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http断点续传简单实现(java)

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/* .11iulQ  
**SiteFileFetch.java K` U\+AE  
*/ u2!8'-Ai  
package NetFox; qOk4qbl[  
import java.io.*; wN*e6dOF  
import java.net.*; IG#=}q  
g\X"E>X  
P= S)V   
public class SiteFileFetch extends Thread { ~){*XJw6  
g3Ff<P P  
/n:s9eq  
SiteInfoBean siteInfoBean = null; //文件信息Bean > m5j.GP;  
long[] nStartPos; //开始位置 KsHovv-A  
long[] nEndPos; //结束位置 q A G0t{K  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 C \}m_`MR  
long nFileLength; //文件长度 ty7a&>G  
boolean bFirst = true; //是否第一次取文件 4;j #7  
boolean bStop = false; //停止标志 i 5-V$Qh  
File tmpFile; //文件下载的临时信息 gA.G:1v  
DataOutputStream output; //输出到文件的输出流 iv56zsR  
KiCZEA  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) -/FCd(  
public SiteFileFetch(SiteInfoBean bean) throws IOException . vYGJ8(P  
{ fHwh6|  
siteInfoBean = bean; D./e|i?  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); tuUk48!2I  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); -|V@zSKr3  
if(tmpFile.exists ()) 4jar5Mz  
{ 3 :f5xF  
bFirst = false; czedn_}%Q  
read_nPos(); SX*os$  
} _ sM$O>  
else tCA |sN  
{ {_Ke'" k  
nStartPos = new long[bean.getNSplitter()]; 5*4P_q(AxD  
nEndPos = new long[bean.getNSplitter()]; TmO\!`  
} 0w(<pNA  
 ~LkReQI  
bt~-=\  
5"@<7/2qI  
} ^t#]E#  
_}Z*%sT  
&A%#LVjf  
public void run() xb1)ZJH  
{ (VC_vz-  
//获得文件长度 mp@JsCU  
//分割文件 ,`H=%#  
//实例FileSplitterFetch 'jmcS0f -  
//启动FileSplitterFetch线程 XFd[>U<X  
//等待子线程返回 sRY: 7>eg  
try{ />+JK5  
if(bFirst) ^DIN(0u)  
{ a1om8!C  
nFileLength = getFileSize(); I ][8[UZ  
if(nFileLength == -1) {V:?r  
{ b_][Jye&P  
System.err.println("File Length is not known!"); s{A-K5S  
} ^\_`0%`>  
else if(nFileLength == -2) Npq=jlj  
{ ]c$%;!ZE  
System.err.println("File is not access!"); ]>:%:-d6  
} s31^9a  
else @dcW0WQ\  
{ qf7.Sh  
for(int i=0;i<nStartPos.length;i++) pz-`Tp w  
{ V ;>{-p  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); tF`>.=  
} tT'd]  
for(int i=0;i<nEndPos.length-1;i++) }V9146  
{ kv)LH{  
nEndPos = nStartPos[i+1]; <pi q?:ac  
} l65'EO|  
nEndPos[nEndPos.length-1] = nFileLength; ztb2Ign<  
} =Jem.Ph  
} =m-_0xo  
 Ya=QN<  
yP[GU| >(  
//启动子线程 (U-p&q>z  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; R_Eu*Qu j  
for(int i=0;i<nStartPos.length;i++) zSkM8LM2  
{ )\^%w9h  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d8Upr1_  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), hRA.u'M  
nStartPos,nEndPos,i); J-u,6c  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); t,MK#Ko  
fileSplitterFetch.start(); )rj.WK.  
} BNzL+"W  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n1$##=wK]  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); R HF;AX n  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Yh"Z@D[d  
nEndPos = " + nFileLength); \ iP[iE=  
// fileSplitterFetch[nPos.length-1].start(); zBc7bbK  
s"a*S\a;b  
P,wFib^1  
//等待子线程结束  eKu&_q  
//int count = 0; iUl{_vb  
//是否结束while循环 #0^Q UOp  
boolean breakWhile = false; R o%S_!  
]qpcA6%a|  
rJNf&x%6  
while(!bStop) GWP"i77y0s  
{ |y=CmNG,  
write_nPos(); (EohxLl!p  
Utility.sleep(500); OFUN hbg  
breakWhile = true; dQizM^j  
fM2[wh@  
bfa5X<8  
for(int i=0;i<nStartPos.length;i++) ZJw9 2Sb  
{ \,(tP:o  
if(!fileSplitterFetch.bDownOver) R>Zn$%j\  
{ 4.VEE~sH$  
breakWhile = false; 2TAy'BB;)  
break; _q8s 7H  
} X>Xpx<RY!  
} kfmIhHlYQ  
if(breakWhile) <v{jJ7w  
break; ,lN!XP{M6w  
OTV)#,occ  
:I&iDS>u1  
//count++; 4P` \fz  
//if(count>4)  sRoZvp 5  
// siteStop(); WUqAPN  
} X;}_[ =-  
sI^1c$sBN  
2y<d@z:K  
System.err.println("文件下载结束!"); bNL E=#ro  
} }hBv?B2/1  
catch(Exception e){e.printStackTrace ();} 0+S:2i/G  
} WMI/Y 9N  
xr6Q5/p1  
v}cm-_*v  
//获得文件长度 wOa_"  
public long getFileSize() ,*C^ixNE  
{ M{(Y|3W  
int nFileLength = -1; P- vA.7  
try{ t zV"|s=o  
URL url = new URL(siteInfoBean.getSSiteURL()); g@j:TQM_0  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \64(`6>  
httpConnection.setRequestProperty("User-Agent","NetFox"); 2_Pe/  
-<<!eH  
i!Ne<Q  
int responseCode=httpConnection.getResponseCode(); \SMH",u  
if(responseCode>=400) t@4vEKw?.X  
{ E8-p ,e,  
processErrorCode(responseCode); "#m*`n  
return -2; //-2 represent access is error w=f8UtY9@A  
} ^Xb!dnT.*a  
b UWtlg  
1hMk\ -3S  
String sHeader; I#A`fJ  
*tP,Ol  
JLG5`{  
for(int i=1;;i++) n*;mFV0s  
{ 16aaIK  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !BQ!] u  
//Utility.log(in.readLine()); ;eA~z"g  
sHeader=httpConnection.getHeaderFieldKey(i); S)[2\Z{**T  
if(sHeader!=null) Xt~/8)&  
{ bqLv81V  
if(sHeader.equals("Content-Length")) _ !Ph1  
{ ]_-$  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); wTTQIo 60  
break; J7E/2Sl  
} 61C&vm  
} p]aIMF_  
else |a"(Ds2U  
break; |%M%j'9  
} d&U;rMEv  
} oiR` \uY  
catch(IOException e){e.printStackTrace ();} #u2PAZ@qd  
catch(Exception e){e.printStackTrace ();} }M9'N%PU  
yBr{nFOgdY  
S@*@*>s^  
Utility.log(nFileLength); h2tzv~  
\zoJr)  
o-(jSaH :;  
return nFileLength; xr?r3Y~^e  
} R'80{  
JUXK}0d%eN  
o= 8yp2vG  
//保存下载信息(文件指针位置) 4<O[d  
private void write_nPos() %_3{Db`R>  
{ K+GjJ8  
try{ \(A>~D8Fo  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?s_q|d_  
output.writeInt(nStartPos.length); Lv5AtZl}  
for(int i=0;i<nStartPos.length;i++) ^^%*2^  
{ 7"S|GEs:  
// output.writeLong(nPos); OrRve$U*|  
output.writeLong(fileSplitterFetch.nStartPos); g xLA1]>{  
output.writeLong(fileSplitterFetch.nEndPos); Z> &PM06  
} QVFa<>8/md  
output.close(); JEAqSZak#  
} y[$e]N  
catch(IOException e){e.printStackTrace ();} RSkpf94`  
catch(Exception e){e.printStackTrace ();} r2hm`]\8M  
} P|6m%y  
i\ PN  
j5RM S V  
//读取保存的下载信息(文件指针位置) D)!k  
private void read_nPos() b>waxQxjS  
{ #}vcffgZ  
try{ Cf10 ud   
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); WIhf*LF"  
int nCount = input.readInt(); ?Dfgyz  
nStartPos = new long[nCount]; *X)OdU  
nEndPos = new long[nCount]; B)c.`cfr*\  
for(int i=0;i<nStartPos.length;i++) #6YNgJNk  
{ G[wa,j^hu  
nStartPos = input.readLong(); !WIL|\jbh  
nEndPos = input.readLong(); lvFHr}W  
} &XZ>}^lD^  
input.close(); Fs=nAn#  
} *F9uv)[kz  
catch(IOException e){e.printStackTrace ();} [` i;gx[^  
catch(Exception e){e.printStackTrace ();} 4e5Ka{# <  
} 00 $W>Gr  
-MU^%t;-  
CE+\|5u W  
private void processErrorCode(int nErrorCode) c8u&ev.U  
{ jy1*E3vQ  
System.err.println("Error Code : " + nErrorCode); DLz~$TF^  
} %iX +"  
uS&bfx2  
/Db~-$K  
//停止文件下载 1 8&^k|  
public void siteStop() S]9xqiJW  
{ Q"(i  
bStop = true; yX)2 hj:s  
for(int i=0;i<nStartPos.length;i++) '8W }|aF  
fileSplitterFetch.splitterStop(); LS \4y&J40  
;=E3f^'s  
KQ2]VN"?_  
} E.BMm/WH  
} 'DKP-R"  
//负责部分文件的抓取 {j(,Q qB;f  
**FileSplitterFetch.java L>PpXTWwy  
*/ gfp#G,/B  
package NetFox; `5gcc7b  
C f<,\Aav  
T{ojla(  
import java.io.*; h?idRaN_  
import java.net.*; b0 5h,  
|m?0h.O,  
ABx0IdOcI  
public class FileSplitterFetch extends Thread { {Ji[d.cY  
fdPg{3x*k  
UyvFR@  
String sURL; //File URL <7)@Jds\  
long nStartPos; //File Snippet Start Position /FQumqbnt  
long nEndPos; //File Snippet End Position gsZCWT  
int nThreadID; //Thread's ID 2B*9]AHny  
boolean bDownOver = false; //Downing is over ]pFYAe ?  
boolean bStop = false; //Stop identical u9?85  
FileAccessI fileAccessI = null; //File Access interface 7o ;}"Y1  
uODpIxN  
H7R1GaJ  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException vZk+NS<  
{ \=nY&Ml  
this.sURL = sURL; J%%nv5y  
this.nStartPos = nStart; @(ev``L5g  
this.nEndPos = nEnd; l3.HL> o  
nThreadID = id; 2"2b\b}my  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 xKIm2% U9  
} 7gv kd+-*  
m'a3}vRV(  
TMq\}k-I5  
public void run() [P"#?7 N  
{ *P9)M%  
while(nStartPos < nEndPos && !bStop) (m@({  
{ 6Si z9  
*)"`v]  
(LGx;9S?  
try{ " Z#&A  
URL url = new URL(sURL); Vw+U?  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ) |*HkdF`  
httpConnection.setRequestProperty("User-Agent","NetFox"); QQ pe.oF  
String sProperty = "bytes="+nStartPos+"-"; {E>kFeg  
httpConnection.setRequestProperty("RANGE",sProperty); 3F<My+J  
Utility.log(sProperty); rrmr#a  
9.>v ;:vL  
L0Xb^vx}m  
InputStream input = httpConnection.getInputStream(); T?Hs_u{  
//logResponseHead(httpConnection); /}(w{6C  
S_1R]n1/  
l'mgjv~  
byte[] b = new byte[1024]; 5a_1x|Fhi  
int nRead; Dy5'm?  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) z0doL b^!  
{ vrQ/Yf:\B  
nStartPos += fileAccessI.write(b,0,nRead); c"6<p5j!  
//if(nThreadID == 1) ,7<5dIdZ  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ECQ>VeP  
} #_|6yo}  
bT0CQ_g21  
L`3 g5)V  
Utility.log("Thread " + nThreadID + " is over!"); Fvl_5l  
bDownOver = true; h=?#D0  
//nPos = fileAccessI.write (b,0,nRead); eSJ5YeY)  
} ^ WidA-  
catch(Exception e){e.printStackTrace ();} 0~)cAKus  
} YY'46  
} qMKXS,s  
= gOq >`  
..;}EFw5  
//打印回应的头信息 ub7|'+5  
public void logResponseHead(HttpURLConnection con) /+iU1m'(  
{ yB,$4:C  
for(int i=1;;i++) 4E<iIA\x  
{ 6 [w_ /X"  
String header=con.getHeaderFieldKey(i); D O#4E<]5  
if(header!=null) I6X_DPY  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %^kBcId  
Utility.log(header+" : "+con.getHeaderField(header)); |3QKxS0  
else A^*0{F?,)  
break; &Z#g/Hc  
} NRgNh5/  
} 'z>|N{-xG  
FK{Vnj0  
R~PD[.\u  
public void splitterStop() yC(xi"!  
{ hZ[,.  
bStop = true; M9M~[[   
} R:fERj<s  
hCuUX)>Bt  
j/ow8Jmc*  
} ,_F@9Up  
^FIpkhw  
#2^eGhwnI  
/* 2mRm.e9?  
**FileAccess.java ]>B>.s  
*//文件访问(定位,写) <My4 )3  
package NetFox; 1-.6psE  
import java.io.*; D!^&*Ia?2  
*@^9 ]$*$  
Mj2`p#5wKh  
public class FileAccessI implements Serializable{ lhZXq!2p  
>;:235'(M  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 GHaD32  
RandomAccessFile oSavedFile; XOe)tz L  
long nPos; 4"at~K` Q  
a9}7K/Y=d  
p.~hZ+ x_  
public FileAccessI() throws IOException *6IytW OX5  
{ 5%Hw,h   
this("",0); =ss(~[  
} ] -iMo4H  
avxr|uk  
FN0)DN2d}  
public FileAccessI(String sName,long nPos) throws IOException waT'|9{  
{ THEpW{.E  
oSavedFile = new RandomAccessFile(sName,"rw"); ' d' Dlg  
this.nPos = nPos; KW`^uoY$  
oSavedFile.seek(nPos); o"wvP~H  
} "tdF#>x  
{wA(%e3_  
EX@wenR  
public synchronized int write(byte[] b,int nStart,int nLen) @ LPs.e  
{ R2,Z`I  
int n = -1; wIeF(}VM  
try{ /u?ZwoTzY  
oSavedFile.write(b,nStart,nLen); vLCyT=OB`  
n = nLen; ,6@s N'c  
} %dn!$[D@  
catch(IOException e) z{$2bV  
{ w>S;}[fM  
e.printStackTrace (); 7n}$|h5D  
} lrQNl^K}=  
?gYQE&M !  
*62Cf[a  
return n; = j)5kY`  
} [/E|n[Bx  
wB'GV1|jL  
'rl?'~={p  
} e\)r"!?H`  
-A1@a= q  
=2XAQiUR\  
/* -,:^dxE'  
**SiteInfoBean.java }ZqnsLu[)  
*/ b,h@.s  
package NetFox;  T&'p5h=l  
@qUgp*+{  
~  p~  
public class SiteInfoBean { 6K Cv  
)>"|<h.2]  
tW-wO[2  
private String sSiteURL; //Site's URL " l;=jk]  
private String sFilePath; //Saved File's Path 7! sR%h5p  
private String sFileName; //Saved File's Name :Eb=jWA  
private int nSplitter; //Count of Splited Downloading File s$g3__|Y  
p`qy57  
@V}!elV  
public SiteInfoBean() E|_J  
{//nSplitter的缺省值为5 w 3kX!%a:  
//default value of nSplitter is 5 LS:^K  
this("","","",5); 7H])2:)  
} u!CcTE*  
GD-L0kw5  
9z#z9|hj)3  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) N++ ;}j  
{ E%%iVFPX  
sSiteURL= sURL; utzf7?nIS  
sFilePath = sPath; >Py :9~g,  
sFileName = sName; )Szn,  
this.nSplitter = nSpiltter; + *)Kyk  
xYp-Y"a.  
9ERyr1-u v  
} &v)/mc7D  
do[w&`jw8  
x1`4hB  
public String getSSiteURL() `eEiSf  
{ w!_6*  
return sSiteURL; ;UpdkY 1  
} u u$Jwn!S  
Yr)<1.K4,M  
<sTY<iVR  
public void setSSiteURL(String value) 7TtDI=f  
{ yz7Fe  
sSiteURL = value; 7u`:e,'  
} Og-v][  
oL U!x  
hsAk7KC  
public String getSFilePath() sa?s[  
{ .^xQtnq  
return sFilePath; 0e +Qn&$#4  
} laRn![[  
#EA` |  
a9_KoOa.H  
public void setSFilePath(String value) 1lYQR`Uh  
{ ~KYA{^`*  
sFilePath = value; 0" F\ V  
} ku)/ 8Z`$  
HDi_|{2^  
B7.<A#y2  
public String getSFileName() 7Hg;SK6t0  
{ : #OaE,  
return sFileName; 9 K>~9Za  
} zeshM8=  
5cj&D74o  
O/.8;.d;4Y  
public void setSFileName(String value) 0nPg`@e.  
{ Ca["tks  
sFileName = value; .npD<*  
} >r>pM(h  
 c?*x2Vk  
KK?R|1VK9  
public int getNSplitter() u p zBd]  
{ ]E|E4K6g  
return nSplitter; q*!Vyk  
} I6i qC"BK  
jZk dTiI  
?aQVaw&L!7  
public void setNSplitter(int nCount) rRX F@  
{ -amNz.`[PR  
nSplitter = nCount; *JOp)e0b  
} &,QBJx<#  
} gm$<U9L\v  
;EsfHCi)  
&`}d;r|yn1  
/* 79uAsI2-Y  
**Utility.java ~zoZ{YqP  
*/ S;" $02]  
package NetFox; #Cb~-2:+7  
`j4OKZ  
r*c x_**  
public class Utility { =%S*h)}@  
Q sPZ dC  
-sx=1+\nf  
public Utility() .7HEI;4  
{ WM0-F@_  
D1V^DbUm_  
5 Nt9'"  
} sWq@E6,I  
"`V:4uz  
//线程睡眠  [33=+C a  
public static void sleep(int nSecond) #[]B: n6  
{ ]4Q~x  
try{ # ';b>J  
Thread.sleep(nSecond); ),@m 3wQ  
}  Cy5M0{  
catch(Exception e) b2^O$ l  
{ c3)6{  
e.printStackTrace (); }-@h H(  
} $e%m=@ga  
} RijFN.s  
R=C+]  
//日志 g6H`uO  
public static void log(String sMsg) brdY97s4  
{ n],"!>=+  
System.err.println(sMsg); 7Q|v5@;pU  
} \98|.EG  
{A\y 4D@  
pYj}  
public static void log(int sMsg) hM[I}$M&O  
{ 1`9'.w+r  
System.err.println(sMsg); }0 Fu  
} d&X <&)a7  
} A<-3u  
+ 7nA; C  
yG<Q t+D  
/* ^= '+#|:  
**TestMethod.java $*7AG  
*/ 7G%^8 ce{!  
package NetFox; v"sN K  
#&Zj6en}M]  
Gdr7d  
public class TestMethod { r#c+{yY  
`L"l{^cH  
{qFAX<{D  
public TestMethod() [?n}?0  
{ ///xx/weblogic60b2_win.exe Vah.tOU  
try{ Zzv,p  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); (kJ"M4*<F'  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); QKh vP>  
SiteFileFetch fileFetch = new SiteFileFetch(bean); qbo W<W<H1  
fileFetch.start(); 960rbxKy3  
} fn.}LeeS>  
catch(Exception e){e.printStackTrace ();} t7/a5x  
XtIY8wsP  
FD^s5>"Y+  
} 0{>P^z  
Lu~M=Fh  
M!iYj+nrP  
public static void main(String[] args) _UUp+Hz  
{ tH9BC5+r}  
new TestMethod(); `BY&&Bv#?  
} &uxwz@RC0  
} Mh5 =]O+  
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