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http断点续传简单实现(java)

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/* >MTrq%.  
**SiteFileFetch.java Aof)WKo  
*/ R6(sWN-  
package NetFox; \ F\ /<  
import java.io.*; &:>3tFQSH  
import java.net.*; \?$`dA[  
;\N )RZ  
Rm&^[mv  
public class SiteFileFetch extends Thread { Z[ NO`!<  
;S&PLgZ  
mp !S<m  
SiteInfoBean siteInfoBean = null; //文件信息Bean .S5%Qa [uW  
long[] nStartPos; //开始位置 '-,$@l#  
long[] nEndPos; //结束位置 ^"\3dfzKM  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 0[# zn  
long nFileLength; //文件长度 _#dBcEH[  
boolean bFirst = true; //是否第一次取文件 s%& /Zt  
boolean bStop = false; //停止标志 KT 4h3D`,  
File tmpFile; //文件下载的临时信息 }Wk^7[Y  
DataOutputStream output; //输出到文件的输出流 qG6?k}\\  
"jUM}@q5  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) |;(95  
public SiteFileFetch(SiteInfoBean bean) throws IOException P&>!B,f  
{ q&DM*!Jq  
siteInfoBean = bean; wV604eO(  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); N4[`pXM6  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); .jXD0~N8q  
if(tmpFile.exists ()) Kl Kk?6 >  
{ 8gHOs#\  
bFirst = false; 483/ZgzT`  
read_nPos(); Nv~H797B  
} $_ BoG  
else ~6Xr^An/Z  
{ V 6*ohC:  
nStartPos = new long[bean.getNSplitter()]; (u{?aG~  
nEndPos = new long[bean.getNSplitter()]; tk5zq-/ d  
} f-!P[6bY  
wv7XhY}  
+55+%oGl  
M+L8~BD@  
} S"@/F- 81  
)bgaqca_{  
.c5)`  
public void run() u_Wftb?9  
{ {vhP'!a6W  
//获得文件长度 anzt;V.;Y  
//分割文件 #Q]^9/;|4n  
//实例FileSplitterFetch NT0im%  
//启动FileSplitterFetch线程 G%HuB5:u  
//等待子线程返回 ^H(,^cVN  
try{ ^vY[d]R _\  
if(bFirst) +%~/~1  
{ q:/3uC7   
nFileLength = getFileSize(); ^[6S]Ft(  
if(nFileLength == -1) SWLt5dV  
{ ${F4x"x  
System.err.println("File Length is not known!"); +F4SU(T  
} q`0wG3  
else if(nFileLength == -2) .N>Th/K8  
{ MS~+P'  
System.err.println("File is not access!"); JW}O`H9  
} +V` *  
else l+UUv]:1  
{ T&q0TBT  
for(int i=0;i<nStartPos.length;i++) \3WQ<t)W  
{ Wb%t6N?  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ?r'2GR2Sk4  
} h@{mcz  
for(int i=0;i<nEndPos.length-1;i++) g}OZ!mKd  
{ 1!=^mu8  
nEndPos = nStartPos[i+1]; 6b wzNY 7  
} Bln($lOz  
nEndPos[nEndPos.length-1] = nFileLength; v,d bto0  
} @OGHS}-\  
} N \t( rp  
t) l  
IZs NMY  
//启动子线程 T^DJ/uhd  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; m#,AD,s  
for(int i=0;i<nStartPos.length;i++) \|YIuzlO4  
{ :V!F~  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M-V{(  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \\)9QP?  
nStartPos,nEndPos,i); >3?p23|;  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); I/hq8v~S  
fileSplitterFetch.start(); !zQbF&>  
} hd1aNaF-  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l 2ARM3"  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +pY-- 5t  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", tyU'[LF?  
nEndPos = " + nFileLength); ?p'DgL{  
// fileSplitterFetch[nPos.length-1].start(); w(oi6kg  
})y B2Q0  
gLK_b;:  
//等待子线程结束 ?J,K[.z  
//int count = 0; oe*CZ  
//是否结束while循环 P[%nD cB  
boolean breakWhile = false; REGk2t.L  
LEC=@) B  
I&9Itn p$  
while(!bStop) '\% Kd+k  
{ E}g)q;0v|2  
write_nPos(); Q;?rqi ,  
Utility.sleep(500); y#{v\h Cz  
breakWhile = true; _KJ!C!  
n+57# pS7  
NHQi_U  
for(int i=0;i<nStartPos.length;i++) rK[;wD<  
{ t Uk)S  
if(!fileSplitterFetch.bDownOver) b!JrdJO,DP  
{ d T7!+)s5-  
breakWhile = false; ;R([w4[~  
break; 3_ ZlZ_Tq  
} [tk6Kx8a  
} M.9w_bW]#D  
if(breakWhile) cBtQ2,<6  
break; uI\6":/u  
WXQ+`OH7  
%+iAL<S  
//count++; \YPv pUg  
//if(count>4) _P9*78  
// siteStop(); <!q_C5>XJ  
} oV'G67W  
57Bxx__S4`  
JqV}>"WMV  
System.err.println("文件下载结束!"); fb8)jd'~}O  
} !;Vqs/E  
catch(Exception e){e.printStackTrace ();} X?.tj Z,  
} w/e?K4   
x c|1?AFj  
E5yn,-GyE0  
//获得文件长度 J^-a@' `+  
public long getFileSize() 8`z  
{ DJb9] ,=a  
int nFileLength = -1; # TZ`   
try{ o]DYS,v  
URL url = new URL(siteInfoBean.getSSiteURL()); 30W.ks5(  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); WOQ>]Z  
httpConnection.setRequestProperty("User-Agent","NetFox"); E?FUr?-[  
*)L~1;7j>  
gu "@*,hL  
int responseCode=httpConnection.getResponseCode(); yRR[M@Y  
if(responseCode>=400) 9v/=o`J#  
{ )|6OPR@(#/  
processErrorCode(responseCode); H.< F6  
return -2; //-2 represent access is error @RHG@{x{K  
} ~3)d?{5  
H 3so&_  
"(mF5BE-E  
String sHeader; p,BoiYdi  
tYp 185  
u\(>a  
for(int i=1;;i++) Gkm {b[  
{ W~FU!C?]  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *|ef#-|D  
//Utility.log(in.readLine()); 1&RB=7.h  
sHeader=httpConnection.getHeaderFieldKey(i);  Vqr]Ui  
if(sHeader!=null) ar _@"+tZ  
{ jLn|zK  
if(sHeader.equals("Content-Length")) !JtM`x/yR  
{ B,] AfH  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 3oV2Ek<d  
break; 3+&k{UZjt  
} t +|t/1s2  
} &F8*>F^7  
else v]#[bqB.b  
break; 2({|LQqk  
} n~ZZX={a  
} <}G/x*N  
catch(IOException e){e.printStackTrace ();} rv c%[HfW;  
catch(Exception e){e.printStackTrace ();} 1DlXsup&?#  
=7[}:haB{  
Zb&"W]HSf  
Utility.log(nFileLength); zt!7aVm n  
^VEaOKMr  
V -_MwII-  
return nFileLength; $o/i / wcj  
} ~])Q[/=p  
;I*N%a TK  
MDBqIL]Hc  
//保存下载信息(文件指针位置) ~~@dbB  
private void write_nPos() _WZ{i,  
{ sR^b_/ElxT  
try{ t'Zv)Wu1E  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ] Upr<!  
output.writeInt(nStartPos.length); vl~HV8MAv  
for(int i=0;i<nStartPos.length;i++) UW1i%u k  
{ 51-'*Y  
// output.writeLong(nPos); }0sLeGJ!  
output.writeLong(fileSplitterFetch.nStartPos); 5"ooam3  
output.writeLong(fileSplitterFetch.nEndPos); y&/bp<Z  
} MnlD87x@X  
output.close(); b~2LD3"3  
} 6z]y =J  
catch(IOException e){e.printStackTrace ();} _sn<"B%>  
catch(Exception e){e.printStackTrace ();} jO9! :L>b`  
} nNeCi  
,~/WYw<o  
_ ^'QHWP  
//读取保存的下载信息(文件指针位置) ilyF1=bp  
private void read_nPos() ?_r{G7|D  
{ G7i0P j  
try{ N)PkE>%X  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); KWM.e1(  
int nCount = input.readInt(); .<Ays?  
nStartPos = new long[nCount]; ?vFtv}@\  
nEndPos = new long[nCount]; eaDR-g"  
for(int i=0;i<nStartPos.length;i++) < {h \Msx%  
{ eJ6 #x$I,  
nStartPos = input.readLong(); >f4[OBc  
nEndPos = input.readLong(); i(;.Y  
} 6uTC2ka[&R  
input.close(); %`~+^{Wp  
} x4h.WDT$  
catch(IOException e){e.printStackTrace ();} G9Noch9 g  
catch(Exception e){e.printStackTrace ();} 4Dy1M}7  
} @R<z=n"  
W.%p{wB |  
8llXpe  
private void processErrorCode(int nErrorCode) NwdrJw9  
{ >I-rsw2  
System.err.println("Error Code : " + nErrorCode); &3J^z7kU  
} {jv+ J L"5  
ohs`[U=%~  
fg lN_  
//停止文件下载 ox_DEg7l  
public void siteStop() R"l6|9tmP  
{ B_D0yhh  
bStop = true; zeq")A  
for(int i=0;i<nStartPos.length;i++) @n=&muC}  
fileSplitterFetch.splitterStop(); vvs2:87zvJ  
6=qC/1,l  
X{(?p=]  
} MPKrr  
} )a5ON8?  
//负责部分文件的抓取 y4r?M8]"r  
**FileSplitterFetch.java (5CgC <  
*/ =>kg]  
package NetFox; io(!z-$  
aX zb]">  
vxug>2  
import java.io.*; =qbN?a/?2  
import java.net.*; VFMn"bYOB  
'p78^4'PL  
)Gk?x$pY@  
public class FileSplitterFetch extends Thread { vexF|'!}0#  
EZzR"W/  
f*A B Im  
String sURL; //File URL mU  
long nStartPos; //File Snippet Start Position 3ZI:EZ5  
long nEndPos; //File Snippet End Position cNN0-<#c  
int nThreadID; //Thread's ID fUfd5W1"  
boolean bDownOver = false; //Downing is over aOd|;Z  
boolean bStop = false; //Stop identical KJv%t_4'F  
FileAccessI fileAccessI = null; //File Access interface `(gQw~|z  
cK2;)&U7  
Ux{0)"fj  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3)L#V .  
{ +>%51#2.Q  
this.sURL = sURL; 8'_MCx(  
this.nStartPos = nStart; ;(jL`L F  
this.nEndPos = nEnd; =v 'Aub  
nThreadID = id; q317~ z_nl  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 M,X)rM}Q  
} }_F:]lI*R  
hW9!  
d[5v A/8O  
public void run() [La}h2gz  
{ D?8(n=#[  
while(nStartPos < nEndPos && !bStop) _ker,;{9C  
{  zY7M]Az  
Q`NdsS2  
:WsHP\r  
try{ /Oi(5?Jn  
URL url = new URL(sURL); Z {:;LC  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); RZKx!X4=q  
httpConnection.setRequestProperty("User-Agent","NetFox"); s$,G5Feub  
String sProperty = "bytes="+nStartPos+"-"; PIXqd,  
httpConnection.setRequestProperty("RANGE",sProperty); 4mKH |\g  
Utility.log(sProperty); `rK@> -  
CE!cZZ  
>,tJq %  
InputStream input = httpConnection.getInputStream(); bfEH>pQ>#  
//logResponseHead(httpConnection); $7]?P;$  
U;*t5l  
sDR Av%w  
byte[] b = new byte[1024]; YJ-<t6  
int nRead; + !" Y C  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .C5<uW5-R  
{ 7[uN;B#V  
nStartPos += fileAccessI.write(b,0,nRead); 'r ^ .Ao5  
//if(nThreadID == 1) w{lj'3z I  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :-lq Yd5^  
} DU)q]'[u  
m/jyc# L:u  
%'=2Jy6h  
Utility.log("Thread " + nThreadID + " is over!"); "KS" [i!3j  
bDownOver = true; 7'65+c[&  
//nPos = fileAccessI.write (b,0,nRead); gm n b  
} evD=]iVD  
catch(Exception e){e.printStackTrace ();} !syyOfu`}  
} fAz4>_4  
} NFtA2EMLu[  
MK@rx6<9  
jJNl{nyq  
//打印回应的头信息 3TLym&  
public void logResponseHead(HttpURLConnection con) J]zhwM  
{ o8H\l\(  
for(int i=1;;i++) 98| v.d  
{ FGie*t  
String header=con.getHeaderFieldKey(i); >R_m@$`  
if(header!=null) \ykA7Y%  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 6d6Dk>(V  
Utility.log(header+" : "+con.getHeaderField(header)); K7.ayM 0  
else 3-6MGL9  
break; [` }w7  
} PFx.uqp  
} f Ayh9  
iOCs% J  
;K|K]c  
public void splitterStop() f2pA+j5[  
{ ^c/3 !"wK  
bStop = true; <gGO  
} S.`hl/  
z C$F@  
t9*e"QH  
} t^>P,%$  
"PWGtM:L8Y  
-P-8D6   
/* 0u&x%c  
**FileAccess.java nUVk;0at  
*//文件访问(定位,写) w-$iKtb.  
package NetFox; (x@J@ GP*  
import java.io.*; TuPD5-wB&  
F|/6;&*?M  
~`^kP.()  
public class FileAccessI implements Serializable{ BB9eQ: xO  
$cuBd  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 1{]S[\F]  
RandomAccessFile oSavedFile; \CE+P5  
long nPos; R.l!KIq  
0%;| B  
UWhHzLcXh  
public FileAccessI() throws IOException !FyO5`v  
{ PX0N7L  
this("",0); 1:- M<=J?f  
} J7oj@Or9  
]B8iQr-!  
}.U(Gxu$  
public FileAccessI(String sName,long nPos) throws IOException OC-d5P  
{ CS*lk!C  
oSavedFile = new RandomAccessFile(sName,"rw"); [`E_/95  
this.nPos = nPos; [Mc Hl1a  
oSavedFile.seek(nPos); H^`J(J+  
} ])bgUH  
#Tag"b`  
f\=,_AQ  
public synchronized int write(byte[] b,int nStart,int nLen) ZAeJTCCk  
{ ]9'F<T= $_  
int n = -1; N+5f.c+S-  
try{ {R[V  
oSavedFile.write(b,nStart,nLen); RhT:]  
n = nLen; =h=-&DSA  
} `1Md1e:J  
catch(IOException e) sh0x<_  
{ Q%!xw(  
e.printStackTrace (); 7<(U`9W/q  
} {M=B5-  
B-L@ 0gH  
Q>;Aq!mr=  
return n; W>Pcj EI  
} 4T"L#o1  
r8N)]Hs ZH  
)ezkp%I5D  
} 5 ';[|f  
;9fWxH  
EV* |\ te  
/* -iW>T5f  
**SiteInfoBean.java S;iD~>KP  
*/ !B{(EL=g  
package NetFox; qC& xuu|  
4DP<)KX  
OI:=>Bk  
public class SiteInfoBean { 0$Zh4Y  
)@y'$)5s  
&gC)%*I 4  
private String sSiteURL; //Site's URL @m:' L7+  
private String sFilePath; //Saved File's Path <&B] p  
private String sFileName; //Saved File's Name N!v>2"x8q  
private int nSplitter; //Count of Splited Downloading File [AD%8 H  
#a9R3-aP  
\>w 2D  
public SiteInfoBean() <; Td8O89_  
{//nSplitter的缺省值为5 ?;(!(<{  
//default value of nSplitter is 5 x 2l}$(7  
this("","","",5); N>P" $  
} f4dHOH  
prIJjy-F  
Oq3t-omXS  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !^1oH**  
{ @^-f +o  
sSiteURL= sURL; %4#ChlXB  
sFilePath = sPath; ntL%&wY  
sFileName = sName; Q'ib7R;V,  
this.nSplitter = nSpiltter; Zw/??Tq b  
K7(GdKZe  
eISHV.QV  
} MC B2  
_jxysFl=  
sv "GX< +  
public String getSSiteURL() g&ba]?[A  
{ ^Ga_wJP8S  
return sSiteURL; TC:t!:  
} 4zBcq<R7  
;t@^Z_z,CR  
Tn38]UL  
public void setSSiteURL(String value) %F;uW[4r  
{ (15.?9  
sSiteURL = value; NB(  GE  
} '$ G%HUn  
9N) Ea:N  
V|nJ%G\  
public String getSFilePath() )^E6VD&6  
{ %6@m~;c0  
return sFilePath; pf=CP%L  
} {gDoktC@M  
^*~4[?]S  
*iPBpEWC  
public void setSFilePath(String value) d+8|aS<A  
{ [t5 Dd  
sFilePath = value; L>57eF)7  
} g^\>hjNX  
2Myz[)<P_  
oOQ0f |MGp  
public String getSFileName() ]ddL'>$c$  
{ L'>0E(D  
return sFileName; ^c sOXP=Yp  
} 8Y;>3z th7  
,/Y$%.Rp  
_9iF`Q  
public void setSFileName(String value) ]U 1S?p  
{ +gb"} cN  
sFileName = value; &23t/`   
} l~*d0E-$  
M3)Id?|]6  
oYeFO w`  
public int getNSplitter() lJ4/bL2I/  
{ lstnxi%x  
return nSplitter; >LEp EMJ\  
} S?~/ V]  
7{f{SIB  
(*!4O>]  
public void setNSplitter(int nCount) qKuHd~M{ 1  
{ $I\lJ8  
nSplitter = nCount;  <>=abgg  
} twPD'X!r  
} TiI3<.a!  
.ldBl  
(i^<er q  
/* k,[[ CZ0j  
**Utility.java FWyfFCK  
*/ #~qY%X  
package NetFox; 9z?B@;lMc  
FzFP 0  
FOX0  
public class Utility { gAy"W$F  
DEKO] i  
8uetv  
public Utility() ,aSK L1  
{ sRGIHT#  
V"sm+0J  
5U JMiwP{  
} <d3N2  
(_~Dyvo  
//线程睡眠 "eKM<S  
public static void sleep(int nSecond) BH?fFe&J:`  
{ K%>3ev=y.s  
try{ 1f5;^T I  
Thread.sleep(nSecond); th|TwD&mO  
} ebB8.(k9G3  
catch(Exception e) 0J9Ub   
{ YoRD9M~iG~  
e.printStackTrace (); G/}nwj\  
} K6oQx)|  
} A)o%\j  
f<2<8xS  
//日志 o}lA\A  
public static void log(String sMsg) T:EUI]  
{ 0]t7(P"F6  
System.err.println(sMsg); JuXuS  
} dw< b}2  
!tv+,l&L  
0[SrRpD  
public static void log(int sMsg) BQ77 n2(@  
{ tumYZ)nW  
System.err.println(sMsg); i.>d#S  
} 17;qJ_T)  
} 4ew#@  
v@]\  P<E  
:.NCS`z_  
/* hc5iIJ]  
**TestMethod.java AU H_~SY  
*/ H-Or  
package NetFox; UNKXfe(X9  
5B+I\f&  
W q>qso  
public class TestMethod { -VRKQNT  
$t42?Z=N&z  
eop7=!`-~~  
public TestMethod() C2Af$7c  
{ ///xx/weblogic60b2_win.exe 6ALUd^  
try{ AG<TY<nqL  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); \"hP*DJ"  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); r#' E;Yx  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Fpf-Fa-K\b  
fileFetch.start(); .ID9Xd$fky  
} W2j@Q=YDS  
catch(Exception e){e.printStackTrace ();} C*,PH!$k  
_8nT$!\\  
+h? z7ZY^  
} _f~m&="T!  
e.pq6D5  
i?pC[Ao-_  
public static void main(String[] args) g|V0[Hnq6  
{ YXjWk),  
new TestMethod(); TP&&' 4?D1  
} 5iP{)  
} ! V;glx[  
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