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http断点续传简单实现(java)

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/* dLQ!hKD~  
**SiteFileFetch.java }4eSB  
*/ -I4@` V  
package NetFox; @BW~A@8  
import java.io.*; 42# rhgW  
import java.net.*; !30Dice  
5p=T*Y  
z4{|?0=C  
public class SiteFileFetch extends Thread { Eer rIV  
v9M ;W+J  
"hs`Y4U  
SiteInfoBean siteInfoBean = null; //文件信息Bean /A <L  
long[] nStartPos; //开始位置 2,NQ(c_c$  
long[] nEndPos; //结束位置 6PvV X*5T  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 c(YNv4*X  
long nFileLength; //文件长度 ,VJ0J!@  
boolean bFirst = true; //是否第一次取文件 =$b^ X?x  
boolean bStop = false; //停止标志 ,pf<"^li  
File tmpFile; //文件下载的临时信息 &:'Uh W-t  
DataOutputStream output; //输出到文件的输出流 \ J9@p  
oEKLuy  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) sbkWJy  
public SiteFileFetch(SiteInfoBean bean) throws IOException &*MwKr<y  
{ a#j0N5<Nl  
siteInfoBean = bean; #p=/P{*  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); %Vive2j C  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); %3z-^#B=  
if(tmpFile.exists ()) zy+|)^E  
{ 4HkOg)a  
bFirst = false; f&{2G2 O%  
read_nPos(); t55 '  
} 0QEVL6gw  
else U.?,vw'aai  
{ /Pi{Mv eZM  
nStartPos = new long[bean.getNSplitter()]; =AZ>2P  
nEndPos = new long[bean.getNSplitter()]; 9{xP~0g  
} |910xd`Z  
u]"oGJj1  
FS`{3d2K +  
{T m-X`  
} g4I(uEJk  
lh8`.sWk4V  
mm:\a-8j  
public void run() Os?~U/  
{ 8BLtTpu  
//获得文件长度 "{L%5:H@  
//分割文件 AP/5, M<  
//实例FileSplitterFetch yy/wSk  
//启动FileSplitterFetch线程 &m+s5  
//等待子线程返回 s?E7tmaM  
try{ !cp ,OrO\  
if(bFirst) -b r/  
{ e[w)U{|40  
nFileLength = getFileSize(); "E 8-76n  
if(nFileLength == -1) DghX(rs_  
{ GG%j+Ed  
System.err.println("File Length is not known!"); >8>`-  
} >9Ub=tZm  
else if(nFileLength == -2) .T4"+FTzP  
{ J%3S3C2*m  
System.err.println("File is not access!"); u -CY-  
} }&`#  
else 0=L:8&m  
{ qK;n>BTe  
for(int i=0;i<nStartPos.length;i++) c%Kv"Z%f  
{ & UL(r  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); pmIQD"  
} }T4"#'`  
for(int i=0;i<nEndPos.length-1;i++) \7*9l%  
{ !=|3^A  
nEndPos = nStartPos[i+1]; 2/qfK+a  
} b\dBt#mB!  
nEndPos[nEndPos.length-1] = nFileLength; l|U=(aA]h  
} osPX%k!yw  
} Q5{i#F7nJm  
9IC"p<D  
T3%yV*F,  
//启动子线程 ~*THL0]~  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $PHKI B(  
for(int i=0;i<nStartPos.length;i++) 2O`uzT$  
{ c i_XcG  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Wi hQj  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), gWv/3hWWB  
nStartPos,nEndPos,i); ?fCLiK  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >77 /e@  
fileSplitterFetch.start(); }g5h"N\$o  
} K?(ls$  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j#3}nJB%#i  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); j}#48{  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", :7@"EW  
nEndPos = " + nFileLength); Yf7n0Etd,  
// fileSplitterFetch[nPos.length-1].start(); .e"De-u  
LL#7oBJdM  
!gW$A-XD  
//等待子线程结束 vA;ml$  
//int count = 0; !ck=\3pr  
//是否结束while循环 Y}(v[QGV  
boolean breakWhile = false; 6V*@ {  
4US8B=jk  
TW:vL~L  
while(!bStop) k2,n:7  
{ V.: a6>]  
write_nPos(); = 14'R4:  
Utility.sleep(500); ]J5[ZVz  
breakWhile = true; it D%sKo  
{~[H"h537t  
KFCuv15w,3  
for(int i=0;i<nStartPos.length;i++)  ORp6  
{ f|w+}z  
if(!fileSplitterFetch.bDownOver) .A&Ey5  
{ +2|X 7wA  
breakWhile = false; >"5^]o2?~l  
break; NnGQ=$e  
} KaBze67<|  
} J &u&G7#S  
if(breakWhile) Bl3G_Ep   
break; =_D82`p  
9Rb-QI  
lWd)(9K j  
//count++; =}Bq"m  
//if(count>4) DTl M}  
// siteStop(); T,`'qZ>  
} MDGcK/$')f  
--Dw8FR9  
A WMR0I  
System.err.println("文件下载结束!"); }sd-X`lZ  
} xAjLn*d|N  
catch(Exception e){e.printStackTrace ();} L!3{ASIN0  
} ^qIp+[/'  
mhnD1}9,Ih  
`0=0IPVd  
//获得文件长度 |.*),t3 (w  
public long getFileSize() gmj a2F,  
{ c zL[W2l   
int nFileLength = -1; zVGjXuNa  
try{ 42Tjbten_u  
URL url = new URL(siteInfoBean.getSSiteURL()); ]Qkto4DQ5  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !5? #^q  
httpConnection.setRequestProperty("User-Agent","NetFox"); [j 'Ogm7"  
jF Bq>  
fP&F$"o8  
int responseCode=httpConnection.getResponseCode(); d[kb]lC  
if(responseCode>=400) n-}:D<\7  
{ yodJGGAzk  
processErrorCode(responseCode); 4+$<G/K  
return -2; //-2 represent access is error ~Rs|W;  
} 9hmCvQgtf  
\-#~)LB]M  
xX{uDMYa;  
String sHeader; L<1"u.3Z`}  
9bMM-~  
wI1[I  
for(int i=1;;i++) {iYu x;(  
{ 4CW/  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); U#Wc!QN-t  
//Utility.log(in.readLine()); J= ia  
sHeader=httpConnection.getHeaderFieldKey(i); x +q"%9.c  
if(sHeader!=null) *O)_D bj  
{ 8v*>~E/0  
if(sHeader.equals("Content-Length")) A AH-Dj|&l  
{ fh b&_T  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); K.*?\)&  
break; N`8!h:yL  
} f0IljY!.  
} d?v#gW  
else 83412@&  
break; )XnG.T{0|  
} wf=#w}f  
} uZ]B?Z%y#  
catch(IOException e){e.printStackTrace ();} bhOyx  
catch(Exception e){e.printStackTrace ();} 5y(irbk7  
r{YyKSL1*K  
L`R,4mI.W  
Utility.log(nFileLength); vk5pnCM^3  
xv$^%(Ujp  
T!"<Kv]J  
return nFileLength; >m:.5][yu  
} xp)#a_}  
8!VjXj"  
lE?e1mz{  
//保存下载信息(文件指针位置) JjfNH ~  
private void write_nPos() yD#w @yG  
{ 8MX/GF;F  
try{ `RthX\Tof  
output = new DataOutputStream(new FileOutputStream(tmpFile)); $\81WsL '  
output.writeInt(nStartPos.length); Eh!%Ne O  
for(int i=0;i<nStartPos.length;i++) d%t]:41=Z  
{ umcbIi('  
// output.writeLong(nPos); W#u}d2mP  
output.writeLong(fileSplitterFetch.nStartPos); T55l-.>  
output.writeLong(fileSplitterFetch.nEndPos); )_GM&-  
} I%e7:cs>  
output.close(); JV36@DVQ  
} 7Kk rfJqN  
catch(IOException e){e.printStackTrace ();} }h +a8@  
catch(Exception e){e.printStackTrace ();} D4 {gt\V  
} :54|Z5h|  
#7lkj:j4  
fOE:~3Q  
//读取保存的下载信息(文件指针位置) i#kRVua/  
private void read_nPos() c*RZbE9k  
{ K[~Wj8W0  
try{ $#]?\psf  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Qc[[@=S%  
int nCount = input.readInt(); reu[}k~  
nStartPos = new long[nCount]; IH\k_Yf#u  
nEndPos = new long[nCount]; 2O<S ig=  
for(int i=0;i<nStartPos.length;i++) )P|%=laE8  
{ >z>UtT:  
nStartPos = input.readLong(); F#X\}MvEU  
nEndPos = input.readLong(); ~q4DePVE  
} *VHBTO9  
input.close(); 4TwU0N+>  
} _q6+]  
catch(IOException e){e.printStackTrace ();} ua|qL!L+  
catch(Exception e){e.printStackTrace ();} oxO}m7 ULH  
} oq8~PTw  
e!tgWYN  
<' P|g  
private void processErrorCode(int nErrorCode) a(x[+ El  
{ aCGPtA'  
System.err.println("Error Code : " + nErrorCode); U|{WtuR  
} vbDw2  
:&?#~NFH  
D1o 8Wo  
//停止文件下载 ?z:xQ*#X  
public void siteStop() 82O`<Ci  
{ "MoV*U2s,  
bStop = true; "5{Yn!-:  
for(int i=0;i<nStartPos.length;i++) LTzf&TZbx5  
fileSplitterFetch.splitterStop(); ^ / f*5k  
2<ef&?ljk  
/R|"/B0  
} )z/j5tnvm  
} +S;8=lzuV  
//负责部分文件的抓取 s3J T1TX  
**FileSplitterFetch.java d57(#)`  
*/ m G?a)P  
package NetFox; KOi%zE%  
WCR+ZXI?1  
elKQge  
import java.io.*; nJ*NI)  
import java.net.*; /jj!DO#  
_x UhDu%  
oC4rL\d{  
public class FileSplitterFetch extends Thread { (/k,q  
(]7@0d88  
,P auP~L  
String sURL; //File URL NA/+bgyuT>  
long nStartPos; //File Snippet Start Position {F@;45)o  
long nEndPos; //File Snippet End Position zh/+1  
int nThreadID; //Thread's ID Bj@&c>  
boolean bDownOver = false; //Downing is over  }Ecm  
boolean bStop = false; //Stop identical ARQ1H0_B  
FileAccessI fileAccessI = null; //File Access interface QRdb~f;<hj  
 n8:2Z>  
.-RWlUe;,  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]nfS vPb  
{ N"E\o,_  
this.sURL = sURL; ioa 1n=j  
this.nStartPos = nStart; i w m7M  
this.nEndPos = nEnd; A% Bz52yg  
nThreadID = id; c$e~O-OVD?  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =WO{h48]  
} xHD!8 B)  
.zegG=q  
\2NiI]t]  
public void run() qZ1fQN1yG  
{ 0 ?2#SM  
while(nStartPos < nEndPos && !bStop) YLFTf1G9  
{ r5s*"z  
}\gpO0Ox  
Uj!L:u2b  
try{ 4 Qw;r  
URL url = new URL(sURL); @&EP& $*  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $7BD~U   
httpConnection.setRequestProperty("User-Agent","NetFox"); k?S-peyRO  
String sProperty = "bytes="+nStartPos+"-"; 58v5Z$%--  
httpConnection.setRequestProperty("RANGE",sProperty); u[dI81`  
Utility.log(sProperty); V KR6i  
YO,GZD`-o  
pkk0?$l ",  
InputStream input = httpConnection.getInputStream(); E&[ox[g{  
//logResponseHead(httpConnection); ~4\bR  
7,+:Q Y@  
)%MB o.NL  
byte[] b = new byte[1024]; rcyH2)Y/e  
int nRead; 7gJy xQ  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @l;f';+  
{ /1OhW>W3eH  
nStartPos += fileAccessI.write(b,0,nRead); c69C=WQ  
//if(nThreadID == 1) ~z< ? Wh  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); SnXYq 7`t  
} F[?t"d  
7 'f>  
KRXe\Sx  
Utility.log("Thread " + nThreadID + " is over!"); `mWg$e,  
bDownOver = true; 9]7^/g*!  
//nPos = fileAccessI.write (b,0,nRead); vkt)!hl `  
} q g%<>B&"  
catch(Exception e){e.printStackTrace ();} Zmp ^!|=X!  
} h[lh01z  
} 5k\61(*s  
kwyvd`J8  
(JF\%Yj/  
//打印回应的头信息 7vHU49DV  
public void logResponseHead(HttpURLConnection con) 54'z"S:W  
{ 3gGF?0o  
for(int i=1;;i++) FD`V39##  
{ IzL yn  
String header=con.getHeaderFieldKey(i); TnKe"TA|9  
if(header!=null) Zd5fr c$  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); zCco/]h  
Utility.log(header+" : "+con.getHeaderField(header)); Zd~Z`B} &  
else 9xWeVlfQ  
break; n=yFw\w'  
} `Y(/G"]  
} ChBZGuO:  
XS1>ti|<  
/sYD+*a  
public void splitterStop() qQ|v~^  
{ ey Cg *  
bStop = true; F5*Xx g}N  
} Rq\.RR](  
)fC^h=Qp  
w-\GrxlbX  
} J@)6]d/,  
QGYmQ9m{kL  
Wm"W@LPx5  
/* \.*aC)  
**FileAccess.java lJKU^?4S8  
*//文件访问(定位,写) 7d9%L}+q  
package NetFox; IRcZyry  
import java.io.*; :Tjo+vw7$H  
xl<Cstr  
e <IT2tv>u  
public class FileAccessI implements Serializable{ J[<:-$E  
\Mi y+<8$  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9 s>JdAw?  
RandomAccessFile oSavedFile; XLzHm&;  
long nPos; ~A6QX8a  
0_%u(?  
BGUP-_&  
public FileAccessI() throws IOException 8WaVs6  
{ 7[8PSoo  
this("",0); paiF ah  
} km8[azB o  
+='.uc_  
j[c|np4k\  
public FileAccessI(String sName,long nPos) throws IOException SFh6'v'1N@  
{ Z,Q)\W<'-  
oSavedFile = new RandomAccessFile(sName,"rw"); R[Pyrs!H  
this.nPos = nPos; M#2DI?S@  
oSavedFile.seek(nPos); Mb+cXdZb  
} \E0Uj>9+[  
mF#{"  
<S5Am%vo  
public synchronized int write(byte[] b,int nStart,int nLen) PiM@iS  
{ Y.=v!*p?}  
int n = -1; !v94FkS>  
try{ {HQ?  
oSavedFile.write(b,nStart,nLen); 7]G3yt->  
n = nLen; Dmn6{jy P  
} ;JDxl-~  
catch(IOException e) 72Ft?;R  
{ Bm.%bA>  
e.printStackTrace (); \J:/l|h  
} R`A @F2  
/1g_Uv;  
M2mte#h  
return n; MSsboSxA  
} mZ*!$P:vy"  
@/XA*9]l  
hcwKi  
} fY$M**/,  
XkOsnI8n  
_KC()OIeC  
/* B&`#`]  
**SiteInfoBean.java dz&8$(f,  
*/ i5q VQo  
package NetFox; wjQu3 ,Cj  
'$;S?6$eW  
5c! ~WckbJ  
public class SiteInfoBean { 9SXFiZA(r  
DNC2]kS<  
8"Hy'JA$O  
private String sSiteURL; //Site's URL s9@/(_  
private String sFilePath; //Saved File's Path t|%wVj?_  
private String sFileName; //Saved File's Name f9F@G&&Ugg  
private int nSplitter; //Count of Splited Downloading File [C9->`(`  
ON\_9\kv  
'eZ UNX  
public SiteInfoBean() J9zSBsp_  
{//nSplitter的缺省值为5 % sbDH  
//default value of nSplitter is 5 @|idlIey  
this("","","",5); "i(k8+i K  
} Bc`jkO.q  
z*"zXL C  
5iwJdm  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) L "P$LEk  
{ SBg BZm}%  
sSiteURL= sURL; 3g`uLA X>u  
sFilePath = sPath; :q<8:,rP  
sFileName = sName; 00[Uk'Q*5  
this.nSplitter = nSpiltter; k$j>_U? P  
6DD"Asi+  
nM>oG'm[n  
} LaG./+IP  
pMe'fC~*  
MOKg[ j  
public String getSSiteURL() 0V@u]  
{ c-(,%0G0  
return sSiteURL; pPuE-EDk  
} cLEBcTx  
odD^xg"L  
kG^DHEne  
public void setSSiteURL(String value) /Q 8E12  
{ x$tx!%,)/S  
sSiteURL = value; FO&U{(Q  
} K?8{ y  
rzsb(  
[kM)K'-  
public String getSFilePath() vT#zc)j  
{ QX1QYwcmG  
return sFilePath; ~k'KS 7c  
} ]v{f!r=}  
;!v2kVuS]  
R'`q0MoN1  
public void setSFilePath(String value) /GD4GWv :  
{ yZj:Kp+7  
sFilePath = value; =* oFs|v  
} zxTcjC)y  
^2rNty,nH  
s`B]+  
public String getSFileName() !`LaX!bmp  
{ ,]+P#eXgE  
return sFileName; cah1'Y  
} ^mz&L|h  
R@ N I  
a{v1[i\  
public void setSFileName(String value) Ne!F  p  
{ /g BB  
sFileName = value; d!mtSOh  
} ms@*JCL!t  
[p^N].K$  
X`JWYb4  
public int getNSplitter() "7mY s)=  
{ RB`Emp&T  
return nSplitter; #  -e  
} WvQK$}Ax4N  
*$~H=4t  
DN3#W w2[r  
public void setNSplitter(int nCount) BQu_)@  
{ kclClB:PS  
nSplitter = nCount; W ZdEfY{  
} %5Hsd  
} \ 'G%%%;4  
#9M6 q  
^x-vOG lR  
/* uu@Y]0-  
**Utility.java (&HAjB  
*/ :34]}`-  
package NetFox; `?r]OVe{y  
S{' /=Px+  
ErIAS6HS'  
public class Utility { yr?*{;  
a+sHW<QeS  
 AV{3f`  
public Utility() 7N9~nEU  
{ #-*7<wN   
91d@/z  
. J[2\"W  
} t[*;v  
o8Vtxnkg  
//线程睡眠 u>SGa @R)  
public static void sleep(int nSecond) exT O#*o  
{ wTb7 xBI  
try{ Whp;wAz  
Thread.sleep(nSecond); B7BXS*_b  
} zea=vx>`  
catch(Exception e) v'gP,UO-%D  
{ )[_A{#&  
e.printStackTrace (); 29]-s Utqv  
} 3 r4QB  
} k]?M^jrm  
)NAC9:8!  
//日志 GG%X1c8K  
public static void log(String sMsg) {uH 4j4)2  
{ `2`Nu:r^  
System.err.println(sMsg); DID&fj9m  
} GPlAQk  
pie<jZt  
*qdf?' R  
public static void log(int sMsg) hd{Vz{;W  
{ ?|!167/O  
System.err.println(sMsg); /^ *GoB  
} 3 d $  
} _%^t[4)q  
Z)}q=NjA  
7oaa)  
/* !_0kn6 S5  
**TestMethod.java uis;S)+  
*/ Pl^-]~  
package NetFox; Y*nzOD$  
4bXAA9"  
94C)63V  
public class TestMethod { bL*;6TzRK  
SxV(.i'  
\|^fG9M~  
public TestMethod() %~%1Is`4J  
{ ///xx/weblogic60b2_win.exe P5M+usx  
try{ zWvG];fsN  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); R{{d4=:S  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); n.zVCKN H  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 'A@[a_  
fileFetch.start(); Bfhw0v]Z  
} GBOz,_pw  
catch(Exception e){e.printStackTrace ();} $[9,1.?C  
c*MSd  
" a;z  
} $__e7  
nsR^TD;  
Cr0 \7  
public static void main(String[] args) q@ !p  
{ lsmzy_gV7  
new TestMethod(); R:=C  
}  FkJa+ZA  
} Kp,}7%hDw!  
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