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http断点续传简单实现(java)

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/* R\ <HR9r  
**SiteFileFetch.java qAHQZKk  
*/ >t3%-Kc  
package NetFox; 0x[v)k9"0  
import java.io.*; -7$7TD`'7  
import java.net.*; DMsxHAE1  
QUwSnotgU  
 b-yfBO  
public class SiteFileFetch extends Thread { wHAoO#`wn5  
kk )9!7  
~bg?V0  
SiteInfoBean siteInfoBean = null; //文件信息Bean ^4h/6^b0c  
long[] nStartPos; //开始位置 bK<'J=#1  
long[] nEndPos; //结束位置 Mb"i}Yt{  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 H Y\-sl^  
long nFileLength; //文件长度 %N=-i]+Id  
boolean bFirst = true; //是否第一次取文件 oj;Rh!O  
boolean bStop = false; //停止标志 QI.{M$,m~  
File tmpFile; //文件下载的临时信息 Pur~Rz\ \  
DataOutputStream output; //输出到文件的输出流 OZB(4{vnyC  
/*B-y$WQk  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 3g0[( ;  
public SiteFileFetch(SiteInfoBean bean) throws IOException `og 3P:y  
{ Zu,rf9LMj  
siteInfoBean = bean; "+~La{ POc  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 'K"V{  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); DUFfk6#X}  
if(tmpFile.exists ()) {OXKXRCa  
{ =hjff/ X  
bFirst = false; )C|[j@MD  
read_nPos(); Fr`"XH  
} PsjSL8]  
else \U\ W Q  
{ 6f v{?0|  
nStartPos = new long[bean.getNSplitter()]; -M/DOTc  
nEndPos = new long[bean.getNSplitter()]; eR$qw#%c*  
} 2I3MV:5  
,Tvfn`;(  
Lf4c[[@%gd  
jO&sS?  
} )Gi!wm>zvN  
2g$PEwXe  
>;-.rJFr  
public void run() x_GD  
{ A9`& Wnw?  
//获得文件长度 2"cUBFc1I  
//分割文件 :* 4b,P  
//实例FileSplitterFetch om@GH0o+  
//启动FileSplitterFetch线程 Z@4 BTA  
//等待子线程返回 'avzESe~'  
try{ ...|S]a  
if(bFirst) | :7O  
{ :70[zo7n'  
nFileLength = getFileSize(); Bvk 8b  
if(nFileLength == -1) s{#rCc)  
{ 7O',X Y  
System.err.println("File Length is not known!"); 8eCC =Az:  
} JPJ&k( P  
else if(nFileLength == -2) qb'4x){  
{ h mC. 5mY  
System.err.println("File is not access!"); KzZ|{ !C  
} &FHzd/  
else 8b\XC%k  
{ /@h)IuW  
for(int i=0;i<nStartPos.length;i++) `@!4#3H  
{ I?<5 %  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); GTgG0Ifeh  
} 8vpB(VxV+  
for(int i=0;i<nEndPos.length-1;i++) JVy-Y  
{ ~\B1\ G  
nEndPos = nStartPos[i+1]; I.As{0cc  
} Tk\?$n  
nEndPos[nEndPos.length-1] = nFileLength; C^oj/} ^  
} v50w}w'  
} < Ih)h$8`  
R~TzZ(Ah]  
)(V|d$n  
//启动子线程 lKKg n{R  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; "jS @ug  
for(int i=0;i<nStartPos.length;i++) %xv }  
{ j N":9+F  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V9  Z  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 90<z*j$EK  
nStartPos,nEndPos,i); 2%o@?Rp  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b/"&E'5-`\  
fileSplitterFetch.start(); "V|&s/9  
} i286 J.  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mu`:@7+Yp  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); NNDW)@p6z  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", T)4pLN E  
nEndPos = " + nFileLength); CNP!v\D  
// fileSplitterFetch[nPos.length-1].start(); [[ {L#  
t,H=;U#  
O\0]o!  
//等待子线程结束 &q8oalh  
//int count = 0; mcO/V-\5'  
//是否结束while循环 d rRi<7 i  
boolean breakWhile = false; W@S>#3,  
nD#QC=}  
W5a7HkM  
while(!bStop) '$nm~z,V  
{ &}}UdJ`  
write_nPos(); fib#)KE  
Utility.sleep(500); % \N52  
breakWhile = true; 8);G'7O  
iwM$U( 9  
J[0o 6  
for(int i=0;i<nStartPos.length;i++) r2!\Ts5v  
{ H 5\k`7R  
if(!fileSplitterFetch.bDownOver) 9W5~I9%  
{ uUmkk  
breakWhile = false; L F<{/c9,  
break; vT1StOx<V  
} iG+hj:5  
} =*2_B~`  
if(breakWhile) * z85 2@  
break; ^W8kt  
zH)M,+P  
qK=uSL o\+  
//count++; nev@ykP6  
//if(count>4) {"e)Jj_=  
// siteStop(); V7~tIhuJH  
} GQ -fEIi{  
]]"O)tWHj  
gdr"34%vbM  
System.err.println("文件下载结束!"); ^\"@r%|  
} , yd]R4M  
catch(Exception e){e.printStackTrace ();} zvEofK  
} NAg9EaWja{  
HgY [Q}7s  
8_*31Y   
//获得文件长度 2?c##Izn  
public long getFileSize() ]:"<if gp$  
{ Q3h_4{w  
int nFileLength = -1; .R";2f3  
try{ U=ek_FO  
URL url = new URL(siteInfoBean.getSSiteURL()); z.vE RP56  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M_BG :P5  
httpConnection.setRequestProperty("User-Agent","NetFox"); rg5ZxN|g  
"39\@Ow  
AT{rg/oSf  
int responseCode=httpConnection.getResponseCode(); MJ.K,e  
if(responseCode>=400) Z(h.)$yH*=  
{ Wxeg(L}E  
processErrorCode(responseCode); t@"i/@8x$  
return -2; //-2 represent access is error arWP]%E0W  
} $:l>g)c  
A.YXK%A%  
=%=lq0GF0  
String sHeader; &hnI0m=X  
KA#P_e{<@  
v w  
for(int i=1;;i++) 'r 0kX||  
{ @'AjEl:&-_  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _-+xzdGvX  
//Utility.log(in.readLine()); j:>_1P/  
sHeader=httpConnection.getHeaderFieldKey(i); 9'" F7>d  
if(sHeader!=null) K`vc&uf  
{ ?zP/i(1y  
if(sHeader.equals("Content-Length")) x9!3i{_  
{ {r>iUgg  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); j0wpaIp  
break; z?3t^UPW  
} :HiAjaA1pg  
} '-KYeT\;  
else 14DHU  
break; u5Tu~  
} T9'd?nw9  
} 2j=i\B  
catch(IOException e){e.printStackTrace ();} ]_5qME#N  
catch(Exception e){e.printStackTrace ();} _TbQjE&6  
~NV 8avZ  
'qy LQ:6  
Utility.log(nFileLength); o'?[6B>oj  
Kg;u.4.-M  
h<0&|s*a)  
return nFileLength; l^k/Y ]  
} iwVsq_[]L  
yQz6K6p  
;Pw\p^wz  
//保存下载信息(文件指针位置) A||,|He~  
private void write_nPos() 6"djX47j  
{ S*3*Q l*  
try{ YQ-!>3/)-  
output = new DataOutputStream(new FileOutputStream(tmpFile)); )W,.xP  
output.writeInt(nStartPos.length); @{q:179w^  
for(int i=0;i<nStartPos.length;i++) cF V[k'F  
{ CqVeR';2  
// output.writeLong(nPos); Wc HL:38  
output.writeLong(fileSplitterFetch.nStartPos); om oD +  
output.writeLong(fileSplitterFetch.nEndPos); Rp0`%}2 o  
} tv 7"4$T  
output.close(); 4`[2Te>  
} nRHxbE}::  
catch(IOException e){e.printStackTrace ();} VV+gPC  
catch(Exception e){e.printStackTrace ();} xO_u  
} 8\VP)<<  
{9Ug9e{ ~  
3YO %$  
//读取保存的下载信息(文件指针位置) J\l'nqS"  
private void read_nPos() ;O~k{5.iS  
{ e2_p7   
try{ dJ(<zz+;b  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]8+ D  
int nCount = input.readInt(); Ys@OgdS@:  
nStartPos = new long[nCount]; Q)[DSM  
nEndPos = new long[nCount]; dMw}4c3E  
for(int i=0;i<nStartPos.length;i++) Liv.i;-qE  
{ !)4'[5t"U  
nStartPos = input.readLong(); %M5{-pJ|C  
nEndPos = input.readLong(); kxH` c  
} ?RPVd8PUhN  
input.close(); =1r!'<"h  
} ,CxIA^  
catch(IOException e){e.printStackTrace ();} 90Bn}@t=Q  
catch(Exception e){e.printStackTrace ();} *8Kx y@  
} vdaG?+_o  
f2iA5 rCV]  
#V$h?`qhwr  
private void processErrorCode(int nErrorCode) 7!g"q\s  
{ K0fuN)C  
System.err.println("Error Code : " + nErrorCode); 1:;S6{oQ  
} 1smKU9B2)  
SpC6dkxD\  
[/Sk+ID  
//停止文件下载 $W;f9k@C!  
public void siteStop() SVn $!t  
{ %7hf6Xo=  
bStop = true; kyH0J[/n  
for(int i=0;i<nStartPos.length;i++) 9)*218.  
fileSplitterFetch.splitterStop(); Am@:<J  
2|A?9aE%0  
k?;@5r)y-  
} qYP;`L}o#  
} J{U 171  
//负责部分文件的抓取 ]o?r( 1  
**FileSplitterFetch.java f=hT o!i  
*/ VOSq%hB  
package NetFox; eq(1'?7]`G  
uGpLh0  
G S&I6  
import java.io.*; ZJ8"5RW  
import java.net.*; }eAV8LU  
/hSEm.<  
*X /i<  
public class FileSplitterFetch extends Thread { G{74o8  
7 MS-Gs|  
|,Kk#`lW<f  
String sURL; //File URL cV4]Y(9  
long nStartPos; //File Snippet Start Position 3gv@JGt7`  
long nEndPos; //File Snippet End Position tx7B?/5D  
int nThreadID; //Thread's ID :/R>0n,  
boolean bDownOver = false; //Downing is over t{-*@8Ke  
boolean bStop = false; //Stop identical : G'a"%x  
FileAccessI fileAccessI = null; //File Access interface l:+$Ks  
<Rfx`mn  
k&9[}a*  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Bn{i+8I  
{ wx8Qz,Z  
this.sURL = sURL; }R!t/ 8K  
this.nStartPos = nStart; 4Opf[3]  
this.nEndPos = nEnd; 4I8QM&7  
nThreadID = id; wvmcD%   
fileAccessI = new FileAccessI(sName,nStartPos);//定位 w0X})&,{`m  
} FQ"ED:lks  
= N^Ec[u(l  
~gdnD4[G  
public void run() ?sv[vR(  
{ a+^,EY  
while(nStartPos < nEndPos && !bStop) 9@8'*a{`m  
{ WP{U9YF2  
9aBz%* xo  
Qp9QS yMs}  
try{ 8ZCR9%  
URL url = new URL(sURL); 'Q"Mu  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); eD|"?@cE  
httpConnection.setRequestProperty("User-Agent","NetFox"); uD\rmO{  
String sProperty = "bytes="+nStartPos+"-"; 3 MCV?"0  
httpConnection.setRequestProperty("RANGE",sProperty); $ {e5Ka  
Utility.log(sProperty); biG :Xn  
3BSZz%va  
XS$#\UQ  
InputStream input = httpConnection.getInputStream(); :_|Xr'n`A  
//logResponseHead(httpConnection); ojyP.R  
D63?f\  
Z*n4$?%W  
byte[] b = new byte[1024]; qpjiQ,\:b  
int nRead; \]0#jI/:  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) OX7a72z  
{ WmOu#5*;  
nStartPos += fileAccessI.write(b,0,nRead); D?FmlDTr[  
//if(nThreadID == 1) pVM1%n:#  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ITy/h]0  
} ?pWda<&  
N/eus"O;  
i|rCGa0}  
Utility.log("Thread " + nThreadID + " is over!"); \D1@UyE  
bDownOver = true; DzIV5FG  
//nPos = fileAccessI.write (b,0,nRead); P%;lHC #i  
} \5-Dp9vG  
catch(Exception e){e.printStackTrace ();} E`Br#"/Bl  
} .kTOG'K\e  
} }`aT=_B  
g 'td(i[  
;9<?~S  
//打印回应的头信息 ,$ Cr9R&/  
public void logResponseHead(HttpURLConnection con) G8WPXj(  
{ YU XxQ|  
for(int i=1;;i++) x*p'm[Tdtm  
{ XQ2 YUe]DJ  
String header=con.getHeaderFieldKey(i); l.(|&U~  
if(header!=null) rk47 $36X  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); .Fx3WryF  
Utility.log(header+" : "+con.getHeaderField(header)); ++eT 0  
else u2IU/z8 ^  
break; {Iz"]Wh<f  
} DyCkz"1S  
} O^q~dda  
T*g}^TEh  
$Wjx$fD  
public void splitterStop() ] &SmeTe  
{ ?Yx2q_KZk  
bStop = true; !DUOi4I  
} CM6! 1 7  
[{>3"XJ'  
FOteN QTj  
} \t%iUZ$  
/l+"aKW 2  
:2V|(:^ '  
/* 1,7 }ah_  
**FileAccess.java 7'gk=MQc  
*//文件访问(定位,写) I%b5a`7  
package NetFox; MdFFt:y:  
import java.io.*; "<Yxt"Z4  
<g&.UW4  
\}\# fg  
public class FileAccessI implements Serializable{ ~Kl"V% >  
lbGPy'h<rt  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :9e4(7~ona  
RandomAccessFile oSavedFile; ?mF:L"i  
long nPos; S..8,5mBH  
 :YPi>L5  
1!yd(p=cL  
public FileAccessI() throws IOException xLms|jS  
{ Xpv<v[a  
this("",0); -zWNQp$  
} B)/c]"@89  
qO/3:-  
#*%?]B=  
public FileAccessI(String sName,long nPos) throws IOException 7VskZbj\  
{  6@"E*-z$  
oSavedFile = new RandomAccessFile(sName,"rw"); =A~5?J=  
this.nPos = nPos; {c~w Ms#  
oSavedFile.seek(nPos); _~ 'MQ`P  
} H?FiZy*[Y  
s8 u`v1  
tvBLfqIr  
public synchronized int write(byte[] b,int nStart,int nLen) q#1G4l.  
{ | O9b  
int n = -1; s8'!1rHd  
try{ G$luGxl[  
oSavedFile.write(b,nStart,nLen); ]o8yZ x  
n = nLen; fqBz"l>5A  
} k!G{#(++&6  
catch(IOException e) /q8B | (U  
{ ?NvE9+n  
e.printStackTrace (); 0:-z+`RHE  
} J1 w3g,  
5s;@;V  
C(UWir3mW?  
return n; !Pt4\  
} Spu;   
l8:!{I?s=  
-x:7K\=$SX  
} kd_! S[  
!T2{xmHKv$  
$5\!ws<cZ  
/* {=,G>p  
**SiteInfoBean.java %_!0V*X*  
*/ [k75+#'  
package NetFox; =M9R~J!  
0l/7JH_@V  
;JgSA&'e  
public class SiteInfoBean { EQk omjv  
-0BxZ AW=  
Q&lb]U+\u  
private String sSiteURL; //Site's URL a8v\H8@X  
private String sFilePath; //Saved File's Path >rSCf=  
private String sFileName; //Saved File's Name C1(RgY|  
private int nSplitter; //Count of Splited Downloading File & P%#  
:'xZF2  
{<a)+S.6U  
public SiteInfoBean() sva-Sd8  
{//nSplitter的缺省值为5 [z"oi'"fQ  
//default value of nSplitter is 5 )2 q r^)  
this("","","",5); !I\eIV>0b  
} P : L6Zo-J  
,7Ejb++/M,  
&x=_n'  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) _/"e'@z  
{ F>^KXq:Z  
sSiteURL= sURL; t:P7ah  
sFilePath = sPath; f="ZplW  
sFileName = sName; E{QjmlXQ<  
this.nSplitter = nSpiltter; +]GP"yv-  
OoRg:"9{#  
he@Y1CY  
} <%W&xk  
f3^qO9R  
SUIu.4Mz  
public String getSSiteURL() O_GHvLO=  
{ >wL!`:c'"  
return sSiteURL; B.smQt  
} MRZN4<}9  
ZsCwNZR  
Nf2lw]-G4  
public void setSSiteURL(String value) b|G~0[g  
{ :7X{s4AU6  
sSiteURL = value; Vq/hk  
} ,aq>9\ pi  
+fKV/tSWi  
;8 *"c  
public String getSFilePath() ;CoD5F!  
{ __1Hx?f  
return sFilePath; \TnK<83  
} {X<_Y<  
S6C DK:  
MtgY `p  
public void setSFilePath(String value) 2P${5WT  
{ *a0#PfS[  
sFilePath = value; `Fe/=]< $  
} bD3d T>(+  
K6)IBV;  
I2NMn5>  
public String getSFileName() [} d39  
{ 9eE FX7  
return sFileName; : ;hm^m]Y  
} a;kiAJ'  
jsF5q~F  
<Wj /A/  
public void setSFileName(String value) TEGg)\+D>  
{ Im};wJ&  
sFileName = value; (lq%4h  
} bE=[P}E  
Jk:ZO|'Z  
()$m9%x  
public int getNSplitter() &B1!,joH~  
{ SOMAs'=  
return nSplitter; ,%zE>^~  
} {w,<igh  
7|bBC+;(  
YguW2R=6]  
public void setNSplitter(int nCount) FPZ@6  
{ cRCji^,KJ  
nSplitter = nCount; "(~fl<;  
} OwgPgrV  
} !\$4A,  
paYS< 8In  
G9#3 |B-?  
/* vXSA_" 0t  
**Utility.java E@l@f  
*/ 2#CN:b]+  
package NetFox; s0h0Ep ED  
Sht3\cJ8  
%,@e- &>  
public class Utility { m(5LXH Jnv  
ae2I,Qt%  
e5lJ)_o  
public Utility() Jvj* z6/a  
{ Cv&>:k0V  
T :^OW5d  
:RYYjmG5;  
} /?|;f2tbV2  
vS:=%@c>ta  
//线程睡眠 k^B7M}  
public static void sleep(int nSecond) Wcl =YB%  
{ Gg:W%&#  
try{ _g D9oK  
Thread.sleep(nSecond); EpCNp FQT<  
} $bBUL C  
catch(Exception e) CG J_k?h  
{ sebuuL.l0<  
e.printStackTrace (); jxq89x  
} &Ot9"Aq:  
} ,?%o ~  
YluvWHWi  
//日志 ]D^; Ca  
public static void log(String sMsg) Y[m*  
{ N ;n55N  
System.err.println(sMsg); N[DKA1Ei  
} %+;amRb  
@kba^z  
41rS0QAM  
public static void log(int sMsg) &`-e; Xt  
{ O -p^S  
System.err.println(sMsg); <K/iX%b?  
} >Il{{{\>  
} :g-vy9vb  
nn">   
`Cy;/95m  
/* [s%uE+``S  
**TestMethod.java g(S4i%\  
*/ |uRYejj#j  
package NetFox;  ZLf(m35  
>{rD3X"d  
r-[YJzf@P  
public class TestMethod { 9):^[Wkx  
}Py Z{yS  
Z%SDN"+'g  
public TestMethod() ?fpI,WFu  
{ ///xx/weblogic60b2_win.exe O31.\ZR2  
try{ |+<o(Q(  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >{0,dGm  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); N~(?g7  
SiteFileFetch fileFetch = new SiteFileFetch(bean); /de~+I5AB~  
fileFetch.start();  %Rm`YH?  
} PA,\o8]x  
catch(Exception e){e.printStackTrace ();} vv`53 Pbw)  
;jlI>;C;V  
k4"O} jQO  
} Rp}Sm,w(  
Q[aBxy (  
H^$7=  
public static void main(String[] args) COH>B1W@  
{ &>ykkrY  
new TestMethod(); _w%{yF6   
} A{DE7gp!  
} Z[\nyj  
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