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http断点续传简单实现(java)

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/* X#e1KZ  
**SiteFileFetch.java M6}3wM*4  
*/ 'UYR5Y>  
package NetFox; kbMYMx.[  
import java.io.*; $bsG]  
import java.net.*; ]X^rU`":  
t8dm)s[r8  
IqD_GL)Ms  
public class SiteFileFetch extends Thread { M-giR:,  
AqV7\gdOC  
|0%+wB  
SiteInfoBean siteInfoBean = null; //文件信息Bean X3V'Cy/sy  
long[] nStartPos; //开始位置 fF V!)Zj  
long[] nEndPos; //结束位置 iySRY^  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 >mjNmh7  
long nFileLength; //文件长度 YxP@!U9dE,  
boolean bFirst = true; //是否第一次取文件  0gfA#|'  
boolean bStop = false; //停止标志 -]t,E,(!  
File tmpFile; //文件下载的临时信息 ]~E0gsq  
DataOutputStream output; //输出到文件的输出流 n;:rf7hGY  
)kkhJI*v  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) R@`y>XGNJ  
public SiteFileFetch(SiteInfoBean bean) throws IOException .Fa4shNV  
{ ZAXN6h  
siteInfoBean = bean; Y2?.}ZO  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 9s_,crq5  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); b%S62(qP  
if(tmpFile.exists ()) 4-[J@  
{ I:d[Q s  
bFirst = false; :=[XW?L%x  
read_nPos(); n8D xB@DI  
}  z~>pVs  
else |K|h+fgG6*  
{ g'|MA~4yB  
nStartPos = new long[bean.getNSplitter()]; _`pD`7:aI^  
nEndPos = new long[bean.getNSplitter()]; H[='~%D  
} [mPjP%{=@  
@!8ZPiW<  
d:i;z9b@to  
Jyqc2IH  
} #Z<a  
6KOlY>m]  
*Otg*, \  
public void run() mI>,.&eo  
{ ]TyisaT  
//获得文件长度 b&5lYp"d  
//分割文件 UF@XK">  
//实例FileSplitterFetch P'O#I}Dmw<  
//启动FileSplitterFetch线程 W[^qa5W<FB  
//等待子线程返回 C|?o*fQ  
try{ {U_$&f9s  
if(bFirst) R?p00  
{ {4-[r#R<M  
nFileLength = getFileSize(); Yp:KI7  
if(nFileLength == -1) ($~RoQ=0S  
{ Y)}Rb6qGW  
System.err.println("File Length is not known!"); s$a09x  
} iIP8`! O  
else if(nFileLength == -2) *<u2:=_s  
{ 6}KZp~s  
System.err.println("File is not access!"); '`Wwt.A  
} aN,M64F  
else $e /^u[~:  
{ bk\yCt06y;  
for(int i=0;i<nStartPos.length;i++) VV9_`myN7  
{ -k7X:!>QHC  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); bHI<B)=`  
} V,[d66H=N  
for(int i=0;i<nEndPos.length-1;i++) wX*K]VMn  
{ :,DM*zBV p  
nEndPos = nStartPos[i+1]; 7H|$4;X^  
} 5Fz.Y}  
nEndPos[nEndPos.length-1] = nFileLength; Q"7Gy<  
} "1-}A(X  
} _IdRF5<4  
HWVtop/  
o#hjvg  
//启动子线程 L*x[?x;)@  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; \2vg{  
for(int i=0;i<nStartPos.length;i++) nO)X!dp}J  
{ =k oSUVO0  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 51QRM32Y  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7k(Kq5w.  
nStartPos,nEndPos,i); t&(PN%icD  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %DQhM,c@  
fileSplitterFetch.start(); V3ndV-uQE  
} RTFZPq84  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]7Z{ 8)T  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); H`geS  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >|Cw\^  
nEndPos = " + nFileLength); R+7oRXsu  
// fileSplitterFetch[nPos.length-1].start(); yZWoN&  
1u|Rl:Q  
ZZyDG9a>7  
//等待子线程结束 j6g[N4xr  
//int count = 0; A mwa)  
//是否结束while循环 # (- Qx  
boolean breakWhile = false; %~QO8q_7  
LbII?N8`N  
T t>8?  
while(!bStop) +z$pg  
{ O%ug@& S{  
write_nPos(); W\L`5CW  
Utility.sleep(500); "ax..Mh\y  
breakWhile = true; <u=4*:QE  
|> _!eS\=<  
>pr=|$zk=  
for(int i=0;i<nStartPos.length;i++) 36n>jS&  
{ e*.b3 z  
if(!fileSplitterFetch.bDownOver) VnT>K9&3  
{ SnYLdwgl  
breakWhile = false; H&yD*@  
break; XB[<;*Iz  
} 0j_bh,zG#  
} 8O"U 0  
if(breakWhile) .E@|D6$D  
break; RO3oP1@B  
-!8(bjlJ&  
_A~4NW{U7  
//count++; :#lIx%l  
//if(count>4) ${8?N:>t  
// siteStop(); 4Ua> Yw0  
} 1lpwZ"  
-&e92g&n   
[JaS??ig  
System.err.println("文件下载结束!"); wlPx,UqZ  
} @p|$/Z%R,  
catch(Exception e){e.printStackTrace ();} F]I=+T   
} $.:mai  
W k}AmC  
X.TI>90{  
//获得文件长度 nJbbzQ,e  
public long getFileSize() (S^8UV  
{ Ou>vX[{  
int nFileLength = -1; )}L??|#  
try{ YQ0)5}  
URL url = new URL(siteInfoBean.getSSiteURL()); |~ _'V "  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^bLRVp1  
httpConnection.setRequestProperty("User-Agent","NetFox"); 8_!.!Kde |  
v{ <[)cr  
 P5gN#G  
int responseCode=httpConnection.getResponseCode(); [+Y{%U  
if(responseCode>=400) DE IB!n   
{ emW:C-/h/@  
processErrorCode(responseCode); v~/~ @jv  
return -2; //-2 represent access is error d HJhFw  
} 9*:gr#(5  
wIf {6z{  
,]5Ic.};p  
String sHeader; _xLHrT!y  
X1vNF|o~  
HBB{m  
for(int i=1;;i++) DS xUdEK6  
{ .6~`Ubr}E  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); **>/}.%?K  
//Utility.log(in.readLine()); /xJqJ_70X  
sHeader=httpConnection.getHeaderFieldKey(i);  LZ~"VV^  
if(sHeader!=null) $M:3XAN  
{ Em7 WDu0  
if(sHeader.equals("Content-Length")) J# kl 7  
{ RL[E X5U  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .O0O-VD+a  
break; 9GdB#k6W`  
} 3u33a"nL8  
} 7}_!  
else RB?V7uX  
break; -xD*tf*  
} ejXMKPE;  
} Hk7K`9  
catch(IOException e){e.printStackTrace ();} -]:G L>b  
catch(Exception e){e.printStackTrace ();} 7'N S9|  
[\Qr. 2  
cubUq5  
Utility.log(nFileLength); \x >65;  
O3o: qly!  
>ulY7~wUv  
return nFileLength; \b*X:3g*  
} ]8;n{ }X  
#;# 3%?  
`8\Ja$ =  
//保存下载信息(文件指针位置) /VHi >  
private void write_nPos() H UWxPIu  
{ .C]cK%OO N  
try{ 3^=+gsc  
output = new DataOutputStream(new FileOutputStream(tmpFile)); jKIc09H|  
output.writeInt(nStartPos.length); 4Tct  
for(int i=0;i<nStartPos.length;i++) V|MY!uV  
{ ZlKw_Sq:  
// output.writeLong(nPos); W9zE{)Sc~  
output.writeLong(fileSplitterFetch.nStartPos); iK_c.b  
output.writeLong(fileSplitterFetch.nEndPos); 5y4u5Tm-%  
} y/c%+ Ca/  
output.close(); kWj \x|E  
} ,572n[-q  
catch(IOException e){e.printStackTrace ();} X%9*O[6{  
catch(Exception e){e.printStackTrace ();} 4F MAz^  
} Br d,Eg  
Cz^Q5F`  
 StYzGJ  
//读取保存的下载信息(文件指针位置) /Y^8SO4  
private void read_nPos() nF)uTk  
{ [XlB<P=|>  
try{ "'Z- UV  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [*m2  
int nCount = input.readInt(); 4QJ8Z t  
nStartPos = new long[nCount]; ] q~<=   
nEndPos = new long[nCount]; GQ_Ia\  
for(int i=0;i<nStartPos.length;i++) SJgY  
{ o{-<L  
nStartPos = input.readLong(); ;2giZ\  
nEndPos = input.readLong(); f*xpE`&  
} <JI& {1  
input.close(); 1MA@JA:T  
} G.U 5)4_^  
catch(IOException e){e.printStackTrace ();} 4-v6=gz.  
catch(Exception e){e.printStackTrace ();} 5 ZfP  
} Me:{{-V4  
?PPZp6A3L=  
v@EQ^C2.&  
private void processErrorCode(int nErrorCode) yy(A(}  
{ bb=uF1  
System.err.println("Error Code : " + nErrorCode); F#+.>!  
} Ey&aB YR  
84&XW  
~y0R'oi  
//停止文件下载 uL?vG6% ^1  
public void siteStop() 7]2 2"mc  
{ d @rs3Q1z  
bStop = true; t"s5\;IJ  
for(int i=0;i<nStartPos.length;i++) UU@fkk  
fileSplitterFetch.splitterStop(); 8}BBOD  
PoD^`()FR{  
'=cKU0 G#  
} `EMi0hm&H  
} msk/p>{O  
//负责部分文件的抓取 $->d!  
**FileSplitterFetch.java Q1tpCT  
*/ 6/mF2&&g  
package NetFox; rj  H`  
So4nJ><p  
s'_,:R\VM>  
import java.io.*; ms~8QL  
import java.net.*; )fh0&Y; R  
et$uP  
.]76!(fWZ  
public class FileSplitterFetch extends Thread { =ak7ld A=2  
9XV^z*E(J  
IjZ@U%g@;  
String sURL; //File URL !Ua&0s%  
long nStartPos; //File Snippet Start Position 0\a8}b||  
long nEndPos; //File Snippet End Position [N|xzMe  
int nThreadID; //Thread's ID {0's~U+@  
boolean bDownOver = false; //Downing is over g*-2* \  
boolean bStop = false; //Stop identical N\R=cwk  
FileAccessI fileAccessI = null; //File Access interface Rrqg[F+  
kR6A3?[  
F!8=FTb  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^ @.G,u  
{ Gq]d:-7l  
this.sURL = sURL; ]h~o],:  
this.nStartPos = nStart; D[>W{g $  
this.nEndPos = nEnd; ^9ng)  
nThreadID = id; M#0 @X  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7U:=~7GH  
} 6[==BbZ  
,d 7Z  
+8^_D?*\n  
public void run() ^g!B.ll`  
{ A4_>LO_qL  
while(nStartPos < nEndPos && !bStop) :)P<jX-G  
{ ,$Tk$  
Vm!i  
eoJ]4-WFq  
try{ cgyo_ k  
URL url = new URL(sURL); 4 iH&:Al  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v.`+I-\.z)  
httpConnection.setRequestProperty("User-Agent","NetFox"); :t2B^})\  
String sProperty = "bytes="+nStartPos+"-"; /PC` 0/b  
httpConnection.setRequestProperty("RANGE",sProperty); #%cR%Z  
Utility.log(sProperty); jzrt7p*k}  
6An{3 "  
 `$-lL"  
InputStream input = httpConnection.getInputStream(); dt ~iw  
//logResponseHead(httpConnection); ]P*!'iYN(  
97x%w]kV  
@}eNV~ROu  
byte[] b = new byte[1024]; j-* TXog  
int nRead; c$#GM57V  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .3g&9WvN!Z  
{ 2X_>vIlEm  
nStartPos += fileAccessI.write(b,0,nRead); ;c)! @GoA  
//if(nThreadID == 1) @+dHF0aXd  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); oEAfowXSqk  
} ~V$ f #X  
@"8~Y|L93  
8_iHVc;<  
Utility.log("Thread " + nThreadID + " is over!"); t F/nah  
bDownOver = true; .&(8(C  
//nPos = fileAccessI.write (b,0,nRead); 4e/cqN 6  
} sV'v* 1|  
catch(Exception e){e.printStackTrace ();} |#cAsf_{  
} 9cOx@c+/  
} E$T(Qu<-  
A\C'dZ <N  
#HDesen  
//打印回应的头信息 !Mil?^  
public void logResponseHead(HttpURLConnection con) _m7c o :  
{ {]M>Y%j48  
for(int i=1;;i++) .93S>U<_  
{ )l{A{f6O  
String header=con.getHeaderFieldKey(i); YOKR//|3  
if(header!=null) N ^f}ui i  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); > Z++^YVE  
Utility.log(header+" : "+con.getHeaderField(header)); .Qk{5=l6P  
else `]hCUaV   
break; ZvyjMLf  
} ;o%:7 &  
} IQoH@l&Xk  
sU*3\  
UKYupLu5  
public void splitterStop() p5`ZyD ]+  
{ +3HPA#A  
bStop = true; iUCwKpb9  
} U IQ 6SvM  
K#;txzi  
)"-fHW+fy  
} 7*g(@d  
?.j,Bq5At  
2MT_#r_  
/* ?w8p LE~E  
**FileAccess.java um}N%5GAa  
*//文件访问(定位,写) 4 4<v9uSK  
package NetFox; r?afv.@L2  
import java.io.*; ^#7viZ*  
fOJj(0=y  
c&A]pLn+x  
public class FileAccessI implements Serializable{ 7BK46x  
776 nWw)  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !*8#jy  
RandomAccessFile oSavedFile; H-m`Dh5{  
long nPos; &]*|6cR$E  
aa!a&L|!  
}JH`' &3  
public FileAccessI() throws IOException *XOS.$zGz  
{ B%y! aQep  
this("",0); >eu `!8  
} 8k%H[Smn:  
gTuX *7w  
XX:q|?6_ 4  
public FileAccessI(String sName,long nPos) throws IOException V-:`+&S{^  
{ 9kUV1?  
oSavedFile = new RandomAccessFile(sName,"rw"); R;.d/U|av  
this.nPos = nPos; 9g4QVo|  
oSavedFile.seek(nPos); jvWI_Fto  
} 7Qt2gf  
/Q]:Uf.J  
Ef-a4Pi  
public synchronized int write(byte[] b,int nStart,int nLen) BQuRHi IV  
{ 7_1W:-A7W  
int n = -1; B'!PJj  
try{ G+fd.~aGE  
oSavedFile.write(b,nStart,nLen); (}6wAfGo  
n = nLen; #,)P N @P  
} 3^'#ny?l  
catch(IOException e) GU5W|bS  
{ *|sxa#  
e.printStackTrace (); Io09W^  
} 98jD"*W5  
.r(^h/IF  
h1E PaL  
return n; FBcm;cjH  
} M,ppCHy/$  
?C FS}v  
[Yn;G7cK  
} N*HH,m&  
u1wg C#  
kz$(V(k<  
/* >QA/Mi~R  
**SiteInfoBean.java 'G52<sF  
*/ .Dc28F~t  
package NetFox; +tPx0>p;  
ofVEao  
P4i3y{$V  
public class SiteInfoBean { KU*`f{|  
@pTD{OW?  
SHytyd  
private String sSiteURL; //Site's URL Q +R3H,  
private String sFilePath; //Saved File's Path U2VV[e)Z!  
private String sFileName; //Saved File's Name B<(Pd  
private int nSplitter; //Count of Splited Downloading File omNpE_  
`:V}1ioX5  
uAc@ Z-  
public SiteInfoBean() IPwj_jvw  
{//nSplitter的缺省值为5 ZK%Kgk[\:~  
//default value of nSplitter is 5 sbs[=LW4  
this("","","",5); o?;F.W_  
} `8mD7xsg$  
RfD{g"]y  
fFjLp l  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) U.HoFf+HN  
{ .MzOLv   
sSiteURL= sURL; mu 2 A%"7  
sFilePath = sPath; @Q/x&BV  
sFileName = sName; hEVjeC  
this.nSplitter = nSpiltter; +SAk:3.#CV  
~*jsB=XM/  
@gH(/pFX  
} @X3 gBGY)  
 Y>xi|TWN  
nXv 7OEpTx  
public String getSSiteURL() "xL;(Fqu  
{ lv=yz\  
return sSiteURL; e 4 p*51ra  
} q-A`/9  
fEx+gQW_  
<jpeu^7  
public void setSSiteURL(String value) Rrh<mo(yj#  
{ x%_qJ]o  
sSiteURL = value; oNiToFbQu  
} := ]sq}IN  
JmnBq<&,0  
A4~D#V  
public String getSFilePath() V"w`!  
{ -iY9GN89c  
return sFilePath; w> Tyk#7lw  
} IXbdS9,>F  
?BWHr(J  
M(_^'3u  
public void setSFilePath(String value) BM|-GErE  
{ %'RI 3gy  
sFilePath = value; HiQoRk  
} fBHkLRFH  
= 4BLc  
73&]En  
public String getSFileName() $ /}:P  
{ (eC F>Wh^m  
return sFileName; 9 Q0#We*  
} ,[Dh2fPM,  
S4#A#a2J  
N>uA|<b,  
public void setSFileName(String value) S^3g]5YX  
{ [$hptQv  
sFileName = value; zAKq7'_=  
} /Ki0+(4  
p2pTs&}S  
`E./p  
public int getNSplitter() Rel(bA-[N  
{ LFk5rv'sM0  
return nSplitter; hEyX~f  
} c%q}"Y0oh  
J0IdFFZ|w  
;FV~q{  
public void setNSplitter(int nCount) !L &=?CX  
{ Zp/qs z(]  
nSplitter = nCount; ^2&O3s  
} O!#L#u53  
} \SYPu,ZT  
&Iv\jhq  
,Hik(22  
/* IeR l6r%:  
**Utility.java S(g<<Te  
*/ sh',"S#=@  
package NetFox; L#t-KLJ  
o{ ,ba~$.w  
*Gk<"pEeS  
public class Utility { 3Ew"[FUs  
a -z23$3  
X";QA":  
public Utility() ^yn[QWFO  
{ '0'"k2"vC  
hW0,5>[7%  
Ff)~clIK '  
} H3 A]m~=3  
C$N4   
//线程睡眠 [oQ`HX1g  
public static void sleep(int nSecond) /7UovKKbz  
{ 5~`|)~FA  
try{ IQ(]66c ,  
Thread.sleep(nSecond); (5f5P84x  
} t7U,AQ=;P5  
catch(Exception e) 4=?Ok":8  
{ 8>%jZ%`a  
e.printStackTrace (); /{eih]`x(  
} Z4wrXss~  
} p%1xj2 ?nN  
SX Hru Z  
//日志 F8|5_214'  
public static void log(String sMsg) 1+16i=BF)  
{ N=O+X~  
System.err.println(sMsg); [[*0MA2Y  
} bWX[<rh'  
k$UzBxR  
Mm>zpB`qP  
public static void log(int sMsg) 3/A[LL|  
{ 6k@%+<1  
System.err.println(sMsg); C*W.9  
} 9sfB+]}h  
} \dp9@y[^  
yZj}EBa  
;qT!fuN;  
/* (!XYH@Mz<w  
**TestMethod.java JR? )SGB  
*/ i(&6ys5  
package NetFox; &9RW9u "  
e-Ybac%  
6g~o3  
public class TestMethod { i-i}`oN  
 MrKU,-  
|mQtjo  
public TestMethod() )"pxry4v7J  
{ ///xx/weblogic60b2_win.exe ery?G-  
try{ \V"P maP\  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 07T;IV3#C5  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); j &0fC!k  
SiteFileFetch fileFetch = new SiteFileFetch(bean); =E"kv!e   
fileFetch.start(); |`q)/ 08b  
} % L %1g  
catch(Exception e){e.printStackTrace ();} iS:PRa1  
rr07\;  
FkJ>]k  
} 2h|(8f:y  
/C,>  
|ZST Y}RXA  
public static void main(String[] args) ?|Q5]rhs  
{ Vtz yB  
new TestMethod(); .qqb> 7|q  
} \ ]kb&Qw  
} bzj!d|T`  
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