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http断点续传简单实现(java)

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/* m7~[f7U  
**SiteFileFetch.java M)!:o/!cS  
*/ od~`q4p1(-  
package NetFox; js8\"  
import java.io.*; 7Om)uUjU4  
import java.net.*; P;!4 VK  
QprzlxB  
T+|V;nP.  
public class SiteFileFetch extends Thread { 05m/iQ  
{cBLm/C  
Y4dTv<=K@i  
SiteInfoBean siteInfoBean = null; //文件信息Bean cP MUu9du  
long[] nStartPos; //开始位置 UT7".1H  
long[] nEndPos; //结束位置 &t w   
FileSplitterFetch[] fileSplitterFetch; //子线程对象 =rDIU&0Y  
long nFileLength; //文件长度 u(|k/~\  
boolean bFirst = true; //是否第一次取文件 )SYZ*=ezl.  
boolean bStop = false; //停止标志 ;j/-ndd&&  
File tmpFile; //文件下载的临时信息 )04lf*ti  
DataOutputStream output; //输出到文件的输出流 ';?b99  
R0*+GIRA(  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) O[fgn;@|  
public SiteFileFetch(SiteInfoBean bean) throws IOException ]]Da/^K=Z  
{ eX>X=Ku  
siteInfoBean = bean; JSQ*8wDcl  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); .o5r;KD  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); tr\Vr;zd  
if(tmpFile.exists ()) !j.jvI%e;  
{ ;.r >  
bFirst = false; g$ *V A} s  
read_nPos(); zorTZ #5  
} 7a:mZ[Vh  
else ;{~F7:i  
{ '3@WF2a  
nStartPos = new long[bean.getNSplitter()]; ;zO(bj>  
nEndPos = new long[bean.getNSplitter()]; >AW=N  
} hrRX=  
A fctycQ-  
V F'! OPN  
hOx">yki  
} 3f :I<S7  
B1A5b=6G<  
2JYt.HN  
public void run() YA>du=6y\  
{ ^50/.Z >  
//获得文件长度 ;pNHT*>u,  
//分割文件 $|YIr7?R  
//实例FileSplitterFetch _k@{> ?(a  
//启动FileSplitterFetch线程 Q(KLx)  
//等待子线程返回 0fPqO2  
try{ 5i$~1ZC  
if(bFirst) 4 1TB  
{ 9c=_p'G3Fw  
nFileLength = getFileSize(); K/u`W z~A  
if(nFileLength == -1) WLWE%bDP  
{ ?WX&,ew~  
System.err.println("File Length is not known!"); Zh.fv-Ecp  
} BKm$H! u  
else if(nFileLength == -2) O/\jkF  
{ ?fEX&t,'  
System.err.println("File is not access!"); 2eu`X2IBcT  
} [hS?d.D   
else 8E Y< ^:  
{ 5b[:B~J  
for(int i=0;i<nStartPos.length;i++) aM9St!i  
{ O.E   
nStartPos = (long)(i*(nFileLength/nStartPos.length)); `B6{y9J6  
} rQ'tab.,]  
for(int i=0;i<nEndPos.length-1;i++) G1~|$X@@  
{ k[ Iwxl;/  
nEndPos = nStartPos[i+1]; 8Db~OYVJG  
} bhSpSul  
nEndPos[nEndPos.length-1] = nFileLength; < P5;8  
} q9oF8&O,  
} Co19^g*  
=D4EPfQn1  
LZG^\c$  
//启动子线程 H9w*U  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; g}3c r .  
for(int i=0;i<nStartPos.length;i++) *ma/_rjK  
{ Em@h5V  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K. R2)o`  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }FMl4 _}u  
nStartPos,nEndPos,i); [JVI@1T  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,/W< E  
fileSplitterFetch.start(); lrh6lt)  
} fu=}E5ScK  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), tT yu,%/m  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); .KT+,Y  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", AEnS_Q  
nEndPos = " + nFileLength); ja7Z v[  
// fileSplitterFetch[nPos.length-1].start(); :<&}/r  
9rao&\eH  
Bw*z4qb{yH  
//等待子线程结束 _T5~B"*  
//int count = 0; d!KX.K\NM,  
//是否结束while循环 BdO$  
boolean breakWhile = false; &J hN&Ur  
~~zw[#'  
!qcu-d5b  
while(!bStop) 9v cUo?/  
{ |k/;.  
write_nPos(); \Zf&&7v  
Utility.sleep(500); Ip4NkUI3T  
breakWhile = true; #4//2N  
-t6d`p;dR  
m4Wn$Z  
for(int i=0;i<nStartPos.length;i++) E}@8sY L  
{ pN0c'COy^  
if(!fileSplitterFetch.bDownOver) : 1fik  
{ d<7J)zUm3  
breakWhile = false; +H&_Z38n  
break; i8B%|[ nm  
} 2 J4|7UwJ  
} _;B!6cRLps  
if(breakWhile) fr#lH3  
break; `8dE8:# Y  
Xp} vJl   
~#a1]w  
//count++; eN> (IW  
//if(count>4) >>$IHz4Z"  
// siteStop(); RaU.yCYyu  
} ){YPP!8cI  
Ix"c<1 I  
cZ!s/^o?f  
System.err.println("文件下载结束!"); iQ9#gPk_9  
} uAjGR  
catch(Exception e){e.printStackTrace ();} <Z m ,q}  
} gv[7h'}<  
l(]\[}.5  
"j a0,%3  
//获得文件长度 ZHC sv]l  
public long getFileSize() [QZ~~(R  
{ 2/7=@>|  
int nFileLength = -1; %o"Rcw|  
try{ 9uS7G*  
URL url = new URL(siteInfoBean.getSSiteURL()); gs8L/veP  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ox~'w0c,f  
httpConnection.setRequestProperty("User-Agent","NetFox"); Tc88U8Gc  
_).'SU)>  
99ha /t  
int responseCode=httpConnection.getResponseCode(); 'hek CZZ_I  
if(responseCode>=400) ?Nh%!2n  
{ s3+O=5  
processErrorCode(responseCode); gw*d"~A  
return -2; //-2 represent access is error Xl/G|jB9  
} f0D Ch]  
$k`8Zx w  
KV5lpN PC  
String sHeader; 4*+EUJ|  
7@lXN8_f  
j&Hn`G  
for(int i=1;;i++) }a9C /t3  
{ p_z"Uwp  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); sRZ:9de+  
//Utility.log(in.readLine()); YjX=@  
sHeader=httpConnection.getHeaderFieldKey(i); 42wcpSp  
if(sHeader!=null) Mb>6.l  
{ 5pok%g  
if(sHeader.equals("Content-Length")) *[SsvlFt  
{ H*\[:tPa  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )2FO+_K?T  
break; tH'VV-!MZ  
} poeXi\e!(  
} OpL 6Y+<  
else w//w$}v  
break; }=|ZEhtOp  
} -1_Z*?=-  
} {cv;S2  
catch(IOException e){e.printStackTrace ();} _#gsR"FZ$  
catch(Exception e){e.printStackTrace ();} bY2Mw8e%  
lXPn]iLJ  
4 P;O8KA5y  
Utility.log(nFileLength); `{wku@  
kW!:bh  
=P#!>*\ar  
return nFileLength; $0*47+f  
} Mz G ryM-  
xI<dBg|]+  
f oVD+\~Y  
//保存下载信息(文件指针位置) m4DH90~a8  
private void write_nPos() *h4m<\^U  
{ h]Oplp4 \W  
try{ Q'a N|^w"f  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1ZL_;k  
output.writeInt(nStartPos.length); fv_wK_. %:  
for(int i=0;i<nStartPos.length;i++) Dgm%Ng  
{ 84!4Vz^  
// output.writeLong(nPos); SNU bY6  
output.writeLong(fileSplitterFetch.nStartPos); AY;+Ws  
output.writeLong(fileSplitterFetch.nEndPos); v 2GhR*  
} ^ <VE5OM  
output.close(); z`5I 1#PVA  
} Ozv.;}SE  
catch(IOException e){e.printStackTrace ();} ]-'9|N*}l  
catch(Exception e){e.printStackTrace ();} S1zw'!O5  
} S <_pGz$V  
9Bk}g50$#  
b e/1- =m  
//读取保存的下载信息(文件指针位置) I.u,f:Fl'  
private void read_nPos() 3rY /6{  
{ Mak9qaWqF>  
try{ >>bYg  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _cw ^5  
int nCount = input.readInt(); kVrT?  
nStartPos = new long[nCount]; +2}(]J=-  
nEndPos = new long[nCount]; ,&?q}M  
for(int i=0;i<nStartPos.length;i++) | q16%6q  
{ \z`d}\3( R  
nStartPos = input.readLong(); b(q&}60  
nEndPos = input.readLong(); J\so8uT:  
} qE72(#:R*  
input.close(); -HsBV>C  
} DP_Pqn8p&M  
catch(IOException e){e.printStackTrace ();} iFCH$!  
catch(Exception e){e.printStackTrace ();} (<C%5xk  
} 6h_k`z  
IJc#)J.2A  
_~nex,;r  
private void processErrorCode(int nErrorCode) R{o*O_qX  
{ 0o|,& K  
System.err.println("Error Code : " + nErrorCode); _A|\.(t  
} g$"eI/o  
C9H11g7{  
<M OL{jan  
//停止文件下载 ,;P`Mf'YC  
public void siteStop() e-cb?.WU?  
{ gwaC?tf[  
bStop = true; &8AS=v  
for(int i=0;i<nStartPos.length;i++) >v_5xd9  
fileSplitterFetch.splitterStop(); thPH_DW>eb  
!;*2*WuO;  
\ui^ d  
} 4D8yb|o  
} (I[h.\%  
//负责部分文件的抓取 A]?O& m |  
**FileSplitterFetch.java c;rp@_ULG?  
*/ 7oe@bS/Z  
package NetFox; M y"!j,Up  
C9g~l}=$&  
#KNq:@wp6  
import java.io.*; gZEA;N:H%<  
import java.net.*; DVoV:pk  
q&$0i   
CotMV^   
public class FileSplitterFetch extends Thread { Z)O>h^0  
Eb[H3v48,  
R, w54},  
String sURL; //File URL T:S{3  
long nStartPos; //File Snippet Start Position uP=_-ZUW  
long nEndPos; //File Snippet End Position , q@(L  
int nThreadID; //Thread's ID &/hr-5k  
boolean bDownOver = false; //Downing is over ar qLp|  
boolean bStop = false; //Stop identical y[WYH5 &DJ  
FileAccessI fileAccessI = null; //File Access interface !bV(VRbu  
#8f"}>U9.,  
.-u k   
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException txfwLqx  
{ Pv-V7`{  
this.sURL = sURL; :y-0qz D?  
this.nStartPos = nStart; mERZ_[a2  
this.nEndPos = nEnd;  mz VuQ  
nThreadID = id; A[ECa{ v  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2V2x,!  
} "">fn(  
%cr]ZR  
W3V{Xk|  
public void run() LYy:IBI7_  
{ T3t~=b>&L  
while(nStartPos < nEndPos && !bStop) )Kk(P/s  
{ Fma`Cm.  
;*4tVp,  
t6%xit+  
try{ H=o-ScA  
URL url = new URL(sURL); \eMYw7y5 M  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); J]Gc  
httpConnection.setRequestProperty("User-Agent","NetFox"); tD~PvUJ  
String sProperty = "bytes="+nStartPos+"-"; 4}8+)Pd  
httpConnection.setRequestProperty("RANGE",sProperty); p-yOiG8b}  
Utility.log(sProperty); a,57`Ks+n<  
>,"D9!  
&Rl3y\ r  
InputStream input = httpConnection.getInputStream();  `\|3 ~_v  
//logResponseHead(httpConnection); `/wq3+?  
G\:psx/  
M*~v'L_sI  
byte[] b = new byte[1024]; H8<7#  
int nRead; :&1=8^BY  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) rGn5Q V  
{ %hQMC'c  
nStartPos += fileAccessI.write(b,0,nRead); kk /+Vx~  
//if(nThreadID == 1) %j[LRY/  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nhQ44qRgQ  
} AeY$.b  
%is,t<G  
! F;<xgw  
Utility.log("Thread " + nThreadID + " is over!"); =wlm  
bDownOver = true; o9T@uWh+  
//nPos = fileAccessI.write (b,0,nRead); \+?,c\x  
} S1az3VJI\  
catch(Exception e){e.printStackTrace ();} 8MeO U  
} r8 Zyld_@  
} x^#6>oOR  
(w#slTFT  
5y[b8mur  
//打印回应的头信息 "x.6W!  
public void logResponseHead(HttpURLConnection con) ~^%0V<*-}  
{ K?FX<PT  
for(int i=1;;i++) [aWDD[#j~  
{ 5&-j{J0iV  
String header=con.getHeaderFieldKey(i); T[4[/n> i  
if(header!=null) =!g/2;-or  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ph8Jn+|E  
Utility.log(header+" : "+con.getHeaderField(header)); |?2 hml  
else {7K'<ti  
break; oc3dd"8}@  
} l6 S19Kv  
} BDm88< ]  
[V2omSZo  
~E<PtDab  
public void splitterStop() GTp?)nh^  
{ ^EC)~HP@C  
bStop = true; `bZ2x@  
} :tjgg]  
409x!d~it  
_UH/}!nqB  
}  d-ag  
un$ Z7W/  
T1Gp$l  
/* GCP{Z]u  
**FileAccess.java [xZ/ZWb/  
*//文件访问(定位,写) SG dfhno;  
package NetFox; y~== waZw  
import java.io.*; 2,8/Cb  
*l>[`U+  
(^DLCP#*  
public class FileAccessI implements Serializable{ WA]%,6  
:Wyn+  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 P0'e"\$  
RandomAccessFile oSavedFile; H})Dcg3  
long nPos; i14[3bPLk!  
7x[LF ^o  
( Lok  
public FileAccessI() throws IOException \A'|XdQ  
{ /-!&k  
this("",0); SE,o7_k'S  
} H )BOSZD  
), nCq^Bp  
iA55yT+  
public FileAccessI(String sName,long nPos) throws IOException )(:+q(m  
{ 4 |zdXS  
oSavedFile = new RandomAccessFile(sName,"rw"); b(P HZCy#  
this.nPos = nPos; 9SRfjS{7  
oSavedFile.seek(nPos); u( V  
} [K/O5_  
NCowt|#t  
YVQ_tCC_!  
public synchronized int write(byte[] b,int nStart,int nLen) 4 [R8(U[g  
{ RLYU\@kK?  
int n = -1; 18DTv6?QG  
try{ sBP}n.#$  
oSavedFile.write(b,nStart,nLen); _o@(wGeu#  
n = nLen; G$?|S@I,  
} 4zo4H~@gk  
catch(IOException e) ~q0I7M  
{ ?1GY%-  
e.printStackTrace (); ^l Hb&\X  
} 1fz*S IjG  
-M7K8  
9">zdFC'  
return n; BA~a?"HS  
} g".d"d{  
:V&N\>Wo  
[D*J[?yt  
} +3M$3w{2  
eV[`P&j_C  
t$U3|r  
/* nc3sty1`  
**SiteInfoBean.java ES^>[2Y  
*/ ;j>*;Q`  
package NetFox; 0lX)Cl  
mgi,b2  
[<]Y+33  
public class SiteInfoBean { Uby,Tu  
eq^TA1>T  
vS7/~:C  
private String sSiteURL; //Site's URL C>*5=p|T  
private String sFilePath; //Saved File's Path 6-mmi7IfO  
private String sFileName; //Saved File's Name |ZS 57c:  
private int nSplitter; //Count of Splited Downloading File 7%{R#$F  
Hze-Ob8  
G 6Wx3~  
public SiteInfoBean() ( MB`hk-d  
{//nSplitter的缺省值为5 M (+.$uz  
//default value of nSplitter is 5 o .l;: Un  
this("","","",5); p]wP36<S!  
} /SnynZ.q  
mgy"|\]  
{F'Az1^I=  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) T#\p%w9d  
{ (7IqY1W  
sSiteURL= sURL; <A)+|Y"^h6  
sFilePath = sPath; 6!ZVd#OM%  
sFileName = sName; \.c]kG>k-  
this.nSplitter = nSpiltter; M6J/mOVx5  
zL9VR;q  
,5/V@;i  
} y)6,0K {k  
i\(\MzW*'  
M(qxq(#{U  
public String getSSiteURL() PKi_Zh.D  
{ GtF2@\  
return sSiteURL; Z`rK\Bc  
} >4,{6<|  
-g:lOht  
DKh}Y !Q=:  
public void setSSiteURL(String value) L'>s(CR  
{ 1<`9HCm  
sSiteURL = value; w|=gSC-o  
} N6h1|_o  
6MuWlCKF8  
(YIhTSL"]  
public String getSFilePath() mKV'jm0  
{ 1xz\=HOT  
return sFilePath; [_h%F,_ A  
} gF3TwAr  
lY.B  
B]1HS`*7  
public void setSFilePath(String value) x"vwWJNQ  
{ z+jh ;!i  
sFilePath = value; tG/1pW  
} wa" uFW  
NUMi])HkN  
3@G;'|z  
public String getSFileName() WE")xhV6  
{ )%s +?  
return sFileName; B#]_8svO  
} tVunh3-  
:y\09)CJK  
S."7+g7Ar  
public void setSFileName(String value) I0DM=V>;  
{ hm3jpWi 8  
sFileName = value; vVAb'`ysv  
} 7$ d}!S  
cS}r9ga Q  
P<u"97@8a  
public int getNSplitter() 6^sHgYR  
{ e&2wdH&  
return nSplitter; J/t!- !  
} }w@gj"\H  
MD<-w|#8IV  
1i u =Y  
public void setNSplitter(int nCount) +3Y!xD?=  
{ W}h|K:-S  
nSplitter = nCount; X/Y#U\  
} GQx9u ^>  
} 0qv$:w)g+v  
pW{8R^vKm  
0N{+y}/G  
/* -u|l}}bh  
**Utility.java O6iCZ  
*/ ~s#e,Kav"  
package NetFox; X2gz6|WJ  
^Gq5ig1rxy  
8%[HYgd5)  
public class Utility { B;!f<"a8  
+yWR#[`n  
cn%2OP:L^  
public Utility() Sj)}qM-y#  
{ [Uli>/%JB  
TFy7HX\Oq  
fYBH)E  
} YUscz!rM  
2zK"*7b?  
//线程睡眠 &x0C4Kh  
public static void sleep(int nSecond) f7J,&<<5w  
{ iITp**l  
try{ C0fmmI0z~  
Thread.sleep(nSecond); YsP/p-  
} !8*McO I  
catch(Exception e) 'L{p,  
{ gDCOLDM  
e.printStackTrace (); ]TSg!H  
} m_* R.a  
} .#fPw_i  
:[sOKV i  
//日志 K;U39ofW  
public static void log(String sMsg) kX[fy7rVt  
{ We}lx{E  
System.err.println(sMsg); Z^zbWFO]5  
} m&IsDAn  
%M&3VQ9w  
aq Mc6N`z  
public static void log(int sMsg) kq-6HDR  
{ e"Rm_t  
System.err.println(sMsg); 5)'P'kVi7.  
} o2=A0ogz?  
} K=6UK%y A  
=MLf[   
XoR>H4xh  
/* +y&d;0!  
**TestMethod.java dB;3.<S=  
*/ "&lN\&:  
package NetFox; Z0ReWrl;`  
~ y;y(4<  
jxw_*^w"  
public class TestMethod { t`G)b&3_O  
:eOR-}p'  
nrpI5t.b  
public TestMethod() M3pjXc<O  
{ ///xx/weblogic60b2_win.exe f v LC_'M  
try{ 4_LQ?U>$  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); }Qrab#v  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); WM,i:P)b  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 4/*H.Fl  
fileFetch.start(); ~p*1:ij  
} Pxhz@":[  
catch(Exception e){e.printStackTrace ();} |d7$*7TvV  
}+R B=#~o  
6)e5zKW!?  
} ?znSx}t  
C+%K6/J(  
lIf(6nm@  
public static void main(String[] args) ^0tw%6:  
{ @Bs0Avj.  
new TestMethod(); 4h|dHXYZ  
} otr>3a*'  
} B@t'U=@7  
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