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http断点续传简单实现(java)

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/* eHd{'J<  
**SiteFileFetch.java |LiFX5!\  
*/ )bPwB.}kq  
package NetFox; P@ 1D  
import java.io.*;  ,Ad\!  
import java.net.*; $aG]V-M>  
|`_TVzA  
9S.R%2xw`  
public class SiteFileFetch extends Thread { kZSe#'R's  
.oAg (@^6  
*E+) mB"~  
SiteInfoBean siteInfoBean = null; //文件信息Bean /.7x[Yc  
long[] nStartPos; //开始位置 w.^k':,"  
long[] nEndPos; //结束位置 ;bkS0Vmg  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 K xh)'aal  
long nFileLength; //文件长度 QO%>RG  
boolean bFirst = true; //是否第一次取文件 {l\v J#r:  
boolean bStop = false; //停止标志 %+xh  
File tmpFile; //文件下载的临时信息 lT1*e(I  
DataOutputStream output; //输出到文件的输出流 I{B8'n{cN  
klv^310  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) Scxf5x-  
public SiteFileFetch(SiteInfoBean bean) throws IOException Y2<Z"D`  
{ LEHlfB#z`@  
siteInfoBean = bean; |I85]'K9a  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); $N:m 9R  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 8Bo'0  
if(tmpFile.exists ()) u&2uQ-T0  
{ dpGaI  
bFirst = false; Hagj^8  
read_nPos(); ?8YHz  
} zSDiJ$Xk  
else >d#B149  
{ ;( VJZ_  
nStartPos = new long[bean.getNSplitter()]; M /Bn^A8@  
nEndPos = new long[bean.getNSplitter()]; pd>EUdbrp&  
} BU]9eF!>h  
@*A(#U8p3  
O_(J',++  
1B,RRHXn6  
} Kd7OnU  
Ca?pK_Y  
AO>K 6{  
public void run() _EjS(.e/=  
{ /`:5#O  
//获得文件长度 O:p~L`o>>  
//分割文件 AkT_ZU>  
//实例FileSplitterFetch m' z<d  
//启动FileSplitterFetch线程 +%'0;  
//等待子线程返回 g&riio7lx  
try{ T~`m'4"+c  
if(bFirst) tUz!]P2BUO  
{ -%%2Pz0I  
nFileLength = getFileSize(); N@;6/[8  
if(nFileLength == -1) r|?2@VE  
{ [eG- &u  
System.err.println("File Length is not known!"); > YN<~z-  
} Tet,mzVuu  
else if(nFileLength == -2) YNk?1#k?i  
{ ?Za1  b  
System.err.println("File is not access!"); L{<E'#@F  
} "1h|1'S50?  
else |]\qI  
{  yZdM4`  
for(int i=0;i<nStartPos.length;i++) n8R{LjJ2@  
{ ?}B_'NZ%  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 4+ yd/^S  
} #UI@<0P)  
for(int i=0;i<nEndPos.length-1;i++) 0^:O:X  
{ &ATjDbW*(  
nEndPos = nStartPos[i+1]; }g>&l.2X  
} ]>*Z 1g;  
nEndPos[nEndPos.length-1] = nFileLength; =GFlaGD  
} |w:7).P  
} ]U'KYrh  
DQKhR sC  
"sL#)<%  
//启动子线程 J&{E  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length];  Ur]5AJ  
for(int i=0;i<nStartPos.length;i++) 9K FWa0G  
{ L!-T`R8'c  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \CU.'|X  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -DU[dU*~  
nStartPos,nEndPos,i); 'OkF.bs  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); CW, Kw  
fileSplitterFetch.start(); l(%bdy  
} OC"W=[Myl  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), J"I{0>@  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^om(6JL2  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", s.Yywy  
nEndPos = " + nFileLength); .i@e6JE~;  
// fileSplitterFetch[nPos.length-1].start(); ECU:3KH>MF  
? 0nbvV5v7  
(Cqhk:F  
//等待子线程结束 )[G5qTO  
//int count = 0; H.!M_aJH  
//是否结束while循环 Sf lHSMFw  
boolean breakWhile = false; b_cD >A  
<:>a51HBX  
:2K0/@<x  
while(!bStop) Z`q?pE>R  
{ @/B&R^aVZ  
write_nPos(); b.;F)(  
Utility.sleep(500); &YqgMC  
breakWhile = true; %3'80u6BCJ  
e"[o2=v;5  
V mKMj'  
for(int i=0;i<nStartPos.length;i++) Hco [p+  
{ M(I 2M  
if(!fileSplitterFetch.bDownOver) g2w0#-  
{ b@z/6y!  
breakWhile = false; hPD2/M  
break; dhsQfWg#}  
} }3=]1jH6  
} NC@OmSR\0  
if(breakWhile) z.P) :Er  
break; VmV/~-<Z  
|c dQJW  
m~#98ZJ^  
//count++; NR^z!+oSR  
//if(count>4) T+N%KRl  
// siteStop(); Z?CmD ;W  
} w*\)]bTs  
>%'|@75K  
/nGsl<  
System.err.println("文件下载结束!"); hJ+>Xm@@!  
} 9q;+ Al^Z  
catch(Exception e){e.printStackTrace ();} r Fdq \BSi  
} wUW+S5"K  
\ec,=7S<Zf  
7 45Uo'  
//获得文件长度 JX`+b  
public long getFileSize() DY0G ;L 3  
{ zF3fpEKe  
int nFileLength = -1; |jO&qT]{  
try{ OUS@)Tyh  
URL url = new URL(siteInfoBean.getSSiteURL()); zD7\Gv  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); kImS'i{A  
httpConnection.setRequestProperty("User-Agent","NetFox"); '-S^z"ZrI  
u ;f~  
V!a\:%#^Y  
int responseCode=httpConnection.getResponseCode(); )TBBYCL3  
if(responseCode>=400) O: :X$O7  
{ e>z3 \4  
processErrorCode(responseCode); d%u|) =7  
return -2; //-2 represent access is error \h,S1KmIBD  
} 8u!!a^F  
j<Lj1 P3  
>z.o?F  
String sHeader; rpQB# Pz  
,eF}`  
aOA;"jR1  
for(int i=1;;i++) d^!)',`  
{ 89k9#i X  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); [8(e`6xePb  
//Utility.log(in.readLine()); ~4`LOROC  
sHeader=httpConnection.getHeaderFieldKey(i);  -*M/,O  
if(sHeader!=null) 'k{pWfn=<  
{ 8{(;s$H~  
if(sHeader.equals("Content-Length")) 59F AhEg  
{ yL7a*C&  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0!eZ&.h?4  
break; NYm2fFPc  
} q1.w8$  
} y4w{8;Mh  
else /P Qz$e-!Y  
break; (kK6=Mrf  
} #\GWYWkR  
} a=.A/;|0*  
catch(IOException e){e.printStackTrace ();} "z1\I\ ^  
catch(Exception e){e.printStackTrace ();} $*\[I{Zau}  
jyb/aov  
Pp*|EW 1  
Utility.log(nFileLength); WIa4!\Ky!  
`h+sSIko  
!X e  
return nFileLength; wm%9>mA%  
} OjCTTz  
/608P:U  
nNSq6 Cj  
//保存下载信息(文件指针位置) soRt<83  
private void write_nPos() _%?}e|epy  
{ '+hiCX-_  
try{ Pe6MDWR  
output = new DataOutputStream(new FileOutputStream(tmpFile)); v2 T+I]I  
output.writeInt(nStartPos.length); Q"h/o"-h  
for(int i=0;i<nStartPos.length;i++) MRMsw NQ  
{ E=_M=5]  
// output.writeLong(nPos); Mm;kB/ 1  
output.writeLong(fileSplitterFetch.nStartPos); b*+Od8r  
output.writeLong(fileSplitterFetch.nEndPos); /U4F\pZl  
} A36dj  
output.close(); K@)Hm\*  
} EC<g7_0F  
catch(IOException e){e.printStackTrace ();} 3P2H!r  
catch(Exception e){e.printStackTrace ();} $Y5R^Y  
} Fo|6 PoSo  
jeFX?]Q  
^i&sQQ( {  
//读取保存的下载信息(文件指针位置) a^ hDxeG  
private void read_nPos() xX.fN7[  
{ k1e0kxn  
try{ C!6?.\U/:c  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); P:eY>~m<;  
int nCount = input.readInt(); f02 <u  
nStartPos = new long[nCount]; 8J-$+ ;  
nEndPos = new long[nCount]; :G=N|3  
for(int i=0;i<nStartPos.length;i++) "g;^R/sfq  
{ b)"bX}  
nStartPos = input.readLong(); t :B~P,r  
nEndPos = input.readLong(); Rf||(KC<  
} 6 9_etv  
input.close(); A.8{LY;  
} hsr,a{B%$  
catch(IOException e){e.printStackTrace ();} A>8"8=C  
catch(Exception e){e.printStackTrace ();} vq-Tq>  
} ]:uJ&xUar  
_Q_"_*e  
xE`uFHuS}  
private void processErrorCode(int nErrorCode) u(iEuF;7  
{ |75>8;  
System.err.println("Error Code : " + nErrorCode); F)Oe;z6  
} Z7a~M3VnZ  
P1tc*2Z  
5v >0$Y{  
//停止文件下载 r%\(5H f  
public void siteStop() $ lz\t e  
{ *8{PoD   
bStop = true; :y^0]In  
for(int i=0;i<nStartPos.length;i++) 'id] <<F  
fileSplitterFetch.splitterStop(); p uEu v6F  
fTQRn  
^Tgu]t   
} dF$a52LS  
} lO&TSPD^  
//负责部分文件的抓取 Eh/B[u7T[  
**FileSplitterFetch.java kcGs2Y_*&  
*/ )!M %clm.  
package NetFox; 7DQ{#Gf#G  
Z.TYi~d/9D  
pxy=edd  
import java.io.*; ' P5t tI#|  
import java.net.*; zg L0v5vk  
{=};<;_F  
E:'TZ4Z  
public class FileSplitterFetch extends Thread { /qM:;:N%j  
N.R,[K  
*S,5  
String sURL; //File URL mux_S2x9m\  
long nStartPos; //File Snippet Start Position nW#UBtZ  
long nEndPos; //File Snippet End Position *Y'nDv6_P  
int nThreadID; //Thread's ID YL*yiZ9  
boolean bDownOver = false; //Downing is over 4&]Sb}  
boolean bStop = false; //Stop identical Jm0o[4  
FileAccessI fileAccessI = null; //File Access interface .h O ) R.  
/E8{:>2  
H&Jp,<\x  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2 u:w  
{ wtlIyE  
this.sURL = sURL; >#~!03  
this.nStartPos = nStart; 4B? 8$&b  
this.nEndPos = nEnd; $3.hZx>  
nThreadID = id; av|r^zc  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2wCTd:e:  
} kYMKVR  
2GB)K?1M  
/B eA-\B  
public void run() 2UqLV^ZY  
{ EMK>7 aks  
while(nStartPos < nEndPos && !bStop) $d\]s]}`  
{ ^I2+$  
mY!os91KoO  
#2AKO/  
try{ XL SYE   
URL url = new URL(sURL); i~1bfl   
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Fb8~2N"3  
httpConnection.setRequestProperty("User-Agent","NetFox"); wNQhz.>y  
String sProperty = "bytes="+nStartPos+"-"; ,n )f=q*%  
httpConnection.setRequestProperty("RANGE",sProperty); 6jS:_[p  
Utility.log(sProperty); #Xdj:T<*  
A6-K~z^  
 M18<d1*  
InputStream input = httpConnection.getInputStream(); L>:YGM"sL  
//logResponseHead(httpConnection); D3,9X#B=  
pYXusS7S  
^&^~LKl~  
byte[] b = new byte[1024]; _4~'K?  
int nRead; ;.dyuKlI  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) woI.1e5  
{ r5#8V zr  
nStartPos += fileAccessI.write(b,0,nRead); Z]VmTB  
//if(nThreadID == 1) m3Ma2jLWC  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !mX-g]4E  
} 2GRL`.1  
:<Z>?x  
mQ~0cwo)  
Utility.log("Thread " + nThreadID + " is over!"); /<"<N<X  
bDownOver = true;  Y7q=]  
//nPos = fileAccessI.write (b,0,nRead); B}O M:0  
} Xx)PyO  
catch(Exception e){e.printStackTrace ();} b# v+_7  
} W.67};',  
} A!xx#+M  
@B e7"Fm  
_'OXrT#Q  
//打印回应的头信息 }wY6^JF  
public void logResponseHead(HttpURLConnection con) Lt|'("($*  
{  :oN$w\A  
for(int i=1;;i++) jEa U;  
{ <d`ksZ+  
String header=con.getHeaderFieldKey(i); Jw -?7O  
if(header!=null) MTyBG rs(  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); : _,oD  
Utility.log(header+" : "+con.getHeaderField(header)); TAd~#jB9  
else <4{Jm8zJ  
break; uC2-T5n'  
} 108cf~2&  
} Qf=+%-$Y  
on0MhW  
r0xmDJ@y  
public void splitterStop() ]; CTr0  
{ DERhmJ;>H  
bStop = true; V:Z}cfR.7  
} L'A>IBrz  
v%|S)^c?:  
VyF|d? b  
} >)+ -:  
3_5]0:?]-  
h! yI(cY  
/* 2*[Gm e  
**FileAccess.java $27QY  
*//文件访问(定位,写) N?Nu'  
package NetFox; ;1gWz  
import java.io.*; 8? U!PW  
kuX{2h*`  
655OL)|cD6  
public class FileAccessI implements Serializable{ IH2V .>h  
3=@lJ?Ym  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 A ,$CYLj+  
RandomAccessFile oSavedFile; 16cc9%   
long nPos; Qo%IZw$l  
/[<1D|f%  
F4R0A6HL  
public FileAccessI() throws IOException "kdmqvTHK0  
{ @)^|U"  
this("",0); X`s6lV%\  
} ,SZYZ 25  
O3*}L2 j@  
vAV{HBQ*  
public FileAccessI(String sName,long nPos) throws IOException Kn#CIFbBN  
{ C2a2K={  
oSavedFile = new RandomAccessFile(sName,"rw"); Fk4T>8q2;  
this.nPos = nPos; WL#E%6p[  
oSavedFile.seek(nPos); !:^?GN#~x  
} lL<LJ :L  
f6$$e+  
\OlB (%E7  
public synchronized int write(byte[] b,int nStart,int nLen) 9CNeMoA$p:  
{ Dr oa1_FX  
int n = -1; `|2p1Ei  
try{ zKllwIf i  
oSavedFile.write(b,nStart,nLen); .@`5>_  
n = nLen; <Na .6P  
} z&Kh$ $)[  
catch(IOException e) y$Rh$e K  
{ N"zg)MsX  
e.printStackTrace (); EvJ<X,Bo  
} 0e,U&B<W  
t(.jJ>|+*  
<aR sogu"P  
return n; #-<n@qNg[  
} RF|r@/S  
4))5l9kc.  
*U}cj A:ZN  
} W|I<hY\X  
:G8:b.  
]IM/R@  
/* E=&":I6O  
**SiteInfoBean.java 04E S>'@  
*/ ,bRYqU?#0  
package NetFox; VLP'3 qX  
Sdr,q9+__  
ZQ)vvD<  
public class SiteInfoBean { OTmw/#ug  
']__V[  
G5T(  
private String sSiteURL; //Site's URL $*S&i(z  
private String sFilePath; //Saved File's Path nYE' 'g+x  
private String sFileName; //Saved File's Name F5s`AjU  
private int nSplitter; //Count of Splited Downloading File ;/R\!E   
}7+`[g  
"IA :,j.#g  
public SiteInfoBean() tm|YUat$]r  
{//nSplitter的缺省值为5 LUfo@R  
//default value of nSplitter is 5 6-t:eo9  
this("","","",5); 9H%dK^C  
} OBEHUJ5  
o @(.4+2m  
iQ8T3cC+  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) szw|`S>o  
{ ph~ d%/^jI  
sSiteURL= sURL; 3DX@ggE2  
sFilePath = sPath; 4SNDKFw  
sFileName = sName; 3:mZ1+  
this.nSplitter = nSpiltter; s*9lYk0  
T/nG\WZbZn  
^o-)y"GJ  
} D6vhW:t8?  
w^=uq3X?  
M=t;t0  
public String getSSiteURL() :\cid]y3  
{ qbq.r&F&  
return sSiteURL; -& T.rsp  
} bqcwZ6r<  
Fu\!'\6  
OeYZLC(  
public void setSSiteURL(String value) Rz:1(^oA  
{ {osadXd C  
sSiteURL = value; i~i ?M)  
} >mUSRf4  
lDVw2J'p  
}Q-%ij2  
public String getSFilePath() Gg# 1k TK  
{ J_}Rsp ED  
return sFilePath; iVZ X  
} o! Y61S(  
xWxgv;Ah  
Sh;Z\nj  
public void setSFilePath(String value) u_'XUJ32!  
{ )tp;2rJ/  
sFilePath = value; 3\Tqs  
} {D`_q|  
s#4Q?<65u  
%j. *YvveW  
public String getSFileName() #QM9!k@9k  
{ =j^wa')  
return sFileName; rL23^}+^`  
} `-yiVUp1:z  
1{$=N 2U  
)F3>  
public void setSFileName(String value) 5XF&yYWq  
{ wfq}NK;  
sFileName = value; * amZ  
} "YoFUfaNg  
Z11I1)%s  
}_,={<g  
public int getNSplitter() L5n/eg:Q  
{ xW+ XN`77  
return nSplitter; }S=m: VKH  
} @ev8"JZ1  
aFd87'^  
Zd~Q@+sH  
public void setNSplitter(int nCount) E, ;'n  
{ 5.U4P<qS  
nSplitter = nCount; Mp_SL^g|  
} ^wW{7Uq>  
} kPezR: 31  
fK; I0J  
4)].{Z4 q  
/* V\P .uOI  
**Utility.java 5z@QAQ  
*/ (AswV7aGe  
package NetFox; ZeE(gtM  
b.mWB`59  
!I+F8p   
public class Utility { Np>0c -S  
k!ac_}&NNv  
sUN9E4  
public Utility() XEb+Z7L1  
{ T&u25"QOf  
B/gI~e0  
H5/w!y@  
} WF`  
NUM+tg>KM  
//线程睡眠 ;s!GpO7+  
public static void sleep(int nSecond) #/o1D^  
{ G&@vTcF  
try{ P.'$L\  
Thread.sleep(nSecond); naiy] oY"  
} aB)G!Rm&  
catch(Exception e) @i>o+>V  
{ )O$T; U  
e.printStackTrace (); NzC&ctPk  
} w(UZmZb}  
} oG' 'my#3  
=0mXTY1  
//日志 $x;(C[  
public static void log(String sMsg) &O|qx~(  
{ UmOK7SPi  
System.err.println(sMsg); pL`)^BJ  
} z2god 1"  
(/gMtIw  
)g[7XB/w  
public static void log(int sMsg) yPT\9"/  
{ mJa8;X!r6  
System.err.println(sMsg); *ez7Q   
} M(#]NTr ~4  
} YnW,6U['{g  
eDL0Vw  
g#r,u5<*?  
/* ~vstuRRST  
**TestMethod.java 41^ $  
*/ Ep8 y  
package NetFox; MUR Hv3  
Z.3*sp0 yv  
$##LSTA  
public class TestMethod { X,ok3c4X  
 "xp>Vj  
*%jd>e7d  
public TestMethod() *FC26_pH  
{ ///xx/weblogic60b2_win.exe EQ2HQz ]  
try{ v0,&wdi  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); e|Mw9DIW  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $X]Z-RCK3  
SiteFileFetch fileFetch = new SiteFileFetch(bean); R*>EbOuI  
fileFetch.start(); Yy4l -}"  
} 0w ;#4X:m  
catch(Exception e){e.printStackTrace ();} w02t9vz  
Ujfs!ikh&F  
vlx\hJ<I  
} d1hXzJs  
#b+>O+vx8  
aKk0kC   
public static void main(String[] args) "-A@d&5.  
{ `!7QegJa"  
new TestMethod(); oxJ#NGD  
} ^|lG9z%Foy  
} 02mu%|"  
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