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http断点续传简单实现(java)

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/* %c [F;ug  
**SiteFileFetch.java a_ `[Lj  
*/ h~p>re  
package NetFox; o4%y>d)  
import java.io.*; C":o/;,1  
import java.net.*; t: IN,Kl4  
FRS>KO=3  
{2+L @  
public class SiteFileFetch extends Thread { ;[W"mlM  
<IC~ GqXv  
g q}I[N  
SiteInfoBean siteInfoBean = null; //文件信息Bean >j'ZPwj^  
long[] nStartPos; //开始位置 ooV3gj4  
long[] nEndPos; //结束位置 rN%F) q#  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 baP^<w^  
long nFileLength; //文件长度 ]]&M@FM2z  
boolean bFirst = true; //是否第一次取文件 qWx][D"  
boolean bStop = false; //停止标志 (vB<%l.&  
File tmpFile; //文件下载的临时信息 @E-\ J7 yh  
DataOutputStream output; //输出到文件的输出流 m^#rB`0;L  
d ,Y#H0`  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) &CIVL#];e  
public SiteFileFetch(SiteInfoBean bean) throws IOException un=2}@ '  
{ Oer^Rk  
siteInfoBean = bean; .>mr%#p  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); a9T@$:  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); !O#dV1wAa  
if(tmpFile.exists ()) 0%Z]h?EYy|  
{ .%^]9/4  
bFirst = false; :pF_GkG  
read_nPos(); A5H3%o(6k  
} Vm df8[5  
else T<L^N+<,{N  
{ Pf_S[ sm  
nStartPos = new long[bean.getNSplitter()]; E-{^E.w1  
nEndPos = new long[bean.getNSplitter()]; ;?6No(/  
} KMV=%o  
?qX)ihe%k  
9&2Vm;F_  
V~hlq$jn<Y  
} PZm:T+5H  
;i"*Ll>Q)  
Y)$ ;Ax-D  
public void run() #."Hh<C  
{ 3` #6ACF  
//获得文件长度 (lGaPMEU}  
//分割文件 N,f4*PQ  
//实例FileSplitterFetch 2PeR   
//启动FileSplitterFetch线程 E^rbcGJ  
//等待子线程返回 =Me5ft w  
try{ sj8~?O  
if(bFirst) Ht-t1q  
{ k $f Gom  
nFileLength = getFileSize(); F! X}(N?t  
if(nFileLength == -1) Z{ u a=0  
{ $F/EJ>  
System.err.println("File Length is not known!"); [tH-D$V  
} A 5+rd{k/  
else if(nFileLength == -2) JGFt0He]  
{ =fYL}m5E  
System.err.println("File is not access!"); PT^c^{V  
} AxZD-|.  
else @_"9Dy Y%  
{ O4g+D#Lu  
for(int i=0;i<nStartPos.length;i++) s (0*  
{ 1O!/g  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); DEw8*MN  
} s%!`kWVJ.  
for(int i=0;i<nEndPos.length-1;i++) v @O&t4  
{ V=X:=  
nEndPos = nStartPos[i+1]; ; h`0ir4[A  
} )m&U#S _;  
nEndPos[nEndPos.length-1] = nFileLength; H%1$,]F  
} X<MO7I  
} c=[O `/f  
oM2UzB{(  
{ K _kPgKS  
//启动子线程 x%<  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =B];?%  
for(int i=0;i<nStartPos.length;i++) 1Fe^Qb5G  
{ (Si=m;g  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), p:OPw D+  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2qHf'  
nStartPos,nEndPos,i); >F@qpjoQE  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ooj~&fu  
fileSplitterFetch.start(); ?+t1ME|  
} 8LI-gp\ 2  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {Rear 2  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); JI/_ce  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", X>I)~z}9#  
nEndPos = " + nFileLength); a|BcnYN  
// fileSplitterFetch[nPos.length-1].start(); $x#FgD(iI  
^Q{Bq  
H3H_u4_?SE  
//等待子线程结束 /R LI,.%  
//int count = 0; NJ MJ  
//是否结束while循环 X]y )ZF26  
boolean breakWhile = false; Dl&GJ`&:p  
<X_!x_x  
!~ZP{IXyo  
while(!bStop) m,R Dr  
{ jDRe)bo4  
write_nPos(); ;c -3g]  
Utility.sleep(500); ;&b%Se@#p  
breakWhile = true; u0RS)&  
%y<ejM  
g2R@`./S  
for(int i=0;i<nStartPos.length;i++) ya -i^i\  
{ *<'M!iRC  
if(!fileSplitterFetch.bDownOver) o]LRzI  
{ / EMJSr  
breakWhile = false; "{E q hR~  
break; vZ#!uU^a:  
} f7hXQ|$  
}  Q2p)7G  
if(breakWhile) $>R(W=Q  
break; @cq`:_.[  
&48_2Q"{  
7dX/bzUVz8  
//count++; rxO2js  
//if(count>4) AY SSa 1}  
// siteStop(); [Qdq}FYr  
} ir:d'g1k  
 ?W0(|9  
)ZejQ}$  
System.err.println("文件下载结束!"); sLcFt1  
} R 4wr  
catch(Exception e){e.printStackTrace ();} +jqj6O@Tjr  
}  jAND7&W  
t=R6mjb  
]bgY6@M  
//获得文件长度 #*c F8NV-  
public long getFileSize() 'ZQWYr9R  
{ tVqmn  
int nFileLength = -1; X8<2L 2:  
try{ n(lk dw  
URL url = new URL(siteInfoBean.getSSiteURL()); lM#A3/=K  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O}#yijU3e  
httpConnection.setRequestProperty("User-Agent","NetFox"); &s)0z)mR8&  
3,);0@I  
7W9~1 .SC  
int responseCode=httpConnection.getResponseCode(); IC{F.2D  
if(responseCode>=400) Gy@7Xf  
{ : &J8.G^  
processErrorCode(responseCode); (D{Ys'{q  
return -2; //-2 represent access is error }'=h 4yI  
} 0+b 0<  
On1v<SD$[  
#vf_D?^  
String sHeader; l #@&~f[  
p8,0lo  
cX At :m  
for(int i=1;;i++) 1Qh`6Ya f  
{ Z0fJ9 HW  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); L|^o7 1t|  
//Utility.log(in.readLine()); DI&MC9j(   
sHeader=httpConnection.getHeaderFieldKey(i); YCw('i(|  
if(sHeader!=null) sg'NBAo"  
{ 6U,fz#<,}  
if(sHeader.equals("Content-Length")) d `j?7Z  
{ {5Eyr$  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); c-5jYwV  
break; E/za @W  
} )Hf~d=GG  
} EX?h0Uy  
else ~4)Y#IxL  
break; qSQ@p\O~  
} -{9Gagy2&  
} LxT rG)4  
catch(IOException e){e.printStackTrace ();} PaVO"y]C  
catch(Exception e){e.printStackTrace ();} !%mi&ak(Rn  
W>L@j(  
Q-zdJt  
Utility.log(nFileLength); l_v*7d  
1. SkIu%  
wk 02[  
return nFileLength; E '%lxr  
} n=`w9qajd  
<{019Oa  
DzPs!(5[I  
//保存下载信息(文件指针位置) 9NWloK6bT  
private void write_nPos() kUHie   
{ n9 fk,3  
try{ Q#WE|,a  
output = new DataOutputStream(new FileOutputStream(tmpFile)); '8r8%XI  
output.writeInt(nStartPos.length); :pd&dg!5  
for(int i=0;i<nStartPos.length;i++) 8Inx/>eOI  
{ (^H5EeGV{  
// output.writeLong(nPos); pN$;!  
output.writeLong(fileSplitterFetch.nStartPos); 8U^D(jrz  
output.writeLong(fileSplitterFetch.nEndPos); S?,_<GD)w  
} 6;JP76PD  
output.close(); >I-g[*  
} ?`A9(#ySM  
catch(IOException e){e.printStackTrace ();} \Hs|$   
catch(Exception e){e.printStackTrace ();} e}Q>\t45  
} vOgLEN&]  
'\L0xw4  
Wg(bD,  
//读取保存的下载信息(文件指针位置) pruWO'b`  
private void read_nPos() {NeWdC  
{ l.7d$8'\  
try{ IIax gfhZ  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5w-JPjH  
int nCount = input.readInt(); zKJ. Tj W  
nStartPos = new long[nCount]; _[1^s$  
nEndPos = new long[nCount]; kV 1vb  
for(int i=0;i<nStartPos.length;i++) QV/";A3k  
{ d +xA:  
nStartPos = input.readLong(); P Ey/k.  
nEndPos = input.readLong(); 1CiA 8  
} S$K}v,8.sr  
input.close(); .b _?-Fv  
} 3G&0Ciet  
catch(IOException e){e.printStackTrace ();} ~@YQ,\Y  
catch(Exception e){e.printStackTrace ();} wA r~<  
} ! o^Ic`FhS  
cno;>[$  
u 6(GM  
private void processErrorCode(int nErrorCode) 6+Jry@  
{ V5X i '=  
System.err.println("Error Code : " + nErrorCode); =z-5  
}  0dh#/  
?{j@6,  
N<"`ShCNM  
//停止文件下载 %|jzEBz@  
public void siteStop() /=trj5h  
{ 1uC;$Aj6:  
bStop = true; ^5>du~d  
for(int i=0;i<nStartPos.length;i++) " <*nZ~nE)  
fileSplitterFetch.splitterStop(); 8;8YA1@w  
K>LpN')d  
.ujj:>  
} -? Tz.y&  
} 3]_qj*V  
//负责部分文件的抓取 'f6PjI  
**FileSplitterFetch.java /B=l,:TnJ  
*/ (h|ch#  
package NetFox; =Pj@g/25u  
s@ z{dmL  
QxA0I+i  
import java.io.*; S"{GlRpd  
import java.net.*; \2Xx%SX  
vQy$[D*  
08O7F  
public class FileSplitterFetch extends Thread { 3/l\ <{  
u6p5:oJj,  
77^ "xsa  
String sURL; //File URL ~BtKd*~*  
long nStartPos; //File Snippet Start Position s~)L_ p  
long nEndPos; //File Snippet End Position f^u^-l  
int nThreadID; //Thread's ID J& )#G@fRX  
boolean bDownOver = false; //Downing is over  Db,= 2e  
boolean bStop = false; //Stop identical XW^8A 77H  
FileAccessI fileAccessI = null; //File Access interface 0&Qsk!-B  
\ boL`X  
$kIo4$.Y$  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &8waih(|  
{ $mD>r x  
this.sURL = sURL; ret0z|  
this.nStartPos = nStart; 9,w}Xe=C  
this.nEndPos = nEnd; H):-! ?:  
nThreadID = id; 1N>6rN  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 `LE^:a:8,  
} L!&$c&=xf  
2@4x"F]U;  
m]1!-`(*  
public void run() N-D(y  
{ ,b:n1  
while(nStartPos < nEndPos && !bStop) {:3.27jQ  
{ l3BD <PB2S  
2DUr7r M  
[h^f%  
try{ C#ZhsWS!b  
URL url = new URL(sURL); Y=3X9%v9g  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ckAsGF_B~!  
httpConnection.setRequestProperty("User-Agent","NetFox"); QP+c?ct}hF  
String sProperty = "bytes="+nStartPos+"-"; 'xsbm^n6a&  
httpConnection.setRequestProperty("RANGE",sProperty); :cEd[Jm9  
Utility.log(sProperty); G{/;AK  
pK<%<dIc  
,;7`{Nab  
InputStream input = httpConnection.getInputStream(); E3LBPXK  
//logResponseHead(httpConnection); r7RU"H:j8  
b#Jo Xa9  
Ew>~a8! Fq  
byte[] b = new byte[1024]; Oq[i &  
int nRead; WBy[m ?d  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <8g=BWA  
{ !8we8)7  
nStartPos += fileAccessI.write(b,0,nRead); L#`7FaM?  
//if(nThreadID == 1) >kt~vJI  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <sO?ev[  
} >6XDX=JVI  
c%jsu"  
bd} r#^'K  
Utility.log("Thread " + nThreadID + " is over!"); y-%nJD$  
bDownOver = true; k?o^5@b/  
//nPos = fileAccessI.write (b,0,nRead); &|s+KP|d  
} &K+  
catch(Exception e){e.printStackTrace ();} ^@M [t<  
} O<4Q$|=&?  
} i^/ eN  
L7s>su|c(  
r >E\Cco  
//打印回应的头信息 hx*HY%\P  
public void logResponseHead(HttpURLConnection con) `i=JjgG@  
{ Ft)t`E'%j  
for(int i=1;;i++) qo)Q}0  
{ j p!  
String header=con.getHeaderFieldKey(i); *1\z^4=a]  
if(header!=null) 1V-=$Q3 V7  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); C2CYIo k$&  
Utility.log(header+" : "+con.getHeaderField(header)); <%M\7NDWDA  
else 5?Uo&e  
break; Tt{U"EFO  
} A*rZQh b[  
} -)4uYK*  
U~oBNsU"  
1d/NZJ9  
public void splitterStop() Po'-z<}wS  
{ +ylxezc  
bStop = true; }Q!h ov  
} Q^*G`&w,  
TNyK@~#m  
f#'8"ff*1  
} |sA4:Aq  
UCe,2v%  
\s.1R/TyD  
/* rny@n^F  
**FileAccess.java q1U&vZ3]c  
*//文件访问(定位,写) i:V0fBR[>  
package NetFox; rn5"o8|  
import java.io.*; : : F!   
8$2l^  
ov?.:M  
public class FileAccessI implements Serializable{ 17WNJ  
7vi i9Am7  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 h9w@oRp`~  
RandomAccessFile oSavedFile; <P|`7wfxE  
long nPos; n33JTqX  
 KYnW7|*  
Sg/:n,68  
public FileAccessI() throws IOException !S~,> ,yd  
{ O3_D~O ."  
this("",0); I++W0wa.n  
} z0T`5N G@  
\Pw8wayr%  
I(z>)S'7r  
public FileAccessI(String sName,long nPos) throws IOException ^t\kLU  
{ @`w'   
oSavedFile = new RandomAccessFile(sName,"rw"); `V]egdO  
this.nPos = nPos; =nJOaXR0  
oSavedFile.seek(nPos); S1D9AcK  
} ExN j|*  
hknwis%y  
skk-.9  
public synchronized int write(byte[] b,int nStart,int nLen) a"`g"ZRx  
{ Iq4Kgc  
int n = -1; 3S[w'  
try{ T^/Gj|N*  
oSavedFile.write(b,nStart,nLen); }ZEfT]  
n = nLen; X@6zI-Y %  
} ke3HK9P;  
catch(IOException e) q`/amI0  
{ 7sQ]w   
e.printStackTrace (); 1$='`@8I  
} '#cT4_D^lI  
K$MJ#Zx^  
s=H/b$v  
return n; pRQ fx^ On  
} zCKy`u .  
s`8M%ZLu  
L Q I: ]d  
} XBfiaj  
K#9(|2 J%  
Hj5WJ{p.  
/* ;kyL>mV{  
**SiteInfoBean.java &%f]-=~  
*/ 5XSxQG@k^z  
package NetFox; {V]Qwz)1  
]MqH13`)A  
w8m8r`h  
public class SiteInfoBean { @e.OU(Bf  
jV,(P$ 5;  
V e$5w}a4  
private String sSiteURL; //Site's URL T3u5al  
private String sFilePath; //Saved File's Path j61BP8E  
private String sFileName; //Saved File's Name M `9orq<  
private int nSplitter; //Count of Splited Downloading File } #\;np  
E<zT  
v@$evmA  
public SiteInfoBean() 'f=)pc#&g  
{//nSplitter的缺省值为5 Ckl7rpY+  
//default value of nSplitter is 5 0@sr NuW  
this("","","",5); V7B=+(xK  
} fG8}=xH_&  
X]JpS  
.T#y N\S1  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #q~3c;ec  
{ *!r\GGb  
sSiteURL= sURL; :Fi%Cef|  
sFilePath = sPath; IS0HV$OI  
sFileName = sName; zbIwH6  
this.nSplitter = nSpiltter; zJG x5JC  
.WL\:{G8;  
 =BqaGXr  
} 5I8FD".i  
[x$eF~Kp  
F9u:8;\@`  
public String getSSiteURL() rB.=f[aX[  
{ I9:G9  
return sSiteURL; >?G|Yz*kEJ  
} 9z| >roNe  
L6[rvM|9_  
L5zG0mC8  
public void setSSiteURL(String value) DK@w^ZW6JA  
{ e~t}z_>F  
sSiteURL = value; :"<B@Z  
} 6PzN>+t^y  
7/^TwNsv  
~q8V<@?  
public String getSFilePath() Zv1Bju*y  
{ BqLtTo?'  
return sFilePath; BuEQ^[Ex  
} -KIVnV=&m  
A<YZBR_  
U2[3S\@  
public void setSFilePath(String value) (jo(bbpj  
{ 86^ZYh  
sFilePath = value; ]df9'\  
} 9aF..  
:bM$;  
/v bO/Mr  
public String getSFileName() RXx?/\~yd;  
{ qa0JQ_?o]  
return sFileName; r_g\_y7ua  
} Cb@S </b  
ohc/.5Kl  
S0Bl?XsD_  
public void setSFileName(String value) _ntW}})K  
{ 7>#L  
sFileName = value; ~G{$P'[  
} WnJLX ^;  
I?>-  
#)PGQ)(  
public int getNSplitter() MOqA$b  
{ i"sYf9,  
return nSplitter; cT>z  
} U3_yEvZ  
}<\65 B$1  
\6`%NhkM_  
public void setNSplitter(int nCount) ?2<6#>(7a  
{ Ltic_cjYd?  
nSplitter = nCount; $Va]vC8?  
} }lNuf u  
} H%NLL4&wu  
9$Pl'>5  
F'5d\v  
/* :`>+f.)  
**Utility.java Z z; <P  
*/ #hE3~+ i  
package NetFox; o$blPTN  
,I2re G  
jC/JiI  
public class Utility { (;2J(GZ:$U  
{ck  
>uPde5"ZF-  
public Utility() @rK>yPhf  
{ Z'EO   
/qkIoF2  
X,!OWz:[  
} se n{f^U  
~gi( 1<#  
//线程睡眠 L$TKO,T  
public static void sleep(int nSecond) d"d)<f   
{ %\{?(baOA  
try{ Eps\iykB  
Thread.sleep(nSecond); tFST.yT>zg  
} bJ,=yB+0  
catch(Exception e) eZ.0,A*1B1  
{ MY<!\4/  
e.printStackTrace (); AXU!-er$  
} Acq>M^E3  
} ^0ZKHR(}e  
xwH|ryfs,Z  
//日志 6dS1\Y  
public static void log(String sMsg) Znh uIA AG  
{ KEVy%AP=*h  
System.err.println(sMsg); rd 35)  
} F{H0 %  
-< dMD_  
W'2-3J  
public static void log(int sMsg) R:IS4AaS  
{ |v %RjN  
System.err.println(sMsg); l3pW{p  
} 9y|&T  
} Fx88 R !  
In9|n^=H@  
jVFRqT%  
/* Hj4w i|  
**TestMethod.java p4t!T=o/  
*/ ^a#&wW  
package NetFox; Q0"F> %Cn  
fddbXs0Sn  
QWW7I.9r  
public class TestMethod { (Q]Y> '  
4\'81"e i  
vzrD"  
public TestMethod() q(ET)xCeD  
{ ///xx/weblogic60b2_win.exe pffw5Tc  
try{ Z Lio8  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); MoR-8vnJ  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~lalc ^  
SiteFileFetch fileFetch = new SiteFileFetch(bean); < ,cIc]eX  
fileFetch.start(); "1`i]Y\'  
} M Xt +  
catch(Exception e){e.printStackTrace ();} ]S2[eS  
gS<{ekN  
pS@VLXZP  
} gK#fuQ$hH  
x< y[na  
fJ"~XTN}T  
public static void main(String[] args) L+ETMk0  
{ gZ >orZL'  
new TestMethod(); w4MMo  
} & Dl'*|  
} ND9>`I 5  
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