http断点续传简单实现（java)

/* jF|LPWl  
**SiteFileFetch.java ivJTE  
*/ /9SNXjfbt  
package NetFox; :\"g}A
X  
import java.io.*; R|R3Ob.e  
import java.net.*; \x=!'  
tW"s^r=95  
z9ZS&=>  
public class SiteFileFetch extends Thread { k;pU8y6Y  
u^+ (5|  
V5S6?V\  
SiteInfoBean siteInfoBean = null; //文件信息Bean e/F+Tf  
long[] nStartPos; //开始位置 6yhRcvJ}  
long[] nEndPos; //结束位置 YbP}d&L  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 9 N9Q#o$!.  
long nFileLength; //文件长度 2 D!$x+|  
boolean bFirst = true; //是否第一次取文件 ky@DH(^>  
boolean bStop = false; //停止标志 GW!%DT  
File tmpFile; //文件下载的临时信息 Wo<kKkx2  
DataOutputStream output; //输出到文件的输出流 f(.t0{Etq  
>^Y)@J
 
//负责整个文件的抓取，控制内部线程（FileSplitterFetch类） |k=5`WG  
public SiteFileFetch(SiteInfoBean bean) throws IOException 2>Sr04Pt  
{ uEDvdd#V.  
siteInfoBean = bean; yvV]|B@sO  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); o`7B@]  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); xqzB=0  
if(tmpFile.exists ()) `lN Z|U  
{ E9:p A5H-j  
bFirst = false; 7` IO mTk  
read_nPos(); !E9A=
u{  
} hSU|rVi  
else m
9Hdg^L  
{ WZ^u%Z  
nStartPos = new long[bean.getNSplitter()]; TPWqiA?3Cp  
nEndPos = new long[bean.getNSplitter()]; x*0mmlCb  
} <77v8=as5  
[:cZDVaA|  
J3AS"+]  
f<P>IE  
}  q{RT~,%  
q=_tjg  
T``~YoIdz  
public void run() yNN_}9  
{ znu[i&\=  
//获得文件长度 21.N+H'  
//分割文件 WkK.ON^  
//实例FileSplitterFetch c4xXsUBQk  
//启动FileSplitterFetch线程 mY/x|)MmM  
//等待子线程返回 Ub<^;Du5  
try{ ,v>|Ub,  
if(bFirst) cKH By  
{ C_ (s  
nFileLength = getFileSize(); hwdZP=X  
if(nFileLength == -1) YOY{f:ew  
{ t7b\#o  
System.err.println("File Length is not known!"); _-bEnF+/0  
} F)4;:".zna  
else if(nFileLength == -2) @-5V~itW  
{ \_PD@A9  
System.err.println("File is not access!"); hYv;*
]  
} .GNl31f0  
else bAm ,gP  
{ vV7L :>  
for(int i=0;i<nStartPos.length;i++) /2AeJH\-  
{ ]!:0^|  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ,?Nc\Q<:  
} ~4[4"Pi>|  
for(int i=0;i<nEndPos.length-1;i++) YztW1GvI  
{ Wf!<Qot|R#  
nEndPos = nStartPos[i+1]; JB
vP {5  
} !L\P.FP7b  
nEndPos[nEndPos.length-1] = nFileLength; LFV',1+  
} 8f{;oO  
} xlU:&=|  
$09PZBF,i  
O^yDb  
//启动子线程 6qzyeli  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; u[2B0a  
for(int i=0;i<nStartPos.length;i++) SY
miDR  
{ !xo; $4  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ? {vY3~  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), cpg+-Zf%  
nStartPos,nEndPos,i); E]IPag8C  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Wo8.tu-2  
fileSplitterFetch.start(); 8ECBi(  
} UO{3vry48  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 
%K|+4ZY3  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0-a[[hL?  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", /QK H30E  
nEndPos = " + nFileLength); S6pvbaMZ  
// fileSplitterFetch[nPos.length-1].start(); 4c/.#?  
0?d}Oj  
}|!9aojr  
//等待子线程结束 &*3O+$L  
//int count = 0; xfJ&11fG2  
//是否结束while循环 bTN0n  
boolean breakWhile = false; Msea kF  
 y+.E}  
<.qhW^>X  
while(!bStop) o(_~ st<  
{ n:d7 Tv1Z8  
write_nPos(); k%S;N{Qh@  
Utility.sleep(500); >s+TD4OfY  
breakWhile = true; #O2e[ E-  
yC<[LH  
"P_PqM  
for(int i=0;i<nStartPos.length;i++) L=9w 3VXS  
{ 5? rR'0  
if(!fileSplitterFetch.bDownOver) ek3,ss3  
{ >'GQB  
breakWhile = false; |?KdQeL  
break; PC3-X['[  
} wmf#3"n  
} hi(uL>\  
if(breakWhile) MH8Selnv  
break; YPY'[j(p`n  
9q=\_[\[  
+@c-:\K%  
//count++; HECZZnM  
//if(count>4) z8"(Yy7m  
// siteStop(); xf?6_=  
} J6VG j=/  
O]nZr  
~ [4oA$[a|  
System.err.println("文件下载结束！"); aAX(M=3  
} 0,x<@.pW  
catch(Exception e){e.printStackTrace ();} KW~fW r8  
} Vg+jF!\7  
u3>Dvl@  
%!;6h^@
 
//获得文件长度 tLzX L*  
public long getFileSize() a.5^zq7#!  
{ *7yu&a8  
int nFileLength = -1; D\H)uV`  
try{ X+*"FKm S.  
URL url = new URL(siteInfoBean.getSSiteURL()); mCY+V~^~kz  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =H\ig%%E@  
httpConnection.setRequestProperty("User-Agent","NetFox"); < x==T4n/  
9W[ ~c"Ku  
cG`R\$  
int responseCode=httpConnection.getResponseCode(); 8+irul{H_  
if(responseCode>=400) ?z2k74&M^  
{ ~e)`D nJ  
processErrorCode(responseCode); <CJ`A5N  
return -2; //-2 represent access is error >,v,4,c  
} +$YluGEJ  
KT
)A{i  
Kw%n;GFl'  
String sHeader; USKa6<:{W  
a!1\,.  
::\7s  
for(int i=1;;i++) L{hP&8$k  
{ >g+ogwZ  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); CvwC| AW  
//Utility.log(in.readLine()); n]/7UH}(<&  
sHeader=httpConnection.getHeaderFieldKey(i); <bPn<QI  
if(sHeader!=null) A=7  [^I2  
{ L}bS"=B[&W  
if(sHeader.equals("Content-Length")) a'LM6A8~x  
{ 7/"g} F}Q  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); AXV+8$ :R  
break; H!y%FaTi  
} &></l| hY  
} Wx;`=9  
else cxhS*"Ph  
break; ,[To)x5o  
} SBBDlr^P  
} -q9`Btz  
catch(IOException e){e.printStackTrace ();} sLE@Cm]k  
catch(Exception e){e.printStackTrace ();} -r9G5Z!|n  
MtYi8"+<e.  
b(lC7Xm  
Utility.log(nFileLength); \vBpH'hR,'  
-5Qsc/s&  
[p%@ pV  
return nFileLength; 7l"N%e  
} 5*=a*nD11  
`!?SA<a:  
DP=4<ES%+  
//保存下载信息（文件指针位置） hadGF%> O6  
private void write_nPos() %m:T?![XO  
{ 9kcp(  
try{ 4}:a"1P"  
output = new DataOutputStream(new FileOutputStream(tmpFile));  '&/"_  
output.writeInt(nStartPos.length); KmoPFlw  
for(int i=0;i<nStartPos.length;i++) $:I~y| !1  
{ ^c1%$@H  
// output.writeLong(nPos); S0V%JY;Gv  
output.writeLong(fileSplitterFetch.nStartPos); $9v:(:!Bm  
output.writeLong(fileSplitterFetch.nEndPos); #un#~s 7Q  
} VmLV:"P}^  
output.close(); tcYbM+4e  
} 2.=3:q!H<%  
catch(IOException e){e.printStackTrace ();} 38IVSK_  
catch(Exception e){e.printStackTrace ();} c?i=6CdD'  
} 9Ny{2m=Ye  
i]{M G'tg  
bd[zdL#4K  
//读取保存的下载信息（文件指针位置） )Yvf9dl  
private void read_nPos() _5I" %E;S  
{ SRq0y,d  
try{ k$nQY  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); q^],K'  
int nCount = input.readInt(); >#z*gCO5,  
nStartPos = new long[nCount]; =:rR%L!a  
nEndPos = new long[nCount]; hETTD%  
for(int i=0;i<nStartPos.length;i++) %\?2W8Qv_J  
{ 1<_i7.{k  
nStartPos = input.readLong(); ($^XF:#5  
nEndPos = input.readLong(); {l=!  
} * ";A~XNx  
input.close(); T$/6qZew  
} vS%r_gf(  
catch(IOException e){e.printStackTrace ();} vKppXm1  
catch(Exception e){e.printStackTrace ();} I^'kt[P'FZ  
} =/MAKi}g  
Rt{qbM|b&  
)P\Vd #  
private void processErrorCode(int nErrorCode) L-[<C/`;t  
{ V2kNJwwk  
System.err.println("Error Code : " + nErrorCode); }?xu/C  
} g:MpN^l  
=BpX;n<  
"FI]l<G&  
//停止文件下载 $-9m8}U(Y  
public void siteStop() $aT
ZC>R  
{ Riid,n  
bStop = true; az3rK4g  
for(int i=0;i<nStartPos.length;i++) 'S<ebwRd=  
fileSplitterFetch.splitterStop(); hRZ9[
F[[  
`-S6g^Y  
z-nhL=  
} Q}ho Y  
} aloP@U/\Sn  
//负责部分文件的抓取 (u@p
[ncN}  
**FileSplitterFetch.java  lTsl=  
*/ DPIiGRw  
package NetFox; u(\O  

;Ad$Q9)EE  
bWAhK@epI  
import java.io.*; 'Uqz,  
import java.net.*; hh`7b,+ 4  
w$UWfL(  
lil1$K: i  
public class FileSplitterFetch extends Thread { aB~?Y+m  
qazM@  
75}BI&t3k  
String sURL; //File URL
hb7H- Z2  
long nStartPos; //File Snippet Start Position "1_eZ`  
long nEndPos; //File Snippet End Position =xFw4D9  
int nThreadID; //Thread's ID k,O("T[  
boolean bDownOver = false; //Downing is over ^.
y}2  
boolean bStop = false; //Stop identical 7a 4G:  
FileAccessI fileAccessI = null; //File Access interface ziCTvT  
r8rU+4\8<  
TG'_1m*$  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -L(F:
 
{ 6}A1^RB+w  
this.sURL = sURL; dX-Xzg  
this.nStartPos = nStart; 4vcUHa|4  
this.nEndPos = nEnd; yhg^1l|t,  
nThreadID = id; hSE\RX 9  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8W Mhe=[  
} (gZKR2hO  
w N9I )hB  
yZ=wT,Y  
public void run() B uV@w-|  
{ \&|)?'8rS  
while(nStartPos < nEndPos && !bStop) gtWJR  
{ IG
Es1
  
pTPWToKh  
 chW 1UE  
try{ {(#Dou  
URL url = new URL(sURL); =B_v
QJF2  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #-kG\}  
httpConnection.setRequestProperty("User-Agent","NetFox"); 5]
DgfwX  
String sProperty = "bytes="+nStartPos+"-"; 'Y{fah  
httpConnection.setRequestProperty("RANGE",sProperty); 7<
['4*u  
Utility.log(sProperty); @DG$  
Q[J%  
Ub!MyXd{q  
InputStream input = httpConnection.getInputStream(); EEmYfP[3  
//logResponseHead(httpConnection); CL oc  
Y S )Q#fP  
)OxcJPo  
byte[] b = new byte[1024]; P 0v&*y3Y  
int nRead; N0h
* |  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &y"e|aE  
{ [h20y  
nStartPos += fileAccessI.write(b,0,nRead); 7xidBVx  
//if(nThreadID == 1) i
bo{!>m  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~LqjW
U  
} k_$:?$  
gOaL4tu  
0w[#`  
Utility.log("Thread " + nThreadID + " is over!"); @%mJw u  
bDownOver = true; uzjP!qO  
//nPos = fileAccessI.write (b,0,nRead); (F9U`1~4  
} x-0S-1M  
catch(Exception e){e.printStackTrace ();} :s|" ZR  
} V4kt&61  
} 5lehASBz  
#5*|/LD  
e7rD,`NiV  
//打印回应的头信息 jinDKJ,n;  
public void logResponseHead(HttpURLConnection con) 2)oT\m  
{ *V}T}nK7  
for(int i=1;;i++) TV#X@jQ  
{ @}sxA9a  
String header=con.getHeaderFieldKey(i); Bo.< 4P  
if(header!=null) 62{(i'K  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _?Q0yVH;,  
Utility.log(header+" : "+con.getHeaderField(header)); Hg<d%7.  
else fX"cQ&  
break; Z_^i2eJYT  
} JRfG]u6GU  
} );X&J:-l+  
ro:B[XE  
7mG/f
 
public void splitterStop() 4O}ZnE1[  
{ a B(_ZX'L  
bStop = true; DL$O274uZ  
} yb{ud  
X
)P;UVR0  
/{h@A~<96  
} AXbDCDA  
Ll4/P[7:?  
[=f(u wY>g  
/* xLID@9Hbu  
**FileAccess.java OUoN  
*//文件访问(定位，写) 1< 22,  
package NetFox; 0^?:Zds  
import java.io.*; _Z9H
Ol@  
>J4Tk1//b  
~cC=DeX  
public class FileAccessI implements Serializable{ E]T>m!6  
zn!H&!8&  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8OV;&Z,x  
RandomAccessFile oSavedFile; ~8fy qE$  
long nPos; VTM*=5|c  
xLZJ[:gr  
,# i@jB  
public FileAccessI() throws IOException |AgdD  
{ (T
&rvE  
this("",0); p]z< 43O$  
} hh%fmc  
K'/,VALp  
q oA?  
public FileAccessI(String sName,long nPos) throws IOException 2kG(\+\  
{ JI"&3H")g%  
oSavedFile = new RandomAccessFile(sName,"rw"); $-x@P9im  
this.nPos = nPos; `=}w(V8pc  
oSavedFile.seek(nPos); $_ &Lp\  
} yaDK_fk  
l*l?aI  
G0e]PMeFl  
public synchronized int write(byte[] b,int nStart,int nLen) S9cAw5E(yN  
{  gAFu  
int n = -1; 9V]{q  
try{ Ll2yJ .C4  
oSavedFile.write(b,nStart,nLen); Y! 8 I  
n = nLen; u;@~P  
} PM(M c]6  
catch(IOException e) +1uAzm4SL  
{ T6Oah:50EM  
e.printStackTrace (); zYCS K~-GW  
} {Yt@H

 
cPx]:sC  
7{"urs7 T  
return n; e-@.+f2CC  
} J>o%6D  
L lNd97Z  
o.o$dg(r!  
} GC#s;X  
R&vV!d  
O7})1|>1  
/* @7}
]\}SR  
**SiteInfoBean.java [B2g{8{!  
*/ $vC}Fq  
package NetFox; Hv3<gyD  
%}`zq8Q
;  
j0X Jf<  
public class SiteInfoBean { ~uUN\qx52  
&"R`:`XF  
D_)i%k\  
private String sSiteURL; //Site's URL .)Wqo7/Gx  
private String sFilePath; //Saved File's Path #a$k3C  
private String sFileName; //Saved File's Name uOv0ut\\G  
private int nSplitter; //Count of Splited Downloading File ab@1JAgs  
uXm_ pQpF  
U3-cH
 
public SiteInfoBean() A,u}p rwH  
{//nSplitter的缺省值为5 Q7{/ T0  
//default value of nSplitter is 5 k@=w? m  
this("","","",5); c>)_I  
} ^)i1b:4  
_@_w
6Rh  
YacLYo#  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) U:+wt}-T"  
{ cd3;uB4\,  
sSiteURL= sURL; vNIQ1x5Za  
sFilePath = sPath; 5m\T~[`%  
sFileName = sName; tEl_a~s*3?  
this.nSplitter = nSpiltter; 6_a~ 4_#  
(-bLP
 
xL#UMvZ>;h  
} rI;84=v2&9  
n/vKxtW  
3?Tk[m1b  
public String getSSiteURL() sF!nSr  
{ 6Sr}I,DG  
return sSiteURL; i286`SLU  
} VqBb=1r%o7  
01&J7A2  
D)){"Q!b  
public void setSSiteURL(String value) 0hoi=W6AQ  
{ ` Clh;  
sSiteURL = value; [W
,}&  
}  Y!*F-v@  
w^N3Ma  
]O 8hkGa  
public String getSFilePath() ^R;rrn{^  
{ %[J|n~8_Z  
return sFilePath; @/ G$ C9<  
} ZT1IN6;8W  
D
B>.Uf"  
x!^u$5c  
public void setSFilePath(String value) C'oNGOEd  
{ p8_ CY[U  
sFilePath = value; V^/]h u  
} \
95O  
J%SuiT$L&Y  
t IO 'ky  
public String getSFileName() 8-uRn38  
{ 8AQ@?\Rc"2  
return sFileName; ZGZ+BOFL  
} eA'1  
9}*<8%PSt,  
@teNT"  
public void setSFileName(String value) 8sz|9~  
{ o'auCa,N  
sFileName = value; dRu|*s  
} Z&[_8Y5j  
hQPNxpe  
4o``t]  
public int getNSplitter() qG?svt  
{ H(,D5y`k1  
return nSplitter; (yxHXO9N  
} 7,:$, bL  
j]5mzz~  
OS7^S1r-  
public void setNSplitter(int nCount) QxS=W2iN  
{  V9cKl[  
nSplitter = nCount; GiGXV @dq  
} J_ y+.p- 5  
} {j!+\neL  
c3]X#Qa#m$  
[8$
K i$;  
/* [t}\8^y  
**Utility.java \I[50eh|  
*/ e_Un:r@)  
package NetFox; gtVnn]Jh  
yhzZ[vw7k  
K|^'`FpPO  
public class Utility { 'vc>uY  
;eQOBGX9  
$7 FT0?kG  
public Utility() /ij)[WK@  
{ 66 @#V  
H4{CiZ  
guc[du  
} B;=-h(E}vJ  
%S9YjMR@  
//线程睡眠 ecIZ+G)k  
public static void sleep(int nSecond) H)VzPe#{  
{ |ryV7VJ8  
try{ T\3aT  
Thread.sleep(nSecond); \:vHB!2E  
} E=eK(t(8  
catch(Exception e) m?)REE  
{ 7>,(QHl
 
e.printStackTrace (); IVdM}"+  
} :Y)jf
 
} O~~
WP*N  
HmQ.'  
//日志 D6L5X/#  
public static void log(String sMsg) ,C97|6rC  
{ g*]/HS>e<G  
System.err.println(sMsg); 43m@4Yb  
} 2/F";tc\'  
e:uk``\  
8
;\  
public static void log(int sMsg) 56`Tna,t  
{ )F,IPAA#  
System.err.println(sMsg); jRGslak;  
} cM 5V%w  
} 1XXuFa&  
dgp1B\  
~H4wsa39  
/* cN3!wE  
**TestMethod.java xP+`scv*m#  
*/ )Bw}T  
package NetFox; ~;S  
3LW_qX  
CR8szMa  
public class TestMethod { <N'v-9=2jl  
!%X#;{  
tN1xZW:  
public TestMethod() OUF
x M  
{ ///xx/weblogic60b2_win.exe {16]8-pe  
try{ KBOp}MEz  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 
%iR"eEE  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); SE<?l  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 1tIJ'#6
 
fileFetch.start(); pt$\pQ  
} Ek6z[G` O  
catch(Exception e){e.printStackTrace ();} i@m@]-2  
N3(.7mxo  
Aw$+Ew[8 2  
} yQ!I`T>a  
\)`OEGdOR\  
ItD&L ))  
public static void main(String[] args) )lZoXt_3  
{ NH'Dz6K5  
new TestMethod(); MSaOFv_Q  
}
MAQ(PIc>T  
} )_olJCdaP^  
点击下载更多相关资料