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http断点续传简单实现(java)

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/* YGr^uTQb  
**SiteFileFetch.java BW%"]J  
*/ Fd@:*ER  
package NetFox; 0:3<33]x  
import java.io.*; JheF}/Bx  
import java.net.*; HtGGcO'bqg  
.+hM1OF`x  
OcGHMGdn  
public class SiteFileFetch extends Thread { |DMa2}%  
e025m}%SU  
(eJYv: ^  
SiteInfoBean siteInfoBean = null; //文件信息Bean 7= x]p  
long[] nStartPos; //开始位置 gDjs:]/YR  
long[] nEndPos; //结束位置 oyY0!w,Y  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 \%N | X  
long nFileLength; //文件长度 Ga} &%  
boolean bFirst = true; //是否第一次取文件 '74-rL:i  
boolean bStop = false; //停止标志 (@1*-4l  
File tmpFile; //文件下载的临时信息 1A b=1g{  
DataOutputStream output; //输出到文件的输出流 :$>TeCm  
D$ +"n  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) O8% Y .SK  
public SiteFileFetch(SiteInfoBean bean) throws IOException y #Xq@  
{ FGG 7;0(  
siteInfoBean = bean; Qs.g%  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); zg83->[  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); &r Lg/UEV-  
if(tmpFile.exists ()) l4s_9  
{ {JlW1;Jc7  
bFirst = false; 79 ZBVe(}  
read_nPos(); 'Nbae-pf  
} 1Q ^YaHzuW  
else YaDr.?  
{ (C EXPf  
nStartPos = new long[bean.getNSplitter()]; gr")Jw7  
nEndPos = new long[bean.getNSplitter()]; ,pz^8NJAI  
} HrZ\=1RB  
xW;-=Q  
$G5;y>  
=@d IM  
} U{2UKD@PM  
d= -/'_'  
duKR;5:  
public void run() 1MCHwX3/  
{ P]@m0f  
//获得文件长度 0=r.I}x  
//分割文件 D{aN_0mT  
//实例FileSplitterFetch .Qp5wCkM  
//启动FileSplitterFetch线程 6NV- &0 _  
//等待子线程返回 |? !Ew# w  
try{ ^rc!X]C9  
if(bFirst) ,afh]#  
{ OwwlQp ~!J  
nFileLength = getFileSize(); y+XB  
if(nFileLength == -1) I4Ys ,n  
{ .1.Bf26}d  
System.err.println("File Length is not known!"); _tg&_P+kV  
} T/" 6iv\1  
else if(nFileLength == -2) i[~oMwc&  
{ `R]9+_"N  
System.err.println("File is not access!"); Mlp[xk|  
} *FkG32k  
else %:/_O*~)Yg  
{ T6|zT}cb  
for(int i=0;i<nStartPos.length;i++) 8}0W_CU,  
{ {iqH 27\E  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); $e;_N4d^  
} OgNt"Vg  
for(int i=0;i<nEndPos.length-1;i++) yFT)R hN  
{ *sqq]uD  
nEndPos = nStartPos[i+1]; 63d' fgVp  
} Eg?6$[U`8<  
nEndPos[nEndPos.length-1] = nFileLength; GQTMQXn(  
} qJj;3{X2  
} 8VJUaL@  
dlC)&Ai  
N9D<wAK##)  
//启动子线程 f~u]fpkz  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length];  b]s*z<|%  
for(int i=0;i<nStartPos.length;i++) #5kQn>R  
{ cbl2D5s+i]  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "SyAOOZ  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),  = uZ[  
nStartPos,nEndPos,i); adh=Kp e!w  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d_&R>GmR$  
fileSplitterFetch.start(); |~bl%g8xP  
} 0(;d<u)fS  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [Z484dS`_  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0l6z!@GhT  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?k~(E`ZE3  
nEndPos = " + nFileLength); 0hXI1@8]`  
// fileSplitterFetch[nPos.length-1].start(); uYlC*z{  
rLNo7i  
udDhJ?  
//等待子线程结束 V+X>t7.Q  
//int count = 0; |b{XnD_g  
//是否结束while循环 z!5^UD8"W  
boolean breakWhile = false; }\`MXh's  
^ad p<?q4  
a3 <D1"  
while(!bStop) W6D|Rr.q  
{ ja}_u}:  
write_nPos(); 6)m}e?D>  
Utility.sleep(500); Ns2M8  
breakWhile = true; !CROc}  
3hr&p{/  
-:`$8/A|  
for(int i=0;i<nStartPos.length;i++) ~AxA ,  
{ "W;Gv I  
if(!fileSplitterFetch.bDownOver) u-3A6Q  
{ Fd-PjW/E8  
breakWhile = false; - *!R  
break; j`A%(()d  
} ppjd.  
} @ 9D, f  
if(breakWhile) bR6.Xdt.n  
break; 1HG~}E  
YYHtd,0\+  
40N8?kQ}?  
//count++; D\]gIXg  
//if(count>4) `3^ *K/K\  
// siteStop(); *SQ hXTn  
} Iodk1Y;  
"qUUH4mR`  
6+(g4MW  
System.err.println("文件下载结束!"); 6wx;grt'Z  
} :}0y[qc3  
catch(Exception e){e.printStackTrace ();} F6R+E;"4R'  
} 4bqi&h3  
 XeDiiI  
BRbx.  
//获得文件长度 EV| 6._Z(D  
public long getFileSize() _eM\ /(v[  
{ ^AtAfVJN0  
int nFileLength = -1; u HqPb8  
try{ = ;#?CAa:  
URL url = new URL(siteInfoBean.getSSiteURL()); m!5P5U x  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &U ]L@ ]x  
httpConnection.setRequestProperty("User-Agent","NetFox"); PXG)?`^NX  
nIJ2*QJ  
4%1sOnl  
int responseCode=httpConnection.getResponseCode(); v{ Md4 p  
if(responseCode>=400) bmVksi2b  
{ ]#;;)K}>  
processErrorCode(responseCode); T;qP"KWZ  
return -2; //-2 represent access is error m07= _4  
} x zu)``?  
|uI d:^ {  
p 9Zi}!  
String sHeader; Ac}+U q  
1@sy:{ d`  
<QFT>#@T  
for(int i=1;;i++) A ><  
{ 8R"c}87  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >%5Ld`c:SD  
//Utility.log(in.readLine()); Tt #4dm-  
sHeader=httpConnection.getHeaderFieldKey(i); \,)('tUE  
if(sHeader!=null) /]m5HW(P7K  
{ 6r{NW9y'  
if(sHeader.equals("Content-Length")) Ya{$:90(4  
{ Bee`Pp2  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Jt5\  
break; $(B|$e^:(  
} \=PnC}7I  
} P}hHx<L  
else chk1tFV  
break; &SuWmtq  
} jsB%RvX  
} %0l'Nuz  
catch(IOException e){e.printStackTrace ();} *Z'*^Y1le  
catch(Exception e){e.printStackTrace ();} ,]RMa\Q4Wg  
*P2_l Q=  
xa#;<8 iV  
Utility.log(nFileLength); Qc1NLU9:  
LG3D3{H(.  
o;5 J=  
return nFileLength; Em8q1P$tm>  
} n4A_vz  
"IQ' (^-P  
f_v@.vnn.  
//保存下载信息(文件指针位置) A)6xEeyR  
private void write_nPos() +l'l*<  
{ %gUf  
try{ *|WS,  
output = new DataOutputStream(new FileOutputStream(tmpFile)); DmzK* O{  
output.writeInt(nStartPos.length); D>tex/Of3  
for(int i=0;i<nStartPos.length;i++) }#%3y&7M7  
{ $>^DkrOd  
// output.writeLong(nPos); NMJX `  
output.writeLong(fileSplitterFetch.nStartPos); \%& BK.t  
output.writeLong(fileSplitterFetch.nEndPos); wJc~AP)I%z  
} ^#-d^ )f;  
output.close(); jlaU3qXL  
} i/UDda"E  
catch(IOException e){e.printStackTrace ();} M~'4>h}  
catch(Exception e){e.printStackTrace ();} 0Va+l)F  
} /`6Y-8e2  
2IMU &  
V9KI?}q:W  
//读取保存的下载信息(文件指针位置) RHO | g0  
private void read_nPos() ctg U  
{ ]k+XL*]'A  
try{ G-7!|&  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Qc4r?7S<  
int nCount = input.readInt();  ;IV  
nStartPos = new long[nCount]; jGm`Qg{<  
nEndPos = new long[nCount];  SXqWq  
for(int i=0;i<nStartPos.length;i++) *Wbs{>&No  
{ wPr9N}rf  
nStartPos = input.readLong(); <O<Kf:i&c1  
nEndPos = input.readLong(); Q[PVkZ  
} vbA<=V*P  
input.close(); ws/e~ T<c  
} K Eda6zZH  
catch(IOException e){e.printStackTrace ();} M[eq)a$  
catch(Exception e){e.printStackTrace ();} FS'|e?WU  
} TEJn;D<1I,  
DsJ ikg(J  
g2 RrBK,  
private void processErrorCode(int nErrorCode) gm^j8  B  
{ {beu  
System.err.println("Error Code : " + nErrorCode); 7C;oMh5  
} YL?2gBT  
d9=i{i3  
{UeS_O>(  
//停止文件下载 jm ORKX+)  
public void siteStop() +DsdzR`Gx,  
{ #}xw *)3  
bStop = true; [,bra8f[C  
for(int i=0;i<nStartPos.length;i++) !l(D0 C  
fileSplitterFetch.splitterStop(); F>F2Yql&W  
UWXl c  
"1P[D'HV4|  
} 42oW]b%P{;  
} z@<OR$/`L  
//负责部分文件的抓取 a Fh9B\n  
**FileSplitterFetch.java n2V $dF4m  
*/ vZiuElxKi  
package NetFox; s' 4O] k`  
OH >#f6`[  
$,.XPK5Q u  
import java.io.*; ""f'L,`{.  
import java.net.*; c 80Ffq  
Qx")D?u  
+dG3/vV  
public class FileSplitterFetch extends Thread { c 8t  
5r1u_8)'  
=vs]Kmm  
String sURL; //File URL @=ro/.  
long nStartPos; //File Snippet Start Position h`n) b  
long nEndPos; //File Snippet End Position y9Q #%a8V  
int nThreadID; //Thread's ID "Cz0r"N  
boolean bDownOver = false; //Downing is over Q2>o+G  
boolean bStop = false; //Stop identical @B`nM#X#  
FileAccessI fileAccessI = null; //File Access interface S[;d\Z]~  
=OeLF  
fi~jT"_CI  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException yU"lJ>Eh}}  
{ h-<Qj,L{W  
this.sURL = sURL; ],~H3u=s3  
this.nStartPos = nStart; 2C Fgit  
this.nEndPos = nEnd; J#DN2y <  
nThreadID = id; %<O0Yenu  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~H c5M5m  
} $KVCEe!X  
L O;?#e7  
N mA6L+  
public void run() 7'!DK;=TD6  
{ sj3[ny;b  
while(nStartPos < nEndPos && !bStop) 5m yQBKE  
{  y 2C Jk~  
hLr\;Swyp  
sOO_J!bblP  
try{ `]=0oDG:1!  
URL url = new URL(sURL); FL {$9o\@  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @R_ON"h  
httpConnection.setRequestProperty("User-Agent","NetFox"); "s.hO0Z  
String sProperty = "bytes="+nStartPos+"-"; W6s-epsRmT  
httpConnection.setRequestProperty("RANGE",sProperty); Jr=XVQ(F  
Utility.log(sProperty); c2u*<x  
n%6ba77  
\beYb0(+  
InputStream input = httpConnection.getInputStream(); TT oW>RP#  
//logResponseHead(httpConnection); T0{X,  
BS=~G+/:|  
z22:O"UHa  
byte[] b = new byte[1024]; 9&bJ]  
int nRead; '!F'B:  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) NRT@"3,1YP  
{ Pj1k?7  
nStartPos += fileAccessI.write(b,0,nRead); }tO>&$ Z6f  
//if(nThreadID == 1) ^fQa whub  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W9QVfe#s  
} .^6yCs5~`  
SZUo RWx  
3lTnfc&  
Utility.log("Thread " + nThreadID + " is over!"); L_tjclk0J  
bDownOver = true; Us.k,  
//nPos = fileAccessI.write (b,0,nRead); k;Fxr%  
} 0YC|;`J  
catch(Exception e){e.printStackTrace ();} F!fsW9  
} cua( w  
} (((|vI3 <  
\&l@rMD3s  
^zW=s$\Fo  
//打印回应的头信息 B1A:}#  
public void logResponseHead(HttpURLConnection con) qLPuKIF  
{ pqTaN=R8  
for(int i=1;;i++) eM@xs<BR  
{ kA> e*6  
String header=con.getHeaderFieldKey(i); "|Kag|(qB  
if(header!=null) D"2bgw  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); s\< @v7A  
Utility.log(header+" : "+con.getHeaderField(header)); CDPu(,^  
else 6Jq3l_  
break; >?#zPweA  
} r@}8TE*|P  
} \8g= Ix  
~(#iGc]7  
M!D6i5k,   
public void splitterStop() U~d%5?q  
{ GKKDO+A=!  
bStop = true; CvR-lKV<  
} }KO <II  
LIrebz  
1:r#m- \  
} \._|_+HiW  
pSI8"GwQ  
vvu $8n  
/* |?]doBm|  
**FileAccess.java , 6Jw   
*//文件访问(定位,写) 4U16'd  
package NetFox; 4*D"*kR;  
import java.io.*; $ai;8)C6  
Rt:^'Qi$!  
]G D` f  
public class FileAccessI implements Serializable{ )\j dF-s  
CZ'm|^S  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 g~$UU(HX  
RandomAccessFile oSavedFile; n @,.  
long nPos; f$tm<:)Y  
RehraY3q  
J .VZD  
public FileAccessI() throws IOException awI{%u_(nA  
{ rL&Mq}7QK  
this("",0); 3m9b  
} i(OeE"YA  
l^$'6q"  
}%-iJ\  
public FileAccessI(String sName,long nPos) throws IOException =R~zD4{"  
{ #vhN$H:&q  
oSavedFile = new RandomAccessFile(sName,"rw"); QxN1N^a0  
this.nPos = nPos; ]31=8+D  
oSavedFile.seek(nPos); 6Ol9P56j  
} kN78j  
3!osQ1  
}r!+wp   
public synchronized int write(byte[] b,int nStart,int nLen) Wy*+8~@A  
{ <,rOsE6  
int n = -1; 7 7y+ik  
try{ <9piKtb|L  
oSavedFile.write(b,nStart,nLen); dq`{fqGl  
n = nLen; 7Xu#|k  
} {=?(v`88  
catch(IOException e) }]PHE(}7  
{ \@WVeFr  
e.printStackTrace (); HZZZ [km  
} $A-X3d;'\/  
""XAUxo  
gBi3^GxjM?  
return n; eBs.RR ]O  
} hc+B+-,  
CoNaGb  
-egnMc67  
} 1}c'UEr%)  
U1X"UN)  
)\ceanS  
/* DKu$u ]Z  
**SiteInfoBean.java <Q/)SN6_E  
*/ ~/9RSdv7  
package NetFox; e\ cyiW0  
ruvfp_:  
BZHoRd{EH  
public class SiteInfoBean { !5C"`@}q>  
}O>1tauI  
cS7\,/4S  
private String sSiteURL; //Site's URL 7/51_=%kR  
private String sFilePath; //Saved File's Path _1qR1< V  
private String sFileName; //Saved File's Name } O $]xB  
private int nSplitter; //Count of Splited Downloading File 7xv9v1['  
n#b{  
?z#*eoPr  
public SiteInfoBean() qar{*>LCG  
{//nSplitter的缺省值为5 f"P866@oWn  
//default value of nSplitter is 5 #gO[di0WhC  
this("","","",5); ~M-L+XZl(  
} xh$yXP0/  
&C+2p  
[B+F}Q^;  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Yq6 @R|u  
{ Y;_F,4H  
sSiteURL= sURL; qb=2J5su  
sFilePath = sPath; GI/NouaNfm  
sFileName = sName; r8:"\%"f>  
this.nSplitter = nSpiltter; xS tsw5d  
T`fT[BaY  
<_<zrXc]  
} \f? K74  
=3QhGFd  
o cW~I3  
public String getSSiteURL() D^6iQW+.P  
{ LdG?kbJ&y  
return sSiteURL; 3kC|y[.&  
} $Y_S`#c@i  
pXO09L/nv  
U|tacO5w`  
public void setSSiteURL(String value) I <D7 Jj  
{ /qy6YF8;y  
sSiteURL = value; 6`Tx meIP  
} mz6]=]1w  
7WS$fUBi  
SR?mSpq5  
public String getSFilePath() NL$z4m0  
{ ;!S5P(  
return sFilePath; n({%|O<|  
} 8Lx/ZGy  
,4t6Cq!  
*{#C;"  
public void setSFilePath(String value) 4h|*r !  
{ 1gkpK`u(B  
sFilePath = value; rIcgf1v70  
} AaA!U!B  
S._2..%G  
.(q'7Q Z/  
public String getSFileName() sk39[9  
{ 3{?X>6T  
return sFileName; -_t4A *  
}  d=^QK{8  
!;|#=A9  
["Ts7;q9[  
public void setSFileName(String value) K*T^w3=  
{ %_5#2a  
sFileName = value; -fFtHw:kHh  
} bpZA% {GS  
U&BCd$  
6WZffB{-TK  
public int getNSplitter() (@XQ]S}L  
{ &mVClq  
return nSplitter; 6H'A]0  
} "NA<^2W@J  
_LwF:19Il  
4RVqfD  
public void setNSplitter(int nCount) mTtaqo_Bh  
{ P'tXG  
nSplitter = nCount; ,M{G X  
} v%cCJ SO#  
} xA7~"q&u  
PF/K&&9}  
l%_K$$C  
/* VBi gUK4  
**Utility.java 3f^Pr  
*/ J";N^OR{A%  
package NetFox; bVU4H$k  
>"!ScYn  
&^#iS<s1  
public class Utility { d"Zu10  
v%T'!(0j/  
tWy.Gz\  
public Utility() EB!ne)X  
{ 37kFbR@x  
i \NV<I  
Ny7*MZ-  
} WC<[<uI*  
TSewq4`K  
//线程睡眠 7d%x7!E   
public static void sleep(int nSecond) 0ex.~S_Oj4  
{ 7\%JJw6h  
try{ 3E;@.jD  
Thread.sleep(nSecond); uT, i&  
} 1-E6ACq  
catch(Exception e) K0( S%v|,}  
{ q]OIP"yv  
e.printStackTrace (); n?cC]k;P~  
} ZAfuW^r  
} x@q.u3o9  
hJ ^+asr  
//日志 W{'hn&vU  
public static void log(String sMsg) {Cm!5QYy  
{ `$JvWN,kB  
System.err.println(sMsg); EP@u4F  
} W !j-/ql  
\;N+PE  
Vxap+<m  
public static void log(int sMsg) 9pnOAM}  
{ }p6]az3  
System.err.println(sMsg); Jyg1z,B <  
} {H[N|\  
} lfDd%.:q4S  
M^oL.'  
L>IP!.J]?  
/* nm#23@uZ4K  
**TestMethod.java hQx*#:ns  
*/ `ZEFH7P  
package NetFox; D^O[_/i&  
zs]ubJC@  
h+B7BjA>G  
public class TestMethod { 2{=D)aC$f  
?:9y !Q=  
vVo'f|fW  
public TestMethod() u]NsCHKlT  
{ ///xx/weblogic60b2_win.exe i kfJ!f  
try{ C <:g"F:k  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); neM)(` gp  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8[J%TWq%9  
SiteFileFetch fileFetch = new SiteFileFetch(bean); VC/n}7p  
fileFetch.start(); L@T/4e./  
} sG#Os  
catch(Exception e){e.printStackTrace ();} 7I w^  
TfZM0Wz  
eG(YORkR  
} m-uXQS^@G  
KdozB!\  
j}.gK6Yq*  
public static void main(String[] args) :a)RMp+^0  
{ S\N l|U[  
new TestMethod(); J&\Q3_vro9  
} `uPO+2  
} wwdmz;0S  
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