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http断点续传简单实现(java)

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/* D622:Y886  
**SiteFileFetch.java /x-tl)(s=  
*/ R U[  
package NetFox; FlS)m`  
import java.io.*; ?Wt_Obl  
import java.net.*; Rpcnpo  
jbOzbxR?  
'H1"z!]  
public class SiteFileFetch extends Thread { + $~HRbo  
,^xsdqpe  
P\c0Q;){h"  
SiteInfoBean siteInfoBean = null; //文件信息Bean *|+ ~V/#  
long[] nStartPos; //开始位置 b(ryk./ogx  
long[] nEndPos; //结束位置 Vfw +m1sS  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 I |D]NY^  
long nFileLength; //文件长度 fv3)#>Dgp>  
boolean bFirst = true; //是否第一次取文件 /7*qa G  
boolean bStop = false; //停止标志 [0+5 Gx  
File tmpFile; //文件下载的临时信息 zJ0'KHF}o  
DataOutputStream output; //输出到文件的输出流 8/34{2048  
nDC5/xB  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) qmnCa&C9  
public SiteFileFetch(SiteInfoBean bean) throws IOException RDG,f/L2  
{ I@a7!ugU65  
siteInfoBean = bean; XeBSHvO_  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ;`bJgSCfo  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); MD:kfPQ  
if(tmpFile.exists ()) G[yN*C  
{ Dc> )js|"  
bFirst = false; \v_t: "  
read_nPos(); qf] OSd  
} [TV"mA  
else xcIZ'V  
{ ,v1-y ?kB  
nStartPos = new long[bean.getNSplitter()]; Z@iMG  
nEndPos = new long[bean.getNSplitter()]; bOmM~pD  
} &sA6o"h~  
+ACV,GG  
.J\U|r  
>Q\H1|?  
} Mz{ Rh+gS  
m9>nv rQ  
Pq7tNM E  
public void run() N<Q}4%^c  
{ Js#c9l{{  
//获得文件长度 /0YNB)  
//分割文件 TbU9 < mY  
//实例FileSplitterFetch 8UL:C?eY  
//启动FileSplitterFetch线程 9'8oOBqm3%  
//等待子线程返回 Mw5!9@Fc7  
try{ :* /``  
if(bFirst) C1rCKKh  
{ :~)Q]G1Nj  
nFileLength = getFileSize(); $v oyXi`*  
if(nFileLength == -1) +#H8d1^5  
{ B 9Mwj:)}  
System.err.println("File Length is not known!"); $kz5)vj "  
} i+cGw  
else if(nFileLength == -2) o-' i)pp  
{ $ .Z2Rdlv(  
System.err.println("File is not access!"); {:FITF3o  
} fAUsJ[  
else s* YFN#Wuc  
{ ujWHO$uz!  
for(int i=0;i<nStartPos.length;i++) S@"=,Xj M  
{ et ~gO!1:*  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ta6 WZu  
} ;qk~>  
for(int i=0;i<nEndPos.length-1;i++) FW.dHvNX  
{ Q#r 0DWo\  
nEndPos = nStartPos[i+1]; zXf+ieo  
} =nL*/  
nEndPos[nEndPos.length-1] = nFileLength; %Z5k8  
} ?RzT0HRd  
} X9gC2iSs]  
Z "=(u wM  
dO//  
//启动子线程 yEqmB4^-  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; yaR;  
for(int i=0;i<nStartPos.length;i++) V= *J9~K  
{ -5 W0K}  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <d5vVn  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), I !<v$  
nStartPos,nEndPos,i); C[&&.w8Pm  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v_@_J!s  
fileSplitterFetch.start(); 6uXYZ.A  
} ?-84_i  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), XP^6*}H.*  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7~Ga>BK  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", yl ;'Ru:  
nEndPos = " + nFileLength); ,"VQ 0Z1  
// fileSplitterFetch[nPos.length-1].start(); 9iy|=  
jr l6):x  
E\*",MGL  
//等待子线程结束 9cmJD5OO  
//int count = 0; +?:V\niQI  
//是否结束while循环 \ +xIH  
boolean breakWhile = false; l>(G3l Iw  
bv4cw#5z$9  
zB$6e!fc  
while(!bStop) 7Mv$.Z(  
{ .nH /=  
write_nPos(); 6qJB"_.  
Utility.sleep(500); 66Xt=US  
breakWhile = true; |\(/dXXP  
%UJ4wm  
)x7hhEk=^  
for(int i=0;i<nStartPos.length;i++) *vO'Z &  
{ oX4uRc7wR  
if(!fileSplitterFetch.bDownOver) GKtQ>39B  
{ ;2|H6IN"  
breakWhile = false; k0IU~y%  
break; RM+E  
} KRZV9AJ  
} U.F65KaKF  
if(breakWhile) PK4UdT  
break; NGY I%:  
qi2dTB  
r*wKYb  
//count++; F]*-i 55S  
//if(count>4) 7&)F;;H  
// siteStop(); k9xKaJ %1  
} cj<@~[uw  
gAY2|/,  
KxwLKaImI  
System.err.println("文件下载结束!"); !gf3%!%  
} UVJ(iNK"  
catch(Exception e){e.printStackTrace ();} VC(|t} L4  
} sEN@q   
3Q}Y?rkJ5  
*$$V, 6O.  
//获得文件长度 K-u/q6ufK  
public long getFileSize() j2Y(Q/i  
{ ;#i$0~lRl  
int nFileLength = -1; @GtZK  
try{ (d#Z-w-  
URL url = new URL(siteInfoBean.getSSiteURL()); SXz([Z{)  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); TMCA?r%Y\  
httpConnection.setRequestProperty("User-Agent","NetFox"); w0Y%}7  
wS0bk<(  
?&m]du#6  
int responseCode=httpConnection.getResponseCode(); \Agg6tY r  
if(responseCode>=400) \W^+vuD8  
{ N=wy)+  
processErrorCode(responseCode); y}HC\A77uD  
return -2; //-2 represent access is error KgWT&^t  
} ?|GxVOl  
Dg+d=I?  
V^+:U>$w  
String sHeader; 'e64%t  
oLMi vy4  
CWQ2iu<_0  
for(int i=1;;i++) m5aaY  
{ ?\M6P?tpo&  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); u(Sz$eV  
//Utility.log(in.readLine()); a?~csP^?}  
sHeader=httpConnection.getHeaderFieldKey(i); ONiI:Z>%  
if(sHeader!=null) z44~5J]  
{ o~&!M_ED  
if(sHeader.equals("Content-Length")) 3&fFIab9  
{ /*^|5>-`i1  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Z;\"pP:  
break; 6ya87H'e@  
} <@2# VG  
} f;H#TSJ  
else oD@jtd>b%  
break; ;w(1Ydo  
} D])YP0|}  
} >?eTbtP  
catch(IOException e){e.printStackTrace ();} Pm(:M:a  
catch(Exception e){e.printStackTrace ();} uE`|0  
]G PJ(+5  
TeCpT2!5j  
Utility.log(nFileLength); p3FnYz-V  
{WeXURp&nF  
8Vhck-wF  
return nFileLength; 2\B9o `Y  
} */y]!<\v!k  
lV6[d8P  
jZT :-w  
//保存下载信息(文件指针位置) CN~NyJL H  
private void write_nPos() -Dxhq& }Y  
{ A{x 7  
try{ IKzRM|/  
output = new DataOutputStream(new FileOutputStream(tmpFile)); v#]v,C-*  
output.writeInt(nStartPos.length); g)?g7{&?>?  
for(int i=0;i<nStartPos.length;i++) cgxF Ev  
{ 5vX 8mPR_  
// output.writeLong(nPos); _pko]F|()  
output.writeLong(fileSplitterFetch.nStartPos); 6eYf2sZ;J  
output.writeLong(fileSplitterFetch.nEndPos); #t2UPLO~  
} ]ZzG!7  
output.close(); q6JW@GT  
} Xu94v{u3  
catch(IOException e){e.printStackTrace ();} DwY<qNWT  
catch(Exception e){e.printStackTrace ();} X0Z-1bs  
} -F+P;S  
=ch Af=  
~K-*q{6Q  
//读取保存的下载信息(文件指针位置) tG2OVRx8u  
private void read_nPos() ' q<EZ {  
{ \btR^;_\A  
try{ #>m, Cm  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile));  ;[KriW  
int nCount = input.readInt(); `o8{qU,*]N  
nStartPos = new long[nCount]; q X%vRf0  
nEndPos = new long[nCount]; n~)HfY  
for(int i=0;i<nStartPos.length;i++) rH&r6Xv[  
{ s'aV qB  
nStartPos = input.readLong(); q bZ,K@0  
nEndPos = input.readLong(); ?(/j<,m^  
} n^pZXb;Y  
input.close(); A?IZ( Zx(`  
} B(\r+"PB  
catch(IOException e){e.printStackTrace ();} me:|!lI7YU  
catch(Exception e){e.printStackTrace ();} &xBK\  
} BnaU)E h  
,> (bt%b  
}x?H ~QQT  
private void processErrorCode(int nErrorCode) 1KYbL8c  
{ 8S1P&+iKs  
System.err.println("Error Code : " + nErrorCode); ,]uX:h-EM  
} )0U3w#,JQ  
!<=%;+  
EN-H4F  
//停止文件下载 ..q63dr  
public void siteStop() v=*Bb3dt  
{ +-aU+7tu  
bStop = true; \7t5U7v8U  
for(int i=0;i<nStartPos.length;i++) `?]rr0.}hp  
fileSplitterFetch.splitterStop(); yD[zzEuQ  
! nCjA\$  
7O+Ij9+{n  
} v dH+>l  
} jKj=#O  
//负责部分文件的抓取 S0N2rU  
**FileSplitterFetch.java (lN;xT`=  
*/ p<HTJ0  
package NetFox; NDRW  
XatA8(_,5  
Cgz&@@j,]  
import java.io.*; Z\|u9DO  
import java.net.*; h eE'S/  
WjY{rM,K  
[Y22Wi  
public class FileSplitterFetch extends Thread { fwi};)K  
1C0Y0{6,  
3'[Rvy{  
String sURL; //File URL vQK n=  
long nStartPos; //File Snippet Start Position <o&o=Y8  
long nEndPos; //File Snippet End Position DIG0:)4R.  
int nThreadID; //Thread's ID Jtp>m?1Ve  
boolean bDownOver = false; //Downing is over m%oGzx+  
boolean bStop = false; //Stop identical llHc=&y#  
FileAccessI fileAccessI = null; //File Access interface .Na&I)udX.  
6.U  "_%  
R%b*EBZ  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /`+Hw dk  
{ k<YtoV  
this.sURL = sURL; 8ji^d1G,  
this.nStartPos = nStart; v}F4R $  
this.nEndPos = nEnd; &gGs) $f[  
nThreadID = id; 7_Ba3+9jpa  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (]3ERPn#y  
} Hs"% S  
NqJ<!q)  
ptV4s=G2  
public void run() L289'Gzg  
{ U@.u-)oX  
while(nStartPos < nEndPos && !bStop) ;RWW+x8IB  
{ 8%o~4u3  
lo+xo;Nd  
FOCoiocPi  
try{ p!+L  
URL url = new URL(sURL); "_K}rI6(t  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m<FF$pTT  
httpConnection.setRequestProperty("User-Agent","NetFox"); ${hyNt  
String sProperty = "bytes="+nStartPos+"-"; R9tckRG#  
httpConnection.setRequestProperty("RANGE",sProperty); ]u rK$   
Utility.log(sProperty); @J-plJ4e  
Qm.z@DwFM{  
;W7hc!  
InputStream input = httpConnection.getInputStream(); mi7sBA9L8  
//logResponseHead(httpConnection); l^k+E-w\  
Mjb 1  
p`>AnfG  
byte[] b = new byte[1024]; 3<c*v/L{C\  
int nRead; [AXsnpa/C  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |EF>Y9   
{ b/}'Vf[  
nStartPos += fileAccessI.write(b,0,nRead); a(8>n Z,V  
//if(nThreadID == 1) $brKl8P  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9v~1We;{$  
} \s=QiPK  
Bu7A{DRf  
%6AYCN?Ih  
Utility.log("Thread " + nThreadID + " is over!"); UhsO\9}qH  
bDownOver = true; 7dSh3f!  
//nPos = fileAccessI.write (b,0,nRead); (E!%v`_0  
} |/@0~O(6  
catch(Exception e){e.printStackTrace ();} A)8rk_92Q  
} qE>i,|rP`  
} {bN Y  
[ZuVUOm  
AK6=Ydu  
//打印回应的头信息 B ,V( LTE  
public void logResponseHead(HttpURLConnection con) +.w[6  
{ aSRjFL^  
for(int i=1;;i++) ^~^mR#<P$  
{ %VzYqj_P"  
String header=con.getHeaderFieldKey(i); /sy-;JDnsu  
if(header!=null) Ll,I-BQ 9  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 7g-Dfg.w  
Utility.log(header+" : "+con.getHeaderField(header)); 4Mk8Cpz  
else f, |QAj=a  
break; I$n+DwKcN  
} ^>-+@+( r  
} <BSSa`N`  
aZ$/<|y~:_  
FIH@2zA  
public void splitterStop() WPIZi[hBs  
{ M3ZOk<O<R  
bStop = true; Q\H_t)-  
} v' C@jsx M  
+a-D#^ 2;  
vyE{WkZxR  
} 5\WUoSgy  
D>P;Izb  
0}B?sNr  
/*  Q.yb4  
**FileAccess.java k=e`*LB\  
*//文件访问(定位,写) &1P(O\ d  
package NetFox; F"I*-!o  
import java.io.*; )`^ /(YG  
byafb+x  
>E, Q  
public class FileAccessI implements Serializable{ yX`#s]M  
n[|6khOL-  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Y,'%7u  
RandomAccessFile oSavedFile; E$ {J  
long nPos; 6.[)`iF+#  
?H`j>]%&  
=LOk13l\"  
public FileAccessI() throws IOException vHS2q >  
{ guU=NQZ  
this("",0); +s ULo  
} #G[t X6gU  
^+wk  
m~;B:LN<  
public FileAccessI(String sName,long nPos) throws IOException Apmw6cc  
{ h(nj,X+  
oSavedFile = new RandomAccessFile(sName,"rw"); d .p'pGL  
this.nPos = nPos;  c-5Ysg  
oSavedFile.seek(nPos); ;= a_B1"9u  
} B[CA 5Ry  
44~hw:   
zZ: xEc  
public synchronized int write(byte[] b,int nStart,int nLen) w-ALCh8o  
{ Fwb5u!_,  
int n = -1; r_^)1w  
try{ W2hA-1  
oSavedFile.write(b,nStart,nLen); )&:L'N  
n = nLen; Jld\8=  
} tF^g<)S;t  
catch(IOException e)  t!jYu<P  
{ "TNVD"RLY  
e.printStackTrace (); P3!Atnv2  
} z6I%wh  
d*2u}1Jo8  
0\Y1}C  
return n; DHv2&zH  
} ^^U%cuKg  
pM9yOY  
2e59Ez%k6  
} ^&Q< tN 7  
E=]]b;u-n  
et` 0Je  
/* QD$Gw-U-l=  
**SiteInfoBean.java FAw1o  
*/ hO \/  
package NetFox; Bd&`Xfebj  
VO_dA4C}z  
FqZgdmwR  
public class SiteInfoBean { M?$ZJ-  
oxzq!U  
/P:EWUf'  
private String sSiteURL; //Site's URL 2)9r'ai?a  
private String sFilePath; //Saved File's Path cS(;Qs]Q  
private String sFileName; //Saved File's Name k"0;D-lTZ>  
private int nSplitter; //Count of Splited Downloading File A?A9`w  
<^c3}  
lL0M^Nv  
public SiteInfoBean() m(_9<bc>  
{//nSplitter的缺省值为5 Us=eq "eu  
//default value of nSplitter is 5 `eR 7H>I  
this("","","",5); Om9jtWk  
} _{)9b24(  
Ac`;st%l.  
T<yb#ak  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^_W40/c3  
{ >g}G}=R~3  
sSiteURL= sURL; 6pp$-uS  
sFilePath = sPath; S)7/0N79A  
sFileName = sName; ix&'0IrX*  
this.nSplitter = nSpiltter; lP3h<j  
orqJ[!u)`  
y' [LNp V  
} cU8xUpq  
<cj{Qk  
Ryv_1gR!  
public String getSSiteURL() 0` 5e  
{ WbcS: !0  
return sSiteURL; =wrP:wYF  
} RB$ z]/=  
[Y8S[YY  
q7_+}"i  
public void setSSiteURL(String value) 0BK5qz  
{ ?\y%]1  
sSiteURL = value; |<c WllN  
} "HK/u(z)  
B(,:haAr  
ue\t,*KYd  
public String getSFilePath() |`0n"x7  
{ pW|u P8#  
return sFilePath; tTuX\;G  
} =J/FJb  
[Y/:@t"2y  
zk}{ dG^M:  
public void setSFilePath(String value) L;/n!k.A  
{ K0Tg|9  
sFilePath = value; x?sI;kUw8  
} ,H[SI0];  
2*AG7  
<[i}n55  
public String getSFileName() f~ U.a.Fb  
{ >5ChcefH  
return sFileName; , ;jGJr  
} m3 -9b"  
*9 D!A  
N`$!p9r  
public void setSFileName(String value) 3WUH~l{UJ  
{ 27#5y_ `  
sFileName = value; D$q'FZH  
} RN9;kB)c  
RUo9eQIPD  
-LWK*q[J;*  
public int getNSplitter() +B"0{>n}F  
{ ;rR/5d1!  
return nSplitter; %!|O.xxRR  
} E^CiOTN  
z]@6fM[  
c$h9/H=~  
public void setNSplitter(int nCount) h"W8N+e\  
{ 5zB~4u  
nSplitter = nCount; ^3~e/PKM  
} ,D=fFpn  
} [TTSA2  
Nneo{j  
&c%Y<1e`%  
/* :dnJY%/q  
**Utility.java KoBW}x9Jp  
*/ }NCL>l;q  
package NetFox; ~Xv=9@,h  
,o#kRWRG  
#wR;|pN  
public class Utility { D4u% 6R|F  
57I}RMT"  
l#qv 5f  
public Utility() Ak BMwV  
{ QP(BZJC  
I;MD>%[W,  
egR-w[{  
} = |U@  
:d,^I@]  
//线程睡眠 >U!*y4  
public static void sleep(int nSecond) 5M_Wj*a}7  
{ l=m(mf?QBg  
try{ lB;FUck9  
Thread.sleep(nSecond); &^.57]  
} n"D ?I  
catch(Exception e) #"*e+.j[;  
{ L 3XB"A#  
e.printStackTrace (); 9pSUIl9|j  
} Ud(`V:d  
} ~mp0B9L%  
1KE:[YQ1  
//日志 H)(jh  
public static void log(String sMsg) Ey `h1 Y  
{ -ysn&d\rV  
System.err.println(sMsg); [2c{k  
} XNH4vG |  
NL"G2[e  
)A8v];.]3  
public static void log(int sMsg) `BXS)xj  
{ c-4STPNQi  
System.err.println(sMsg); $'wq1u  
}  %Y nmuZ  
} dA~ 3>f*b_  
5K%W a]W  
{MBTP;{*~  
/* }"s;\?a  
**TestMethod.java  #ToK$8  
*/ au@a8MP  
package NetFox; lCT{v@pp  
/Lf6WMit  
n# 7Pr/*0  
public class TestMethod { |NFZ(6vNh  
Ctu?o+^;z  
~qP[eWe  
public TestMethod() >{zk qvsQ&  
{ ///xx/weblogic60b2_win.exe b1?xeG#  
try{ =d`5f@'rl  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); t*S." q  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); r%]Qlt ~K  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Jh/ E@}'  
fileFetch.start(); X` YwP/D  
} ]+ Ixi o  
catch(Exception e){e.printStackTrace ();} \,G#<>S  
o*S"KX $  
X[$++p .  
} t#E}NR  
eVh - _  
Sus;(3EX  
public static void main(String[] args) bZwnaM4"F  
{ ~l E _L1-c  
new TestMethod(); kGYTl,A{  
} 2[yBD-":  
} N:5[,O<m_  
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