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http断点续传简单实现(java)

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/* G c \^Kg^#  
**SiteFileFetch.java wn;)La  
*/ %Z p|1J'"  
package NetFox;  T  5F)  
import java.io.*;  !TivQB  
import java.net.*; (g*j+i  
S@'%dN6e  
HB{'MBs  
public class SiteFileFetch extends Thread { SK#&%Yk  
4l7 Ny\J  
P2@Z7DhQ  
SiteInfoBean siteInfoBean = null; //文件信息Bean =P%&]5ts  
long[] nStartPos; //开始位置 j XH9P q4  
long[] nEndPos; //结束位置 $}Ab R:z  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 3vKTCHbk9  
long nFileLength; //文件长度 : 0 ,yq?M  
boolean bFirst = true; //是否第一次取文件 OIJT~Z}  
boolean bStop = false; //停止标志 P@keg*5@  
File tmpFile; //文件下载的临时信息 BN `2UVH  
DataOutputStream output; //输出到文件的输出流 "%)g^Atp>  
T-#4hY`  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) t>AOF\  
public SiteFileFetch(SiteInfoBean bean) throws IOException q-+:1E  
{ 3%bhW9H%  
siteInfoBean = bean; Lg~C:BN F  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); co~NXpqg  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Gx8!AmeX  
if(tmpFile.exists ()) %S"85#R5E  
{ ``P9fd  
bFirst = false; 7f}uRXBV$A  
read_nPos(); l -xc*lC  
} - om9 Z0e  
else .1q}mw   
{ |1 "&[ .  
nStartPos = new long[bean.getNSplitter()]; 9=~ZA{0J  
nEndPos = new long[bean.getNSplitter()]; ;Y[D#Ja-  
} :SS \2  
[{Jo(X  
gHp*QL\?9  
I`_I^C3  
} D*Zj oU  
e.skE>&  
F_(~b  
public void run() rHTZM,zM=H  
{ uE41"?GS  
//获得文件长度 W-l+%T!  
//分割文件 vMB61 |O  
//实例FileSplitterFetch CNefk$/cR  
//启动FileSplitterFetch线程 HWsV_VAw}  
//等待子线程返回 |~e"i<G#  
try{ @t~y9UfF  
if(bFirst) |67Jw2  
{ 60vmjmXl  
nFileLength = getFileSize(); [9${4=Kq  
if(nFileLength == -1) .Pponmy  
{ %*}rLn"?  
System.err.println("File Length is not known!"); XZb=;tYo  
} I09 W=  
else if(nFileLength == -2) zPa2fS8  
{ r=5 S0  
System.err.println("File is not access!"); 8&G9 ?n`I5  
} !:!(=(4$P  
else 6X*vCylI  
{ wn5OgXxG<  
for(int i=0;i<nStartPos.length;i++) LDc EjFK(  
{ J)>DsQ+Cj  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); !iKW1ks  
} 1H-Y3G>jN  
for(int i=0;i<nEndPos.length-1;i++) ]]PNYa  
{ <E4(KE  
nEndPos = nStartPos[i+1]; Ze~P6  
} 7P+1W \  
nEndPos[nEndPos.length-1] = nFileLength; ^)~Smj^d  
} Xx{| [2`  
} |@u2/U9  
|CDM(g>%  
D<6$@ZJ  
//启动子线程 /e0B$UymFu  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; (Lgea  
for(int i=0;i<nStartPos.length;i++) ?Fl}@EA#M  
{ v1,#7s AW'  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), fWmc$r5n](  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), H54RA6$>  
nStartPos,nEndPos,i); o~~;I  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6kH6"  
fileSplitterFetch.start(); !FL"L 9   
} o9 9ExQ.  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zWC| Qe  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1?Y>Xz  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #"N60T@  
nEndPos = " + nFileLength); yjjq&Cn  
// fileSplitterFetch[nPos.length-1].start(); {$z54nvw$  
5G`HJ6  
:hZM$4  
//等待子线程结束 IE`3I#v  
//int count = 0; idYB.]Y(  
//是否结束while循环 TmG);B}  
boolean breakWhile = false; Hh1_zd|  
V'&;r'#O  
.yj@hpJM  
while(!bStop) :*}Q/]N  
{ ( V4Ppg  
write_nPos(); Y"mFUW4  
Utility.sleep(500); 5skN'*oG  
breakWhile = true; kEDpF26!  
lcdhOjz!N  
;7P '>j1?U  
for(int i=0;i<nStartPos.length;i++) |(.\J`_e  
{ qdix@ @  
if(!fileSplitterFetch.bDownOver) /Q;wz!V$  
{ 4H#-2LV`  
breakWhile = false; j}^w :W76  
break; [./FzlAs  
} CPOH qK`k  
} aJ+V]WmA  
if(breakWhile) ~m6=s~Vn  
break; =Wcvb?;*  
B]X8KzLu  
p3M!H2W  
//count++; " @D  
//if(count>4) ab6I*DbF  
// siteStop(); 8FuxN2  
} )=5 &Q  
\l59/ZFan  
)pHtsd.eP  
System.err.println("文件下载结束!"); &en. m>9,  
} Wlc&QOfF  
catch(Exception e){e.printStackTrace ();} O%EA ,5U.  
} wEjinP$2  
4,)9@-|0R  
I){4MoH.  
//获得文件长度 \qG ?'Iy  
public long getFileSize() 9nG^_.}|  
{ /7UvV60  
int nFileLength = -1; , #)d  
try{ 9+@h2"|N4*  
URL url = new URL(siteInfoBean.getSSiteURL()); ~+Gh{,f  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &r1(1<  
httpConnection.setRequestProperty("User-Agent","NetFox"); 1&MCS%UTL  
[M\ an6h6O  
3}|[<^$  
int responseCode=httpConnection.getResponseCode(); :c/54Ss~  
if(responseCode>=400) kq}byv}3I  
{ G8av5zR  
processErrorCode(responseCode); ?AyxRbk  
return -2; //-2 represent access is error zZ%[SW&vC  
}  >. K  
vJ&_-CX   
~Gfytn9x.;  
String sHeader; GLf!i1Z  
?EFRf~7JP  
_WEJ,0* #'  
for(int i=1;;i++) ,6>3aD1w~q  
{ `]KX`xGK  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); NxHUOPAJc  
//Utility.log(in.readLine()); ~Zr}QO}G  
sHeader=httpConnection.getHeaderFieldKey(i); aC,adNub  
if(sHeader!=null) D;R~!3f./b  
{ ,U\ s89  
if(sHeader.equals("Content-Length")) %/A>'p,~  
{ +9Tc.3vQ  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); u$d[&|`>_  
break; aj5HtP-  
} '-v:"%s|  
} leC!Yj  
else ^C'S-2nGH  
break; n#">k%bD  
}  LSC[S:  
} z x-[@G  
catch(IOException e){e.printStackTrace ();} P*&[9 )d6  
catch(Exception e){e.printStackTrace ();} uyYV_Q0~;  
nqy*>X`  
:BPgDLL,  
Utility.log(nFileLength);  FSMM  
0b{jox\!B  
,iyy2  
return nFileLength; 0f@+o}i=)  
} :M"+  
_WZx].|A=  
9Vt ^q%DC  
//保存下载信息(文件指针位置) )-4c@  
private void write_nPos() Jinh#iar  
{ 0Q{lyu  
try{ .b";7}9{  
output = new DataOutputStream(new FileOutputStream(tmpFile)); v[ iJ(C_  
output.writeInt(nStartPos.length); AY52j  
for(int i=0;i<nStartPos.length;i++) sx#O3*'>1  
{ 8!2)=8|f  
// output.writeLong(nPos); ;KQU% k$  
output.writeLong(fileSplitterFetch.nStartPos); *HD(\;i-$  
output.writeLong(fileSplitterFetch.nEndPos); ?g ,s<{  
} 4~ }NB%,  
output.close(); (u 7Lh>6%  
} Xe);LhDC  
catch(IOException e){e.printStackTrace ();} 'UX^]  
catch(Exception e){e.printStackTrace ();} D|zuj]  
} ^&<M""Z  
j6l1<3j  
AOg'4  
//读取保存的下载信息(文件指针位置) XCI  
private void read_nPos() 2 ,nhs,FZ  
{ Ar>B_*dr  
try{ T:Cq}4k<  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _#K|g#p5  
int nCount = input.readInt(); WHC/'kvF  
nStartPos = new long[nCount]; +<\LY(o  
nEndPos = new long[nCount]; Tt~4'{Bc  
for(int i=0;i<nStartPos.length;i++) ajycYk9<m  
{ q?LOtN? o  
nStartPos = input.readLong(); Zz} o  t  
nEndPos = input.readLong(); {qw'gJmX  
} q_[y|ETJ]  
input.close(); ;> 7~@ K  
} 5J`w8[;  
catch(IOException e){e.printStackTrace ();} Q9cSrU[$  
catch(Exception e){e.printStackTrace ();} zYaFbNi  
} M %,\2!$  
P.Tnq  
N #v[YO`.  
private void processErrorCode(int nErrorCode) ,It0brF  
{ Kii@Z5R_?  
System.err.println("Error Code : " + nErrorCode); )Cdw_Yx  
} h>V6}(~;.  
BZ\="N#f  
ll5;09  
//停止文件下载 ! #Pn_e  
public void siteStop() pS8\B  
{ x6K_!L*Fx]  
bStop = true; ~Y43`@3H:  
for(int i=0;i<nStartPos.length;i++) 3fLdceT  
fileSplitterFetch.splitterStop(); E0qJ.v  
k:n{AoUc  
ds*gL ~k^  
} xlZh(pf  
} N]yT/8  
//负责部分文件的抓取 7y^)n<'co  
**FileSplitterFetch.java FTUfJIVN(  
*/ 8T"L'{ggWB  
package NetFox; ;ZB=@@l(  
;r2DQg"#@  
~d&&\EZ  
import java.io.*; MY{Kq;FvRP  
import java.net.*; zji9\  
n$ByTmKxv  
X,3"4 SK  
public class FileSplitterFetch extends Thread { tV4yBe<``  
P [aE3Felk  
_9D]1f=&  
String sURL; //File URL T.De1 Q|  
long nStartPos; //File Snippet Start Position )T '?"guh`  
long nEndPos; //File Snippet End Position ]pNM~,  
int nThreadID; //Thread's ID ],AtR1k  
boolean bDownOver = false; //Downing is over Z3o HOy  
boolean bStop = false; //Stop identical +Q"s!\5  
FileAccessI fileAccessI = null; //File Access interface R;AcAJ;  
8r}tf3xMCM  
PU ea`rE?R  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [W$x5|Z}Q  
{ =l2 @'YQ  
this.sURL = sURL; 8Ud.t =2  
this.nStartPos = nStart; Qv,ORm h5  
this.nEndPos = nEnd; Lm$KR!z  
nThreadID = id; c-zW 2;|61  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 yo5-x"ze  
} #U'}g *  
rSDI.m   
Z3zD4-p$_  
public void run() + d>2'  
{ Fu?_<G%Ynp  
while(nStartPos < nEndPos && !bStop) ;t N@  
{ ci%$So 2#  
W;Dik%^tg  
R(> oyxA[F  
try{ 0(5qVJ12  
URL url = new URL(sURL); o7tlkSZ  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cooicKS7  
httpConnection.setRequestProperty("User-Agent","NetFox"); EP4?+"Z  
String sProperty = "bytes="+nStartPos+"-"; WO69Wo\C  
httpConnection.setRequestProperty("RANGE",sProperty); /5 KY6XxR  
Utility.log(sProperty); ?/3{gOgI$`  
rk+s[Qi~  
|I]G=.*E  
InputStream input = httpConnection.getInputStream(); ,o2x,I  
//logResponseHead(httpConnection); {JQV~rfh`  
SP  =8v0  
" u]X/ {L  
byte[] b = new byte[1024]; $W;r S7b  
int nRead; W)2k>cS  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) nKwOSGPQt  
{ 22d>\u+c  
nStartPos += fileAccessI.write(b,0,nRead); $*fEgU% c  
//if(nThreadID == 1) w$qdV,s 7  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); dpdp0  
} ]7,0}q.  
9D5v0Qi  
!9S!zRy@  
Utility.log("Thread " + nThreadID + " is over!"); ,=u!hg  
bDownOver = true; 2j^8{Agz  
//nPos = fileAccessI.write (b,0,nRead); O8*yho  
} _Pw5n mH c  
catch(Exception e){e.printStackTrace ();} /GP:W6:6z6  
} FYaBP;@J%  
} #FGj)pu  
:Mu]* N  
0VgsV;  
//打印回应的头信息 #9(iu S+BU  
public void logResponseHead(HttpURLConnection con) mnYzn[d3U  
{ pr \OjpvD  
for(int i=1;;i++) ,7Q b24A  
{ |3EKK:RE  
String header=con.getHeaderFieldKey(i); e>HdJ"S`  
if(header!=null) D<4cpH  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); =6, w~|W  
Utility.log(header+" : "+con.getHeaderField(header)); XJ1<!tl  
else VPDd*32HC  
break; QlnI&o  
} 5F5)Bh  
} }@A{'q5y  
KFHcHz  
/kFw(l_.  
public void splitterStop() yMe;  
{ =.q8*7UY  
bStop = true; *edhJUT  
} 2$> <rB  
Q[%+y.  
d/I*$UC  
} Cbr>\;sc2Z  
KZsJ_t++!W  
8|S}!P"  
/* -]Q6Ril  
**FileAccess.java }FAO.  
*//文件访问(定位,写) -W"  w  
package NetFox; $mDlS  
import java.io.*; X2C&q$8  
tq8rG@-C  
qa)Qf,`  
public class FileAccessI implements Serializable{ k9o LJ<.k  
Q\GSX RP  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 CW;=q[+w  
RandomAccessFile oSavedFile; %@x.km3e2  
long nPos; ^yVKW5x  
{P $sQv  
@6z]Xb  
public FileAccessI() throws IOException 5(&'/U^  
{ 0X4%Ccs  
this("",0); L[.RV*sL  
} }SBpc{ch  
GMYfcZ/,K  
qHra9yuSh  
public FileAccessI(String sName,long nPos) throws IOException Qj',&b  
{ zQyt1&!  
oSavedFile = new RandomAccessFile(sName,"rw"); .Fn7yTQ%  
this.nPos = nPos; m?pm)w  
oSavedFile.seek(nPos); dG*2-v^G  
} ! p|d[  
^|ln q.j  
9w( Wtw'  
public synchronized int write(byte[] b,int nStart,int nLen) hy{1Ea/T  
{ ?*2Uw{~}  
int n = -1; Jde@T h  
try{ QcG-/_,'}  
oSavedFile.write(b,nStart,nLen); Avn)%9  
n = nLen; w{5v*SHl}`  
} tw%z!u[a  
catch(IOException e) Dt\rMSjZ9  
{ a\?-uJ+  
e.printStackTrace (); ! 4{T<s;q  
} eg Zb)pP  
LyA}Nd]pyq  
/#xx,?~xx0  
return n; ,"EgYd8-'  
} &d/x1=  
;<)<4N"  
{m7>9{`  
} bAZ x*qE=  
TIre,s)_  
l.`f^K=8  
/* U>=& 2Z2?  
**SiteInfoBean.java K \_JG $(9  
*/ q7u bRak  
package NetFox; $~FnBD%|{  
|v31weD8  
@Rp#*{  
public class SiteInfoBean { sbV {RSl  
qxW^\u!<  
Ir :y#  
private String sSiteURL; //Site's URL iX\]-_D  
private String sFilePath; //Saved File's Path }10ZPaHjl+  
private String sFileName; //Saved File's Name vm Y*K  
private int nSplitter; //Count of Splited Downloading File n+9rx]W,  
#<EMG|&(  
i]M:ntB"  
public SiteInfoBean() 0G}]d17ho  
{//nSplitter的缺省值为5 7t~12m8x  
//default value of nSplitter is 5 ~rICPR  
this("","","",5); t0-)\kXcA  
} &h_do8R  
7IUu] Fi  
{]V+C=`  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) lbUUf}   
{ FvVR \a  
sSiteURL= sURL; y$6~&X  
sFilePath = sPath; 3; Ztm$8  
sFileName = sName; $zv&MD!&h  
this.nSplitter = nSpiltter; ZxvBo4>tH  
])3(@.  
!bg2(2z  
} tVFydN~  
vE<z0l  
W&`{3L  
public String getSSiteURL() x}B_;&>&"_  
{ (HD8Mm  
return sSiteURL; 2=V~n)'a  
} R7Z7o4jg  
[ 30ta<-  
S&Szc0-|k  
public void setSSiteURL(String value)  A4  
{ 6#za\[  
sSiteURL = value; #[$zbZ(I>:  
} q-|j =  
i4s_:%+  
h5^qo ^;g7  
public String getSFilePath() :Cdqj0O3u  
{ !)-)*T  
return sFilePath; {#C)S&o)6  
} jhF&   
_ISaO C{2-  
iPeW;=-2Wk  
public void setSFilePath(String value) &V77Wn OY  
{ +]dh`8*8>1  
sFilePath = value; 4Mck/i2  
} CEHtr90P  
,6AnuA  
0Q4i<4 XW  
public String getSFileName() $LOwuvu>  
{ ##r9/`A  
return sFileName; MR3\7D+9y  
} 4];<` %  
y)*W!]:7^>  
&@[pJ2  
public void setSFileName(String value) gUWW}*\ U  
{ UVlh7wjg  
sFileName = value; A!uO7".E  
} Da-U@e!  
{v>8Kp7_R  
K'\Jnn  
public int getNSplitter() !))!! {  
{ [x8_ax} w  
return nSplitter; x +]ek  
} W87kE?,  
Y?#aUQc  
?A]/ M~3B  
public void setNSplitter(int nCount) 0T2^$^g  
{ FFq8LM8  
nSplitter = nCount; :`B70D8ku  
} 51gSbkVX  
} @p%WFNR0  
L}=t"y  
>J) 9&?  
/* BT^HlW<  
**Utility.java q#PMQR"C  
*/ }Uue}VOA  
package NetFox; p1!-|Sqq  
Av>xgfX  
vlC$0P  
public class Utility { ~?z u5,vb  
utU ;M*  
^H`4BWc  
public Utility() $EG9V++b3  
{ ib%'{?Q.  
GJIZu&C  
}6"l`$=Ev  
} +:3s f%0  
V;d<S@$  
//线程睡眠 vD76IG jm  
public static void sleep(int nSecond) 3?Fe( !@  
{ :"'*1S*  
try{ `_e5pW=:>  
Thread.sleep(nSecond); snP]&l+  
} nQ@<[KNd  
catch(Exception e) "Pl.G[Buc-  
{ 0-:dzf  
e.printStackTrace (); eCjyx|:J  
} >Z>s R0s7  
} nT9Hw~f<j  
xg;vQKS6  
//日志 bFVY&  
public static void log(String sMsg) M>ntldV#g%  
{ U>0bgL  
System.err.println(sMsg); 3QCCX$,  
} DfX~}km  
VV"w{#XKw  
G^:?)WRG  
public static void log(int sMsg) mhI   
{ 9^E!2CJ  
System.err.println(sMsg); Mtc  -  
} =w7+Yt  
} Fg0!2MKq*  
yCwe:58  
xy]oj  
/* NH4T*R)Vz  
**TestMethod.java ;Irn{O  
*/ ]IH1_?HgP7  
package NetFox; ?8FJMFv;4%  
[U:P&)  
N%9?8X[5  
public class TestMethod { AWg'J  
EFv^uve  
:r7!HG _  
public TestMethod() :mhO/Bx  
{ ///xx/weblogic60b2_win.exe i,rX. K}X  
try{ OHt^e7\  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); thz[h5C?C  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); {s{+MbD  
SiteFileFetch fileFetch = new SiteFileFetch(bean); GK [Hs 1/  
fileFetch.start(); T.W^L'L `  
} tT+W>oA/M  
catch(Exception e){e.printStackTrace ();} |Mgzb0_IiQ  
qMw_`dC  
;]k\F  
} :KqSMuKR  
! F<::fN  
.>S1do+  
public static void main(String[] args) mY]o_\`  
{ 7~);,#[ky  
new TestMethod(); Gd$!xN %O  
} WWC&-Ni  
} 5n1`$T.WG  
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