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http断点续传简单实现(java)

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/* C 'mL&  
**SiteFileFetch.java s4= "kT]  
*/ 0Fr1Ku!  
package NetFox; _!V%fw  
import java.io.*; ^U7OMl4Usq  
import java.net.*; VV_l$E$  
LJzH"K[Gg6  
R!x: C!{  
public class SiteFileFetch extends Thread { "E=j|q  
Pt< s* (  
JcO08n  
SiteInfoBean siteInfoBean = null; //文件信息Bean ~[PKcEX  
long[] nStartPos; //开始位置 m>&HuHf  
long[] nEndPos; //结束位置 ~4,I7c7  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 q!,zq  
long nFileLength; //文件长度 |BU+:+  
boolean bFirst = true; //是否第一次取文件 ^(x^6d  
boolean bStop = false; //停止标志 <I*x0BM=  
File tmpFile; //文件下载的临时信息 Q}AE.Ef@<  
DataOutputStream output; //输出到文件的输出流 uZ6d35MJ  
/'DwfX  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ww d'0P`/  
public SiteFileFetch(SiteInfoBean bean) throws IOException 2h^WYpCm  
{ 4N? v  
siteInfoBean = bean; I?!rOU= 0  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); -0HkTY  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 5ua?I9fY  
if(tmpFile.exists ()) ,5k-.Md>2*  
{ (X[2TT3j!  
bFirst = false; [\ )Ge  
read_nPos(); 3NK ^AaTK  
} =(r* 5vd  
else $6f\uuTU2"  
{ B)SLG]72f  
nStartPos = new long[bean.getNSplitter()]; vFmJ;J  
nEndPos = new long[bean.getNSplitter()]; "kW!{n  
} TJ@Cjy%  
-C7FuD[Xw  
FcbM7/  
%kI} [6J_  
} /M0/-pV 9  
B\`Aojw"E?  
zzpZ19"`1  
public void run() ^+70<#Xc  
{ EmVuwphv  
//获得文件长度 2-If]Fc  
//分割文件 0au)g!ti  
//实例FileSplitterFetch '{?C{MK3Q  
//启动FileSplitterFetch线程 y7u^zH6wj  
//等待子线程返回 > R^@Ww;|q  
try{ ilLBCS}  
if(bFirst) _uxPx21g}  
{ ,8Iv9M}2  
nFileLength = getFileSize(); m 40m<@  
if(nFileLength == -1) y f1CXldi  
{ ;1AG3P'  
System.err.println("File Length is not known!"); / l>.mK()  
} =Ov7C[(  
else if(nFileLength == -2) g;p)n  
{ pNaiXu3  
System.err.println("File is not access!"); Y0uvT7+[hi  
} ~.tvrx g  
else `d]Z)*9  
{ "u^EleE!  
for(int i=0;i<nStartPos.length;i++) m$Y :0_^-  
{ =J'P.  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Qu*1g(el!o  
} <EX7WA  
for(int i=0;i<nEndPos.length-1;i++) |(IO=V4P  
{ Rhgj&4  
nEndPos = nStartPos[i+1]; h,t|V}Wb  
} .=R lOK  
nEndPos[nEndPos.length-1] = nFileLength; ?2J?XS>  
} x!TZ0fq0  
} t={0(  
q%3<Juq~$  
0NE{8O0;Fr  
//启动子线程 ~9o6 W",  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |WQ9a' '  
for(int i=0;i<nStartPos.length;i++) O_,O,1  
{ [uuj?Rbd  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), s'I)A^i+  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7v~j=Z>  
nStartPos,nEndPos,i); 'VnwG  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ggm` ~fS  
fileSplitterFetch.start(); -$8.3\6h  
} XJ\hd,R   
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W.}].7}h  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); a=]W zlz  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", LgqGVh3\s  
nEndPos = " + nFileLength); D#rrW?-z  
// fileSplitterFetch[nPos.length-1].start(); C*~aSl7  
)$M,Ul  
5mB]N%rfW%  
//等待子线程结束 i2,U,>.  
//int count = 0; 1JS2SxF  
//是否结束while循环 7!V @/S}7  
boolean breakWhile = false; Z| 6{T  
d.F)9h]XHO  
?Hz2-Cn  
while(!bStop) &_-](w`  
{ Mhpdaos  
write_nPos();  $g8}^1  
Utility.sleep(500); y.a]r7  
breakWhile = true; 5N/Lk>p1u  
I*)VZW  
>9K//co"of  
for(int i=0;i<nStartPos.length;i++) #;r]/)>  
{ 0&w0a P`Y  
if(!fileSplitterFetch.bDownOver) Ww9;UP'G  
{ j BS4vvX?  
breakWhile = false; %e%7oqR?  
break; _^!vCa7f  
} o+?@5zw -&  
} htJuGfDx1  
if(breakWhile) NP t(MFK \  
break; m2bDHQ+  
6qp5Xt+  
y;`eDS'0.N  
//count++; wz(K*FP  
//if(count>4) 'imU `zeo  
// siteStop(); p]|LV)R n  
} JJk#,AP  
a:!uORQby  
D_D,t8_Y  
System.err.println("文件下载结束!"); /XpSe<3  
} !c(QSf502  
catch(Exception e){e.printStackTrace ();} d,#.E@Po  
} b5`KB75sbo  
c.K =(y*  
FvImX  
//获得文件长度 W4(?HTWZ  
public long getFileSize() C8b''9t.  
{ [1Dm<G u@  
int nFileLength = -1; MWwJzVL8  
try{ 3(_!`0#F%  
URL url = new URL(siteInfoBean.getSSiteURL()); _ n O.-  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2<W&\D o@  
httpConnection.setRequestProperty("User-Agent","NetFox"); HkjEiU  
'p}`i/  
$Xf(^K  
int responseCode=httpConnection.getResponseCode(); G2Qjoe`Uc  
if(responseCode>=400) !k&)EWP?  
{ ~l4f{uOD>]  
processErrorCode(responseCode); p8>%Mflf  
return -2; //-2 represent access is error &r_uQbx  
} fEqC] *s  
KCqqJ}G  
x7ATI[b[  
String sHeader; NPU^) B  
W'$kZ/%[  
Uene=Q6>  
for(int i=1;;i++) S`g;Y '  
{ <|F-Dd  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); g:~+P e  
//Utility.log(in.readLine()); TipHV;|e  
sHeader=httpConnection.getHeaderFieldKey(i); Z7#7N wy4  
if(sHeader!=null) Os&1..$Nb  
{ o}D![/  
if(sHeader.equals("Content-Length")) 9YKDguG  
{ %J P!{mqj  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Da,Tav%b  
break; 8 njuDl  
} X#J6Umutm  
} L(o#4YH}>J  
else gA:TL{X0  
break; bx;f`8SN  
} tbur$ 00  
} {*xBm#  
catch(IOException e){e.printStackTrace ();} ejcwg*i  
catch(Exception e){e.printStackTrace ();} ~ =.CTm]vf  
$$gtZ{ukQ  
0s%6n5>  
Utility.log(nFileLength); SGf9U^ds  
P;U@y" s  
aqL<v94wX  
return nFileLength; YKx 1NC  
} [MmM9J["  
g9V.13k  
d6b.zP  
//保存下载信息(文件指针位置) uQp_':\k  
private void write_nPos() -u6#-}S  
{ UKs$W`  
try{ g [L  
output = new DataOutputStream(new FileOutputStream(tmpFile)); htHv&  
output.writeInt(nStartPos.length); n`<S&KP|  
for(int i=0;i<nStartPos.length;i++) eV;me>,  
{ G11cNr>*  
// output.writeLong(nPos); 3M*Y= ?pI  
output.writeLong(fileSplitterFetch.nStartPos); [j0w\{  
output.writeLong(fileSplitterFetch.nEndPos); "$@,n7 k  
} fM":f| G  
output.close(); xrI}3T  
} iZTa>@   
catch(IOException e){e.printStackTrace ();} yYX :huw  
catch(Exception e){e.printStackTrace ();} <Cq"| A  
} h$&rE@N|  
FAtWsk*pgY  
{hd-w4"115  
//读取保存的下载信息(文件指针位置) OmNn,PCl8  
private void read_nPos() -Enbcz(B  
{ I~RcOiL)  
try{ P9yw&A  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); #s^s_8#&e  
int nCount = input.readInt(); cjT[P"5$  
nStartPos = new long[nCount]; sp{j!NSL  
nEndPos = new long[nCount]; `o-*Tr  
for(int i=0;i<nStartPos.length;i++) 6\`DlUn'*  
{ ^x3EotQ\  
nStartPos = input.readLong(); z93nYY$`Y  
nEndPos = input.readLong(); 1v]t!}W:6  
} W-Of[X{<  
input.close(); yWuIu>VJ  
} 6/7F">@j  
catch(IOException e){e.printStackTrace ();} G"Pj6QUva  
catch(Exception e){e.printStackTrace ();} u}CG>^0C  
} :uvc\|:s  
<Kp+&(l,l  
~XQ$aRl&  
private void processErrorCode(int nErrorCode) N cM3P G  
{ XGk}e4;_  
System.err.println("Error Code : " + nErrorCode); Fwv\pJ}$  
} Zd XKI{b  
nKu(XgFv  
x!+Z{x   
//停止文件下载 }200g_^  
public void siteStop() ua:9`+Dff  
{ m5qCq9Y  
bStop = true; /j %_t  
for(int i=0;i<nStartPos.length;i++) d+1x*`U|  
fileSplitterFetch.splitterStop(); gvr]]}h:O  
.+uVgSN  
am (#Fa  
} J/[7d?hI/  
} \E&thp  
//负责部分文件的抓取 JP%RTGu  
**FileSplitterFetch.java jrcc  
*/ Rk{$S"8S_  
package NetFox; @Yarz1  
`skH-lk,  
$w`veP  
import java.io.*; B3 .X}ys#  
import java.net.*; `&,_xUA  
s kY0\V  
H<z30r/-w  
public class FileSplitterFetch extends Thread { w3d\0ub  
j]Ua\|t  
' tSnH&c  
String sURL; //File URL Q'C 4pn@  
long nStartPos; //File Snippet Start Position <G}m#  
long nEndPos; //File Snippet End Position 7YD\ !2b  
int nThreadID; //Thread's ID _KxX&THaj  
boolean bDownOver = false; //Downing is over i8eA_Q  
boolean bStop = false; //Stop identical {[lx!QF 8&  
FileAccessI fileAccessI = null; //File Access interface V^WQ6G1  
 %|bN@@  
7_7xL(F/  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException pKYLAt+^>  
{ BArJ"t*/z  
this.sURL = sURL; 3l+|&q[v  
this.nStartPos = nStart; 0@w&J9yG  
this.nEndPos = nEnd; 8z0Hx  
nThreadID = id; 6ku8`WyoF  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9?!u2 o  
} d(\1 } l  
m]e0X*Kg  
vj(@.uU)  
public void run() ec#_olG%  
{ c%b\CP\)W  
while(nStartPos < nEndPos && !bStop) du8!3I  
{ Cl{{H]QngX  
Bd QQ9$@5  
VAt>ji7c  
try{ QdirE4W  
URL url = new URL(sURL); g\qX7nIH?  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jigbeHRy  
httpConnection.setRequestProperty("User-Agent","NetFox"); WEps.]s  
String sProperty = "bytes="+nStartPos+"-"; }il%AAI9}r  
httpConnection.setRequestProperty("RANGE",sProperty); cS5w +`,L  
Utility.log(sProperty); zK,~37)\  
"wF*O"WQo  
C\J@fpH(t`  
InputStream input = httpConnection.getInputStream(); #'#4hJ*YC  
//logResponseHead(httpConnection); Dn: Yi8=  
VDPxue  
H]U "+52h  
byte[] b = new byte[1024]; $=7H1 w  
int nRead; U:J /\-  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ZIDFF  
{ D . 77WjwQ  
nStartPos += fileAccessI.write(b,0,nRead); F6~b#Jz&i  
//if(nThreadID == 1) +$'e4EwqV  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7Y4%R`9H  
} l#mtND3  
]}5`7  
Q-:Ah:/  
Utility.log("Thread " + nThreadID + " is over!"); _AVy:~/  
bDownOver = true; +V6j`  
//nPos = fileAccessI.write (b,0,nRead); rknzo]N,  
} Qz'O{f  
catch(Exception e){e.printStackTrace ();} J&(  
} p$B)^S%0i  
} ws#hhW3qK  
l DgzM3  
h)"'YzCt  
//打印回应的头信息 zj%cd;  
public void logResponseHead(HttpURLConnection con) 9]"\"ka3>  
{ bx1G CD  
for(int i=1;;i++) H+nr5!`kz  
{ Z=0iPy,m>  
String header=con.getHeaderFieldKey(i); {|G&W^`  
if(header!=null) u|(aS^H=q  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); -=@K %\\~5  
Utility.log(header+" : "+con.getHeaderField(header)); ><MGZ?-N  
else O2/%mFS.  
break; H 3W_}f  
} x/pC%25  
} w($XEv;  
KwY`<t1lA;  
$cyLI+uz|  
public void splitterStop() Uy:@,DW  
{ &mCs%l  
bStop = true; ( ?atGFgu  
} *4zoAslU1  
h\Z3yAYd  
hLu&lY  
} 4mki&\lw`  
>6n@\n  
BASO$?jf4  
/* N)`tI0/W  
**FileAccess.java x*3@,GmZl  
*//文件访问(定位,写) ]%b0[7[  
package NetFox; ?U7&R%Lh`  
import java.io.*; FuIWiO(  
Z#H@BWN7  
s9^"wN YQ  
public class FileAccessI implements Serializable{ xKRfl1  
F^4*|g  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ,"4X&>_f  
RandomAccessFile oSavedFile; f J,8g/f8  
long nPos; F[Qsv54  
C6Um6 X9/i  
ZS07_6.~  
public FileAccessI() throws IOException @`#OC#  
{ P1M|f4*  
this("",0); +:j4G^V  
} fo/(()  
qg/Y;tGSx  
\Qe'?LRu{  
public FileAccessI(String sName,long nPos) throws IOException x'VeL|  
{ r%O rH-T  
oSavedFile = new RandomAccessFile(sName,"rw"); cj,&&3sbV  
this.nPos = nPos; &1\u#LU  
oSavedFile.seek(nPos); LA(f]Xmc  
} XyN`BDFi  
yTMGISX5  
?)i6:76(  
public synchronized int write(byte[] b,int nStart,int nLen) gME:\ud$  
{ 9 ayH:;  
int n = -1; O% j,:t'"  
try{ So3,Z'z=  
oSavedFile.write(b,nStart,nLen); C{lB/F/|!  
n = nLen; 7!]k#|u  
} 6'3Ey'drH  
catch(IOException e) dA3`b*nC  
{ /jn:e"0~  
e.printStackTrace (); J-HabHv  
} G5C#i7cpm  
JC1BUheeb  
Y+S~b  
return n; sZ\i(eIU  
} ^^W`Lh%9  
dW] Ej"W  
!YuON6{)  
} qX}dbuDE"P  
`0/gs  
k;9#4^4(  
/* O;.d4pO(tC  
**SiteInfoBean.java I+-Rs2wb  
*/ IrVM|8vT3  
package NetFox; vwSX$OZ  
Fp* &os  
Av\ 0GqF  
public class SiteInfoBean { HvL9;^!  
*>R/(Q  
l-JKcsM  
private String sSiteURL; //Site's URL 'JXN*YO  
private String sFilePath; //Saved File's Path ?j ;,q  
private String sFileName; //Saved File's Name OmQuAG ^\x  
private int nSplitter; //Count of Splited Downloading File oD|+X/F K  
B@: XC&R^  
`jl. f  
public SiteInfoBean() y[Fw>g1`q  
{//nSplitter的缺省值为5 $ET/0v"V  
//default value of nSplitter is 5 k/6G j}l'o  
this("","","",5); FL*w(Br.  
} uvAy#,  
)@};lmPR  
9=sMKc%!-  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) lqwJ F &  
{ 3vEjf  
sSiteURL= sURL; _16 &K}<  
sFilePath = sPath; m78MWz]Yo  
sFileName = sName; Rg!aKdDl$  
this.nSplitter = nSpiltter; U~QCN[gh  
Ix l"'Q_z  
~vvQz"  
} ?PH}b?f4  
xHR+((  
$T@xnZ  
public String getSSiteURL() :+X2>Lu$FA  
{ M`f;-  
return sSiteURL; 1]zyME  
} %d~9at6-B  
gEe W1:AB  
A+Pm "|  
public void setSSiteURL(String value) :7AauoI  
{ mqfEs0~I  
sSiteURL = value; =iQ`F$M  
} Y_TL4  
"#"Fp&Z7  
e&VR>VJEA  
public String getSFilePath() 0zk T8'v  
{ c&iK+qvh{  
return sFilePath; 4FP~+  
} |'>E};D  
_S7M5{U_  
clU3#8P!=  
public void setSFilePath(String value) 9jJ/ RXp  
{ JCMEhI6d*  
sFilePath = value; >@92K]J  
} w1/T>o  
MsVI <+JZ  
?5+KHG*)  
public String getSFileName() WSX@0A.&)  
{  z]R!l%`  
return sFileName; U Edl"FwM4  
} I]j/ ab7>  
77[;J  
.]d tRH<  
public void setSFileName(String value) y{},{~FA"  
{ PX>\j&  
sFileName = value; @):NNbtA  
} Bo\dt@0;  
R<YYf^y  
8f`b=r(a>  
public int getNSplitter() h,RUL  
{ 0aN}zUf  
return nSplitter; P+cFp7nC  
} DWevg;_]$(  
Gxt<kz  
nfPl#]ef*  
public void setNSplitter(int nCount) {UVm0AeUq  
{ JnKbd~  
nSplitter = nCount; 38.J:?Q  
} U=<.P;+f9  
} -W"0,.Dvg  
x~Esu}x7  
e, 3(i!47  
/* *,=+R$  
**Utility.java q\Io6=39x  
*/ d+| ! 6  
package NetFox; +!Gr`&w*)  
\:)o'-   
>"My\o  
public class Utility { 2ZIY{lBe  
jm!C^5!  
af5`ktx  
public Utility() /xbF1@XtL  
{ ;. [$  
*Zo o  
|~vQ0D  
} GZ>% &^E  
^T1-dw(  
//线程睡眠 }u*@b10   
public static void sleep(int nSecond) YD>>YaH_3@  
{ zbKW.u]v  
try{ w*R-E4S?2  
Thread.sleep(nSecond); Y8xnvK*  
} r{3 `zqo  
catch(Exception e) Xv(9 Yh S  
{ \36;csu  
e.printStackTrace (); u z2s-,  
} v/6,eIz  
} CoN/L`.SN  
D{d$L9.  
//日志 COJ!b  
public static void log(String sMsg) Rm 1`D  
{ CO+jB  
System.err.println(sMsg); .7^-*HT}  
} r4>I?lD  
93eqFCF.  
8 =Lv7G%  
public static void log(int sMsg) L/+J|_J)  
{ ,^Srd20  
System.err.println(sMsg); %H~gN9Vn#@  
} #\;w::  
} s7.*o@G  
; SM^  
1 3az [  
/* YD.^\E4o  
**TestMethod.java :|mkI#P.  
*/ :pu{3-n.  
package NetFox; %hb5C 4q  
tLXw&hFk`g  
4'=N{.TtO  
public class TestMethod { \uPTk)oaB  
>o= p5#{  
EQhV}9  
public TestMethod() #C7j|9Ew1]  
{ ///xx/weblogic60b2_win.exe CXFAb1m  
try{ P&^7wud-sb  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,(=]6V  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); d iLl>z  
SiteFileFetch fileFetch = new SiteFileFetch(bean); lH>XIEj  
fileFetch.start(); twS3J)UH  
} 6N)1/=)  
catch(Exception e){e.printStackTrace ();} :P1c>:j[  
meD (ja  
`v{X@x  
} =eLb"7C#0  
OYy !4Fp  
'U0I.x(  
public static void main(String[] args) 3 pH` ]m2  
{ A:J{  
new TestMethod(); Xkm2C)  
} -d)n0)9  
} u@'zvkb@  
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