
EO"G(v  
( #rhD}  
public SiteInfoBean() 4B@Ir)^(*  
{//nSplitter的缺省值为5 >uwd3XW5  
//default value of nSplitter is 5 4)d"}j  
this("","","",5); +krDmU9(  
} bE b+oRI  
IhXP~C6  
)odz/\9n3c  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |\N))K-2D  
{ du&9mOrr  
sSiteURL= sURL; 6,(S}x YDZ  
sFilePath = sPath; R!2E`^{Wl  
sFileName = sName; K*N8Vpz(  
this.nSplitter = nSpiltter; [q~3$mjQ  
3PEW0b*]Pf  
$`_xP1bUT  
} t^7}j4lk  
VTn6@z_ x  
vO8CT-)  
public String getSSiteURL() >Slu?{l'  
{ YT<(2u#Ng  
return sSiteURL; O[R   
} Z>hGqFZ0{  
kI,O9z7A7  
8 )= "Ee  
public void setSSiteURL(String value) Cf3<;Mp<  
{ -o YJ&r  
sSiteURL = value; 9O-*iK  
} c@{M),C~E  
IaGF{O3.  
59k-,lyU,  
public String getSFilePath() x%55:8{  
{ tF!-}{c"k  
return sFilePath; ZvSEa{  
} FIpJ>E"n  
E*8 3N@i  
m>+ e;5  
public void setSFilePath(String value) /}=cv>S5V  
{ :7pt=IA  
sFilePath = value; \/?&W[TF  
} `,Y/!(:;  
Q=#Wk$1.  
*zWf8X  
public String getSFileName() j4E`O%@^  
{ V0y_c^x  
return sFileName; x_#'6H\1ga  
} bOK0^$k  
+6f[<^K#  
z}2  
public void setSFileName(String value) CwsC)]{/o  
{ L%I8no-Q  
sFileName = value; /086qB|  
} yVH>Q-{  
Zmy:Etqi  
L!^^3vn  
public int getNSplitter() YH{FTVOt{C  
{ 3'[ g2JR  
return nSplitter; .%_=(C< E  
} rG{,8*  
TTz_w-68  
[+b&)jN*2  
public void setNSplitter(int nCount) P;ovPyoO  
{ DaqpveKa  
nSplitter = nCount; F,JqHa9  
} 89J7hnJC  
}  o*xft6U  
-\M;bQV[C  
d? 4-"9Y  
/* Fy^MI*}BZ  
**Utility.java en29<#8TO  
*/ {r1}ACw{  
package NetFox; U Kf0cU  
Ia-nA|LBxI  
xU'% 6/G  
public class Utility { V)cL=4G  
`<* tp@  
^qV6 khg  
public Utility() ]/odp/jm  
{ MO_;8v~0  
h2vD*W  
AHn Yfxv_  
} z:JJ>mxV  
SHN'$f0Mb  
//线程睡眠 YfVZ59l4y6  
public static void sleep(int nSecond) bw OG|\  
{ ?V4bz2#!1O  
try{ R<e ~Cb-  
Thread.sleep(nSecond); pSS8 %r%S'  
} "M=1Eb$6=  
catch(Exception e) n<Z1i)  
{ {'[S.r`  
e.printStackTrace (); S&F  
}  @+!u{  
} f9La79v  
/xkF9   
//日志 @xN)mi  
public static void log(String sMsg) "i; "  
{ a fUOIM  
System.err.println(sMsg); U )J/so)  
} ^-26K|{3  
/U@Y2$TOF  
@tPptB  
public static void log(int sMsg) d8M8O3  
{ oVeC@[U  
System.err.println(sMsg); +XL|bdK  
} u51Lp  
} p/'09FY+U  
0-Vx!(  
!Bn,f2  
/* y/!jC]!+c  
**TestMethod.java gt Rs||  
*/ z#\YA]1  
package NetFox; ]xN)>A2  
GaLQ/V2R  
I'%ASZ  
public class TestMethod { a,KqTQB  
b1-'q^M  
0v'!(&m  
public TestMethod() wZKEUJpQ  
{ ///xx/weblogic60b2_win.exe 8U7X/L  
try{ aX|LEZ;D>  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); gR@,"6b3  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); yPVK>em5  
SiteFileFetch fileFetch = new SiteFileFetch(bean); +X!QH/ 8  
fileFetch.start(); _W gpk 0  
} t(=Z@9)]4F  
catch(Exception e){e.printStackTrace ();} lIgAc!q(  
eX <@qa4<  
lH%-#2]  
} OjfumZL#  
`6 ?.ihV  
"i~~Q'=7  
public static void main(String[] args) )UAkg  
{ ZA'Qw2fF0  
new TestMethod(); )(l=_[1Z5  
} "E%3q3|"l  
} &T\,kq >)  
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