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http断点续传简单实现(java)

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/* #Pe\Z/  
**SiteFileFetch.java sg!=Q+  
*/ ?X8K$g  
package NetFox; lB5[#z  
import java.io.*; %xH>0  
import java.net.*; ,iA2s i  
73! x@Duh  
B}TInI%H  
public class SiteFileFetch extends Thread { = y,yQO  
dK=D=5r,  
0C9QAJa  
SiteInfoBean siteInfoBean = null; //文件信息Bean i9#`F.7F  
long[] nStartPos; //开始位置 dpc=yXg>"c  
long[] nEndPos; //结束位置 Gaw,1Ow!`2  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 2uI`$A:  
long nFileLength; //文件长度 l(0&6ENyj  
boolean bFirst = true; //是否第一次取文件 ,b2O^tJF#  
boolean bStop = false; //停止标志 xX/Qoq (}i  
File tmpFile; //文件下载的临时信息 1*c0\:BQ;z  
DataOutputStream output; //输出到文件的输出流 Tko CyD9  
% @^VrhS  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) } (GQDJp  
public SiteFileFetch(SiteInfoBean bean) throws IOException B?/12+sR  
{ D6pEQdX`  
siteInfoBean = bean; +v`^_  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Z3u""oM/  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); H|(*$!~e  
if(tmpFile.exists ()) Y/:Q|HnXQ  
{ T$>=+U  
bFirst = false; IdC k  
read_nPos(); 6):sO/es  
} 3'gd'`Hn/  
else g-TX;(  
{ ];wohW%  
nStartPos = new long[bean.getNSplitter()]; f|[5&,2<  
nEndPos = new long[bean.getNSplitter()]; w oY)G7%  
} .{Eg(1At  
}E)8soQR  
x""Mxn]gD  
ZQ-z2s9U  
} HzO0K=Z=R0  
q4IjCu+  
)}zA,FOA*  
public void run() Qbe{/  
{ j:vD9sdQ  
//获得文件长度 WLj_Zo*^x  
//分割文件 Wpg?%+Y  
//实例FileSplitterFetch |L~gNC  
//启动FileSplitterFetch线程 ={&TeMMA  
//等待子线程返回 ,2:L{8_L  
try{ !&`7  
if(bFirst) |[n|=ORI'  
{ ="[+6X  
nFileLength = getFileSize(); YM,D`c[pX  
if(nFileLength == -1) ;R- z3C  
{ A~~| X  
System.err.println("File Length is not known!"); brhJ&|QDE  
} HWao3Lz  
else if(nFileLength == -2) 5kL#V  
{ `A}{ I}xq  
System.err.println("File is not access!"); eJwii  
} :XZJxgx  
else *rMN,B@  
{ <?`e9o  
for(int i=0;i<nStartPos.length;i++) qo&SJDG  
{ h 19.b:JT  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ",,qFM!  
} B#/~U`t*  
for(int i=0;i<nEndPos.length-1;i++) &hM,b!R|  
{ -QHzf&D?  
nEndPos = nStartPos[i+1]; B'#gs'fl  
} d'eM(4R@  
nEndPos[nEndPos.length-1] = nFileLength; ,:Y=,[n  
} =S?-=jPtg  
} d ;Gm{g#  
!z&seG]@  
\2VZkVO9  
//启动子线程 ?2bE=|  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]a@v)aa-  
for(int i=0;i<nStartPos.length;i++) ]MH \3g;  
{ cB{;Nh6"  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), o@V/37!  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), B2+_F"<;  
nStartPos,nEndPos,i); q~A|R   
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); uS+b* :  
fileSplitterFetch.start(); fqp7a1qQl  
} FK,r<+h  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0BU:(o&  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); h"%,eW|^  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", YUE 1 '}  
nEndPos = " + nFileLength); hE3jb.s(>  
// fileSplitterFetch[nPos.length-1].start(); qcoZ2VJ hh  
Sv]"Y/N  
Z( clw  
//等待子线程结束 N`mC_)  
//int count = 0; =P+wp{?AN|  
//是否结束while循环 cH8H)55F  
boolean breakWhile = false; f \%X 7.  
=GS_ G;Dz  
74!JPOpQH  
while(!bStop) uX 5B>32  
{ K {N;k-  
write_nPos(); hQRc,d6x5  
Utility.sleep(500); r?{LQWP>e  
breakWhile = true; ri.|EmH2:D  
Y&:\s8C  
} jy7,+  
for(int i=0;i<nStartPos.length;i++) Iw-6Z+ 94  
{ %4g4 C#  
if(!fileSplitterFetch.bDownOver) 4xC6#:8  
{ !P3tTL!*L  
breakWhile = false; kJ:5msKwC  
break; ~#xs `@{s  
} ^K@ GK  
} R5YtCw]i=  
if(breakWhile) Q0cf]  
break; xuC6EK+  
G`<1>%" F  
\>CBam8d  
//count++; wB 0WR  
//if(count>4) ^{,}, i  
// siteStop(); W2V@\  
} ,DsT:8  
y"n~ET}e7  
$7ME a"a  
System.err.println("文件下载结束!"); %-zH]"Q$  
} ZX RN?b  
catch(Exception e){e.printStackTrace ();} $TUC?e9"h  
} mi3q1npb7[  
8XXTN@&,  
-^%"w  
//获得文件长度 RB 0j!H:  
public long getFileSize() O&1p2!Bk4  
{ "e?#c<p7  
int nFileLength = -1; lIT2 AFX+  
try{ p~y 4q4  
URL url = new URL(siteInfoBean.getSSiteURL()); /IR5[67  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); aQ3vG08L>  
httpConnection.setRequestProperty("User-Agent","NetFox"); +Gs;3jC^  
m^&mCo,  
*^m.V=  
int responseCode=httpConnection.getResponseCode(); ? 9M+fi  
if(responseCode>=400) B,qZwc|  
{ 2QD B'xs3  
processErrorCode(responseCode); T</gWW  
return -2; //-2 represent access is error cnO4N UDv  
} MjosA R  
:)S4MoG  
z^a?t<+  
String sHeader; {nWtNyJpS  
D%}o26K.C  
DWO:  
for(int i=1;;i++) 0iq$bT|  
{ *8HxJ+[,[  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 57%cN-v*  
//Utility.log(in.readLine()); ",oUVl  
sHeader=httpConnection.getHeaderFieldKey(i); =njj.<BO  
if(sHeader!=null) x}24?mP  
{ zT zG&B-  
if(sHeader.equals("Content-Length")) Q9 ",  
{ aj~@r3E ;  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {?_)m/\  
break; 3W00,f^9  
} KV(W|~+rM  
} Vc<n6  
else <GlV!y  
break; 745PCC'FK  
} lY,1 w  
} 0|k[Wha#  
catch(IOException e){e.printStackTrace ();} /9gMcn9EB  
catch(Exception e){e.printStackTrace ();} =hb87g.  
atnbM:t  
%zVv3p:  
Utility.log(nFileLength); y 9mZQq  
 Ue Tp,  
SQvB)NOw  
return nFileLength; EnAw8Gm*  
} qWK7K%-$ E  
TUCp mj  
O\{_)L  
//保存下载信息(文件指针位置) zL}DLfy>R  
private void write_nPos() ZPFTNwf  
{ V,,iKr@TG  
try{ "lAS <dq  
output = new DataOutputStream(new FileOutputStream(tmpFile)); FV,SA3  
output.writeInt(nStartPos.length); LB0=V0|  
for(int i=0;i<nStartPos.length;i++) 2)]*re)  
{ ?NeB_<dLa`  
// output.writeLong(nPos); {[#  
output.writeLong(fileSplitterFetch.nStartPos); !7|9r$  
output.writeLong(fileSplitterFetch.nEndPos); "6h.6_bTw  
} #J9XcD{1  
output.close(); RGOwm~a  
} uQ)]g  
catch(IOException e){e.printStackTrace ();} yQ2[[[@k@  
catch(Exception e){e.printStackTrace ();} SpQ6A]M gm  
} bsDUFXH]  
J?DyTs3 Z  
D]y.!D{l2  
//读取保存的下载信息(文件指针位置) 9a,CiH%@  
private void read_nPos() [X\2U4  
{ 6ng9 o6  
try{ X:bgY  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /d;l:  
int nCount = input.readInt(); =-Tetp  
nStartPos = new long[nCount]; n\,W:G9AR7  
nEndPos = new long[nCount]; X^)5O>>|t  
for(int i=0;i<nStartPos.length;i++) Ue%5 :Sdr  
{ ]>j_ Y ,  
nStartPos = input.readLong(); -': tpJk  
nEndPos = input.readLong(); BGOI  
} %oQj^r!Xd  
input.close(); KO7cZME  
} s^< oU  
catch(IOException e){e.printStackTrace ();} P]^] T}5  
catch(Exception e){e.printStackTrace ();} 4(](' [M  
} HX^ P9jXT  
^4i3#}  
WR%iUO40  
private void processErrorCode(int nErrorCode) OC.@C}u  
{ M1\/ueOe  
System.err.println("Error Code : " + nErrorCode); jeNEC&J  
} 0cVXUTJ|W  
=$J2  
MR: {Ps&,  
//停止文件下载 C5?M/xj  
public void siteStop() F[Up  
{ m5*RB1  
bStop = true; sIe(;%[`  
for(int i=0;i<nStartPos.length;i++) $Vh82Id^  
fileSplitterFetch.splitterStop(); ':@qE\(  
UNae&Zir  
XFYl[?`G  
} X8TZePh  
} [0emOS  
//负责部分文件的抓取 6cvm\ opH  
**FileSplitterFetch.java 4kEFbzwx  
*/ .Dz /MSl  
package NetFox; KYaf7qy]  
c{q`uI;O  
7v_e"[s~  
import java.io.*; ~heF0C_  
import java.net.*; bzS [X  
agzG  
YXEZ&$e'  
public class FileSplitterFetch extends Thread { ycN_<  
I._=q  
a;sZNUSn  
String sURL; //File URL ?u|g2!{_  
long nStartPos; //File Snippet Start Position >F v8 -  
long nEndPos; //File Snippet End Position AseY.0  
int nThreadID; //Thread's ID {cFei3'q  
boolean bDownOver = false; //Downing is over dLq!t@?iu>  
boolean bStop = false; //Stop identical -1:asM7  
FileAccessI fileAccessI = null; //File Access interface "lt[)3*  
2I  
195(Kr<5$  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~Q0}>m,S  
{ Yv)/DsSyL  
this.sURL = sURL; ~cz t=  
this.nStartPos = nStart; DDEn63{  
this.nEndPos = nEnd; Syb:i(Y  
nThreadID = id; AKVmUS;70  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 SF7Kb`>Y  
} Q\Eq(2p  
o/xE O=AW  
[F$3mzx  
public void run() -JK+{<  
{ rm7UFMCR6i  
while(nStartPos < nEndPos && !bStop) C/JFg-r  
{ ZJqmD  
D {mu2'q  
+q;^8d>  
try{ G(- `FH  
URL url = new URL(sURL); wFD .3!  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); x8^Dhpr6  
httpConnection.setRequestProperty("User-Agent","NetFox"); 9bB~r[k  
String sProperty = "bytes="+nStartPos+"-"; a)e2WgVB/E  
httpConnection.setRequestProperty("RANGE",sProperty); Z,z^[Jz  
Utility.log(sProperty); ]KmYPrCl0  
B4?P"|  
Tr8+E;;  
InputStream input = httpConnection.getInputStream(); F=#Wfl-o  
//logResponseHead(httpConnection); |[ge ,MO:  
c=5$bo]LI  
8{RiaF8  
byte[] b = new byte[1024]; 9"rATgN1  
int nRead; px*MOHq K  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Z7Kc`9.0|  
{ 5R4 dN=L*1  
nStartPos += fileAccessI.write(b,0,nRead); Gs%kqD{=  
//if(nThreadID == 1) iR9iI!+;N  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _> *"6  
} KLk37IY2\  
eNNK;xXe#  
B?]^}r  
Utility.log("Thread " + nThreadID + " is over!"); `?)i/jko"  
bDownOver = true; ??F{Gli"C`  
//nPos = fileAccessI.write (b,0,nRead); #KIHq2:.4  
} yC -4wn*  
catch(Exception e){e.printStackTrace ();} C-M op,w  
} xc!"?&\*  
} \<5xf<{  
bvoR?D\-"  
xn-n{U"  
//打印回应的头信息 8ViDh  
public void logResponseHead(HttpURLConnection con) 6l4l74  
{ 0wx`y$~R  
for(int i=1;;i++) 4x:fOhtP  
{ g {00i  
String header=con.getHeaderFieldKey(i); ;y"DEFs,u  
if(header!=null) ykZ)`E]P`  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); vm(% u!_P  
Utility.log(header+" : "+con.getHeaderField(header)); Co'dZd(  
else A9"ho}<  
break; -kJ`gdS  
} 8?PNyO-Wt5  
} }&=C*5JN  
fE(rDQI  
,QK>e;:Be  
public void splitterStop() 4 1Ru@  
{ N-^\e)ln  
bStop = true; qZ4DO*%b3  
} H)5]K9D  
D~-Ri`k.  
P63f0 F-G  
} 'p<(6*,"  
pvX\k X3}  
[u<1DR  
/* ? xy~N?N  
**FileAccess.java Q@2Smtu~c  
*//文件访问(定位,写) x{=ty*E  
package NetFox; us/x.qPy2  
import java.io.*; n04Zji(F@  
7y:J@fh<  
+Ta7b)  
public class FileAccessI implements Serializable{ 6%)dsTAB  
!4|7U\;  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 HH>]"mv  
RandomAccessFile oSavedFile; /@0wbA  
long nPos; .6r&<*  
P5[.2y_qM  
>]Y`-*vw&  
public FileAccessI() throws IOException 5R qkAC  
{ r t f}4.  
this("",0); 291v R]  
} <jxTI%'f59  
Up8#Nz T  
=l {>-`:  
public FileAccessI(String sName,long nPos) throws IOException 5{{u #W%=  
{ %KqXtc`O  
oSavedFile = new RandomAccessFile(sName,"rw"); `*WR[c  
this.nPos = nPos; GR/ p%Y(  
oSavedFile.seek(nPos); 90Q}9T\  
} t; "o,T  
'l2`05   
9Czc$fSSt  
public synchronized int write(byte[] b,int nStart,int nLen) s I#K01;"  
{ cBU>/ zIp  
int n = -1; F$d`Umqs;P  
try{ /']Gnt G.  
oSavedFile.write(b,nStart,nLen); x6m21DWw  
n = nLen; kYx|`-PA<r  
} 0nBAO  
catch(IOException e) zg[ksny  
{ d]CRvzW  
e.printStackTrace (); J3C"W7 94}  
} -V(5U! ^B  
3HWI;  
E: #VS~  
return n; 7,Nd[ oL*7  
} k{uc%6s  
V0"UFy?i  
JWC{"6  
} !YCYmxw#  
+[:}<^p?cG  
ZVViu4]?y  
/* >wZ!1Jq  
**SiteInfoBean.java CJ?Lv2Td  
*/ \=1k29O  
package NetFox; =Bl#CE)X  
H~fZA)W 4Y  
$kg!XT{ V  
public class SiteInfoBean { #k*e>d$  
fZ$8PMZv  
F8.Fp[_tM  
private String sSiteURL; //Site's URL >AJtoJ=j  
private String sFilePath; //Saved File's Path jrG@ +" }  
private String sFileName; //Saved File's Name IX$ $pdQ  
private int nSplitter; //Count of Splited Downloading File 't2"CPZ  
klv ]+F&[  
// g~1(  
public SiteInfoBean() Vc}m_ T]O  
{//nSplitter的缺省值为5 Za5*HCo  
//default value of nSplitter is 5 c)+IX;q-C  
this("","","",5); 0fwo8NgX  
} T-uI CMEf  
5_#wOz0u$  
Y ~xcJH  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) c=h{^![$  
{ l\JoWL  
sSiteURL= sURL; )FYz*:f>&  
sFilePath = sPath; NbSkauF~b  
sFileName = sName; X^7bOFWE  
this.nSplitter = nSpiltter; = T!iM2  
U8;k6WT|  
C([TolZ  
} >^{}Hjt  
|s+y]3-_  
C&D!TR!K  
public String getSSiteURL() RKx" }<#+  
{ YOd 0dKe  
return sSiteURL; 7jvf:#\LtL  
} }]'Z~5T  
Quqts(Q)+  
C5$1K'X@  
public void setSSiteURL(String value) \GEFhM4)  
{ "o+< \B~  
sSiteURL = value; I5 "Z  
} ?l &S:` L  
p$0G EYwM  
 (0bvd  
public String getSFilePath() amK"Z<V F  
{ $<OX\f%  
return sFilePath; GFB(c  
} :D""c*  
i]JD::P_H  
c=0S]_  
public void setSFilePath(String value)  mR)Xq=  
{ VE`5bD+%e  
sFilePath = value; Ys|tGU  
} .i) H1sD  
bx#GOK-  
7jQOwzj  
public String getSFileName() *VG#SK  
{ 40w,:$  
return sFileName; N7v7b<6  
} Tu"bbc  
&!SdO<agZ  
p8aGM-+40W  
public void setSFileName(String value) <%Zg;]2H`  
{ _Ryt|# y  
sFileName = value; R?V s8?  
} G~5EAeG  
{N42z0c  
Z ]V^s8>  
public int getNSplitter() B4Ko,=pg  
{ ["TUSf]  
return nSplitter; gdPv,p19L  
} W$>srdG0$  
5|z>_f.^pS  
&@p_g8r#  
public void setNSplitter(int nCount) [H<![Z1*r  
{ OGpy\0%  
nSplitter = nCount; ">_<L.,I  
} % P .(L  
} K%h9'}pq>1  
SaceIV%(  
V3r1|{Z(  
/* <&^P1x<x  
**Utility.java _4Z|O]  
*/ jM]B\cvN  
package NetFox; h8B:}_Cu  
_IYd^c  
C-O~Oil  
public class Utility { <#/r.}.x  
(&t741DN|  
#; ~`+[y?\  
public Utility() xMsSZ{j%5  
{ .$&mWytw=  
=;A p+}  
gT8Q:8f:  
} z=%&?V  
:59fb"^$  
//线程睡眠 @-ps[b`z  
public static void sleep(int nSecond) Hj(ay4 8  
{ Lu?MRF f  
try{ }x!=F<Q!r  
Thread.sleep(nSecond); ]z3!hgTj  
} >n3w'b  
catch(Exception e) uy'm2  
{ G8AT] =  
e.printStackTrace (); iXLODuI  
} l Oxz&m  
} NN> E1d=  
"}ibH{$lM  
//日志 B}S!l>.z  
public static void log(String sMsg) K!~j}z*  
{ }\ kLh(  
System.err.println(sMsg); r:N =?X`N  
} LL% Aw)Q`  
1'Sr0 oEd3  
?|,dHqh{nM  
public static void log(int sMsg) n1!hfu7@s  
{ NSs"I]  
System.err.println(sMsg); D/U=zDpiB  
} q~:H>;:G-  
} zP554Gr?  
im,H|u_f4  
n $Nb,/o  
/* 9d kuvk}:  
**TestMethod.java <e&88{jJ  
*/ ''D\E6c\  
package NetFox; vtx3a^  
AUk-[i  
~V34j:  
public class TestMethod { py|ORVN(Z  
z3Id8G&>  
=#=<%HPT  
public TestMethod() @kh:o\  
{ ///xx/weblogic60b2_win.exe k]>1@t  
try{ WzinEo{ f  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); oz8z%*9 (  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); #Sg< 9xsW  
SiteFileFetch fileFetch = new SiteFileFetch(bean); [p Y1\$,  
fileFetch.start(); dMd2a4  
} FT'2 J  
catch(Exception e){e.printStackTrace ();} Y9<N#h#  
-ElK=q  
uy'I#^Bt  
} Kx4_`;>  
YzA6*2  
3[{RH*nHD  
public static void main(String[] args) *C~$<VYI  
{ mv,p*0  
new TestMethod(); n3z]&J5fr  
} Z-U-n/6I  
} VsU*yG a  
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