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http断点续传简单实现(java)

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/* 1"pw  
**SiteFileFetch.java kOh{l: 2-+  
*/ hWH:wB  
package NetFox; :1Q!$  m  
import java.io.*; ChCrL [2  
import java.net.*; keB&Bjd&  
UQB "v3Z  
a33TPoj  
public class SiteFileFetch extends Thread { _/wV;h~R  
< yC  
u|4$+ QiD  
SiteInfoBean siteInfoBean = null; //文件信息Bean SPp#f~%m  
long[] nStartPos; //开始位置 r\AyN= y  
long[] nEndPos; //结束位置 ID#I`}h.k  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 765p/**  
long nFileLength; //文件长度 Mi]L]-L  
boolean bFirst = true; //是否第一次取文件 1KjU ] r2  
boolean bStop = false; //停止标志 )Tk1 QHU  
File tmpFile; //文件下载的临时信息 6;|n]m\Vd  
DataOutputStream output; //输出到文件的输出流 9 7ql5  
Z!U)I-x&  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) M`ip~7"  
public SiteFileFetch(SiteInfoBean bean) throws IOException 8T(e.I  
{ J/}:x;Y  
siteInfoBean = bean; ~#kT _*sw)  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); h,Q3oy\s1  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); QR1{ w'c  
if(tmpFile.exists ()) d> {nQF;c  
{ 44-R!  
bFirst = false; <vXGi  
read_nPos(); 8P=o4lO+  
} C`5  
else CZ nOui  
{ $z+8<?YD  
nStartPos = new long[bean.getNSplitter()]; cK 06]-Y  
nEndPos = new long[bean.getNSplitter()]; `F/Tv 5@L  
} yz0zFfiX  
}!6\|;Qsz,  
?wO-cnl  
y.[Mnj  
} e^O(e  
kYLM&&h  
8>7& E-  
public void run() "_`F\DGAZu  
{ $^@)  
//获得文件长度 wQRZ"ri,  
//分割文件 ^$ t7+g  
//实例FileSplitterFetch 6oBfB8]:d  
//启动FileSplitterFetch线程 ?:w1je7  
//等待子线程返回 r3>i+i42  
try{ 8jyG" %WO  
if(bFirst) Sv  &[f}S  
{ QR>gt;  
nFileLength = getFileSize(); U*3uq7  
if(nFileLength == -1) 5< ja3  
{ / z}~zO  
System.err.println("File Length is not known!"); Q:5KZm[[  
} VO"("7L  
else if(nFileLength == -2) 1bH;!J  
{ D:Zy  
System.err.println("File is not access!"); X$yN_7|+  
} 3"O>&Q0c  
else U4cY_p?  
{ &8z[`JW,T  
for(int i=0;i<nStartPos.length;i++) hEw- O;T0  
{ / 4lvP  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); g H G  
} NOp609\^  
for(int i=0;i<nEndPos.length-1;i++) ,u/aT5\_  
{ xKFn.qFr  
nEndPos = nStartPos[i+1]; 7PkJ-JBA  
} ]niJG t  
nEndPos[nEndPos.length-1] = nFileLength; yR4|S2D3xn  
} u?+Kkkk  
} lv]hTH 4T  
N&M~0iw  
Yh>]-SCw  
//启动子线程 SI=yI-  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; P><o,s"v  
for(int i=0;i<nStartPos.length;i++) +-G<c6 |  
{ wR^R M(1  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qkC/\![@  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), VH[hsj  
nStartPos,nEndPos,i); >ss/D^YS  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0)m(;>'70  
fileSplitterFetch.start(); ?`4+cx}n  
} *<J*S#]  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), phgm0D7  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); a AB`G3  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =Jym%m  
nEndPos = " + nFileLength); q#8 [  
// fileSplitterFetch[nPos.length-1].start(); f{FDuIl n  
=XY\iV1J*  
qBCK40   
//等待子线程结束 zF`c8Tsx])  
//int count = 0; rf$X>M=G  
//是否结束while循环 rp0ZvEX  
boolean breakWhile = false; +gLPhX:`  
? 8LXP  
4vwTs*eB `  
while(!bStop) kP?KXT3y  
{ et }T %~T  
write_nPos(); [AW" D3  
Utility.sleep(500); R[;z X(y  
breakWhile = true; V#`fs|e;y  
sxt-Vs7+6  
IhA*"  
for(int i=0;i<nStartPos.length;i++) (e[}/hf6  
{ 8:/e GM  
if(!fileSplitterFetch.bDownOver) r3\cp0P;s  
{ DuOG {  
breakWhile = false; )'4k|@8|  
break; D &/L:  
} z5r$M  
} o5Q{/  
if(breakWhile) IzpZwx^3''  
break; 8A+SjJ4$  
GO^_=EMR[  
?'<nx{!c  
//count++; G 8V,  
//if(count>4) Bn(W"=1  
// siteStop(); Iwc{R8BV  
} GPGm]Gt  
4A2?Uhp y  
o!!yd8~*r  
System.err.println("文件下载结束!"); 0eS)&GdR  
} n2fbp\I  
catch(Exception e){e.printStackTrace ();} <Ce2r"U1e  
} $]A/ o(  
!OuWPH. :  
&Y^WP?HS  
//获得文件长度 -Q U^c2  
public long getFileSize() $n^gmhp  
{ NvvUSyk\;s  
int nFileLength = -1; ]._LLSzWhg  
try{ :.45u}[  
URL url = new URL(siteInfoBean.getSSiteURL()); \ 5,MyB2/`  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~PHB_cyth  
httpConnection.setRequestProperty("User-Agent","NetFox"); B!\;/Vk  
}eRD|1  
WuZ/C_  
int responseCode=httpConnection.getResponseCode(); w18y}mS"H  
if(responseCode>=400) :"!9_p(,,  
{ 14"J d\M8  
processErrorCode(responseCode); ](^(=%  
return -2; //-2 represent access is error %Pqf{*d8  
} |H! 9fZO  
#2EI\E&$  
!1G."fo  
String sHeader; S!sqbLrBn  
$VxA0 =ad  
.({smN,B  
for(int i=1;;i++) ?:L:EW8  
{ mb!9&&2 -t  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); U\sHx68  
//Utility.log(in.readLine()); 8{Fsm;UsY  
sHeader=httpConnection.getHeaderFieldKey(i); dH^<t,v  
if(sHeader!=null) ,-OCc!7K  
{ ;jipe3LU  
if(sHeader.equals("Content-Length")) xQ'2BAEa  
{ 4sP2g&  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); xu'yVt9RC  
break; $]rj73p^tH  
} -^ C=]Medl  
} bpxeznz  
else H Tz  
break; `Ps:d^8*P  
} gB4U*D0[e~  
} +a*^{l}AST  
catch(IOException e){e.printStackTrace ();} (S v~2  
catch(Exception e){e.printStackTrace ();} <dvy"Dx   
+ Q6l*:<|c  
Zw~+Pb  
Utility.log(nFileLength); wX*K]VMn  
:,DM*zBV p  
Q pmsOp|  
return nFileLength; 5Fz.Y}  
} Q"7Gy<  
@_LN3zP  
g=e71DXG2  
//保存下载信息(文件指针位置) %:2+ o'  
private void write_nPos() _{ZqO;[u  
{ PClMQL#  
try{ Zt3)]sB  
output = new DataOutputStream(new FileOutputStream(tmpFile)); &RTX6%'KY  
output.writeInt(nStartPos.length); 25&J7\P*  
for(int i=0;i<nStartPos.length;i++) |eWjYGwJa  
{ l#}.^71+  
// output.writeLong(nPos); SC- $B  
output.writeLong(fileSplitterFetch.nStartPos); UDL RCS8i  
output.writeLong(fileSplitterFetch.nEndPos); !S_^94b@  
} Q8_ d)t|  
output.close(); cDI [PJ9  
} \{EpduwZ  
catch(IOException e){e.printStackTrace ();} &wB\ ~Ie-  
catch(Exception e){e.printStackTrace ();} :(H>2xS,s  
} @GvztVYo  
Z*FrB58  
 fu9Cx  
//读取保存的下载信息(文件指针位置) T =2=k&|  
private void read_nPos() Vy|6E#U  
{ U. @*`Fg  
try{ ''kS*3  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Hp(D);0+)  
int nCount = input.readInt(); o^V(U~m]  
nStartPos = new long[nCount]; E(i[o?  
nEndPos = new long[nCount]; EFc-foN  
for(int i=0;i<nStartPos.length;i++) O%ug@& S{  
{ W\L`5CW  
nStartPos = input.readLong(); "ax..Mh\y  
nEndPos = input.readLong(); Tdc3_<1  
} ^7.h%lSg  
input.close(); \fjMc }'  
} w` DW(hXJ  
catch(IOException e){e.printStackTrace ();} bUY>st'  
catch(Exception e){e.printStackTrace ();} `w.AQ?p@  
} _H^^y$+1  
SKW%X8  
-D^}S"'  
private void processErrorCode(int nErrorCode) ys#i@  
{ >[1W:KQA  
System.err.println("Error Code : " + nErrorCode); 2>l,no39t+  
} ZoB {x*IH  
\t|M-%&)4  
NzW`B^p  
//停止文件下载 NxLXm,  
public void siteStop() :(_+7N[KA  
{ X@|&c]]  
bStop = true; 4Ua> Yw0  
for(int i=0;i<nStartPos.length;i++) 1lpwZ"  
fileSplitterFetch.splitterStop(); -&e92g&n   
42\-~]  
Nlj^D m  
} @EoZI~  
} )aX2jSp  
//负责部分文件的抓取 v<9&B94z  
**FileSplitterFetch.java k'PQ} ,Vb  
*/ 3.)b4T  
package NetFox; o#[ KS:Y  
Q_vW3xz  
_aPh(qprc  
import java.io.*; ]0r|_)s  
import java.net.*; <vUVP\u~$  
lW 81q2n  
P%MfCpyj  
public class FileSplitterFetch extends Thread { p\ Lq}tk<  
JO'>oFv_W  
c )7j QA  
String sURL; //File URL A$WZF/x  
long nStartPos; //File Snippet Start Position ~xIj F1Z  
long nEndPos; //File Snippet End Position LA[g(i 7  
int nThreadID; //Thread's ID v~/~ @jv  
boolean bDownOver = false; //Downing is over |D.O6?v@  
boolean bStop = false; //Stop identical 9RwawTM  
FileAccessI fileAccessI = null; //File Access interface !SKV!xH9  
++Ww88820  
e2-Dq]p  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException x^*1gv $o  
{ pN&c(=If  
this.sURL = sURL; m~'? /!!  
this.nStartPos = nStart; D.%B$Y;G  
this.nEndPos = nEnd; Y[SU&LM  
nThreadID = id; sFDG)  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 W~Z<1[  
} a83g\c5   
<*EZ@XoN>  
n$(p-po  
public void run() |*mL1#bB  
{ Xes|[*Y!V  
while(nStartPos < nEndPos && !bStop) &5t :H 8b  
{ -xD*tf*  
aV1lJ ;0  
%/.a]j!  
try{ ,pBh`av  
URL url = new URL(sURL); fj,m  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); KL'zXkS  
httpConnection.setRequestProperty("User-Agent","NetFox"); 7P7b8 ]  
String sProperty = "bytes="+nStartPos+"-"; g-vg6@6  
httpConnection.setRequestProperty("RANGE",sProperty); !rhk $ L  
Utility.log(sProperty); eb|i 3.  
*xR 2)u  
rNl.7O9b  
InputStream input = httpConnection.getInputStream(); j'p1q  
//logResponseHead(httpConnection); \ /|)HElKR  
*U l*%!?D  
0qFH s  
byte[] b = new byte[1024]; gf)t)-E  
int nRead; j 6ut}Uq  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) jKIc09H|  
{ bqx0d=Z~[  
nStartPos += fileAccessI.write(b,0,nRead); l?*r5[O>n  
//if(nThreadID == 1) nIfCF,6,  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~svO*o Wa  
} Vc3mp;6"  
gX5&d\y  
]+H ?@*b`  
Utility.log("Thread " + nThreadID + " is over!"); Rb}KZ+o "Z  
bDownOver = true; <a le$[  
//nPos = fileAccessI.write (b,0,nRead); gBk5wk_j|  
} sn{AwF%  
catch(Exception e){e.printStackTrace ();}  Zt E##p  
} fMf&?`V  
} kJ)gP2E  
9TxyZL   
as"N=\N  
//打印回应的头信息 /\Q*MLwD  
public void logResponseHead(HttpURLConnection con) nkeI60  
{ B ?%L  
for(int i=1;;i++) cyd~2\Kv~  
{ !~-6wN"k  
String header=con.getHeaderFieldKey(i); C0x "pO7  
if(header!=null) /OGA$eP  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9x`4 RE  
Utility.log(header+" : "+con.getHeaderField(header)); !Ngw\@f  
else KbxR Lx]w  
break; 4-v6=gz.  
} 5 ZfP  
} Me:{{-V4  
?PPZp6A3L=  
v@EQ^C2.&  
public void splitterStop() yy(A(}  
{ UmKX*T9  
bStop = true; ?HR%bn gK  
} X21dX`eMN  
$1*3!}_0  
gH:ArfC  
} Wf>^bFb"$  
t0m*PJcF  
x|~zHFm6  
/* $GF]/;\m  
**FileAccess.java 5@u~3jPd  
*//文件访问(定位,写) #%S0PL"x U  
package NetFox; $;D* n'8Fx  
import java.io.*; ;8B.;%qkL  
CHaE;olo  
msk/p>{O  
public class FileAccessI implements Serializable{ $->d!  
Q1tpCT  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 So4nJ><p  
RandomAccessFile oSavedFile; b7h+?!H]R  
long nPos; )fh0&Y; R  
et$uP  
.]76!(fWZ  
public FileAccessI() throws IOException =ak7ld A=2  
{ 9XV^z*E(J  
this("",0); IjZ@U%g@;  
} !Ua&0s%  
0\a8}b||  
[N|xzMe  
public FileAccessI(String sName,long nPos) throws IOException {0's~U+@  
{ g*-2* \  
oSavedFile = new RandomAccessFile(sName,"rw"); |pWaBh|r  
this.nPos = nPos; # .q#O C  
oSavedFile.seek(nPos); u.6P-yh  
} u3ds QU  
.2X2b<%)  
,8 6K  
public synchronized int write(byte[] b,int nStart,int nLen) /)V4k:#b  
{ fA8ozL T  
int n = -1; WD?Jk9_F  
try{ T{ -2fp8r[  
oSavedFile.write(b,nStart,nLen); 3eg5oAZ)G8  
n = nLen;  ^Omfe  
} |f NMs  
catch(IOException e) |Cf mcz(56  
{ =,Ttw>   
e.printStackTrace (); Y%IJ8P^Y  
} G :4;y7  
&(O06QL  
Q\#UWsN(T/  
return n; `fW{yb  
} _+zVpZ  
1!/-)1t  
jp m#hH{R  
} |NEd@  
fS./y=j(X  
6GKT yN  
/* JE)J<9gf  
**SiteInfoBean.java u7muaSy  
*/ `-D$Fsl  
package NetFox; VG#Q;Xd}  
V.,bwPb{9  
K+mU_+KRp  
public class SiteInfoBean { R`Qp d3  
(2%>jg0M  
5\G)Q<A]*L  
private String sSiteURL; //Site's URL ]_2 yiKv&  
private String sFilePath; //Saved File's Path t:9 ZCu ay  
private String sFileName; //Saved File's Name },6*Y*?{  
private int nSplitter; //Count of Splited Downloading File J~dTVBx  
o>!JrH  
N5\{yV21",  
public SiteInfoBean() #Wx=v$"  
{//nSplitter的缺省值为5 nW&$~d  
//default value of nSplitter is 5 rv?!y8\  
this("","","",5); 2nx9#B*/T  
} vPsq<l}  
X,Zd=  
#{w5)|S#JD  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) g8Aj `O  
{ gfVDqDF  
sSiteURL= sURL; <|V'pim  
sFilePath = sPath; 0 pNo`Bm  
sFileName = sName; #HDesen  
this.nSplitter = nSpiltter; !Mil?^  
_m7c o :  
{]M>Y%j48  
} )G4rJ~#@  
;KS`,<^-  
;fx1!:;.  
public String getSSiteURL() ]Wy.R6  
{ _ _ =s'  
return sSiteURL; hfh.eL  
} x3;jWg~'  
s7|3zqi  
R2Yl)2 D  
public void setSSiteURL(String value) Jy`G]]?  
{ \-G5l+!  
sSiteURL = value; j]HE>  
} uTw|Q{f  
pe#*I/)b  
Yhk6Uog{4  
public String getSFilePath() 2+&R" #I  
{ r./z,4A`  
return sFilePath; 1g81S_T .  
} gA"<MI'y  
+{Gw9h"5g*  
:f]!O@.~  
public void setSFilePath(String value) 7%YYr^d  
{ QqjTLuN  
sFilePath = value; E- KK  
} /KP_Vc:g2_  
b.,$# D{p  
L"9 Gc  
public String getSFileName() 1)gv%_  
{ +/}_%Cf8  
return sFileName; !*8#jy  
} PAr|1i)mB  
.f+9 A>  
RSFJu\0}N  
public void setSFileName(String value) FSVS4mtiX\  
{ ^ `E@/<w8  
sFileName = value; aulaX/'-_  
} [[&)cbv  
WRY~fM  
ny~W]1  
public int getNSplitter() T7ki/hjRb  
{ G ;jF9i  
return nSplitter; rBS2>?  
} fX""xT NPi  
9yDFHz w  
p/4S$ j#Tn  
public void setNSplitter(int nCount) ,?fN#gc :  
{ rQ &S<  
nSplitter = nCount; FQQ@kP$.  
} `TAcZl=8  
} dJaEoF  
=;g=GcVK  
L[1d&d!p  
/* OAY8,C=M  
**Utility.java y 'mlee  
*/ TXx'7[  
package NetFox; v=j>^F Z  
G u6[{u  
>]^>gUmq  
public class Utility { Io09W^  
9ec0^T  
E+:.IuXW$  
public Utility() G~O" /WM  
{ 2[XltjO  
`|uoqKv  
~DK F%}E  
} }]tFz}E\  
l~4_s/  
//线程睡眠 rXlx?GV  
public static void sleep(int nSecond) 5a8JVDLX^  
{ '+tKvTU;  
try{ p[_Yi0U  
Thread.sleep(nSecond); i+U@\:=  
} Ko@zk<~"[  
catch(Exception e) +tPx0>p;  
{ *ZX!EjICk  
e.printStackTrace (); OA!R5sOz"  
} vP-3j  
} KU*`f{|  
^P]?3U\nj  
//日志 7:#  
public static void log(String sMsg) O{Dm;@J-aM  
{ 2B5A!? ~>  
System.err.println(sMsg); Jk%'mEGE  
} (21']x  
zUNH8=U  
~v^%ze  
public static void log(int sMsg) Ri9Kr  
{ id3)6}  
System.err.println(sMsg); 56"#Syj  
} /*AJ+K._  
} -*rHB&e  
 bkxk i@t  
?rky6  
/* ]Jja  
**TestMethod.java vU?b"n  
*/ GJ.kkTMT  
package NetFox; Ng?apaIi@~  
u,:CJ[3  
j l}!T[5  
public class TestMethod { Fecx';_1`  
mx:J>SPA8  
8e]z6:}'E  
public TestMethod() >0kmRVd  
{ ///xx/weblogic60b2_win.exe Czq1 kz  
try{ xX[?L9RGz  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); <Z2(qZ^Z  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); N[#iT&@T}/  
SiteFileFetch fileFetch = new SiteFileFetch(bean); pk;ffq@  
fileFetch.start(); lb-S0plw  
} \8=e |a5`  
catch(Exception e){e.printStackTrace ();} sM #!Xl;  
&G0l&8pa  
.WBI%ci  
} ;Fx')  
_)OA$  
 )GB3=@  
public static void main(String[] args) ){+.8KI  
{ zJz82jMm  
new TestMethod(); :D<:N*9i  
} Oqd"0Qt-  
} HyZVr2  
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