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http断点续传简单实现(java)

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/* aAX 8m  
**SiteFileFetch.java o5)U3U1|  
*/ znM"P|A  
package NetFox; QKVZ![Y!s  
import java.io.*; Nk 7Q  
import java.net.*; vs.q<i-u  
M?_VYK  
$, =n  
public class SiteFileFetch extends Thread { x>t:&Y M  
xT@\FwPr  
L<E`~\C'  
SiteInfoBean siteInfoBean = null; //文件信息Bean 5!AzEB  
long[] nStartPos; //开始位置 5!?><{k=%  
long[] nEndPos; //结束位置 0n1y$*I4  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 W nVX)o  
long nFileLength; //文件长度 gSP|;Gy  
boolean bFirst = true; //是否第一次取文件 d=xweU<  
boolean bStop = false; //停止标志 Q i?   
File tmpFile; //文件下载的临时信息 n&@\[,B  
DataOutputStream output; //输出到文件的输出流 ^7(zoUn:  
vXyaOZ  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ?4xTA  
public SiteFileFetch(SiteInfoBean bean) throws IOException -0>@jfP^D  
{ J L]6o8x  
siteInfoBean = bean; 9#1lxT4%  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); `/#6k>  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); pO"V9[p]  
if(tmpFile.exists ()) [*,`a]z-Q  
{ 65MR(+3  
bFirst = false; xGz$M@f  
read_nPos(); NK d8XQ=%  
} nE,"3X"   
else @ j' I  
{ :U?Kwv8s  
nStartPos = new long[bean.getNSplitter()]; MvObx'+  
nEndPos = new long[bean.getNSplitter()]; W<kJ%42^j  
} mw.9cDf  
z )k\p'0"  
)V+ ;7j<"D  
g,9o'fs`x  
} wz;IKdk[  
eFbr1IV  
O7:JG[tR*  
public void run() m ?LOd9  
{ y1f&+y9e  
//获得文件长度 Q-(twh  
//分割文件 ]{Iy<  
//实例FileSplitterFetch jFnq{L t  
//启动FileSplitterFetch线程 p)d'yj  
//等待子线程返回 lY0^Z  
try{ #O qfyY!  
if(bFirst) < JA5.6<=  
{ <[kdF")  
nFileLength = getFileSize(); 'ym/@h7h  
if(nFileLength == -1) ]uj6-0q){W  
{  !3}vl Y1  
System.err.println("File Length is not known!"); nO2-fW:9]  
} ~ 8RN  
else if(nFileLength == -2) ,J~kwJ$L  
{ u\.7#D>  
System.err.println("File is not access!"); x-mRPH  
} m^%[  
else ~~]L!P  
{ u.gnv dU  
for(int i=0;i<nStartPos.length;i++) c{7!:hi`x  
{ NAlYfbp  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); CUaI66  
} O3PE w4yA  
for(int i=0;i<nEndPos.length-1;i++) xm6cn\e  
{ he;&KzEu  
nEndPos = nStartPos[i+1]; N{ @B@]  
} 7ae8nZ3&  
nEndPos[nEndPos.length-1] = nFileLength; 1Y_Cd  
} D}r,t_]Eb  
} &+u) +<&;(  
Yw vX SA  
{Ug?k<h7|  
//启动子线程 VZ 5EV'D8!  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ! jm>  
for(int i=0;i<nStartPos.length;i++) PTXy:>]M  
{ dd@qk`Zl&A  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K1AI:$H  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), )4vZIU#  
nStartPos,nEndPos,i); q["CT&0  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); PF+v[h;,  
fileSplitterFetch.start(); y2bL!Y<s9  
} _=Ed>2M)no  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {L$]NQdz  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); C0eP/d  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", u[$ \ az7  
nEndPos = " + nFileLength); '5\7>2fI  
// fileSplitterFetch[nPos.length-1].start(); Mhc!v, D$  
/f@VRME  
^p ?O1qTg  
//等待子线程结束 RcIGIt  
//int count = 0; E5(\/;[*`  
//是否结束while循环 \$n?J(N  
boolean breakWhile = false; eLXG _Qb"  
03Pa; n  
yJkERiJV  
while(!bStop) "E =\Vz  
{ #05#@v8.f  
write_nPos(); =(Y 1y$  
Utility.sleep(500); sS/#)/B  
breakWhile = true; z;yb;),  
?&W1lYY  
]V \qX+K  
for(int i=0;i<nStartPos.length;i++) {_t i*#  
{ _R-[*ucq  
if(!fileSplitterFetch.bDownOver) JDrh-6Zgj  
{ Ch8w_Jf1yx  
breakWhile = false; m&(yx| a4+  
break; @|! 9~F  
} &"]Uh   
} C50&SrnBU1  
if(breakWhile) a=}JW]  
break; !mLQdkTE  
U+gOojRy{  
gU1E6V-Jm  
//count++; R L&z\S  
//if(count>4) 4X,fb`  
// siteStop(); lIPy)25~  
} ZS[(r-)$F  
yDh(4w-~gk  
6) {jHnk)  
System.err.println("文件下载结束!"); /Ud<4j-  
} Qwl=/<p1  
catch(Exception e){e.printStackTrace ();} ns`|G;1vv  
} 9i4!^DM_  
~^jdiy5  
)QS4Z{)U  
//获得文件长度 'ap<]mf2  
public long getFileSize() Z'sAu#C  
{ vpR^G`/  
int nFileLength = -1; d3Dw[4  
try{ vowU+Y  
URL url = new URL(siteInfoBean.getSSiteURL()); nk.m G ny  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0 ?kaXD  
httpConnection.setRequestProperty("User-Agent","NetFox"); F&?55@b  
`tZu~ n  
=*EIe z*.x  
int responseCode=httpConnection.getResponseCode(); .Y B}w  
if(responseCode>=400) x;A"S  
{ $50rj  
processErrorCode(responseCode); D4 {?f<G0F  
return -2; //-2 represent access is error .KiJq:$H  
} &6!~Q,;K-  
4u} "ng   
c`:hEQs  
String sHeader; ="E^9!  
N[e QT  
VrL==aTYXs  
for(int i=1;;i++) !<9sOvka{  
{ WT(inf[  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); kO3{2$S6  
//Utility.log(in.readLine()); a^yBtb~,P  
sHeader=httpConnection.getHeaderFieldKey(i); 3#fu; ??1.  
if(sHeader!=null) [Xp{z tGE  
{ fQ>=\*b9x^  
if(sHeader.equals("Content-Length")) |,zcrOo]  
{ |$[WnYP  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =+um:*a.  
break; VAkZ@ u3'~  
}  _@es9  
} ^X2U A{  
else :00 #l]g0q  
break; +<p?i]3CHe  
} |~'D8 g:Ak  
} emZ^d/A  
catch(IOException e){e.printStackTrace ();} eIVCg-l}  
catch(Exception e){e.printStackTrace ();} 3Cq/ o'  
:,.g_@wvG  
W}+f}/&l  
Utility.log(nFileLength); V,,/}f '  
u Qy5t:!  
-ya0!D  
return nFileLength; C N9lK29F)  
} L||_Jsu  
Dd+ f,$  
wg6![Uh  
//保存下载信息(文件指针位置) "BB#[@  
private void write_nPos() e@k`C{{C]o  
{ GH%'YY3|  
try{ AF{k^^|H  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Q;O\tl  
output.writeInt(nStartPos.length); nJ/wtw  
for(int i=0;i<nStartPos.length;i++) ]h (TZu  
{ =~r?(u6d  
// output.writeLong(nPos); m35Blg34  
output.writeLong(fileSplitterFetch.nStartPos); YJgw%UVJ5m  
output.writeLong(fileSplitterFetch.nEndPos); 'BT}'qN  
} mT57NP  
output.close(); $cO"1mu  
} #plwK-tPR  
catch(IOException e){e.printStackTrace ();} fgFBOpG%Gq  
catch(Exception e){e.printStackTrace ();} eqbxf#H!  
} ^G63GYh]y  
7e&R6j  
4)=LOGW  
//读取保存的下载信息(文件指针位置) H[o'j@0  
private void read_nPos() %UJ!(_  
{ & -  
try{ `n8) o%E9  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); &fYx0JT  
int nCount = input.readInt(); jY-i`rJN  
nStartPos = new long[nCount]; Auhw(b>}TW  
nEndPos = new long[nCount]; L K9vvQz  
for(int i=0;i<nStartPos.length;i++) * [*#cMZ   
{ +MC>?rr_u  
nStartPos = input.readLong(); woZ'T  
nEndPos = input.readLong(); G8`q-B}q  
} <\x/Y$jm0n  
input.close(); XgKtg-,  
} [!{*)4$6  
catch(IOException e){e.printStackTrace ();} 8?W!U*0aS  
catch(Exception e){e.printStackTrace ();} k ]x64hgm  
} ,_`\c7@  
JnCY O^Qj  
u;DF$   
private void processErrorCode(int nErrorCode) ?mY )m +  
{ ?n/:1LN,  
System.err.println("Error Code : " + nErrorCode); u*[,W-R&  
} 1W-t})!a  
EF0{o_  
 D@qq=M  
//停止文件下载 ^BjwPh4Z#  
public void siteStop() EA75 D&>I  
{ aEX;yy*  
bStop = true; D`e!CprF  
for(int i=0;i<nStartPos.length;i++) H's67E/>*  
fileSplitterFetch.splitterStop(); {a_= 4a  
q=bJ9iJsq  
5@j?7%_8  
} ^`YSl*:  
} Y,WcHE  
//负责部分文件的抓取 M#})  
**FileSplitterFetch.java ^/R@bp#<  
*/ u4$d#0sA  
package NetFox; {^9,Dy_D  
65ijzZL;  
u 8U>R=M  
import java.io.*; 9R>A,x(  
import java.net.*; G#duZNBdc  
wx(| $2{h  
x:;8U i"&B  
public class FileSplitterFetch extends Thread { S3hJL:3c  
4,FkA_k  
N3vk<sr@  
String sURL; //File URL h'UWf"d  
long nStartPos; //File Snippet Start Position FlVGi3  
long nEndPos; //File Snippet End Position lhQ*;dMj%"  
int nThreadID; //Thread's ID H) q9.Jg  
boolean bDownOver = false; //Downing is over bLu6|YB  
boolean bStop = false; //Stop identical 3KB)\nF#%  
FileAccessI fileAccessI = null; //File Access interface 3z&,>CEX  
L4.yrA-]C%  
k6[t$|lMy  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException jSVb5P  
{ u9mMkzgSkP  
this.sURL = sURL; `mw@"  
this.nStartPos = nStart; ^fnRzX  
this.nEndPos = nEnd; ^ 9;s nr  
nThreadID = id; q7 Uu 8JXF  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 O|7q,bEm^  
} |[!xLqG  
3p!R4f)GN  
$6fHY\i#R  
public void run() }qV4]*+{  
{ ]o,)#/' $  
while(nStartPos < nEndPos && !bStop) ?/#HTg)!B  
{ n{4&('NRFP  
pPQ]#v  
5Odi\SJ&  
try{ E6)FYz7x  
URL url = new URL(sURL); !S(jT?'w  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ` mCcD  
httpConnection.setRequestProperty("User-Agent","NetFox"); WHE*NWz>q  
String sProperty = "bytes="+nStartPos+"-"; Htsa<t F  
httpConnection.setRequestProperty("RANGE",sProperty); 4 Iy\   
Utility.log(sProperty); Vx* =  
J=4S\0Z*  
oVC~RKA*  
InputStream input = httpConnection.getInputStream(); ;=h^"et  
//logResponseHead(httpConnection); / d6mlQS  
Yl-09)7s  
hC6$>tl  
byte[] b = new byte[1024]; BvX!n"QIb  
int nRead; C?hw$^w7T  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 'Iu$4xo`[  
{ dC,F?^  
nStartPos += fileAccessI.write(b,0,nRead); :4Q_\'P  
//if(nThreadID == 1) %gw0^^A  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos);  KsUsj3J  
} !(SaE'  
P?TFX.p7  
GueqpEd2  
Utility.log("Thread " + nThreadID + " is over!"); MHxv@1)K|Y  
bDownOver = true; h ?p^DPo  
//nPos = fileAccessI.write (b,0,nRead); u1]5qtg"  
} $fn Fi|-  
catch(Exception e){e.printStackTrace ();} zyCl`r[}  
} u :m]-'  
} aNXu"US+Sp  
)C|>M'g@v  
rm"bplLZA  
//打印回应的头信息 `86 9XE  
public void logResponseHead(HttpURLConnection con) G3?8GTH  
{ /ebYk-c  
for(int i=1;;i++) $,h*xb.  
{ #~p1\['|M  
String header=con.getHeaderFieldKey(i); ~@sx}u  
if(header!=null) %?RX}37K  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); {W0]0_mI(  
Utility.log(header+" : "+con.getHeaderField(header)); IS!B$  
else gCwg ;c-  
break; ld2 \/9+n  
} @+xkd(RfN  
} @~a52'\  
c]xpp;%]  
wF38c]r`\<  
public void splitterStop() AK [9fxrE  
{ t3bDi/m  
bStop = true; -M[5K/[  
} wetkmd  
M}@^8  
dmE-W S  
} b/S4b  
B>~E6j7[Mp  
Re.fS6y$>  
/* nGyY`wt&Rg  
**FileAccess.java +F67g00T|  
*//文件访问(定位,写) >:wk.<Z-  
package NetFox; !})+WSs'"s  
import java.io.*; $wX5`d 1  
]CHMkuP[k  
F /t;y\)  
public class FileAccessI implements Serializable{ {OQ sGyR?  
$1UN?(r  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 AY *  
RandomAccessFile oSavedFile; QR^pu.k@  
long nPos; LU%g>?m.]  
d5WE^H)E.  
TYLf..i<  
public FileAccessI() throws IOException J/ rQ42d  
{ Mb/R+:C`  
this("",0); (1TYJ. Z  
} [vIO  
Y4b"(ZhM_  
%`g qV9a  
public FileAccessI(String sName,long nPos) throws IOException d5u,x.R  
{ +/UInAM  
oSavedFile = new RandomAccessFile(sName,"rw"); ,sJ{2,]~  
this.nPos = nPos; |r3eq4$Am  
oSavedFile.seek(nPos); ,,,5pCi\  
} L- =^GNh  
az19-QIcg  
[c3hwogf:  
public synchronized int write(byte[] b,int nStart,int nLen) LWIU7dw  
{ U8.DPRa  
int n = -1; [%bshaY:  
try{ QMkLAZ  
oSavedFile.write(b,nStart,nLen); =P2T&Gb  
n = nLen; f)gA.Rz  
} w+ _'BU1#  
catch(IOException e) B%r)~?6DM  
{ _YbHnb  
e.printStackTrace (); WlG/7$  
} Bv/v4(G5g  
WXGLo;+>I  
BDcl1f T  
return n; ?2.< y_1  
} F1 MPo;e  
1k "*@Z<  
vY.p~3q :)  
} i\,#Z!  
gKBcD\F  
v bh\uv&  
/* LoNz 1KJL  
**SiteInfoBean.java Tw|=;m  
*/ -KO E2f  
package NetFox; $'kIo*cZ  
X;zy1ZH  
, gz:2UY#  
public class SiteInfoBean { -S9$C*t  
<51(q_f  
6i>xCb  
private String sSiteURL; //Site's URL +vZ-o{}.jO  
private String sFilePath; //Saved File's Path ?$8OVq.w,  
private String sFileName; //Saved File's Name Ue~M .LZb  
private int nSplitter; //Count of Splited Downloading File /z~;.jRg  
G9^!= v@  
C3WqUf<8`{  
public SiteInfoBean() 'rU 5VrK  
{//nSplitter的缺省值为5 Fe`$mtPu.  
//default value of nSplitter is 5 K]Ed-Tz8QZ  
this("","","",5); s6!aGZ  
} q[**i[+%  
c1!h;(&  
bIwt#:v  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) vvdC.4O  
{ L?<V KT  
sSiteURL= sURL; &o:wSe  
sFilePath = sPath; B!rY\ ?W  
sFileName = sName; 1j3mTP  
this.nSplitter = nSpiltter; BW z*!(   
O,XVA  
If2f7{b  
} |a/"7B|?\  
s#64NG  
q9F(8-J  
public String getSSiteURL() M~p=OM<  
{ D+#QQH  
return sSiteURL; M)( 5S1ndq  
} lP\7=9rh^x  
2["bS++?  
$oe:km1-D  
public void setSSiteURL(String value) ^JJ*pT:  
{ Pr<.ld\  
sSiteURL = value; .$L'Jt2X  
} 4*G#fW-  
Z^>{bW  
+{4ziqYj  
public String getSFilePath() 5fDVJE "9"  
{ b~WiE?  
return sFilePath; Ihw^g <X  
} /87?U; |V  
-Wb/3 X  
nV@k}IJg:?  
public void setSFilePath(String value) \l"1Io=  
{ )zf&`T  
sFilePath = value; n2Q~fx<6%  
} :l'61$=  
iQ~;to;Y  
Q+ $+{g-8  
public String getSFileName() -}AAA*P  
{ +.! F]0ju  
return sFileName; 6f v{?0|  
} JS1$l+1  
[>U'P1@ql  
+Vl\lL -  
public void setSFileName(String value) 5RrzRAxq  
{ mG*[5?=r  
sFileName = value; fb0i6RC~&  
} /5b,&  
]4^9Tw6 _b  
]DHB'NOh,  
public int getNSplitter() 2_'{f1bVxz  
{ 2? 9*V19yu  
return nSplitter; airg[dK  
} JPJ&k( P  
b1>zGC^|  
Ka%u#};  
public void setNSplitter(int nCount) 4! ]28[2B6  
{ He @d~9M  
nSplitter = nCount; ve|ig]$5g<  
} c5Fl:=h  
} &Azfpv   
>1q W*  
*DfwTbg|  
/* jrJ!A(<)  
**Utility.java E]Dcb*t  
*/ ]06orBV  
package NetFox; Wwo'pke  
%P@V7n  
HG kL6o=  
public class Utility { 'b1k0 9'  
/&1FgSARK  
.S4c<pMap  
public Utility() E "9`  
{ ~gZ"8frl  
m ioNMDG  
d7(g=JK<  
} X$mCn#8m  
]c/k%] o~  
//线程睡眠 F%|F-6  
public static void sleep(int nSecond) :qlcN@_  
{ !C]2:+z-MF  
try{ P)D2PVD  
Thread.sleep(nSecond); 9W5~I9%  
} 'LC-/_g  
catch(Exception e) KNvvYwFH]  
{ )DG>omCY  
e.printStackTrace (); ~| CWy  
} ZhvZe/  
} {"e)Jj_=  
t_ju[xL5B  
//日志 kz30! L  
public static void log(String sMsg) L<dJWxf?D  
{ XWd;-%`<  
System.err.println(sMsg); ;zF3e&e(  
} [T}Lq~  
@}{lp'8FYi  
SLsw '<  
public static void log(int sMsg) PPpq"c  
{ ue8"_N  
System.err.println(sMsg); r3;@  
} uPhL?s{  
} :)*+ aS"  
sV']p#HK0  
Q%T[&A}3B  
/* or<n[<D-C  
**TestMethod.java NoAgZ{))  
*/ Ga$J7 R  
package NetFox; Z~S%|{&Br  
,h<xL-  
; <NK  
public class TestMethod { tg~@(IT}j  
-Z(='A  
rGDx9KR4K!  
public TestMethod() D\H;_k8  
{ ///xx/weblogic60b2_win.exe T1~G {@"  
try{ ATG;*nIP  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *DUP$@}k  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); o)]mJb~XG-  
SiteFileFetch fileFetch = new SiteFileFetch(bean); o'?[6B>oj  
fileFetch.start(); OaH1xZNOC`  
} &# < M o  
catch(Exception e){e.printStackTrace ();} '_~qAx@F#c  
) Vf!U"  
\?_M_5Nb  
} YZdV0 -S  
cF V[k'F  
k[Ue}L|  
public static void main(String[] args) JYw_Z*L=m  
{ ]#sF pWI[N  
new TestMethod(); U_KCN09  
} p6c&vEsNj  
} ZJf:a}=h  
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