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http断点续传简单实现(java)

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/*  D**GC  
**SiteFileFetch.java Pp s-,*m  
*/ `om+p?j  
package NetFox; {PcJuRTHB  
import java.io.*; <ZF|2  
import java.net.*; r~lZ8$KC  
P}Kgh7)3  
k(l2`I4V  
public class SiteFileFetch extends Thread { k=hWYe$iAz  
8~]D!c8;a  
iU;e!\A  
SiteInfoBean siteInfoBean = null; //文件信息Bean ||_hET  
long[] nStartPos; //开始位置 m|;(0 rft  
long[] nEndPos; //结束位置 -juG[zn  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 u] };QR  
long nFileLength; //文件长度 q8 ?kBKP  
boolean bFirst = true; //是否第一次取文件 t82'K@sq  
boolean bStop = false; //停止标志 ) ;\c{QF  
File tmpFile; //文件下载的临时信息 ~0a5  
DataOutputStream output; //输出到文件的输出流 6(Pan%  
`X6JZxGyd  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) &$F<]]&  
public SiteFileFetch(SiteInfoBean bean) throws IOException Jpj=d@Of70  
{ vRmn61  
siteInfoBean = bean; 3KkfQ{  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); XiE`_%NW  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); t>I.1AS  
if(tmpFile.exists ()) iqQT ^  
{ 8w&-O~M  
bFirst = false; s|]g@cz an  
read_nPos(); DAB9-[y+  
} [|DKBJ  
else 8AuBs;i  
{ _1p8(n  
nStartPos = new long[bean.getNSplitter()]; 0N.h:21(4  
nEndPos = new long[bean.getNSplitter()]; !hBpon  
} jO-?t9^  
@h%V:c  
/x6p  
a/sjW  
} //q(v,D%Q  
vxOqo)yO  
&12K pEyf  
public void run() _\ToA9m  
{ b-&iJ &>'  
//获得文件长度 ;u UFgDi  
//分割文件 :8A+2ra&  
//实例FileSplitterFetch QPJ \Iu@D$  
//启动FileSplitterFetch线程 elOeXYO0  
//等待子线程返回 G%<}TI1}  
try{ wA=r ]BT  
if(bFirst) ,#A(I#wL~  
{ Ymk?@mV4  
nFileLength = getFileSize(); h:YD $XE  
if(nFileLength == -1) \k.`xG?  
{ N+|NI?R?}  
System.err.println("File Length is not known!"); GM%+yS}(P  
} 1F^Q*t{  
else if(nFileLength == -2) >='/%Ad  
{ Gk,Bx1y  
System.err.println("File is not access!"); E.oJ[;  
} GXtMX ha,  
else jFj11w1FrA  
{ 0bg"Q4  
for(int i=0;i<nStartPos.length;i++) 94u{k1d x  
{ 4Gc M  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); #z*,CU#S9d  
} H_DCdUgC'  
for(int i=0;i<nEndPos.length-1;i++) 1 em,/> "  
{ za>UE,?h  
nEndPos = nStartPos[i+1]; t]yxLl\  
} tE7jTe  
nEndPos[nEndPos.length-1] = nFileLength; m&UP@hUV-  
} 'cW^S7  
} H U|.5tP  
v= 55{  
,fkvvM{mq  
//启动子线程 Td=4V,BN  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -8TJ:#|N  
for(int i=0;i<nStartPos.length;i++) #~*v##^vFH  
{ )h{&O ,s  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z'z)Oo  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), rbw$=bX}  
nStartPos,nEndPos,i); "yn~axk7  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;H_/o+  
fileSplitterFetch.start(); Dyo v}y  
} rf.pT+g.P  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \Pg~j\;F]  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 3nq?Y8yac  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", +)Z]<O  
nEndPos = " + nFileLength); fE#(M+(<  
// fileSplitterFetch[nPos.length-1].start(); M tN>5k c  
CVj^{||eF  
oaY_6  
//等待子线程结束 ;O"?6d0  
//int count = 0; TR"C<&y$j  
//是否结束while循环 *c0H_8e  
boolean breakWhile = false; @T'^V0!-q:  
t un}rdb  
\iuR+I  
while(!bStop) lSj gN~:z  
{ p8 rh`7  
write_nPos(); l& :EKh  
Utility.sleep(500); ]K=#>rZrB  
breakWhile = true; ( ;FxKm<P@  
D JP6Z  
B VBn.ut  
for(int i=0;i<nStartPos.length;i++) ]P4WfV d  
{ R=D]:u<P  
if(!fileSplitterFetch.bDownOver) Njq}M/{U  
{ o-,."|6  
breakWhile = false; vwCQvt  
break; rPV Q#iB  
}  (I[_}l  
} 615Ya<3f8  
if(breakWhile) ,6)N.  
break; H?$dnwR  
xEb>6+-F@  
#8$?# dT  
//count++; Y"Cf84E  
//if(count>4) @= -(H<0  
// siteStop(); P"YdB|I  
} eV;r /4  
i_Kwxn$  
E C?}iP  
System.err.println("文件下载结束!"); 0YH5B5b  
} =7Ln&tZ  
catch(Exception e){e.printStackTrace ();} }0'=}BE  
} xQoZ[  
u?osX;'w  
L\:|95Yq  
//获得文件长度 H4$qM_N  
public long getFileSize() 'o AmA=  
{ !8{ VLg  
int nFileLength = -1; ?Oyo /?/  
try{ 5cSiV7#Y:  
URL url = new URL(siteInfoBean.getSSiteURL()); @Jt$92i5PS  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -JW~_Q[  
httpConnection.setRequestProperty("User-Agent","NetFox"); S}6Ld(_  
 5NU{y+  
Ln"wj O ,  
int responseCode=httpConnection.getResponseCode(); @HT\Y%E  
if(responseCode>=400) =|3BkmO  
{ "J VIkC  
processErrorCode(responseCode); m%'nk"p9  
return -2; //-2 represent access is error L9GLj Rp-  
} q+g,?;Yx  
b--=GY))F  
~Y 6'sM|  
String sHeader; O<u=Vz3c~0  
S{c/3k~  
_~kw^!p>Kr  
for(int i=1;;i++) 'Wlbh:=$  
{ bJ d| mm/v  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); =i/Df ?  
//Utility.log(in.readLine()); {)YbksrJ{  
sHeader=httpConnection.getHeaderFieldKey(i); @rl5k(  
if(sHeader!=null) r- 8Awa  
{ ^y+k6bE  
if(sHeader.equals("Content-Length")) Z,&O8Jelf  
{ |OeyPD#  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); _v!7 |&\  
break; GQ2GcX(E(  
} aZ#FKp^8H  
} rRTKF0+  
else |IgR1kp+.  
break; >m%_`68  
} "1O_h6 C  
} n,N->t$i  
catch(IOException e){e.printStackTrace ();} i3-5~@M  
catch(Exception e){e.printStackTrace ();} 2)}n"ibbT  
Q*DT" W/0  
m\:^9A4HCg  
Utility.log(nFileLength); V!}I$JiJ  
]RVu[k8  
>xWS>  
return nFileLength; -@v^. @[Z&  
} iZGbNN  
Lg:1zC  
Wu>]R'C  
//保存下载信息(文件指针位置) @0+\:F  
private void write_nPos() P1#g{f  
{ 5Xq+lLW>  
try{ G%F#I  
output = new DataOutputStream(new FileOutputStream(tmpFile)); B=SA +{o  
output.writeInt(nStartPos.length); SN6 QX!3  
for(int i=0;i<nStartPos.length;i++) Ly= .  
{ pPReo)  
// output.writeLong(nPos); ~q>jXi  
output.writeLong(fileSplitterFetch.nStartPos); :;$MUOps  
output.writeLong(fileSplitterFetch.nEndPos); /[R=-s ;  
} inu.U[.  
output.close(); RdCGK?s  
} aDS:82GMQ  
catch(IOException e){e.printStackTrace ();} V@'Xj .ze  
catch(Exception e){e.printStackTrace ();} l@`k:?  
} p=+Y7NE)  
[(X~C*VdxM  
0h-NT\m  
//读取保存的下载信息(文件指针位置) &;Ncc,jb  
private void read_nPos() O,$*`RZpx  
{ fB2ILRc  
try{ FZ*"^=)`G  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); " ityx?  
int nCount = input.readInt(); CD1Ma8I8  
nStartPos = new long[nCount]; R|?n  
nEndPos = new long[nCount]; Np\NStx2  
for(int i=0;i<nStartPos.length;i++) snbXAx1L  
{ SSe;&Jk2d  
nStartPos = input.readLong(); ={g"cx  
nEndPos = input.readLong(); Et6j6gmif  
} ko%mZ0Y  
input.close(); Z$z-Hx@%  
} uQ=u@qtp  
catch(IOException e){e.printStackTrace ();} FSuC)Xg  
catch(Exception e){e.printStackTrace ();} Fe8X@63  
} 3M#x)cW  
"&_+!TBg,  
M$x,B#b  
private void processErrorCode(int nErrorCode) xQR/Xp!h  
{ ; _%zf5;'  
System.err.println("Error Code : " + nErrorCode); #JUh"8N'  
} aB%.]bi  
T{prCM  
| BaEv\$K  
//停止文件下载 yY]x' 'K  
public void siteStop() &dB@n15'A  
{ xM())Z|2  
bStop = true; "rdpA[>L  
for(int i=0;i<nStartPos.length;i++) FM]clC;X?  
fileSplitterFetch.splitterStop(); +|C@B`h  
ch# )XomN  
3MQHoxX  
} WUS%4LL(  
} _'p/8K5)=  
//负责部分文件的抓取 =CzGI|pb  
**FileSplitterFetch.java T m"B  
*/ |AvPg  
package NetFox; .7.G}z1  
k$=L&id  
le:}M M  
import java.io.*; R3g)LnN  
import java.net.*; gmp@ TY=:L  
@tT`s^e  
O%%Q./oh  
public class FileSplitterFetch extends Thread { $uLTYu  
@ 5d^ C  
6{I7=.V  
String sURL; //File URL &D<6Go/)_*  
long nStartPos; //File Snippet Start Position >p&"X 2 @  
long nEndPos; //File Snippet End Position &5}YTKe}|  
int nThreadID; //Thread's ID JCH9~n.  
boolean bDownOver = false; //Downing is over UV(`.  
boolean bStop = false; //Stop identical x@ X2r  
FileAccessI fileAccessI = null; //File Access interface h<L_ =)lH  
a>C;HO  
:@(1~Hm  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6TRLHL~B  
{ 2UQF:R?LQ  
this.sURL = sURL; Zx8$M5  
this.nStartPos = nStart; iKq_s5|sW  
this.nEndPos = nEnd; (ot,CpI(I  
nThreadID = id; "%K'~"S#Q,  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 H~*N:$C  
} F=5+JjrX  
)]n>.ZmLCB  
g Cp`J(2v:  
public void run() kNP-+o  
{ KXZ G42w  
while(nStartPos < nEndPos && !bStop) LYAGpcG  
{ <hzHrx'o{  
Cuylozj$&  
Dx\~#$S!=  
try{ f0eQq;D$K  
URL url = new URL(sURL); PE.UNo>o  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S))B^).0-  
httpConnection.setRequestProperty("User-Agent","NetFox"); *vQ 6LF;y  
String sProperty = "bytes="+nStartPos+"-"; =pzTB-G  
httpConnection.setRequestProperty("RANGE",sProperty); 42e[OG-  
Utility.log(sProperty); lP=,|xFra  
J"#6m&R_q  
)P? 0YC  
InputStream input = httpConnection.getInputStream(); xM{[~Kh_x  
//logResponseHead(httpConnection); ,7$&gx>2&  
}S"gZ6   
w#2apaz  
byte[] b = new byte[1024]; >'n[B    
int nRead; AK lr a$  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop)  Z/Wf  
{ Wrbv<8}%c  
nStartPos += fileAccessI.write(b,0,nRead); ke@OG! M/  
//if(nThreadID == 1) _9-;35D_  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _W@sFv%sj  
} */~|IbZ`o  
DK2Wjr;  
.|"E:qTD  
Utility.log("Thread " + nThreadID + " is over!"); ,&Zp^  
bDownOver = true; =ZS Yg K  
//nPos = fileAccessI.write (b,0,nRead); .NWsr*Tel  
} A46dtFD{  
catch(Exception e){e.printStackTrace ();} CUB;0J(  
} ?i_2ueVR  
} Vuy%7H  
TlO=dLR7d  
LQqba4$  
//打印回应的头信息  irh Z  
public void logResponseHead(HttpURLConnection con) 2K3j3|T  
{ l_2Xao$  
for(int i=1;;i++) &n]v  
{ BZOl&G(  
String header=con.getHeaderFieldKey(i); Z9H2! Cp  
if(header!=null) ^0"fPG`  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); GRpwEfG  
Utility.log(header+" : "+con.getHeaderField(header)); t<+>E_Xw  
else Z$i?p;HnW  
break; "cS7E5-|  
} 0^L:`[W+  
} |0^IX   
;"f9"  
&'neOf/~  
public void splitterStop() R,7.o4Wt  
{ p%Q{Rqc)  
bStop = true; e`B!)Sr  
} x`2dN/wDhf  
;B< rw ^h5  
+ S5uxO  
} Tq^B>{S "  
(^T}6t3+4  
ZCK#=:ln  
/* /:-ig .YY  
**FileAccess.java ; p+C0!B2  
*//文件访问(定位,写) \k$cg~  
package NetFox; )4o k@^.  
import java.io.*; { zL4dJw  
F:Vl\YZ  
Hl}m*9<9us  
public class FileAccessI implements Serializable{ >y}> 5kv  
7u1o>a %9  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 hQ)?LPUB  
RandomAccessFile oSavedFile; Yjy%MR  
long nPos; 8eCh5*_$  
amQiH!}8R  
'mv|6Y  
public FileAccessI() throws IOException _x-2tnIxXv  
{ D41.$t[  
this("",0); }WR@%)7ay  
} #cikpHLXG  
"<L9-vb  
gjJ:s,Fg  
public FileAccessI(String sName,long nPos) throws IOException W;X:U.  
{ i'ZnU55=  
oSavedFile = new RandomAccessFile(sName,"rw"); u9 *ic~Nh  
this.nPos = nPos; G=Xas"|  
oSavedFile.seek(nPos); 5a5JOl$8  
} 4X:mb}(  
<e|B7<.  
Sw{rNzh%$  
public synchronized int write(byte[] b,int nStart,int nLen) C:!&g~{cKi  
{ fX LsLh+~D  
int n = -1; B|>eKI  
try{ }PMlG  
oSavedFile.write(b,nStart,nLen); IQ JFL +f  
n = nLen; GB*^?Ii  
} !bW^G} <t  
catch(IOException e) W9GjUswv!  
{ 3;//o<  
e.printStackTrace (); P=ubCS'  
} j;_E0j#  
1"l48NLL|  
3!KyO)8  
return n; *TL3-S?   
} So NgDFD  
wG 5H^>6u>  
[MAvU?;  
} E0A[{UA   
-t*P=V|@  
O/l/$pe  
/* h?QGJ^#8  
**SiteInfoBean.java gE23C*!'&:  
*/ H'@@%nO (  
package NetFox; =4/K#cQ  
%u?A>$Jn  
P?=}}DI  
public class SiteInfoBean { |l~#qeZ%  
=EHKu|rX~  
P!R`b9_U  
private String sSiteURL; //Site's URL H/0b3I^  
private String sFilePath; //Saved File's Path |i(@1 l  
private String sFileName; //Saved File's Name Z%{`j!!p  
private int nSplitter; //Count of Splited Downloading File ) Cm95,Y  
{ZUgyGE{  
TaG (sRI  
public SiteInfoBean() $ 3Sm?  
{//nSplitter的缺省值为5 @ +>>TGC  
//default value of nSplitter is 5 nI`9|W  
this("","","",5); 5N#Sic M  
} (]"`>, ray  
>)F)@KAuN4  
[WR*u\FF  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) V4<f4|IL  
{ *Fd(  
sSiteURL= sURL; ZjgfkZAS  
sFilePath = sPath; dsZ-|C  
sFileName = sName; KctbNMU]k  
this.nSplitter = nSpiltter; 2 o5u02x  
`$] ZT>&  
\uOR1z  
} _BND{MsX  
_y9NDLRs8  
.|LY /q\A  
public String getSSiteURL() 9'O@8KB_  
{ \k%j  
return sSiteURL; RPTIDA))  
} u0Opn=(_  
?2S<D5M Sb  
Cyp%E5b7  
public void setSSiteURL(String value) 'Y5l3xQk  
{ %PM8;]  
sSiteURL = value; WQNFHRfO*n  
} {%v{iE>  
%bB:I1V\  
~T\:".C  
public String getSFilePath() :w9s bW  
{ 9d+z?J:  
return sFilePath; E>1%7" i<  
} hhJ>>G4R2  
(7|!%IO.  
-aM7>YR  
public void setSFilePath(String value) \~:_ h#bW  
{ X> V`)  
sFilePath = value; -pN'r/$3V  
} K^[Dz\ov5  
j'LO '&sQ(  
@=6$ImU  
public String getSFileName() _^NL{R/  
{ oazy%n(KZ  
return sFileName; q[~+Zm  
} 8sU}[HH*1  
IoxdWQ4]A  
iRI7x)^0"z  
public void setSFileName(String value) 0PJ7o#}_{@  
{ SuJ4)f;'0  
sFileName = value; "tU,.U  
} *qw//W   
bP1]:^ x@W  
3Ebkq[/*%  
public int getNSplitter() 4nD U-P#f  
{ CQET  
return nSplitter; 82w=t  
} cG4$)q;q  
wGx*Xy1n<  
q4KYC!b  
public void setNSplitter(int nCount) Z:<6Ck  
{ NfXEW-  
nSplitter = nCount; oedLe9!  
} Si=u=FI1e  
} [_3L  
f5vsxP)Y[  
X/<Q3AK  
/* }&/_ S  
**Utility.java +#7)'c  
*/ T']G:jkb  
package NetFox; \']_y\  
>?^_JE C6  
Qr]`flQ8  
public class Utility { =.6JvX<d1*  
, n47.S  
cy( WD#^  
public Utility() Y~-P9   
{ ck#MpQ!An  
),4c b  
%gV~e@|  
} Kd').w  
oz/Nx{bg  
//线程睡眠 q,2 +\i  
public static void sleep(int nSecond) eGlPi|  
{ ,&rHBNS  
try{ rL<a^/b/=  
Thread.sleep(nSecond); E9v_6d[  
} = GZ,P (  
catch(Exception e) >jg"y  
{ OVU+V 0w1a  
e.printStackTrace (); rI;tMNs  
} 9\a;75a  
} "tg?V  
pcO0xrI  
//日志 oC1Nfc+  
public static void log(String sMsg)  ^#&:-4/  
{ ffoLCx4o0E  
System.err.println(sMsg); vjO@"2YEw  
} 5YnTGf&  
:B5M#D!dO  
^U]B&+m  
public static void log(int sMsg) ;wj8:9 ;  
{ QX|y};7\e  
System.err.println(sMsg); :6y;U  
} Gq9pJ  
} v0'`K 5M  
"/qm,$  
I2<5#|CXpZ  
/* >sm<$'vZ/  
**TestMethod.java -)$5[jM]  
*/ )~H&YINhn  
package NetFox; #Bi8>S  
B0"55g*c  
 nypG  
public class TestMethod { 0XUWK@)P  
y6N }R  
hSF4-Vvb  
public TestMethod() _!Ir|j.A  
{ ///xx/weblogic60b2_win.exe h!q_''*;  
try{ $ {5|{`  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); h YEUiQ  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .GOF0puiM  
SiteFileFetch fileFetch = new SiteFileFetch(bean); &ub0t9R  
fileFetch.start(); {~+o+LV  
} VJ()sbl{k  
catch(Exception e){e.printStackTrace ();} &BS*C} },  
rM{V>s:N  
*_CzCl^   
} xJ|_R,>.H  
0`%Ask  
We?cRb  
public static void main(String[] args) g]E>e v{`  
{ CH+mzy  
new TestMethod(); u#~q86k  
} ;{f4E)t 7  
} qttJ*zu  
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