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http断点续传简单实现(java)

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/* l .8@F  
**SiteFileFetch.java <<zYF.9L]  
*/ (p2jigP7a[  
package NetFox; XY[uyR4Z  
import java.io.*; e12.suv  
import java.net.*; yG)zrRU  
S}q6CG7 u  
Y<'T;@  
public class SiteFileFetch extends Thread { 6!|-,t><  
2]Nc@wX`p  
CS;bm `8a  
SiteInfoBean siteInfoBean = null; //文件信息Bean f$G{7%9*  
long[] nStartPos; //开始位置 jl;%?bx  
long[] nEndPos; //结束位置 iRo/~(  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 '!)|;qe  
long nFileLength; //文件长度 Jww LAQ5  
boolean bFirst = true; //是否第一次取文件 !TJCQ[Aa }  
boolean bStop = false; //停止标志 _S43_hW  
File tmpFile; //文件下载的临时信息 _b+=q:$/  
DataOutputStream output; //输出到文件的输出流 bk@F/KqL  
~bSPtH ]6d  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) GA, 6G [E  
public SiteFileFetch(SiteInfoBean bean) throws IOException lg)jc3  
{ 1gEeZ\B-&  
siteInfoBean = bean; 1m*fkM#  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); dqU bJc]  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ?mdgY1  
if(tmpFile.exists ()) a#iJXI  
{ $ e<&7  
bFirst = false; 50 :gk*hy  
read_nPos(); nE!h&}(  
} (nWi9(}J  
else YQb43Sh`  
{ ;naD`([  
nStartPos = new long[bean.getNSplitter()]; vf=b5s(7Q  
nEndPos = new long[bean.getNSplitter()]; <IWO:7*#  
} I:4m]q b  
-!OFt}  
teO%w9ByY  
P8l x\DA  
} `uz15])1<  
$9pFRQC'q  
`GsFvxz  
public void run() Sm6hyZFy  
{ 1wX0x.4d  
//获得文件长度 FL}k0  
//分割文件 6I0G.N  
//实例FileSplitterFetch *Uvh;d{  
//启动FileSplitterFetch线程 H 1`}3}"  
//等待子线程返回 otQulL)T/  
try{ *~~&*&+  
if(bFirst) :x*|?zII  
{ ^l}Esz`-M  
nFileLength = getFileSize(); [<;4$}f\  
if(nFileLength == -1) 6xk~Bt  
{ v7?sXW  
System.err.println("File Length is not known!"); Pqe{C?7B  
} xh$1Rwa  
else if(nFileLength == -2) "PM!03rb  
{ !;";L5()  
System.err.println("File is not access!"); p>w{.hC@  
} M_-LI4>  
else M=Y}w?  
{ DH(Q md  
for(int i=0;i<nStartPos.length;i++) \ /(;LHWQ  
{ DYS|"tSk  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 8`e75%f:2  
} =+K2`=y;WF  
for(int i=0;i<nEndPos.length-1;i++) s68&AB   
{ %E\&9,  
nEndPos = nStartPos[i+1]; L0\97AF  
} e;1n!_l\  
nEndPos[nEndPos.length-1] = nFileLength; ?}y{tav=  
} y:6&P6`dx  
} os|Y=a  
NdpcfZ q  
XU f]gQu3=  
//启动子线程 ^T):\x(  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Nqih LUv  
for(int i=0;i<nStartPos.length;i++) E'|@hL-jn  
{ X2avo|6e  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), k 7 !{p  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), H-&Z+4 +Xs  
nStartPos,nEndPos,i); E;[ANy4L  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V2< 4~J2:9  
fileSplitterFetch.start(); m_{?py@tZ  
} . zM  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), dgb#PxOMH  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Ho3$T  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 'Xl[ y  
nEndPos = " + nFileLength); 9|Z25_sS  
// fileSplitterFetch[nPos.length-1].start(); 1 J3h_z6/  
Ok7i^-85  
rFY% fo  
//等待子线程结束 oLJP@J  
//int count = 0; qA4w*{JN  
//是否结束while循环 yDwG,)m 4s  
boolean breakWhile = false; h^{D "  
&X 0qH8W  
Ne^md  
while(!bStop) %O$4da"y  
{ 5v51:g>c  
write_nPos(); f0S&_gt  
Utility.sleep(500); p&Usl.  
breakWhile = true; qPJU}(9#B  
SiN22k+  
Q fI =  
for(int i=0;i<nStartPos.length;i++) 8mM^wT  
{ JGS4r+   
if(!fileSplitterFetch.bDownOver) mlolSD;7  
{ 3*13XQ  
breakWhile = false; v!oXcHK/  
break; 4~<  :Pj  
} &. sfu$]  
} ;Drt4fOxX  
if(breakWhile) -p|@Enn  
break; .Rq|F  
Jf<+VJ>t  
(A.%q1h  
//count++; -]1F ] d  
//if(count>4) Isa]5>  
// siteStop(); Iu`B7UOF  
} *,w9#?2x  
[[{y?-U  
tx=~bm"*?  
System.err.println("文件下载结束!"); JFw<Po,MEa  
} k_)H$*  
catch(Exception e){e.printStackTrace ();} ^rd]qii"  
} p 4k*vuu>  
ISy\g`d`C  
(h NSzG\  
//获得文件长度 _<?lP$Xr  
public long getFileSize() wgm?lfX<  
{ mT8")J|2  
int nFileLength = -1; :Gyv%> .  
try{ ^P&)2m:s  
URL url = new URL(siteInfoBean.getSSiteURL()); Z!Y ^iN  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); QO;W}c:N  
httpConnection.setRequestProperty("User-Agent","NetFox"); V\nQHzjF<6  
-3 }  
cwK 6$Ax  
int responseCode=httpConnection.getResponseCode(); @pueM+(L&  
if(responseCode>=400) ]|cL+|':y  
{ !(=bH"P  
processErrorCode(responseCode); K8 Y/sHl  
return -2; //-2 represent access is error j(Tt-a("z  
} Xj:?V;  
]d]tQPEU  
u@v0I$  
String sHeader; PxENLQ3a=  
^cO^3=  
Q`#Y_N-h+  
for(int i=1;;i++) <&3qFK*9r  
{ !|P>%bi  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \wY? 6#;  
//Utility.log(in.readLine()); _9!_fIY  
sHeader=httpConnection.getHeaderFieldKey(i); Xz`?b4i  
if(sHeader!=null) m7z6c"?lB  
{ g0-hN%=6  
if(sHeader.equals("Content-Length")) +(d\`{A  
{ <<>?`7N  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Q>y2C8rnJ/  
break; vJg|}]h>L  
} +'qzk>B  
} !QoOL<(){  
else k8E'wN  
break; =k]RzeI  
} <5*cc8  
} eup#.#J  
catch(IOException e){e.printStackTrace ();} RFyeA. N  
catch(Exception e){e.printStackTrace ();} *Q bPz4,"  
^J0*]k%   
YKbR#DC\  
Utility.log(nFileLength); y"= j[.  
OA#AiQUR  
mgeNH~%m@*  
return nFileLength; KL]@y!QU  
} d, j"8\@  
?`?"j<4e  
;kO Op@e  
//保存下载信息(文件指针位置) B6tp,Np5,  
private void write_nPos() 3rX5haD\  
{ c!@g<<}[(  
try{ 8E`rs)A  
output = new DataOutputStream(new FileOutputStream(tmpFile)); .%>UA|[~:  
output.writeInt(nStartPos.length); Q8.SD p  
for(int i=0;i<nStartPos.length;i++) Q5'DV!0aSv  
{ 6AgevyVG  
// output.writeLong(nPos); 3{o5AsVv  
output.writeLong(fileSplitterFetch.nStartPos); h amn9  
output.writeLong(fileSplitterFetch.nEndPos); vluA46c  
}  ol^J-  
output.close(); P@LYa_UFsN  
} 56(S[  
catch(IOException e){e.printStackTrace ();} XBv:$F.>$  
catch(Exception e){e.printStackTrace ();} M/ @1;a@\  
} Nq>74q]}n8  
Ct[{>asun  
xcO Si>  
//读取保存的下载信息(文件指针位置) m_~!Lj[u.  
private void read_nPos() :Mr_/t2(  
{ xk=5q|u_-  
try{ yRaB\'  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); T1ZAw'6(K  
int nCount = input.readInt(); b!VaEK  
nStartPos = new long[nCount]; 9j458Yd4*  
nEndPos = new long[nCount]; E.kGBA;a?  
for(int i=0;i<nStartPos.length;i++) MH|!tkW>:  
{ )24r^21.q  
nStartPos = input.readLong(); `mV&[`NZ  
nEndPos = input.readLong(); +5(#~  
} B5"(NJ;  
input.close(); !%n3_tZC  
} |<&9_Aq_  
catch(IOException e){e.printStackTrace ();} @K`2y'#b  
catch(Exception e){e.printStackTrace ();} GD?4/HkF  
} ] dB6--  
Jvt| q5  
HJT}v/FZ  
private void processErrorCode(int nErrorCode) 7r#U^d(  
{ -AcLh0pc  
System.err.println("Error Code : " + nErrorCode); 0?525^   
} :Rc>=)<7  
@O b$w1c  
_W]qV2j  
//停止文件下载 L 1=HD  
public void siteStop() +VSJve |  
{ \v bU| a  
bStop = true; g+h)s!$sB  
for(int i=0;i<nStartPos.length;i++) #|76dU  
fileSplitterFetch.splitterStop(); xwG=&+66  
o*H j E  
VH1PC  
} B '\^[  
} Y3G$(+i8  
//负责部分文件的抓取 ]MJyBz+k  
**FileSplitterFetch.java JgXP2|Y!  
*/ Ld>y Fb(`  
package NetFox; qCg`"/0  
24Lo .  
tW;?4}JR  
import java.io.*; kxU <?0  
import java.net.*; Vrl)[st!;I  
;pu68N(B  
C=L_@{^Rgb  
public class FileSplitterFetch extends Thread { =E@wi?  
kW>Q9Nc=V  
](yw2c;m e  
String sURL; //File URL ~[bS+ ]d!  
long nStartPos; //File Snippet Start Position i{zg{$U  
long nEndPos; //File Snippet End Position BG!;9Z{u  
int nThreadID; //Thread's ID '3B`4W,  
boolean bDownOver = false; //Downing is over F/z$jj)  
boolean bStop = false; //Stop identical cRBdIDIc  
FileAccessI fileAccessI = null; //File Access interface Onoi^MDy  
NQzpgf|h  
=qH9<,p`H  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException |5|^[v   
{ ^LgaMmz  
this.sURL = sURL; X6s6fu;  
this.nStartPos = nStart; =~Oi:+L  
this.nEndPos = nEnd; "5*n(S{ks  
nThreadID = id; K 8CjZpzq  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 `WvNN>R  
} (u`[I4z`  
%/!n]g-  
hXr`S4aJ  
public void run() e6n1/TtqM  
{ !l!^`c  
while(nStartPos < nEndPos && !bStop) (.Tkv Uj`  
{ i1RU5IRy|j  
tX)l$oRPr  
*oLAO/)n  
try{ sdP% Y<eAT  
URL url = new URL(sURL); gAt[kW< n  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); gIv :<EJ9  
httpConnection.setRequestProperty("User-Agent","NetFox"); [v$_BS#u^3  
String sProperty = "bytes="+nStartPos+"-"; J~7E8  
httpConnection.setRequestProperty("RANGE",sProperty); v%c r   
Utility.log(sProperty); O8#}2  
 |/K+tH  
$#ks`$v M  
InputStream input = httpConnection.getInputStream(); +tFm DDx=  
//logResponseHead(httpConnection); JF7n|o-`?  
\5UwZx\  
Z'c{4b`N  
byte[] b = new byte[1024]; WS6pm6@A*!  
int nRead; z[:UPPbW  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) K$_Rno"  
{ lk8g2H ,  
nStartPos += fileAccessI.write(b,0,nRead); MK"PCE5^i6  
//if(nThreadID == 1) zh7#[#>t  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f&=y\uP]  
} 1Y iUf  
NQS@i'W=g  
7MIu-x|  
Utility.log("Thread " + nThreadID + " is over!"); !%b.k6%>w  
bDownOver = true; Pe@M_ r  
//nPos = fileAccessI.write (b,0,nRead); Qd"{2>  
} 41 sClC"  
catch(Exception e){e.printStackTrace ();} ~J1;Z0}#  
} |0:&d w?*!  
} g0t$1cUR  
W tF  
I,dH\]^h=  
//打印回应的头信息 )%p.v P'p  
public void logResponseHead(HttpURLConnection con) o_   
{  `=b)fE  
for(int i=1;;i++) 0JTDJZOz@#  
{ "(j.:jayd  
String header=con.getHeaderFieldKey(i); <]I[|4J 7  
if(header!=null) -Si'[5@  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); U1(<1eTyu  
Utility.log(header+" : "+con.getHeaderField(header)); \.p{~ Hv  
else | ZBv;BW  
break; V#jFjObTN  
} {'dpRq{c|  
} |aef$f5  
rqk1 F~j|  
Ro :/J  
public void splitterStop() CpHF3o`Z6  
{ H?tonG.^(  
bStop = true; <V)T_  
} R?3^Kx  
S N_!o2F2  
^S!^$d*  
} 3XY;g{`=q  
n,sl|hv2U  
)qs>Z?7  
/* X~XpX7d!  
**FileAccess.java  4"72  
*//文件访问(定位,写) *=i|E7Irg  
package NetFox; -E~pCN(E  
import java.io.*; ~6!{\un   
Y%!3/3T  
g+BW~e)  
public class FileAccessI implements Serializable{ :NJb<%$  
*IWO ,!  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 z VleJ!d  
RandomAccessFile oSavedFile; @F)51$Ld  
long nPos; un|+YqLf  
)@)wcf!b  
FNlzpCT~L  
public FileAccessI() throws IOException 6L Z(bP'd;  
{ ]CyWL6 z  
this("",0); ^ sIxR*C[v  
} {M: Fsay>p  
5|YpkY  
dn/0>|5OF(  
public FileAccessI(String sName,long nPos) throws IOException n[4F\I>  
{ }R5>ja0  
oSavedFile = new RandomAccessFile(sName,"rw"); g2L^cP>2  
this.nPos = nPos; <)c/PI[j  
oSavedFile.seek(nPos); {U8Sl.  
} 9ui_/[K  
QXx<Hi^ /  
nTO,d$!Kp  
public synchronized int write(byte[] b,int nStart,int nLen) 4$9WJ ~V{  
{ -1t"(v  
int n = -1; xZAc~~9tD  
try{ L?!*HS7 m  
oSavedFile.write(b,nStart,nLen); Fy^*@&  
n = nLen; x,YC/J  
} /CX_@%m}e=  
catch(IOException e) HRO :U%  
{ Aa t _5p  
e.printStackTrace (); =*0<.Lo':  
} @8X)hpHf  
^t4T8ejn  
-U;2 b_  
return n; uP bvN[~t  
} Ut4cli&cC  
VS0 &[bl  
l6ayV  
} --E_s /   
1~\YJEsb}d  
=$3]%b}  
/* 8Z{&b,Y4L  
**SiteInfoBean.java b%<-(o/  
*/ bL\ab  
package NetFox; +O P8U]~  
"PH}\Dl=  
O#}T.5t  
public class SiteInfoBean { 8Wx>,$k  
/Zw^EM6c  
3'WJx=0?  
private String sSiteURL; //Site's URL l;^Id#N  
private String sFilePath; //Saved File's Path BL1$ ~0  
private String sFileName; //Saved File's Name EhDKh\OY5  
private int nSplitter; //Count of Splited Downloading File .}gGtH,b3  
y]$%>N0vLX  
B|E4(,]^  
public SiteInfoBean() v-u53Fy  
{//nSplitter的缺省值为5 7+wy`xi  
//default value of nSplitter is 5 EJ7}h?a]U_  
this("","","",5); ^eke,,~  
} L+y}hb r  
7i?"akr4  
c p.c$  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) iev02 8M  
{ \k\ {S2SU  
sSiteURL= sURL;  GZ.Xx  
sFilePath = sPath; 3>X]`Oj7y  
sFileName = sName; A*tG[)  
this.nSplitter = nSpiltter; %9ef[,WT  
KEF"`VTB@  
KSsv~!3Yf  
} O>UG[ZgW  
&u) R+7bl,  
#&zNYzI  
public String getSSiteURL() }gw \w?/  
{ 'J(rIH3U  
return sSiteURL; $<R\|_6J  
} M6J~%qF^  
$g? ]9}p  
. 7WNd/WG  
public void setSSiteURL(String value) W@<(WI3  
{ e<wA["^  
sSiteURL = value; C-Y~T;53  
} 4%#Y)z o.e  
V<&x+?>S  
x { Z_rD  
public String getSFilePath()  A.nU8   
{ >*/\Pg6^  
return sFilePath; q~_DR4xZ  
} It$'6HV~Sb  
# +OEO  
ph*9,\c8  
public void setSFilePath(String value) qRk&bF/  
{ ;tK%Q~To  
sFilePath = value; t"[ xx_i  
} [Q(FBoI|  
49S*f  
m$b5Vqq  
public String getSFileName() LLp/ SWe  
{ /[ _aw&W}Z  
return sFileName; ]o}g~Xn  
} :E ]Ys  
epw*Px  
8 nCw1   
public void setSFileName(String value) J^t-pU  
{ .W4P/P w'  
sFileName = value; -|s w\Q  
} N.r8dC  
f.Wip)g  
FvX<(8'#a  
public int getNSplitter() PuyJ:#a  
{ ko-|hBNv  
return nSplitter; |C;8GSw>|F  
} uL!QeY>k\  
hp ?4w),  
.!#0eAT  
public void setNSplitter(int nCount) nymF`0HYe1  
{ KVQ^-^  
nSplitter = nCount; zx<:1nF,]  
} 8%C7!l q  
} S#km`N`  
@ \{L%y%a0  
aMa ICM  
/* @E Srj[  
**Utility.java gumT"x .^  
*/ QH~;B[->  
package NetFox; +fh@m h0[  
c3S}(8g5.  
!4"(>Rnw  
public class Utility { QH z3  
X/< zxM  
~SKV%  
public Utility() 'OrGt_U  
{ !e>+ O^  
)Z4ilpU,  
r 7 dwj  
} z4CqHS~%  
T'VZ=l[  
//线程睡眠 &6 ymGo  
public static void sleep(int nSecond) EI+RF{IKh  
{ Ep>} S  
try{ jh7-Fl`  
Thread.sleep(nSecond); I8ZBs0sfF{  
} B{}<DP.  
catch(Exception e) 1f 3c3PJ  
{ [)efh9P*  
e.printStackTrace (); S($8_u$U  
} q!L@9&KAQ  
} Jd]kg,/  
pl#2J A8  
//日志 tVI6GXH  
public static void log(String sMsg) 244[a] %&;  
{ 4gR;,%E\TO  
System.err.println(sMsg); aMU0BS"   
} .wH`9aq;5@  
<'y}y}%  
rdQKzJiX=U  
public static void log(int sMsg) P8& BtA  
{ |DUWB;  
System.err.println(sMsg); uU$YN-  
} #)3luf3G  
} HB|R1<t;HB  
7~zd % o  
|B{@noGX  
/* MUQj7.rNa  
**TestMethod.java + *xi&|%  
*/  =1MVF  
package NetFox; H18.)yHX  
LyRbD$m  
"O}u2B b  
public class TestMethod { ;?h+8Z/{  
K*!qt(D&  
`;~A  
public TestMethod() ?hC,49  
{ ///xx/weblogic60b2_win.exe {>v5~G  
try{ gT-"=AsxZQ  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); \iP=V3  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); NIo!WOi  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Uf}u`"$F  
fileFetch.start(); 0jJ:WPR  
} &~Hx!]uc  
catch(Exception e){e.printStackTrace ();} n0a|GZyO]  
!"d"3coQ?  
SH1S_EQ<  
} FF5|qCV/z  
IGnP#@`5]  
5eLm  
public static void main(String[] args) n^lr7(!6  
{ luWr.<1  
new TestMethod(); urbSprdF  
} W9D~:>^YP  
} <5 )F9.$  
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