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http断点续传简单实现(java)

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/* d"XZlEV  
**SiteFileFetch.java Fx^wV^q3  
*/ YPGM||  
package NetFox; ji?Hw  
import java.io.*; %n|  
import java.net.*; _wKwiJs  
(4FVemgy  
PK+sGV  
public class SiteFileFetch extends Thread { x_Ev2 c'4  
Ja6KO2}p  
6*Z7JiQ 0  
SiteInfoBean siteInfoBean = null; //文件信息Bean 3X gJZ  
long[] nStartPos; //开始位置 2F2Hl   
long[] nEndPos; //结束位置 DZqPCMz)^  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 k!Yc_ZB:*l  
long nFileLength; //文件长度 pA!-spgX  
boolean bFirst = true; //是否第一次取文件 RRja{*R  
boolean bStop = false; //停止标志 Kn^+kHh:  
File tmpFile; //文件下载的临时信息 ^*AI19w!Ys  
DataOutputStream output; //输出到文件的输出流 U<'N=#A J  
{T8;-H0H  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) SW9 C 8Q  
public SiteFileFetch(SiteInfoBean bean) throws IOException  {b!{~q  
{ [QnN1k  
siteInfoBean = bean; "W(D0oy  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); g}W`LIasv  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");  I0mp[6  
if(tmpFile.exists ()) W]po RTJ:  
{ `0Udg,KOs  
bFirst = false; nI3p`N8j*  
read_nPos(); *'?ZG/ (  
} Kg 6J:HD49  
else BHr,jC  
{ w-Ph-L/  
nStartPos = new long[bean.getNSplitter()]; 'x%gJi#  
nEndPos = new long[bean.getNSplitter()]; TnQ>v{Rx  
} P&Ke slk  
Ll|-CY $  
.?u<|4jE6  
2^B_iyF;  
} "AagTFs(i  
=NY;#Jjn  
{]\7 M|9\  
public void run() wa@Rlzij>  
{ !Q>xVlPVu  
//获得文件长度 wh(_<VZ  
//分割文件 KkUK" Vc  
//实例FileSplitterFetch KPToyCyR1  
//启动FileSplitterFetch线程 8c) eaDu  
//等待子线程返回 'pt(  
try{ af|h4.A  
if(bFirst) FGn"j@m0  
{ /bykIUTKI  
nFileLength = getFileSize(); 5qM$ahN3wH  
if(nFileLength == -1) lc <V_8  
{ :of([e|u6  
System.err.println("File Length is not known!"); @1o X&#  
} H8YwMhE7  
else if(nFileLength == -2) DZqG7p$u4i  
{ Sn[xI9}O  
System.err.println("File is not access!"); 5M=U*BI  
} DQ8/]Z{H  
else 0h1u W26^  
{ x+Yo#u22  
for(int i=0;i<nStartPos.length;i++) y hKH} kR  
{ '#c#.O  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ?;RY/[IX6  
} uqcG3Pi  
for(int i=0;i<nEndPos.length-1;i++) U$5x#{AFp  
{ J?V$V >d  
nEndPos = nStartPos[i+1]; 2B4.o*Q\  
} TyV~2pc N  
nEndPos[nEndPos.length-1] = nFileLength; L!:NL#M  
} I7_8oq\3D  
} k<1i.rh  
G y[5'J`  
_|\X8o_  
//启动子线程 $R'?OK(`  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -1 dD~S$  
for(int i=0;i<nStartPos.length;i++) >T;!Z5L1  
{ $T K*w8@:  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Lyc6nP;F  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), bhD-;Y!6;  
nStartPos,nEndPos,i); !Q"L)%)'A  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -Y524   
fileSplitterFetch.start(); }aOqoi7w  
} \~8W0q.4M  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8(Az/@=n  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~ g!!#ad  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", p l^;'|=M  
nEndPos = " + nFileLength); ,6]ID1o:y  
// fileSplitterFetch[nPos.length-1].start(); YH58p&up  
= 9Yf o,F  
fuj9x;8X0  
//等待子线程结束 VKPEoy8H  
//int count = 0; wa,`BAKJ+F  
//是否结束while循环 3u j|jwL  
boolean breakWhile = false; S }`f&  
f2c <-}wR  
.QP`Qn6(P  
while(!bStop) Y-})/zFc  
{ X QLP|v;"  
write_nPos(); .iV=ybMT  
Utility.sleep(500); -o~zb-E  
breakWhile = true; J3y _JoS  
#)}BY"C%  
C]Fw*t   
for(int i=0;i<nStartPos.length;i++) Do(G;D`h+_  
{ '|gsmO  
if(!fileSplitterFetch.bDownOver) 6Mk#) ebM  
{ ; s(bd#Q  
breakWhile = false; sq=EL+=j  
break; V06*qQ[  
} f&$Bjq  
} 9iT9ZfaW  
if(breakWhile) A o* IshVh  
break; 2 K_ QZ  
6)sKg{H  
tC'#dU`=qY  
//count++; c9c]1XJ  
//if(count>4) #jBmWaP.  
// siteStop(); IwYfs]-  
} 2@bOy~$A  
gH7  +#/  
\j!/l f)  
System.err.println("文件下载结束!"); =( ZOn=IL  
} 346 z`5  
catch(Exception e){e.printStackTrace ();} 5$+7Q$Gw  
} 7Wef[N\x  
=ttD5 p  
*i*\ dl  
//获得文件长度 ^nZ=B>Yn2  
public long getFileSize() nY MtK  
{ WCd: (8B  
int nFileLength = -1; F~=kMQO  
try{ D)G oWt  
URL url = new URL(siteInfoBean.getSSiteURL()); GTB\95j]  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }],l m  
httpConnection.setRequestProperty("User-Agent","NetFox"); &wU"6E  
,62~u'hR5  
e,#w* |  
int responseCode=httpConnection.getResponseCode(); ;S^"Y:7)  
if(responseCode>=400) \ o2oQ3  
{ KPy)%i  
processErrorCode(responseCode); 5 `TMqrk  
return -2; //-2 represent access is error M>=@Z*u/+  
} ZzK^ bNx)0  
:kcqf,7  
g:RS7od=,  
String sHeader; <`-sS]=d}  
o.Ww .F  
QN;5+p[N  
for(int i=1;;i++) Mm,\e6#*  
{ M5RN Z%  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); M p <r`PM2  
//Utility.log(in.readLine()); #<Y3*^~5d  
sHeader=httpConnection.getHeaderFieldKey(i); =~D[M)UO|  
if(sHeader!=null) A ___| #R  
{ hTO5*5]0zP  
if(sHeader.equals("Content-Length")) m^BXLG:b  
{ 5vD\?,f E  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); h)sT37  
break; EyR/   
} vg?(0Gasm*  
} G "+[@|  
else f\?Rhyz  
break; 1d!s8um;  
} FLJ&ZU=s  
} { #B/4  
catch(IOException e){e.printStackTrace ();} prM)t8SE  
catch(Exception e){e.printStackTrace ();} \aPH_sf,  
w8 S pt  
,y"vf^BE.  
Utility.log(nFileLength); +EA ")T<l  
A]Hz?i  
y)L X?d  
return nFileLength; _GY2|x2c  
} cb'Y a_  
s8:epcL`A  
pno}`Cer  
//保存下载信息(文件指针位置) ]~$@x=p2e  
private void write_nPos() 1 39T*0C  
{ k]gPMhe  
try{ p".wqg*W  
output = new DataOutputStream(new FileOutputStream(tmpFile)); q%k&O9C2]  
output.writeInt(nStartPos.length); <x$nw'H9  
for(int i=0;i<nStartPos.length;i++) XU<owk  
{ h('5x,G%  
// output.writeLong(nPos); !m=Js"  
output.writeLong(fileSplitterFetch.nStartPos); GYy8kp84  
output.writeLong(fileSplitterFetch.nEndPos); w9u|E46  
} ,c&t#mu*0  
output.close(); @lM-+q(tl  
} B]hRYU  
catch(IOException e){e.printStackTrace ();} r]}6iF.  
catch(Exception e){e.printStackTrace ();} 3 u=\d)eq  
} ~%tVb c  
g_PP 9S_?  
VxOWv8}|  
//读取保存的下载信息(文件指针位置) gs0 jwI  
private void read_nPos() 1Cc91  
{ |j/Y#.k;{0  
try{ #N`MzmwS  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1Q^u#m3  
int nCount = input.readInt(); nT 4Ryld  
nStartPos = new long[nCount]; i.K!;E>  
nEndPos = new long[nCount]; }X])055S  
for(int i=0;i<nStartPos.length;i++) LIJ#nb  
{ l' Li!u  
nStartPos = input.readLong(); ' rXf  
nEndPos = input.readLong(); f3vl=EA4|  
} z+M{z r  
input.close(); l`6.(6  
} _"H\,7E  
catch(IOException e){e.printStackTrace ();} &RuTq6)r  
catch(Exception e){e.printStackTrace ();} $uwz` N:  
} ,| 8aDL?  
FW2x  
{{bwmNv"  
private void processErrorCode(int nErrorCode) H #X*OJ  
{ /J"fbBXwY  
System.err.println("Error Code : " + nErrorCode); !:xE X~  
} ":sp0(`h  
AW_YlS  
z<P?p  
//停止文件下载 OP=oSfa  
public void siteStop() P1L+Vnfu  
{ D@5h$ m5  
bStop = true; w|I5x}ZFG  
for(int i=0;i<nStartPos.length;i++) >sAaLR4  
fileSplitterFetch.splitterStop(); 1H%p|'FKA  
1bz^$2/k  
55`p~:&VQ  
} O,+9r_Gh  
} o3GZcH?  
//负责部分文件的抓取 Nv0a]Am  
**FileSplitterFetch.java 4a!%eBhX"K  
*/ SH"<f_  
package NetFox; um<$L  
(-;(wCEE  
L>Ze*dt  
import java.io.*; "`S?q G  
import java.net.*; ',|OoxhbK  
M a{@b$>  
7F2:'3SQ  
public class FileSplitterFetch extends Thread { 3DCR n :  
%WP[V{,F  
C\Ob!sv%H  
String sURL; //File URL )_Hv9!U]e  
long nStartPos; //File Snippet Start Position E@Ewx;P5  
long nEndPos; //File Snippet End Position !z :j-gT3  
int nThreadID; //Thread's ID 0%|)=T3Slu  
boolean bDownOver = false; //Downing is over _h,X3P   
boolean bStop = false; //Stop identical #5^OO ou|  
FileAccessI fileAccessI = null; //File Access interface fQ.S ,lMe  
7N5M=f.DS(  
+|<bb8%  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -)&lsFF  
{ G&Yo2aADR  
this.sURL = sURL; } nIYNeP?D  
this.nStartPos = nStart; L*p7|rq$"  
this.nEndPos = nEnd; x~IrqdmW  
nThreadID = id; ~rq:I<5  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Xmb##:  
} e<8KZ  
W?N+7_%'  
_TJk Yz$  
public void run() +?QHSIQo  
{ VgY6M_V  
while(nStartPos < nEndPos && !bStop) W<O/LHKHdn  
{ <Vh5`-J  
<Nloh+n=  
vy7?]}MvV  
try{ 1 K^-tms  
URL url = new URL(sURL); {65Y Tt%  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5,O:"3>c  
httpConnection.setRequestProperty("User-Agent","NetFox"); ZOppec1D  
String sProperty = "bytes="+nStartPos+"-"; 9qzHy}A  
httpConnection.setRequestProperty("RANGE",sProperty); A;^{%S  
Utility.log(sProperty); _ Fk^lDI-  
 YO fYa  
6/'X$}X  
InputStream input = httpConnection.getInputStream(); b; vVlIG  
//logResponseHead(httpConnection); 2>J;P C[;  
XfEp_.~JM  
)\W}&9 >  
byte[] b = new byte[1024]; 6Y.k<oem  
int nRead; LF (S"Of  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) /7a3*a  
{ 3c:fYE  
nStartPos += fileAccessI.write(b,0,nRead); %rl<%%T#.M  
//if(nThreadID == 1) P=E10  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); TL -AL tG  
} KZ=5"a  
sUk n.g!  
W=#jtU`:5  
Utility.log("Thread " + nThreadID + " is over!"); l;h -`( 11  
bDownOver = true; \f]w'qiW5  
//nPos = fileAccessI.write (b,0,nRead); nkN2Bqt$  
} C(KV5c  
catch(Exception e){e.printStackTrace ();} wk=s3^  
} x6\^dVR}  
} gA 5DEit  
|llmq'Q  
pJo4&Ff  
//打印回应的头信息 )wEXCXr!  
public void logResponseHead(HttpURLConnection con) Y'}c$*OkI  
{ ]N1,"W}  
for(int i=1;;i++) hbx+*KM  
{ ,oEAWNbgQ  
String header=con.getHeaderFieldKey(i); b$*G&d5  
if(header!=null) Jcp=<z*0  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 20A:,pMb  
Utility.log(header+" : "+con.getHeaderField(header)); S4E@wLi  
else @}%kSn5y:  
break; Idj Z2)$  
} D [v225  
} mndEB!b  
,yfJjV*I  
JmBMc }54  
public void splitterStop() xKT;1(Mk  
{ ILHn~d IC  
bStop = true; g,Rh Ut9  
} ;>]dwsA*P  
Z ]OX6G  
0h('@Hb.K#  
} 4i29nq^n  
y7z ,I  
LG?b]'#  
/* bvJ*REPL ?  
**FileAccess.java +xr;X 9  
*//文件访问(定位,写) 1aUu:#c  
package NetFox; #yCnM]cEn  
import java.io.*; a^&RV5o  
LsK fCB}  
tK\$LZ  
public class FileAccessI implements Serializable{ "x3!F&  
?J"Y4,{  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 `K2vG`c  
RandomAccessFile oSavedFile; fKs3H?|  
long nPos; CZCVC (/u  
2\Yv;J+;  
|fn%!d`2  
public FileAccessI() throws IOException /DSy/p0%  
{ RS7J~Q  
this("",0); Vl:M6d1  
} (g tOYEqx  
MR* % lZpB  
(Q|Y*yI  
public FileAccessI(String sName,long nPos) throws IOException woU3WS0  
{ r6+IJxUd  
oSavedFile = new RandomAccessFile(sName,"rw"); 8ePzU c\#  
this.nPos = nPos; ;s-fYS6(>{  
oSavedFile.seek(nPos); !Ome;g S)  
} y8|}bd<Sr  
iz`ys.Fu  
Lo9 \[4FP  
public synchronized int write(byte[] b,int nStart,int nLen) h*mKS -TC  
{ z9zo5Xc=  
int n = -1; lF$$~G  
try{ p"n3JV.~k+  
oSavedFile.write(b,nStart,nLen); m&Y?]nbq  
n = nLen; w`Rt"d_B  
} _b[Pk;8}j;  
catch(IOException e) \@7 4I7  
{ &KeD{M%  
e.printStackTrace (); ZD8E+]+  
} b$B-LvHd1  
 Z Mf,3  
O$Dj_R#  
return n; J]&nZud`  
} 2u} ns8wn  
^cojETOv  
7"{CBbT  
} S`[r]msw  
[]H0{a2{<  
z|N*Gs>,  
/* CDFkH  
**SiteInfoBean.java p?+;[!:  
*/ CWE^:kr6  
package NetFox; 0h"uJco,  
.1""U ']  
i# Fe`Z ~J  
public class SiteInfoBean { ^aL> /'Y#|  
95-%>?4  
/.m}y$@GV  
private String sSiteURL; //Site's URL `Jl_'P}  
private String sFilePath; //Saved File's Path MPJ0>Ly  
private String sFileName; //Saved File's Name mp0! S  
private int nSplitter; //Count of Splited Downloading File HK.Si]:  
7+J<N@.d  
zXeBUbVi  
public SiteInfoBean() MAG /7T5  
{//nSplitter的缺省值为5 C2K<CDVw  
//default value of nSplitter is 5 elb}] +  
this("","","",5); `b[@GGv  
} +L}R|ihkI  
G#z9=NF~V  
hhr>nuA  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Um I,?p  
{ ;DI"9  
sSiteURL= sURL; g_MxG!+(V  
sFilePath = sPath; wafws*b%  
sFileName = sName; `>{S?t<  
this.nSplitter = nSpiltter; yTU'voE.|  
SQf.R%cg$  
a~`,zQ -@  
} [N*`3UZk"  
259:@bi!y  
7Y*Q)DDy  
public String getSSiteURL() @XX7ydG5  
{ d>1#|  
return sSiteURL; 7e<\11uI]a  
} v7D3aWoe  
KKJa?e`C  
6Nz S<  
public void setSSiteURL(String value) #4?:4Im#  
{ U{-[lpd  
sSiteURL = value; c}#(,<8X  
} @-}!o&G0  
Z+! 96LR  
-<gQ>`(0  
public String getSFilePath() x!9bvQT  
{ ut9R] 01:  
return sFilePath; ZvW&%*k=  
} l)91v"vJ  
VV=6v;u`  
]hA]o7 k  
public void setSFilePath(String value) LfG$?<}hR  
{ Kl+4A}Uo  
sFilePath = value; d Y]i AJ  
} K|{&SU_m  
q|R$A8)L.  
4S,/Z{ J.  
public String getSFileName() D$bJs O  
{ <e'l"3+9(  
return sFileName; SrSm%Dv  
} yg@}j   
M9sB2Ips<  
K/XUF#^B]  
public void setSFileName(String value) 3x~AaC.j  
{ 15`,kJSK  
sFileName = value; #.~lt8F  
} VufG7%S{  
.[X"+i\  
3O'X;s2\d  
public int getNSplitter() pB0Do6+{  
{ N!=Q]\ZD  
return nSplitter; 5[>N[}Ck>  
} dZjh@yGP.  
 ,zrShliU  
KXga {]G:  
public void setNSplitter(int nCount) =?- s azF&  
{ N`i`[ f  
nSplitter = nCount; %c,CfhEV%&  
} 55|.MXzq  
} 7!E7XP6,~>  
E 5bo60z  
Z~Z+Yt;,9a  
/* `_H^k !^  
**Utility.java _<G%  
*/ Y@M l}43  
package NetFox; rlVo}kc7:  
i"C?6R  
Ol. rjz9  
public class Utility { de?lO ;8  
<\S j5  
vH9Gf  
public Utility() t>>\U X  
{ +S>}<OE  
yzmwNsu  
wPU<jAQyp  
} <S%kwS  
-)ag9{*  
//线程睡眠 H>2f M^  
public static void sleep(int nSecond) 7Ke#sW.HN  
{ Ty>g:#bogI  
try{ T~'9p`IW  
Thread.sleep(nSecond); vdN0YCXG  
} 66~]7w  
catch(Exception e) Dhe ]f#d  
{ -,#LTW<.  
e.printStackTrace (); z;En Ay{9  
} l<mEGKB#  
} GCEq3 ^/  
-a$7b;gF  
//日志 XZ8;Ow=  
public static void log(String sMsg) mh8~w~/[  
{ aF\?X &|  
System.err.println(sMsg); W e*)RXm%  
} vVi))%&S(  
g$ oe00b  
wUz)9n 6j  
public static void log(int sMsg) uua1_# a  
{ *!y.!v*  
System.err.println(sMsg); lhA<wV1-9G  
} zx{O/v KG  
} r'ydjy  
pJ1Q~tI  
8QGj:3  
/* |.Pl[y  
**TestMethod.java 'qg q8  
*/ mjqVP.  
package NetFox; /RmHG H!  
_}B:SM  
#TX=%x6  
public class TestMethod { |O]oX[~  
K9y!ZoB  
nC5  
public TestMethod() NK@G0p~O  
{ ///xx/weblogic60b2_win.exe &`'gO 9  
try{ O$=)  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); mJ|7Jc  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8\^[@9g3\3  
SiteFileFetch fileFetch = new SiteFileFetch(bean); =Gq 'sy:h  
fileFetch.start(); k(;c<Z{?1  
} ^f,('0p- >  
catch(Exception e){e.printStackTrace ();} XHlx89v7  
+$+'|w  
n'#(iW)f  
} 9)qjW&`  
?DC3BA\)  
N|ut^X+|\  
public static void main(String[] args) $v6dB {%Qu  
{ 7^~pOFdH  
new TestMethod(); -vfV;+3  
} {-]/r  
} oIM]  
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