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http断点续传简单实现(java)

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/* n!8W@qhew  
**SiteFileFetch.java #7'k'(  
*/ m(9I+`  
package NetFox; D{\o*\TN  
import java.io.*; |X XO0  
import java.net.*; }xBO;  
R(&3})VOa  
_fY9u2Y  
public class SiteFileFetch extends Thread { . IY@Q  
ey9hrRMR  
mP6}$ D  
SiteInfoBean siteInfoBean = null; //文件信息Bean 5+oY c-  
long[] nStartPos; //开始位置 8:S+*J[gSn  
long[] nEndPos; //结束位置 {t! &x:  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 V;CRs\aYf  
long nFileLength; //文件长度 "mE/t  (  
boolean bFirst = true; //是否第一次取文件 i!UT =  
boolean bStop = false; //停止标志 E24}?t^|  
File tmpFile; //文件下载的临时信息 F[jqJzCz  
DataOutputStream output; //输出到文件的输出流 k1yqe rA  
IOC$jab@  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) `5Z'8^  
public SiteFileFetch(SiteInfoBean bean) throws IOException ,38M6yD  
{ 3$P  
siteInfoBean = bean; }TZM@{;  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); gk?H@b*  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 80g}<Lwc  
if(tmpFile.exists ()) o(?9vU  
{ 8mdVh\i!Kf  
bFirst = false; Ue Z(@6_:  
read_nPos(); }dMX1e1h8  
} Ho*B<#&(A|  
else -Q<OSa='  
{ -!5l4  
nStartPos = new long[bean.getNSplitter()]; MxX)&327  
nEndPos = new long[bean.getNSplitter()]; kiyKL:6D|  
} #Q["[}flVv  
<wFmfrx+v  
ONpvx5'#  
3w p@OF_  
} BKI-Dh  
a[j]fv*6  
gn.)_  
public void run() 9$9a BW  
{ "x;FE<I  
//获得文件长度 $>_`.*I/  
//分割文件 BT0;I  
//实例FileSplitterFetch Uj 4HVd  
//启动FileSplitterFetch线程 1uKIO{d @  
//等待子线程返回 ,+h<qBsV@  
try{ >jTiYJI_M  
if(bFirst) rc>}3?o  
{ FcZ)^RQ4G  
nFileLength = getFileSize(); reYIF*  
if(nFileLength == -1) hMS:t(N{  
{ <liprUFsn  
System.err.println("File Length is not known!"); A@d 2Ukv  
} Wql=PqF  
else if(nFileLength == -2) bW/T}FN D  
{ Syl9j]  
System.err.println("File is not access!"); (Lh!7g/0N  
} eS4t0`kP  
else VE/m|3%t  
{ izl-GitP  
for(int i=0;i<nStartPos.length;i++) Jc5Y Gj7  
{ N|@ tP:j  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); @sZ' --Y  
} T:K}mLSg  
for(int i=0;i<nEndPos.length-1;i++) 99'c\[fd'  
{ [K4 k7$  
nEndPos = nStartPos[i+1]; .) %, R  
} ~^'t70 :D  
nEndPos[nEndPos.length-1] = nFileLength; ,+v(?5[6  
} x@O )QaBN!  
} (Lj*FXmz  
^j pQfDe6  
iDgc$'%?  
//启动子线程 -R];tpddR5  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; y!S:d  
for(int i=0;i<nStartPos.length;i++) = 4|"<8'  
{ 4/3w *  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \f Kn} ]kG  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5oB#{h  
nStartPos,nEndPos,i); +5R8mbD!  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); n) HV:8j~  
fileSplitterFetch.start(); 4XiQ8"C  
} %Y#W#G  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), q`z1ht nf  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); fU%Mz\t  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", N;}X$b5Y @  
nEndPos = " + nFileLength); ~K|ha26W  
// fileSplitterFetch[nPos.length-1].start(); bYhG`1,$-a  
Y![ i=/  
N 5{w  
//等待子线程结束 \>.[QQVI"l  
//int count = 0; V5 9Vf[i|  
//是否结束while循环 `s=Z{bw  
boolean breakWhile = false; MX!N?k#KhP  
;<0~^,Xm  
"9*MSsU  
while(!bStop) `W1TqA  
{ c;yp}k]\  
write_nPos(); $ 6r> Tc](  
Utility.sleep(500); &:g1*+  
breakWhile = true; e&[~}f?  
w_QWTD 0  
^K~=2^sh  
for(int i=0;i<nStartPos.length;i++) `@6y Wb:X  
{ +>u 8r&Jw.  
if(!fileSplitterFetch.bDownOver) QJx<1#  
{ #!yX2lR  
breakWhile = false; .p'McCV=  
break; [;D1O;c'W.  
} W_/$H_04+  
} 37tJ6R6[  
if(breakWhile) YF;2jl Nm  
break; 4@ny%_/  
J=O_nup6C  
`tKs|GQf  
//count++; ^foCcO  
//if(count>4) DI-CC[  
// siteStop(); I>-1kFma;  
} .ubZ  
pf yJL?_%  
81I9xqvSd~  
System.err.println("文件下载结束!"); Ib/e\+H\  
} z<yqQ[  
catch(Exception e){e.printStackTrace ();} 7o*~zDh@fH  
} 3_i29ghv  
&wkb r2P  
k#V\O2lb  
//获得文件长度 "1DlusmCCB  
public long getFileSize() r=RiuxxTq  
{ (v}l#M7w  
int nFileLength = -1; Rp_}_hL0  
try{ 0Uk;&a0s  
URL url = new URL(siteInfoBean.getSSiteURL()); 8f'r_,"  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v.,D,6qZ  
httpConnection.setRequestProperty("User-Agent","NetFox"); 1^WkW\9kO  
LiGECqWBa'  
(J(SwL|  
int responseCode=httpConnection.getResponseCode(); YXU2UIY<~  
if(responseCode>=400) ]yFO~4Nu  
{ ] J|#WtS  
processErrorCode(responseCode); !\Xrl) $j{  
return -2; //-2 represent access is error $c+:dO|Fb  
} wwa)VgoS[  
tjne[p  
ojIGfQV  
String sHeader; "%rU1/@#  
~qA\u5sB9@  
o6 :]Hvqjr  
for(int i=1;;i++) ~ sWXd~\  
{ zrC1/%T  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $TAsb>W!(  
//Utility.log(in.readLine()); /|v b)J  
sHeader=httpConnection.getHeaderFieldKey(i); a72L%oJ   
if(sHeader!=null) m'ZxmsFo  
{ ehMpo BL  
if(sHeader.equals("Content-Length")) b0N7[M1Xl  
{ h?->A#  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); G*zhy!P  
break; 2jP(D%n  
} IG:CWPU  
} qUQP.4Z95  
else '|&?$g(\h  
break; r|953e  
}  SmAF+d  
} _2}/rwVg  
catch(IOException e){e.printStackTrace ();} _znn`_N:v  
catch(Exception e){e.printStackTrace ();} ,LU|WXRB  
k/Ao?R=@gI  
Y5mk*Q#q  
Utility.log(nFileLength); WBD"d<>'  
>IZ$ .-  
`n`HwDo;i  
return nFileLength; 2kFP;7FO  
} E@Yq2FBpnn  
ZYTBc#f  
]^QO ^{Sz  
//保存下载信息(文件指针位置) mw\Pv|  
private void write_nPos() 4%SA%]a L1  
{ }$3pS:_N~  
try{ \LM{.g zT  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 07,&weQ  
output.writeInt(nStartPos.length); "haJwV6-  
for(int i=0;i<nStartPos.length;i++) a{kLAx[>  
{ Z?."cuTt  
// output.writeLong(nPos); +OO my  
output.writeLong(fileSplitterFetch.nStartPos); U)('}u=b  
output.writeLong(fileSplitterFetch.nEndPos); vC^n_  
} (~#-J7  
output.close(); _J_QB]t  
} L^ U.h  
catch(IOException e){e.printStackTrace ();} W)odaab7  
catch(Exception e){e.printStackTrace ();} m9$lOk4/  
} YE-}1&8  
{>X2\.Rl  
v 5&8C  
//读取保存的下载信息(文件指针位置) ,e*WJh8k[  
private void read_nPos() AIM<mU  
{ 'W p~8}i@  
try{ mbIHzzW>  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); (+bt{Ma  
int nCount = input.readInt(); hx}X=7w  
nStartPos = new long[nCount]; , #(k|Zztc  
nEndPos = new long[nCount]; 9%?a\#C  
for(int i=0;i<nStartPos.length;i++) ,Q+.kAh !G  
{ s`dUie}y<  
nStartPos = input.readLong(); l+^4y_  
nEndPos = input.readLong(); Qf@ha  
} !<0 `c  
input.close(); ,GF(pCZzG  
} fvV5G,lD3h  
catch(IOException e){e.printStackTrace ();} =$< .:b  
catch(Exception e){e.printStackTrace ();} }I~)o!N%7  
} R'B-$:u  
BIjkW.uf  
$< .wQ8:Q  
private void processErrorCode(int nErrorCode) Mg\8m-L^  
{ rJCu6  
System.err.println("Error Code : " + nErrorCode); /+?eSgM/  
} kclZ+E  
iGIry^D  
Rw`64L_  
//停止文件下载 wG&rkg";#  
public void siteStop() <im<0;i&e  
{ 3'tq`t:SQ  
bStop = true; e,@5`aYHM@  
for(int i=0;i<nStartPos.length;i++) O|&SL03Z8  
fileSplitterFetch.splitterStop(); W@vCMy!  
>q1rdq  
|k/;1.b!9(  
} rCdTn+O2  
} h"ATRr^  
//负责部分文件的抓取 "lBYn2W  
**FileSplitterFetch.java 6oq/\D$6~  
*/ Xcci)",!  
package NetFox; b}m@2DR'|m  
VP6_}9:9   
-b'/}zz  
import java.io.*; ?s9f}>  
import java.net.*; n wO5<b;  
TA!6|)BUW  
 e3%dNa  
public class FileSplitterFetch extends Thread { /wJocx]vQ  
c/-PEsk_TP  
m=D9V-P  
String sURL; //File URL BVxk}#d  
long nStartPos; //File Snippet Start Position cbv%1DT3  
long nEndPos; //File Snippet End Position }?,Eb~q  
int nThreadID; //Thread's ID X GDJCN  
boolean bDownOver = false; //Downing is over 1 o\COnt  
boolean bStop = false; //Stop identical ~4`3p=$  
FileAccessI fileAccessI = null; //File Access interface +}^^]J$Nh  
lN[#+n  
L=kETJ:g  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $`"$ZI6[  
{ 8:"s3xaO3  
this.sURL = sURL; md /NMC \  
this.nStartPos = nStart; x UTlM  
this.nEndPos = nEnd; r<_qU3Eaj  
nThreadID = id; l#3jJn  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 #}C6}};  
} ME'LZ"VT  
5DVSaI$ =  
zB#.EW  
public void run() ePiZHqIsv/  
{ c^}DBvG,  
while(nStartPos < nEndPos && !bStop) 4siq  
{ ryt`yO  
_*u$U  
$NwPGy?%  
try{ z v:o$2Z  
URL url = new URL(sURL); )W!\D/C+  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7G  3e  
httpConnection.setRequestProperty("User-Agent","NetFox"); |:LklpdYe  
String sProperty = "bytes="+nStartPos+"-"; m/ngPeZ  
httpConnection.setRequestProperty("RANGE",sProperty); [yDOv Q[  
Utility.log(sProperty); He  LW*  
Ap!i-E,"J  
!w:pb7+G  
InputStream input = httpConnection.getInputStream(); E#c9n%E\sz  
//logResponseHead(httpConnection); D]+@pK b  
rVDOco+w  
2mfG: ^^c  
byte[] b = new byte[1024]; x3 01uf[  
int nRead; T&]IPOH9  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 9PJnKzQ4  
{ muIJeQ.C  
nStartPos += fileAccessI.write(b,0,nRead); Rh{`#dI~=  
//if(nThreadID == 1) 5O:4-} hz  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]nm(V  
} lrK?&a9AB  
7O'u5 N  
9K=K,6 b  
Utility.log("Thread " + nThreadID + " is over!"); /Ca M(^W   
bDownOver = true; 4'H)h'#C  
//nPos = fileAccessI.write (b,0,nRead); C@9K`N[*  
} "Q;Vy t  
catch(Exception e){e.printStackTrace ();} ;H"OZRQ  
} !+n'0{  
} >,c'Z<TM  
OZ2faf  
6Q}>=R^h  
//打印回应的头信息 ;rt\  
public void logResponseHead(HttpURLConnection con) Y|-:z@n6C  
{ ` 6pz9j]  
for(int i=1;;i++) K,Hxe;-  
{ ,gIeQ!+vy  
String header=con.getHeaderFieldKey(i); OwLJS5r@<-  
if(header!=null) f:ep~5] G  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); e J:#vX86  
Utility.log(header+" : "+con.getHeaderField(header)); {5JYu  
else ) {4$oXQ  
break; jN!sL W  
} ``Rg0o  
} ^2"w5F  
%WtF\p  
x=V3_HI/}  
public void splitterStop() >* ]B4Q  
{ ,-1d2y  
bStop = true; M0woJt[&  
} q`HK4~i,  
__)"-\w-_(  
,~XAV ;+  
} G+K`FUNA  
'o1lJ?~kH  
z"V`8D  
/* M&0U@ r-  
**FileAccess.java [m9=e-KS$Q  
*//文件访问(定位,写) 4&H&zST//m  
package NetFox; |i- S}M  
import java.io.*; 1N+ju"2R  
fP{IW`t}]  
?7w7Y;FuR  
public class FileAccessI implements Serializable{ HVNX"`]"  
HUx -8<ws  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 L%/atl!  
RandomAccessFile oSavedFile; aa\?k\h'7X  
long nPos; CjLiLB  
6' 9zpe@`  
(b+o$C  
public FileAccessI() throws IOException }\vw>iHPX@  
{ Gvqu v\  
this("",0); %`]fZr A]#  
} 8!7`F.BX  
>%85S>e  
U6~79Hnt  
public FileAccessI(String sName,long nPos) throws IOException (o1o);AO  
{ D^A#C<Gs  
oSavedFile = new RandomAccessFile(sName,"rw"); GX%r-  
this.nPos = nPos; &M2fcw?  
oSavedFile.seek(nPos); $K_-I8e|  
} VQn]"G( `  
j15t8du&O  
36yIfC,  
public synchronized int write(byte[] b,int nStart,int nLen) FK;2u $:  
{ !FeNx*31i  
int n = -1; y@dTdR2Wc  
try{ HLl"=m1/>  
oSavedFile.write(b,nStart,nLen); =_`cY^ib+  
n = nLen; 8lF:70wia  
} ^\3z$ntF  
catch(IOException e) 5>rjL ;  
{ 'UB"z{w%  
e.printStackTrace (); [<VyH.  
} g HKA:j`c  
Fj1'z5$  
R3E|seR  
return n; 10r9sR  
} $H1igYc  
A "~Oi  
BV]$= e'  
} wQ\bGBks  
=[`gfw  
;>jOB>b{h  
/* XF99h&;9  
**SiteInfoBean.java UsdUMt!u  
*/ l"9$lF}  
package NetFox; uar[D|DcD"  
-FQS5Zb.!  
poXT)2^)  
public class SiteInfoBean { MMf_  
Io<L! =>  
9D51@b6k  
private String sSiteURL; //Site's URL ~lH2# u>g  
private String sFilePath; //Saved File's Path =p#:v  
private String sFileName; //Saved File's Name ie<m)  
private int nSplitter; //Count of Splited Downloading File Ve t<,;Te  
Lq{/r+tt/  
DO ,7vMO  
public SiteInfoBean() tD No; f  
{//nSplitter的缺省值为5 (0zYS_m A  
//default value of nSplitter is 5 l#|M.V6G  
this("","","",5); TJkWL2r0c  
} [ P%'p-Hg_  
910N 1E  
\$2zF8  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Xvn \~Vr  
{ 3y-P-NI~=  
sSiteURL= sURL; }62Q{>`  
sFilePath = sPath; $"`e^J9!!  
sFileName = sName; c.h_&~0qf  
this.nSplitter = nSpiltter; .,gVquqMY  
:/i13FQ  
~{!,ZnO*  
} j4Y] 8  
s7:w>,v/  
]VK9d;0D  
public String getSSiteURL() xO;Qr.3PX  
{ N#7_)S[@0l  
return sSiteURL; PsI{y&.  
} wbh^ZMQ  
seNH/pRb  
qF4DX$$<  
public void setSSiteURL(String value) <u2iXH5w  
{ j9 &0/ ~/  
sSiteURL = value; mv1|oFVW  
} Cj# ?Z7}z  
*jo1?  
)iCg,?SSw=  
public String getSFilePath() a}7P:e*u  
{ r8[Ywn <u  
return sFilePath; eHH9#Vrhc$  
} gO m%?sg  
\`WAG>'l5  
n|!O .+\b  
public void setSFilePath(String value) No(S#,vJ;  
{ 5 OF*PBZ  
sFilePath = value; q??N,  
} Ox+}JB [  
( ALsc@K  
pOIfKd  
public String getSFileName() P%Wl`NA P  
{ t}Kzh`  
return sFileName;  h]?[}&  
} ((tWgSZ3  
X$ 76#x  
)LE#SGJP  
public void setSFileName(String value) _<l9j;6  
{ @wW)#!Mou  
sFileName = value; I}1<epd ,  
} }3y Q*<  
Ui;PmwQc&  
,\E5et4  
public int getNSplitter() WvHy}1W  
{ IR<*OnKn  
return nSplitter; nF{>RD  
} pqxBu  
DP4l %2m0  
0/?=FM >  
public void setNSplitter(int nCount) k{pn~)xg  
{ nokMS  
nSplitter = nCount; %{^kmlO  
} d15E$?ZLH  
} BG2Z'WOH  
@!s(Zkpev  
BZ@v8y _TA  
/* Wx-rW  
**Utility.java ,ikn%l#cm  
*/ /BfCh(B  
package NetFox; B,RHFlp{  
~n!7 ?4%U  
C~:!WRCz  
public class Utility { iVb#X#  
wq`\p['Q,  
p?eQN Y  
public Utility() HZzdelo  
{ ,Y2){8#l  
+0FmeM&`h_  
8:4`q 9  
} h_ J|uu  
j=TG&#e  
//线程睡眠 XX'Rv]T  
public static void sleep(int nSecond) K iG/XnS  
{ [[d@P%X&  
try{ qVmG"et'J  
Thread.sleep(nSecond); iC\t@BVS  
} )ia$pe s  
catch(Exception e) d#wK  
{ 8sxH)"S  
e.printStackTrace (); ?u /i8  
} vxx7aPjC  
} ' C|yUsBC  
h5R5FzY0&  
//日志 H1g"09?h6o  
public static void log(String sMsg) U0%m*i  
{ gSu3\keF  
System.err.println(sMsg); vt-5 3fa|  
} b-,]21  
F6\r"63  
'aW<C>  
public static void log(int sMsg) E>6:59+  
{ e8<[2J)P&  
System.err.println(sMsg); zhFk84  
} BFyVq  
} $2\k| @)s  
YC0FXNV  
*FEY"W+bY  
/* 9Fm><,0'u  
**TestMethod.java 'HDbU#vD  
*/ .]W A/}  
package NetFox; k!6wVJ|_Y  
nFfwVqV  
J#'+&D H  
public class TestMethod { b?FTwjV+#  
'^Ce9r}  
{,rVA(I@  
public TestMethod() Nm]\0m0p-  
{ ///xx/weblogic60b2_win.exe fr<, LC.  
try{ 9K F`9Y  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5);  a7UfRG  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); )q+9_KU q  
SiteFileFetch fileFetch = new SiteFileFetch(bean); xkzC+ _A  
fileFetch.start(); bbO1`b-  
} N/fH%AtM  
catch(Exception e){e.printStackTrace ();} t'0dyQ%u  
`[5QouPV  
sj?7}(s  
} &Kgl\;}  
+e%U6&l{  
q^hL[:ms#  
public static void main(String[] args) <e&*Tx<8  
{ !xxu~j^T  
new TestMethod(); v/yt C/WH"  
} R83Me #&  
} i@M^9|Gh  
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