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http断点续传简单实现(java)

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/* $GUSTV  
**SiteFileFetch.java >\8Bu#&s4  
*/ O1coay  
package NetFox; ^v3ytS  
import java.io.*; LS4c|Dv  
import java.net.*; 5SK{^hw  
FqQm *k_  
SMk{159q&  
public class SiteFileFetch extends Thread { X_|8CD-@6  
TvAA  
z['>`Kt  
SiteInfoBean siteInfoBean = null; //文件信息Bean YU[93@mCh  
long[] nStartPos; //开始位置 [Ym?"YwVX  
long[] nEndPos; //结束位置 Q}W6?XDu  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 N6$pOQ  
long nFileLength; //文件长度 9C$b^wHd  
boolean bFirst = true; //是否第一次取文件 2;5EH 0  
boolean bStop = false; //停止标志 $uawQf+S  
File tmpFile; //文件下载的临时信息 iquB]z'  
DataOutputStream output; //输出到文件的输出流 ._-^ 58[  
&m`1lxT  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) "}Ch2K  
public SiteFileFetch(SiteInfoBean bean) throws IOException >; nE.]  
{ vX)JJ|g  
siteInfoBean = bean; X7{ueP#L  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); $/5Jc[Ow  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 5l2Ph4(  
if(tmpFile.exists ()) %z J)mOu  
{ kG &.|  
bFirst = false; yd`xmc)  
read_nPos(); qWHH% L;  
} R?(0:f  
else Y;p _ff  
{ jB:$+k|~.  
nStartPos = new long[bean.getNSplitter()]; 05LVfgJ'q  
nEndPos = new long[bean.getNSplitter()]; b~Op1p  
} 4Ucg<Z&%  
EJ.oq*W!*J  
"L|Ew#  
xpx=t71Hq  
} (8qMF{  
Nlx7"_R"Q  
UQaLhK v:  
public void run() 'LpJ:Th  
{ 4v33{sp  
//获得文件长度 &v Lz{  
//分割文件 !Sy._NE`z  
//实例FileSplitterFetch v98=#k!F  
//启动FileSplitterFetch线程 u&/q7EBfP  
//等待子线程返回 II3)Cz}xRG  
try{ Sf B+;i'D  
if(bFirst) ^rfY9qMJr8  
{ `$ZX]6G  
nFileLength = getFileSize(); D!h8NZ;El  
if(nFileLength == -1) -GD_xk  
{ &dh%sFy  
System.err.println("File Length is not known!"); y{,HpPp#o  
} 7cr@;%#  
else if(nFileLength == -2) 8V>j-C  
{ =MEv{9_  
System.err.println("File is not access!"); b4Br!PL@G  
} O%H_._#N`  
else X|q&0W=  
{ Y;8Ys&/t  
for(int i=0;i<nStartPos.length;i++) gS_)(  
{ mTz %;+|L  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); l Q]&:%^\  
} = I,O+^  
for(int i=0;i<nEndPos.length-1;i++) _G|hKk^,  
{ U&yXs'3a&  
nEndPos = nStartPos[i+1]; onRxe\?D(  
} ?:vp3f#  
nEndPos[nEndPos.length-1] = nFileLength; &PaqqU.  
} S<rdPS*P  
} veAg?N<c p  
'DO^($N  
7yD=~l\Bbs  
//启动子线程 (4cWq!ax<$  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $h`(toTyF  
for(int i=0;i<nStartPos.length;i++) Ni#!C:q  
{ X1&Ug ^  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3sIW4Cs7)U  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), reR><p  
nStartPos,nEndPos,i); 0{^vqh.La  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Z"#eN(v.N  
fileSplitterFetch.start(); >J[Bf9)>  
} dU1w)Y  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0<_|K>5dS|  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); hr_ 5D  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", F-[zuYGp  
nEndPos = " + nFileLength); M #'br<]  
// fileSplitterFetch[nPos.length-1].start(); C~4_Vc*  
[ -"o5!0<  
\95qH ,w)T  
//等待子线程结束 _;(`u!@/{  
//int count = 0; nlmc/1C  
//是否结束while循环 fZ1v|  
boolean breakWhile = false; EBlfwFd  
R,R[.2Vi  
5OeTOI()&5  
while(!bStop) bwo-9B  
{ _OV\W'RrA  
write_nPos(); E}AOtY5a  
Utility.sleep(500); 9<u^.w  
breakWhile = true; U"$Q$ OFs  
y6NOHPp@  
#=F"PhiX`  
for(int i=0;i<nStartPos.length;i++) uw!  
{ !`=ms1%U  
if(!fileSplitterFetch.bDownOver) K*iy^}  
{ Ay)q %:qx  
breakWhile = false; <"A|Xv'Q  
break; !<r+h, C  
} 8|^dM$  
} uo0g51%9  
if(breakWhile) j,%@%upM  
break; r@N 0%JZZ  
_svEPHU  
$jT&]p  
//count++; Y<|!)JLB2  
//if(count>4) )006\W|t9  
// siteStop(); Td#D\d\R  
} T=r-6eN  
I)#=#eI* :  
fxfzi{}uj  
System.err.println("文件下载结束!"); Y g>W.wA  
} +./c=o/v  
catch(Exception e){e.printStackTrace ();} lv -z[  
} N]n]7(e+0C  
i0F.c\  
VBc[(8o  
//获得文件长度 kN3T/96  
public long getFileSize() |GuIp8~  
{ \zj _6Os  
int nFileLength = -1; f[,9WkC  
try{ fw>@:m_bK  
URL url = new URL(siteInfoBean.getSSiteURL()); *M5 : \+  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bqug o  
httpConnection.setRequestProperty("User-Agent","NetFox"); TDI8L\rr  
0kN;SSX!  
O%)@> 5#S  
int responseCode=httpConnection.getResponseCode(); g\MHv#v*k  
if(responseCode>=400) IV{,'+hT  
{ <S~_|Y*v  
processErrorCode(responseCode); (Wkli:Lq  
return -2; //-2 represent access is error e&[gde(  
} =H*}{'#  
bc}X.IC  
*8}Y0V\s  
String sHeader; Hw"ik6  
4)D#kP  
jvx9b([<sG  
for(int i=1;;i++) 3/I Q]8g"  
{ ~ILig}I  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); vQrce&  
//Utility.log(in.readLine()); QX (x6y>Q  
sHeader=httpConnection.getHeaderFieldKey(i); 97:1L4w.(  
if(sHeader!=null) \RN,i]c-g/  
{ NfLvK o8  
if(sHeader.equals("Content-Length")) /x.TF'Z*  
{ 1|Y(XB^os(  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); gr %8 O-n  
break; ]D^dQ%{  
} "sLdkd}dj  
} tB.;T0n  
else 1lyJ;6i6L  
break; A7U'>r_.  
} H"(:6 `  
} Mr'}IX5  
catch(IOException e){e.printStackTrace ();} 8?] :>  
catch(Exception e){e.printStackTrace ();} 3_=~7B) 8  
Cpaeo0Oq  
Wd4fIegk  
Utility.log(nFileLength); pM~Xh ]/  
Myss$gt}  
1"46O Cu{  
return nFileLength; 2=ZR}8}9Q:  
} \3K6NA!L  
=/=x"q+X  
3ojK2F(1D  
//保存下载信息(文件指针位置) Wu)ATs}  
private void write_nPos() }@yvw*c  
{ 6QdNGpN  
try{ IV^LYu  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^&<~6y}U^  
output.writeInt(nStartPos.length); G],+?E_,  
for(int i=0;i<nStartPos.length;i++) LLmgk"  
{ 1_:1cF{w  
// output.writeLong(nPos);  N>`+{  
output.writeLong(fileSplitterFetch.nStartPos); C>cc!+n%H  
output.writeLong(fileSplitterFetch.nEndPos); Ff>Y<7CQ v  
} qx 3.oU  
output.close(); c?) pn9  
} 7UHqiA`L  
catch(IOException e){e.printStackTrace ();} qGkrG38K  
catch(Exception e){e.printStackTrace ();} yb/< 7  
} QxnP+U~N  
Bir }X  
Td[w<m+p<P  
//读取保存的下载信息(文件指针位置) Z{#^lhHx  
private void read_nPos() cNC\w%  
{ /og}e~q  
try{ Js+d4``W  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); M)Rp+uQ  
int nCount = input.readInt(); bI[!y#_z4  
nStartPos = new long[nCount]; fLI@;*hL0  
nEndPos = new long[nCount]; 7qE V5!  
for(int i=0;i<nStartPos.length;i++) >0 !J]gK  
{ ~ p; <H  
nStartPos = input.readLong(); N=D Ynz_~  
nEndPos = input.readLong(); JmNeqpbB`w  
} #BS]wj2#  
input.close(); Qm`f5-d  
} CW\o>yh  
catch(IOException e){e.printStackTrace ();} 'lC"wP&$  
catch(Exception e){e.printStackTrace ();} t)XV'J  
} ?^BsR  
R'dF<&Kj|  
3\=8tg p  
private void processErrorCode(int nErrorCode) 5YS`v#+  
{ "EEE09~l\  
System.err.println("Error Code : " + nErrorCode); :^%s oEi  
} j,/o0k,  
_Fl]zs<  
74gU 4T  
//停止文件下载 WY 2b  
public void siteStop() w**.8]A"N  
{ s+zb[3}  
bStop = true; /bCrpcH  
for(int i=0;i<nStartPos.length;i++) a]X6)6  
fileSplitterFetch.splitterStop(); R2]?9\II  
@2$PU{dH  
f~Kln^  
} *\VQ%_wg  
} }i[i{lKj  
//负责部分文件的抓取 yE"hgdL  
**FileSplitterFetch.java 2gt08\  
*/ *otJtEI>6  
package NetFox; "Wi`S;  
X0vkdNgW  
S}Mxm 2  
import java.io.*; $Fr2oSTT)  
import java.net.*; ?-@h Nrx  
`dL9sfj>  
1Za\T?V  
public class FileSplitterFetch extends Thread { /c'#+!19  
f7s]:n*Ih  
QJ"B d`wc  
String sURL; //File URL O)9T|, U  
long nStartPos; //File Snippet Start Position yvH:U5%  
long nEndPos; //File Snippet End Position Q;5\( 0w5  
int nThreadID; //Thread's ID m7M*)N8  
boolean bDownOver = false; //Downing is over y~- ?   
boolean bStop = false; //Stop identical Q 5@~0  
FileAccessI fileAccessI = null; //File Access interface %{}Jr`  
<EBp X   
PI{sO |  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException h+Q ==  
{ aaaC8;.  
this.sURL = sURL; u8?ceM^r  
this.nStartPos = nStart; ie$=3nZJ}  
this.nEndPos = nEnd; wh*OD  
nThreadID = id; ~(%G; fZ?x  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 .5 dZaI)  
} K/%aoTO}  
sWX   
D J<c  
public void run() *K+*0_  
{ S>"dUM  
while(nStartPos < nEndPos && !bStop) ~Snw':  
{ *uv\V@0  
pixI&iQ  
P{qn@:  
try{ I 9u=RI s  
URL url = new URL(sURL); tjTF?>^6|  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ';lO[B  
httpConnection.setRequestProperty("User-Agent","NetFox"); u#P7~9ZG-  
String sProperty = "bytes="+nStartPos+"-"; sV*Q8b*  
httpConnection.setRequestProperty("RANGE",sProperty); A{c6XQR~z  
Utility.log(sProperty); ,%jJ ,G,  
/z'j:~`E  
nut7b  
InputStream input = httpConnection.getInputStream(); CjST*(,b  
//logResponseHead(httpConnection); S\X_!|  
z[k2&=c  
N&ddO-r[s  
byte[] b = new byte[1024]; (%r:PcGMEV  
int nRead; A9R}74e4g  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) I3L1|!  
{ 7dakj>JM  
nStartPos += fileAccessI.write(b,0,nRead); Th8Q ~*v  
//if(nThreadID == 1) vIG,!^*3  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L{Th>]X  
} e-s@@k  
ECSC,oJ  
 qJK^i.e  
Utility.log("Thread " + nThreadID + " is over!"); Kr#=u~~M  
bDownOver = true; TcIUo!:z  
//nPos = fileAccessI.write (b,0,nRead); dHu]wog  
} 4 '+)9&g  
catch(Exception e){e.printStackTrace ();} NMDNls&)k  
} Z/I!\  
} Q\r qG  
i3GvTg-X  
t"L:3<U7  
//打印回应的头信息 Rsulp#['  
public void logResponseHead(HttpURLConnection con) 54OYAkPCk  
{ Po_9M4kU  
for(int i=1;;i++) a=J?[qrx  
{ _+. t7q^  
String header=con.getHeaderFieldKey(i); z=xHk|+'  
if(header!=null) 226s:\d  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); a} /Vu"  
Utility.log(header+" : "+con.getHeaderField(header)); j NY8)w_  
else L=p.@VSZ  
break; J8%|Gd0#4  
} w iq{ Jo#  
} -`RJ k(  
8fN0"pymo  
i~,k2*o  
public void splitterStop() 4 hj2rK'y  
{ U %4g:s  
bStop = true; 4/jY;YN,2  
} 70NHU;&N  
j\vK`.z  
RpXQi*c0  
} cC[n~OV  
TM}F9!*je  
? vlGr5#  
/* K c<z;  
**FileAccess.java ArEpH"}@  
*//文件访问(定位,写) {$t*Mb0  
package NetFox; Yyo|W;a]  
import java.io.*; "tark'  
)k1,oUx  
Pjy?&;GvT  
public class FileAccessI implements Serializable{ t[maUy _A  
D 6]$P%t9  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @r43F$bcqo  
RandomAccessFile oSavedFile; 5 QeGx3'  
long nPos; IX(yajc[~M  
%(Ys-GeGr  
n96gDH*  
public FileAccessI() throws IOException )eEvyU  
{ OT[m g4&  
this("",0); Z)A+ wM  
} C]H <L#)ZU  
<f6PULm  
t/1NTa  
public FileAccessI(String sName,long nPos) throws IOException 55DzBV  
{ _PbfFY #  
oSavedFile = new RandomAccessFile(sName,"rw"); h%s  
this.nPos = nPos; Ltw7b  
oSavedFile.seek(nPos); \i+h P1 mz  
} lnWi E}F  
#<PdZl R  
Uq.~3V+u  
public synchronized int write(byte[] b,int nStart,int nLen) 5)7mjyo%  
{ gJxVU41  
int n = -1; UK>=y_FYO  
try{ I 6YT|R  
oSavedFile.write(b,nStart,nLen); 5#)<rK  
n = nLen; }?J5!X  
} mv?H]i`N  
catch(IOException e) -l@W)?$  
{ $tHwJ!<$&  
e.printStackTrace (); PJ@,01  
} Vk_&W.~  
&i^NStqu  
 &n.uNe  
return n; Z{4aGp*  
} "EYj Y->  
8 ysK VF  
[0ffOTy  
} Ti|++oC/&  
T\!SA  
qetP93N_*  
/*  RhNaYO  
**SiteInfoBean.java R(83E B~_  
*/ ]MLLr'6?  
package NetFox; K_|~3g  
Fg\| e%  
;u};& sm  
public class SiteInfoBean { %)Uvf`Xhh4  
H\+c'$  
s!/holu  
private String sSiteURL; //Site's URL _#D\*0J  
private String sFilePath; //Saved File's Path N 3yB1_   
private String sFileName; //Saved File's Name Qy^z*s  
private int nSplitter; //Count of Splited Downloading File Y-3[KHD  
T[XP\!z]B!  
c`i=(D<  
public SiteInfoBean() Ym.l@(  
{//nSplitter的缺省值为5 vMX6Bg8  
//default value of nSplitter is 5 Dyk[u g5  
this("","","",5); X ' #$e{  
} r d6F"W  
( OyY_`  
n;kciTD%wK  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8gbm"!  
{ |aS~"lImh  
sSiteURL= sURL; +dgo-)kP(_  
sFilePath = sPath; Y%)h)El  
sFileName = sName; YNg\"XjJM<  
this.nSplitter = nSpiltter; F!)M<8jL&9  
02W4-*)  
rO(TG  
} nGv23R(?G  
'9 *|N=  
>'ksXA4b  
public String getSSiteURL() XewXTd #x  
{ (~G5t(+  
return sSiteURL; 1<W4>~,wj  
} jom} _  
S!jF:Uc  
hJ;f1dZ7}  
public void setSSiteURL(String value) jSie&V@px  
{ X;OsH  
sSiteURL = value; P /c Q1  
} nIyROhZ  
L}}=yh6r  
i'W_;Y}  
public String getSFilePath() HJfQ]p'nK2  
{ @ ],6SKbG6  
return sFilePath; pcI&  
} )IFl 0<d  
- E8ntY-  
nDHHYp  
public void setSFilePath(String value) ?kL|>1TY  
{ YN,y0t/cQ  
sFilePath = value; I&TTr7  
} Gur8.A;Y  
{cR_?Y@  
~\IF9!  
public String getSFileName() 6R1wn&8  
{ V!T^wh;  
return sFileName; z5XYpi_;[  
} zwM"`z  
Js\-['`  
1MbY7!?PG  
public void setSFileName(String value) S}oG.r 9  
{ VHXI@UT*  
sFileName = value; K&=1Ap  
} w^06z,  
.S~@BI(|<  
A",eS6  
public int getNSplitter() zKIGWH=qqm  
{ U91 &|  
return nSplitter; U7^7/s/.  
} )Rjb/3*!  
cC^W2\  
7JbY}@  
public void setNSplitter(int nCount) R[x7QlA;  
{ kUNj4xp)  
nSplitter = nCount; 4bP13f  
} Q;4}gUmI$  
} iaY5JEV:CA  
PeO]lq  
wk" l[cH>  
/* V?OuIg%=:  
**Utility.java  b<[jaI0  
*/ s(Z(e %  
package NetFox; >BBl 7  
2zz,(RA  
&|)hCJu  
public class Utility { 4w 'lu"U  
Ve)ClH/DW  
yH*hL0mO  
public Utility() xpF](>LC(  
{ WrNLGkt  
85'nXYN{d  
5?Bc Y ;  
} <3b'm*  
f0vJm  
//线程睡眠 T'E ] i!$  
public static void sleep(int nSecond) u^Vh .g]  
{ K4 C ^m|e  
try{ HN{zT&  
Thread.sleep(nSecond); hi!`9k  
} UVrQV$g!  
catch(Exception e) z 5'ZN+  
{ Ejv%,q/T(  
e.printStackTrace (); xOythvO  
} {3LA%xO  
} TXjloGv^  
$_sYfU9  
//日志 6JhMkB^h  
public static void log(String sMsg) uVGa(4u}  
{ K1OkZ6kl  
System.err.println(sMsg); []zua14F6  
} K/^ +eoW(  
)n( Q  
&R,9+c  
public static void log(int sMsg) 3Hw[s0[$  
{  ;\qXbL7  
System.err.println(sMsg); GX  }q9  
} `N}d}O8   
} rFey4zzz  
[[WF0q  
Zsj`F9*e  
/* =\Iu$2r`  
**TestMethod.java }$&xTW_  
*/ L2fZ{bgy  
package NetFox; ^/toz).Q  
_7"5wB?|+  
zT[6eZ8m  
public class TestMethod { ]]2k}A[-I  
\K7t'20  
oh~: ,  
public TestMethod() _'!kuE,*1  
{ ///xx/weblogic60b2_win.exe m|O1QM;T  
try{ &w85[zs  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _w!a`w*3  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); l +'F_a  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6o=G8y  
fileFetch.start(); %d2!\x%bG  
} |quij0_'e  
catch(Exception e){e.printStackTrace ();} lr~0pL  
*jITOR!uF`  
y 9L14  
} QR0(,e$Dl  
tU@zhGb  
eGL<vX  
public static void main(String[] args) ]s_8A`vm  
{ 3@<zg1.9-  
new TestMethod(); 5l{Ts04k%  
} Z[?mc|*x  
} V '.a)6  
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