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http断点续传简单实现(java)

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/* yX$I<L<Suz  
**SiteFileFetch.java apF!@O^}y  
*/ 6LL/wemq  
package NetFox; I7 pxi$8f  
import java.io.*; bsC~ 2S\o  
import java.net.*; Km8btS]n  
I.Co8is  
@y;N u   
public class SiteFileFetch extends Thread { l] WV gu  
#w*1 !  
t@ #sKdv  
SiteInfoBean siteInfoBean = null; //文件信息Bean %O%+TR7Z  
long[] nStartPos; //开始位置 ED"@!M`1  
long[] nEndPos; //结束位置 ct3QtX0B  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Ym(^i h  
long nFileLength; //文件长度 m8rKH\FD}  
boolean bFirst = true; //是否第一次取文件 l2+qP{_4  
boolean bStop = false; //停止标志 9b@L^]Kg  
File tmpFile; //文件下载的临时信息 gTY\B.  
DataOutputStream output; //输出到文件的输出流 +G"=1sxJ  
yrnB]$hf  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) pAtHU(}  
public SiteFileFetch(SiteInfoBean bean) throws IOException x|_%R v  
{ zPe4WE|  
siteInfoBean = bean; R/waWz\D  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); %'kaNpBz  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); v$K`C;  
if(tmpFile.exists ()) 'v* =}k  
{ }$hxD9z  
bFirst = false; W*QD'  
read_nPos(); A)2vjM9}K  
} |Pz-  
else @%IZKYf c~  
{ p \; * :  
nStartPos = new long[bean.getNSplitter()]; HD IB GG~  
nEndPos = new long[bean.getNSplitter()]; A,W-=TC  
} [V  T&  
{lT9gJ+  
mk~i (Ee  
K%Mm'$fTw  
} WiH%URFB  
a^ <  
({yuwH?tH  
public void run() Cmm"K[>Rx  
{ d;Z<")  
//获得文件长度 ilw<Q-o4(  
//分割文件 KM g`O3_16  
//实例FileSplitterFetch =%znY`0b56  
//启动FileSplitterFetch线程 [y\ZnoB  
//等待子线程返回 X1]&j2WR  
try{ d;|e7$F'  
if(bFirst) 8X!UtHml  
{ [z]@ <99/  
nFileLength = getFileSize(); [`_&d7{-4b  
if(nFileLength == -1) 6`]R)i]  
{ /,"Z^=  
System.err.println("File Length is not known!"); KwN o/x| v  
} ?cG+rC%  
else if(nFileLength == -2) Cfyas'  
{ Dw%>y93V  
System.err.println("File is not access!"); f_Y[I :  
} tV9W4`Z2q  
else #] vq <Y  
{ Gnj;=f  
for(int i=0;i<nStartPos.length;i++) (zWzF_v  
{ '&W`x5`t  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Fm3-Sn|Po  
} CM>/b3nOW  
for(int i=0;i<nEndPos.length-1;i++) brb8C%j}9  
{ jZ7/p^c5R  
nEndPos = nStartPos[i+1]; V`TXn[7  
} bS3qX{5  
nEndPos[nEndPos.length-1] = nFileLength; KunK.m  
} "6~pTHT  
} U> (5J,G  
aa_&WHXkt  
hQ i[7r($8  
//启动子线程 2xZg, \  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; t ^&:45~Q  
for(int i=0;i<nStartPos.length;i++) Oo`P +S#  
{ (s %T1 8  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), i92{N$*x  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &jl'1mZ  
nStartPos,nEndPos,i); :@wO' o  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); iH9g5G`O  
fileSplitterFetch.start(); l#7,<@)  
}  V-}d-Y  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :M`|*~V~$  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Xl#vVyO  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1(gb-u0  
nEndPos = " + nFileLength); %/oOM\} ++  
// fileSplitterFetch[nPos.length-1].start(); t^Aios~F  
Fla[YWS  
 / >Wh  
//等待子线程结束 N;F1Z-9  
//int count = 0; 0'Tq W9P  
//是否结束while循环 +%>s\W+?]  
boolean breakWhile = false; X9/V;!  
C(3yJzg>y  
?6p6OB  
while(!bStop) v>c[wg9P  
{ jm =E_86_  
write_nPos(); Oe'Nn250  
Utility.sleep(500); c#OZ=`  
breakWhile = true; S&6}9r  
)*G3q/l1u6  
M`FsKK`  
for(int i=0;i<nStartPos.length;i++) DvG.G+mo#  
{ W2wDSP-   
if(!fileSplitterFetch.bDownOver) ?f1%)]>   
{ H#E   
breakWhile = false; 6ApW+/  
break; ""^9WLH4g-  
} o2 W pi  
} x]euNa  
if(breakWhile) (iP,F]  
break; #v:<\-MjN  
HoT5 5v!o  
2 L%d,Ta>  
//count++; `-\4Dx1!q  
//if(count>4) `kwyF27v]  
// siteStop(); x~$P.X7(~  
} XU2 HWa  
N Rcg~Nu  
L-Xd3RCD  
System.err.println("文件下载结束!"); +DF<o U~  
} S5" xb  
catch(Exception e){e.printStackTrace ();} )FMpfC>An  
} j*I0]!-  
'an{<82i  
jn^i4f>N  
//获得文件长度 GL@s~_;T6  
public long getFileSize() 8hQ"rrj+  
{ cK(}B_D$  
int nFileLength = -1; |O+R%'z'<  
try{ E5jK}1t4V  
URL url = new URL(siteInfoBean.getSSiteURL()); /Or76kE  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %saTyF,  
httpConnection.setRequestProperty("User-Agent","NetFox"); Fy`VQ\%7t  
).9-=P HlX  
Yl&eeM  
int responseCode=httpConnection.getResponseCode(); 5>j,P   
if(responseCode>=400) nkS6A}i3o  
{ 3dcZ1Yrn  
processErrorCode(responseCode); *7ap[YXZ\w  
return -2; //-2 represent access is error 8ji!FZf  
} ,G"?fQ7zR  
e:AB!k^xp$  
>7vSN<w~m  
String sHeader; FDbx"%A  
$ ohwBv3S  
^dZ,Itho  
for(int i=1;;i++) 5irewh'R  
{ >Eik>dQ a  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); HjGT{o  
//Utility.log(in.readLine()); /p<mD-:.M  
sHeader=httpConnection.getHeaderFieldKey(i); ^P"t "  
if(sHeader!=null) I4m)5G?O2  
{ 2}[rc%tV:?  
if(sHeader.equals("Content-Length")) d;D^<-[i  
{ q1r\ 60M  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); tK g%5;v  
break; /%=#*/E7  
} Bpo~x2p  
} j[iJo 5  
else U,RIr8G  
break; Kl(}s{YFn.  
} ]K XknEaxl  
} ;f?OT7>kN  
catch(IOException e){e.printStackTrace ();} d^ipf*aLC  
catch(Exception e){e.printStackTrace ();} A |NX"  
RZOk.~[v  
J-Sf9^G  
Utility.log(nFileLength); tI.(+-q  
g|)e3q{M  
(niZN_qv  
return nFileLength; Qyt6+xL  
} 8uyVx9C0  
Sl:\5]'yJ  
- /#3U{O  
//保存下载信息(文件指针位置) pm5Yc@D  
private void write_nPos() qbqJ1^!6R  
{ n0 !S;HH-  
try{ ai#EFo+#  
output = new DataOutputStream(new FileOutputStream(tmpFile)); `'0opoQRe  
output.writeInt(nStartPos.length); Y)BKRS~  
for(int i=0;i<nStartPos.length;i++) 5kC#uk  
{ +8Peh9"  
// output.writeLong(nPos); 0AR4/5.  
output.writeLong(fileSplitterFetch.nStartPos); 5Tn4iyg;B  
output.writeLong(fileSplitterFetch.nEndPos); !RiPr(m@y  
} ; wW6x  
output.close(); uKpl+>  
} }!n<L:njX  
catch(IOException e){e.printStackTrace ();} {sX*SbJt  
catch(Exception e){e.printStackTrace ();} :JW~$4  
} "q#(}1Zd  
_AVCh)Zb  
I*K^,XY+  
//读取保存的下载信息(文件指针位置) YH<@->Ip  
private void read_nPos() {7(h%]  
{ 8P5xRUkV  
try{ b <=K@I.=  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ^$?8!WE  
int nCount = input.readInt(); eRVu/TY  
nStartPos = new long[nCount]; pKr3(5~  
nEndPos = new long[nCount]; JXPn <  
for(int i=0;i<nStartPos.length;i++) @ o;m!CYB  
{ >x!N@G  
nStartPos = input.readLong(); (&njZdcb*  
nEndPos = input.readLong(); {W `/KU?u  
} :^l*_v{  
input.close(); 2$T~(tem  
} WY*}|R2R  
catch(IOException e){e.printStackTrace ();} ) }?dYk  
catch(Exception e){e.printStackTrace ();} !my5-f>{(  
} laFkOQI  
?#FA a,  
hrS/3c'<Z  
private void processErrorCode(int nErrorCode) ~x4Y57  
{ jg%D G2  
System.err.println("Error Code : " + nErrorCode); XZKOBq B]  
} ghms-.:b8  
<<UlFE9"  
k{@z87+&  
//停止文件下载 .3ic%u;|D  
public void siteStop() JmY"Ja,&  
{ }jIb ^|#CD  
bStop = true; [oKB1GkA  
for(int i=0;i<nStartPos.length;i++) tH W"eag  
fileSplitterFetch.splitterStop(); 78 UT]<Q;K  
rbP.N ?YU%  
vo0[Z,aH5  
} ?d_<S0j-)  
} aP"i_!\.aa  
//负责部分文件的抓取 !w C4ei`  
**FileSplitterFetch.java 8Oc*<^{#  
*/ ](Sp0t  
package NetFox; P!]DV$o  
F"0 tv$  
FEdyh?$  
import java.io.*; c)E'',-J_2  
import java.net.*; -Tz9J4xU&  
ja 9y  
E )Hp.  
public class FileSplitterFetch extends Thread { & JF^a  
aZBaIl6I  
cDAO5^  
String sURL; //File URL $"_D"/*  
long nStartPos; //File Snippet Start Position Z ,T TI>P  
long nEndPos; //File Snippet End Position pl7!O9bo  
int nThreadID; //Thread's ID x&;{4F Nw  
boolean bDownOver = false; //Downing is over %ecg19~L/}  
boolean bStop = false; //Stop identical _oLK" * [#  
FileAccessI fileAccessI = null; //File Access interface [9>1e  
-MOf[f^  
=Wl CE_  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;zh|*F>  
{ H:~LL0Md%  
this.sURL = sURL; hPEK@  
this.nStartPos = nStart; $(_i>&d<  
this.nEndPos = nEnd; c\RDa|B,  
nThreadID = id; v$,9l+p/  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _N*4 3O`  
} (# ?~^ut  
*/Y@:Sjf  
]INbRytvc  
public void run() 3UH=wmG0w  
{ 9D 0ujup  
while(nStartPos < nEndPos && !bStop) \ wnQ[UNjP  
{ p\!+j@H:  
O #0:6QX  
UQhfR}(  
try{ z{tyB  
URL url = new URL(sURL); .c BJA&/  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'zpj_QM  
httpConnection.setRequestProperty("User-Agent","NetFox"); LrK6*y,z  
String sProperty = "bytes="+nStartPos+"-"; P/ug'  
httpConnection.setRequestProperty("RANGE",sProperty); A\ LTAp(I  
Utility.log(sProperty); -M(:z  
? ZN8Ku  
%=_ Iq\lC  
InputStream input = httpConnection.getInputStream(); .}z&$:U9[  
//logResponseHead(httpConnection); |EF*]qI  
* SC~_  
M6g!bK2l  
byte[] b = new byte[1024]; N4$0ptz#}G  
int nRead; Z!hDTT  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #X|'RL($  
{ H!s &]b  
nStartPos += fileAccessI.write(b,0,nRead); n:;2Z  
//if(nThreadID == 1) 0p~:fm  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #V~r@,  
} bup;4~g  
Ig S.U  
c%v%U &  
Utility.log("Thread " + nThreadID + " is over!"); /Nxy?g|,  
bDownOver = true; s V{[~U,|  
//nPos = fileAccessI.write (b,0,nRead); !d"J,.)  
} 9ft7  
catch(Exception e){e.printStackTrace ();} *^QfTKN   
} g*!2.P  
} ,V |>nkQ  
3Vt-]DGX  
PUucYc  
//打印回应的头信息 scrNnO[3j  
public void logResponseHead(HttpURLConnection con) #~ / -n&#  
{ )5e}Id  
for(int i=1;;i++) T!J\Dm-  
{ f<y""0L9  
String header=con.getHeaderFieldKey(i); ,qaIdw[  
if(header!=null) )e Ub@Eu  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); UWmWouA  
Utility.log(header+" : "+con.getHeaderField(header)); 8R-?x/:  
else tl0_as  
break; \N7 E!82  
} b vUYLWzS  
} h-#Glse<  
q/&Z6LJ)  
DBVe69/S  
public void splitterStop() @(oz`|*  
{ l |\Q~ D!o  
bStop = true; _DH,$evS%  
} .D>%-  
\@tt$ m%  
fMhMB |W.  
} @hg1&pfxZ<  
Elm/T]6  
pdmeB  
/* L?0dZY-"  
**FileAccess.java &]uhPx/  
*//文件访问(定位,写) ^[d)Hk}L  
package NetFox; r;}kw(ukC  
import java.io.*; !3d +"tL S  
z <s]Z  
?%;)> :3N  
public class FileAccessI implements Serializable{ m#DC;(Pn  
\6nWt6M  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /sC$;l  
RandomAccessFile oSavedFile; epz2d~;  
long nPos; mltN$b%G=d  
oIX]9~  
t'FY*|xk  
public FileAccessI() throws IOException /__we[$E  
{  [T !#s  
this("",0); Q%q_  
} /GfC/)1_  
ym<G.3%1  
E^Q|v45d  
public FileAccessI(String sName,long nPos) throws IOException Hza{"I*^  
{ i]xyD'0  
oSavedFile = new RandomAccessFile(sName,"rw"); Exk[;lI  
this.nPos = nPos;  t\u0\l>  
oSavedFile.seek(nPos); lSl=6R  
} > : \lDz  
[%z~0\lu8  
P\N$TYeH  
public synchronized int write(byte[] b,int nStart,int nLen)  +'Tr>2V  
{ JdFMSmZ@  
int n = -1; R:Z{,R+  
try{ rEs,o3h?po  
oSavedFile.write(b,nStart,nLen); @yS  
n = nLen; r|6S&Ia>  
}  fW|1AUD,  
catch(IOException e) MQw{^6Z>1  
{ LW0't} z  
e.printStackTrace (); w\s$  
} sf7'8+wj>  
>\3=h8zw  
OB l-6W  
return n; H2|&  
} t&H):P  
-=5z&) X  
D_(xhM  
} j`ggg]"&$  
.6f %"E,  
[6)`wi  
/* vR-rCve$P  
**SiteInfoBean.java l 0jjLqm:  
*/ Y(W>([59  
package NetFox; RY&Wvkjh  
)r5QOa/  
]X;Ty\UD&  
public class SiteInfoBean { _U%!&_m6  
>jRz4%  
mEr* n  
private String sSiteURL; //Site's URL ub0]nov  
private String sFilePath; //Saved File's Path ??ah  
private String sFileName; //Saved File's Name d,6 Z  
private int nSplitter; //Count of Splited Downloading File vw>O;u.]B  
4 Z1- RS  
j+w*Absh  
public SiteInfoBean() P ;PS+S9  
{//nSplitter的缺省值为5 R0, Q`  
//default value of nSplitter is 5 8yA :C  
this("","","",5); Tg)Fr)  
} 1E=%:?d  
3RZP 12x  
 s>76?Q:i  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Qte=<Z)  
{ \y"!`.E7\d  
sSiteURL= sURL;  r,!7TuBl  
sFilePath = sPath; B&+V%~/  
sFileName = sName; OjJKloy'  
this.nSplitter = nSpiltter; #rF|X6P  
rhHX0+  
-=s7Q{O8Z  
} o5 @ l!NQ  
#4Xe zj,g*  
|wQ|h$|  
public String getSSiteURL() 7Ha +@  
{ (zCas}YAKI  
return sSiteURL; .~4%TsBaY  
} wJ/k\  
e(O"V3wq*6  
!!%vs 6  
public void setSSiteURL(String value) u B~/W  
{ JyvXNV,  
sSiteURL = value; l;b5v]~  
} ,3!l'|0jJ  
#]q<fhJhr$  
^mm:u<Yt  
public String getSFilePath() oJvF)d@gU  
{ =Bu d!  
return sFilePath; .3Jggp  
} d_-{-@  
.^X IZ  
{UT^p IP\  
public void setSFilePath(String value) :%{MMhb x  
{ O\q|b#q}/  
sFilePath = value; p>96>7w  
} TGY^,H>J  
]Z&2  
TWK(vEDM  
public String getSFileName() ZUVk~X3  
{ L*6Tz'Qp  
return sFileName; W+Z] Y  
} Z6 E-FuO  
dUk^DI,:l  
% TyR8 %  
public void setSFileName(String value) X25cU{  
{ S6*3."Sk  
sFileName = value; W1w)SS  
} 24}r;=U  
gxycw4kz  
Sx5r u?$.  
public int getNSplitter() wv # 1s3  
{ ]/XNfb  
return nSplitter; BXiuVx  
} JVD#wwic  
5#p [Q _  
6! \a8q'z  
public void setNSplitter(int nCount) _S7GkpoK  
{ Jk!}z+X'A  
nSplitter = nCount; sF :3|Yy0  
} ZX sm9  
} x\)0+c~\}x  
KA# 4iu{  
M~t S *  
/* D"oyl`q  
**Utility.java Y?=+A4v  
*/ 8sOM%y9M  
package NetFox; ?_3K]i1IS  
40<ifz[7  
/0>Cy\eN0  
public class Utility { MoIVval/  
lY yt8H  
$cHA_$ `  
public Utility() 2_6x2Ia4  
{ Z)Nl\e& M  
~9#\+[ d_  
X!2/cgU7  
} U-6b><  
V/j+Z1ZW  
//线程睡眠 7z9gsi  
public static void sleep(int nSecond) k%?wNk>  
{ 2~AGOx  
try{ 6Daz1Pxd+  
Thread.sleep(nSecond); -z)I;R  
} !n~p?joJ*  
catch(Exception e) 'KMyaEh.u  
{ -)(HG)3  
e.printStackTrace (); uli,@5%\  
} |XzqP +t  
} nqg=I  
*q{/`Z{wy  
//日志 9]r6V   
public static void log(String sMsg) ymT&[+V  
{ &ok2Xw  
System.err.println(sMsg); $/ew'h9q  
} qP-*  
;?"2sS!AHQ  
js/N qf2>  
public static void log(int sMsg) T.H S.  
{ x>m_ v  
System.err.println(sMsg); #8z2>&:|  
} r5t C  
} sc\4.Ux%Q  
8q{ %n   
tbrjTeC  
/* s"#>Xc  
**TestMethod.java /\"=egB9  
*/ -&oJ@Aa  
package NetFox; `ySLic`  
zFmoo4P/  
RNE} )B  
public class TestMethod { kaQn'5  
m!L&_ Z|j  
%?1k}(qUeY  
public TestMethod() )"s <hR ,  
{ ///xx/weblogic60b2_win.exe eL[BH8l  
try{ h lD0^8S  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); C vfm ,BL  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); dp\pkx7  
SiteFileFetch fileFetch = new SiteFileFetch(bean); H@GiHej  
fileFetch.start(); Ufd{.o[{-  
} 6|+I~zJ88  
catch(Exception e){e.printStackTrace ();} ;0(|06=  
*6=2UJcJ  
,{MA90!  
} `O ?61YUQH  
AI}29L3C  
fT9$0:eO  
public static void main(String[] args) 422d4Zu  
{ ~ \z7$9Q  
new TestMethod(); }"BXqh"\`  
} gf7%vyMo$  
} RI9&KS  
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