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http断点续传简单实现(java)

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/* RVlAWw(  
**SiteFileFetch.java @<GVY))R8  
*/ ?q}XD c  
package NetFox; 9u3~s <  
import java.io.*; "8p fLI  
import java.net.*; D.e4S6\&  
UV?.KVD~  
F TB@70  
public class SiteFileFetch extends Thread { w(lxq:>"  
gq$]jWtCD  
9J"Y   
SiteInfoBean siteInfoBean = null; //文件信息Bean r#Pkhut  
long[] nStartPos; //开始位置 ;$ot,mH?T  
long[] nEndPos; //结束位置 u )'l|Y  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 P #_8$#G3  
long nFileLength; //文件长度 B3p[A k  
boolean bFirst = true; //是否第一次取文件 j Hd <*  
boolean bStop = false; //停止标志 %h "+J  
File tmpFile; //文件下载的临时信息 6bL"ZOEu  
DataOutputStream output; //输出到文件的输出流 [+=h[DC  
}v0IzGKs  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 0baq696<F  
public SiteFileFetch(SiteInfoBean bean) throws IOException aLwd#/!  
{ Dxc`K?M   
siteInfoBean = bean; 4r@dV%:%<  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); >[4;K&$B  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); myp}DI(  
if(tmpFile.exists ()) ` ,B&oV>  
{ kg2?IL  
bFirst = false; ?}QHEk:H  
read_nPos(); }m?1IU %q  
} tDuQ+|~M  
else P,S$qD*4  
{ /o<tmK_m  
nStartPos = new long[bean.getNSplitter()]; ObDcNq/b!  
nEndPos = new long[bean.getNSplitter()]; l)PEg PSRV  
} +6vm4(3?  
9]Q\Pr\Ub$  
QOG S` fh  
B3 mD0   
} P7IxN)b7  
97H2hYw9l  
# ;,b4O7@  
public void run() _IAvFJI  
{ S9sFC!s1g  
//获得文件长度 R5QSf+/T4  
//分割文件 l8n}&zX  
//实例FileSplitterFetch u8Ul +u  
//启动FileSplitterFetch线程 |?c v5l7E  
//等待子线程返回 |TOz{  
try{ $qN+BKd]3  
if(bFirst) cJ 5":^O  
{ i!/V wGg  
nFileLength = getFileSize(); C[j'0@~V:B  
if(nFileLength == -1) *+p9u 1B5  
{ ;SBM7fwRk  
System.err.println("File Length is not known!"); @Q"%a`mKH  
} &hmyfH&S  
else if(nFileLength == -2) ~lx5RTkp  
{ C9-90,  
System.err.println("File is not access!"); {5+t\~q$  
} s'LY)_n  
else aX=  
{ `sZ/'R6  
for(int i=0;i<nStartPos.length;i++) YW@Ad  
{ 6gS<h \h0  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); =bUVGjr%96  
} !<"H73?fl  
for(int i=0;i<nEndPos.length-1;i++) -9"hJ4  
{ A[lkGQtS4  
nEndPos = nStartPos[i+1]; .tB[8Y=J  
}  D7%`hU  
nEndPos[nEndPos.length-1] = nFileLength; S3-3pJ]~Zk  
} [YT"UVI  
} C7%+1w'D8  
L+@RK6dq  
M9MfO*  
//启动子线程 u</21fz'  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~ifo7,  
for(int i=0;i<nStartPos.length;i++) UzVnC:  
{ P,Fs7  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %g3@m5&  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3@e#E4+ff  
nStartPos,nEndPos,i); !+T9NqDv[  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wi]|"\  
fileSplitterFetch.start(); |H&2[B"l  
} g/+P]c6/  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8U B-(~  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); mDmy637_  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", zBWn*A[4  
nEndPos = " + nFileLength); {z?e<  
// fileSplitterFetch[nPos.length-1].start(); 'xAfcP[^  
clQN@1] M  
7O{c>@\  
//等待子线程结束 /?l@7  
//int count = 0; P@ '<OI  
//是否结束while循环 8W?/Sg`  
boolean breakWhile = false; bet?5Dk  
}E$^!q{  
wy&s~lpV,7  
while(!bStop)  \p"`!n  
{ b_*Y5"(*  
write_nPos(); CuPZ0  
Utility.sleep(500); vukI`(#  
breakWhile = true; yG?,8!/]  
/jih;J|  
#SQao;>  
for(int i=0;i<nStartPos.length;i++) U7U-H\t7  
{ lmb5Z-xB  
if(!fileSplitterFetch.bDownOver) qp>O#tj[  
{ ev>gh0  
breakWhile = false; 1R)4[oYN\<  
break; j+Nun  
} KFHn)+*"  
} UJ1Ui'a(!!  
if(breakWhile) D0,U2d  
break; &eq>>  
v\ggFrG]  
xtL_,ug  
//count++; U3MfEM!x  
//if(count>4)  ^G{3x  
// siteStop(); ny17(Y =  
} xd\k;nq  
w> `3{MTQ  
j{EN %  
System.err.println("文件下载结束!"); uWR\#D'  
} zzi%r=%r&  
catch(Exception e){e.printStackTrace ();} ]ERPWW;^  
} Ia:n<sZU  
$x]'6  
>=c<6#:s<9  
//获得文件长度 g7@G&Ro9J\  
public long getFileSize() Cul^b_UmP#  
{ 6=2M[T  
int nFileLength = -1; wwVK15t  
try{ ',nGH|K.  
URL url = new URL(siteInfoBean.getSSiteURL()); ;1}~(I#Y  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Pq`]^^=be'  
httpConnection.setRequestProperty("User-Agent","NetFox"); ^R\0<\'  
WlU^+ctS  
b Mi,z3z  
int responseCode=httpConnection.getResponseCode(); Iz^~=yV)  
if(responseCode>=400) zh)qo  
{ 2'tZ9mK  
processErrorCode(responseCode); k'Fc:T8:~5  
return -2; //-2 represent access is error B e"D0=<  
} =mYY8c Yl  
)s1W)J?8  
! FbW7"yE  
String sHeader; 0V ,R|Ln  
/\_`Pkd3m  
-:t<%]RfY  
for(int i=1;;i++) 0 } uEM_a  
{ t8 g^W K  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); hv te)  
//Utility.log(in.readLine()); m/3b7c@r  
sHeader=httpConnection.getHeaderFieldKey(i); B<(v\=xZ  
if(sHeader!=null) `s(T (l  
{ ZWaHG_ U)  
if(sHeader.equals("Content-Length")) .)|r!X  
{ xJrRJwL  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader));  )]L:OE  
break; vttmSdY  
} eZR{M\Q  
} }5-^:}gL   
else $J&ww P[  
break; =< j8)2  
} 'S\YNLqQ  
} K?:rrd=7q  
catch(IOException e){e.printStackTrace ();} 6"C$]kF?  
catch(Exception e){e.printStackTrace ();} msOk~ZPE6\  
iZ2|/hnw  
B'>(kZYMs  
Utility.log(nFileLength); `=^;q 6f  
V6Ie\+@.\  
d-nqV5  
return nFileLength; ) D:M_T2  
} !7t,(Id8  
?it49  
pJ-/"Q|:i  
//保存下载信息(文件指针位置) [xq"[*Evv  
private void write_nPos() 9{_D"h}}  
{ 6T0[ ~@g5  
try{ }@Lbv aa  
output = new DataOutputStream(new FileOutputStream(tmpFile)); lx,^Y 647  
output.writeInt(nStartPos.length); .w2X24Mmb  
for(int i=0;i<nStartPos.length;i++) YFgQ!\&59  
{ *.4;7#  
// output.writeLong(nPos); R}7>*&S:  
output.writeLong(fileSplitterFetch.nStartPos); 289teU  
output.writeLong(fileSplitterFetch.nEndPos); n.P$7%G`2  
} {t`UV,  
output.close(); jrT5Rw_}q  
} F }l_=  
catch(IOException e){e.printStackTrace ();} Kg^L 4Q  
catch(Exception e){e.printStackTrace ();} q@1!v  
} ZOvMA]Rf  
F M:ax{  
afOb-G$d=  
//读取保存的下载信息(文件指针位置) v+dt1;  
private void read_nPos() (%]&Pe]  
{ QWG?^T fi  
try{ i~:FlW]  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .n1]Yk;,1  
int nCount = input.readInt(); !~PLW]Z4  
nStartPos = new long[nCount]; ; =.VKW%U  
nEndPos = new long[nCount]; C^I  h"S  
for(int i=0;i<nStartPos.length;i++) uSp=,2)  
{ "J^M@k\!  
nStartPos = input.readLong(); m@  b~  
nEndPos = input.readLong(); `r;e\Cp  
} H~x,\|l#  
input.close(); 'zV/4iE=  
} r168ft?c  
catch(IOException e){e.printStackTrace ();} |Z}uN!Jm  
catch(Exception e){e.printStackTrace ();} Jx[Z[RO2  
} o mstJ9  
U&#1qRm\h  
+*-u_L\'  
private void processErrorCode(int nErrorCode) Q?rb(u(  
{ x"0*U9f  
System.err.println("Error Code : " + nErrorCode); wQiRj.  
} Z[:fqvXQ  
v{9< ATi  
M?pu7wa  
//停止文件下载 r2H_)Oi  
public void siteStop() ~$ } `R=  
{ :{<( )gfk  
bStop = true; W _(  
for(int i=0;i<nStartPos.length;i++) -~T?xs0_  
fileSplitterFetch.splitterStop(); fbp6lE  
y)_T!&ze  
Pda(O;aNU  
} &A>Hq/Y  
} Y0iL+=[k`m  
//负责部分文件的抓取 UV8,SSDTV  
**FileSplitterFetch.java aR30wxW&)  
*/ f;M7y:A8q,  
package NetFox; m5Gt8Z 6a  
#UGm/4C  
RkP g&R;i  
import java.io.*; ukBj@.~  
import java.net.*; e(E6 t_  
3Tv;<hF  
X?5M)MP+I  
public class FileSplitterFetch extends Thread { 1MV\Jm  
A|p O  
1L.H"  
String sURL; //File URL @A6 P[r  
long nStartPos; //File Snippet Start Position X& EcQ  
long nEndPos; //File Snippet End Position o(5Xj$Z  
int nThreadID; //Thread's ID JJlwzH  
boolean bDownOver = false; //Downing is over ;7CE{/Bq.p  
boolean bStop = false; //Stop identical D/C,Q|Ya6  
FileAccessI fileAccessI = null; //File Access interface y1P KoN|K  
Bgs3sM9  
}I_/>58  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `ZL~k  
{ m'H%O-h\  
this.sURL = sURL; v7"' ^sZ?  
this.nStartPos = nStart; qXO@FW]  
this.nEndPos = nEnd; @WVpDhG  
nThreadID = id; BhC.#u/   
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Enr8"+.(  
} )HWf`;VQ  
@mM'V5_#  
ek6PMZF:'  
public void run() 8*y hx  
{ _:F0>=$  
while(nStartPos < nEndPos && !bStop) N q %@(K  
{ dX|(n.}  
\5.36Se  
3D>syf  
try{ LO{{3No  
URL url = new URL(sURL); w7}m T3p,)  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]&%_Fpx  
httpConnection.setRequestProperty("User-Agent","NetFox"); C8i6ESmU  
String sProperty = "bytes="+nStartPos+"-"; 1B+uv0lA  
httpConnection.setRequestProperty("RANGE",sProperty); q]+'{Ci@  
Utility.log(sProperty); Ru8k2d$B  
nE+OBdl  
tM3eB= .*  
InputStream input = httpConnection.getInputStream(); D4WvRxki  
//logResponseHead(httpConnection); "i/ l'  
3x2*K_A5:Q  
7,U^v}$   
byte[] b = new byte[1024]; ?:F#WDD  
int nRead; Iqe=)   
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Q$Y ]KV  
{ ``bIqY  
nStartPos += fileAccessI.write(b,0,nRead); 9 A0wiKp  
//if(nThreadID == 1) 'B&gr}@4O=  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &`hx   
} M]PH1 2Ob  
"@Ir Bi6  
z^s/7Va[  
Utility.log("Thread " + nThreadID + " is over!"); R5=2EwrGP  
bDownOver = true; A?I/[zkc  
//nPos = fileAccessI.write (b,0,nRead); ,YzrqVY  
} )`5k fj  
catch(Exception e){e.printStackTrace ();} w yi n  
} _(=[d  
} w_o|k&~,  
rMkoE7n  
--*Jv"/0  
//打印回应的头信息 t,|`#6Ft  
public void logResponseHead(HttpURLConnection con) _kR);\V.8  
{ (}1 gO  
for(int i=1;;i++) \]pRu"  
{  ;ew j  
String header=con.getHeaderFieldKey(i); <:=}1t.Z  
if(header!=null) B;f\H,/59  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); F!m/n!YR  
Utility.log(header+" : "+con.getHeaderField(header)); 0c*y~hUVZ  
else R zG7Xr=t  
break; Z9rmlVU6!  
} $*EK v'g[n  
} d $~q  
\ci'Cbn\o  
)Zx;Z[  
public void splitterStop() #P[d?pY  
{ oJ}!qrrH  
bStop = true; Qu4Bd|`(k  
} et[n;nl>V  
6`(x)Q9  
w6ZyMR,T  
} Y>v(UU  
bs{i@1$  
D|`O8o?)  
/* !Yuu~|  
**FileAccess.java 7q_B`$ata  
*//文件访问(定位,写) @&!`.Y oy  
package NetFox; Th&-n%r9K  
import java.io.*; 8%-+@ \=  
#gjhs"$~  
AWkXW l}  
public class FileAccessI implements Serializable{ dN'2;X  
$#q:\yQsPC  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \ZSZ(p#1  
RandomAccessFile oSavedFile; q1C) *8*g  
long nPos; ry bs9:_}  
c s0;:H*N*  
]P lD e8  
public FileAccessI() throws IOException ,khB*h14;h  
{ t+C9QXY  
this("",0); 72J@Dc  
} Y`$dtg {  
A UCk]  
!*Hgl\t6a  
public FileAccessI(String sName,long nPos) throws IOException \Km gFyF  
{ Rw8l"`  
oSavedFile = new RandomAccessFile(sName,"rw"); 9='a9\((mH  
this.nPos = nPos; a:$hK%^ \  
oSavedFile.seek(nPos); v X=zqV  
} 6:Eu[PE~w  
p6=L}L  
=3KK/[2M  
public synchronized int write(byte[] b,int nStart,int nLen) .9r+LA{  
{ ;IklS*p]  
int n = -1; HoA[U T  
try{ rof&O   
oSavedFile.write(b,nStart,nLen); >kK!/#ZA  
n = nLen; Co`O{|NS}!  
} VK/@jrL+  
catch(IOException e) Snm m (.  
{ R.KqTEs<k  
e.printStackTrace (); P<&-8QA  
} 6$42 -a%b  
~nul[>z  
!VNLjbee.  
return n; Vn:BasS%  
} P3[!-sv  
.m',*s<CMQ  
qIm?F>> @  
} ,:RHhg  
n.}A :Z  
{R`,iWV  
/* Ml)0z&jQX  
**SiteInfoBean.java iR k.t=B  
*/ \?n4d#=$o  
package NetFox; -Fi{[%&u  
n%N|?!rB  
tCkKJ)m  
public class SiteInfoBean { vn5X]U"  
HTfHAc?W  
Z^P]-CB|6A  
private String sSiteURL; //Site's URL Jptzc:~B  
private String sFilePath; //Saved File's Path B.:DW3  
private String sFileName; //Saved File's Name dy>iIc>  
private int nSplitter; //Count of Splited Downloading File RL0#WBR  
014p= W  
P<Wtv;Z1Z  
public SiteInfoBean() oH;0_!  
{//nSplitter的缺省值为5 o: \&4z&=  
//default value of nSplitter is 5 al{;]>W  
this("","","",5); V1aWVLltj  
} TDvUiJm  
41\r7 BS  
z^tws*u],5  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #g)$m}tv?  
{ HiTn5XNf  
sSiteURL= sURL; :g1C,M~  
sFilePath = sPath; 3Thb0\<"  
sFileName = sName; )(&Z&2~A  
this.nSplitter = nSpiltter; gY)NPi}!`  
qU ESN!  
a' sa{>  
} /^#8z(@B  
^]iIvIp  
G@4ro<  
public String getSSiteURL() {|Ew]Wq  
{ !8cS1(a  
return sSiteURL; H l'za  
} <IiX_*  
f 7g?{M  
'|v??`o#  
public void setSSiteURL(String value) IU f1N+-z  
{ ~d+.w%Z `  
sSiteURL = value; < 5%:/j  
} 43i@5F]  
g>])O  
Vl91I+Ev  
public String getSFilePath() qu}`;\9@ld  
{ AOh\%|}  
return sFilePath; (%\vp**F  
} )v1y P  
%RlG~a  
+ ?z=,')  
public void setSFilePath(String value) I-@A{vvPK  
{ r9),F.6,  
sFilePath = value; [K(|V  
} *pu ,|  
};rxpw>ms  
+/">]QJ  
public String getSFileName() Eb9 eEa<W  
{ K^H{B& b8  
return sFileName; =Gka;,n  
} Ek0zFnb[Gx  
O$'BJKj-4  
?*2DR:o>@  
public void setSFileName(String value) v'x)AbbC  
{ ^lF'KW$  
sFileName = value; s7x&x;-  
} 'X()|{  
f-w-K)y$ht  
XkG:1H;Q%  
public int getNSplitter() =qQH,{]c6  
{ ?CaMn b8  
return nSplitter; p};B*[ki  
} [| \Z"   
-k$*@Hq  
5>E]C=maD  
public void setNSplitter(int nCount) B%~hVpm,eM  
{ 5xHP5+&  
nSplitter = nCount; WtT* 1Z  
} z>\vYR$  
} "OIra2O  
||M;[-JoJ  
}8H_^G8  
/* /dT7:x*  
**Utility.java !B&OK&*  
*/ M Y2=lT  
package NetFox; a>3#z2#  
O WJv<3  
U Bo[iZ|%  
public class Utility { F\!Va  
G5C=p:o{/  
PrA?e{B5m  
public Utility() lT`y=qR|  
{ 0E6>P E;  
S;!l"1[;  
: h"Bf@3  
} {8!\aYI  
W@X/Z8.(  
//线程睡眠 v;S_7#  
public static void sleep(int nSecond) q%G"P*g$(  
{ t`b!3U>I  
try{ ;y"=3-=vM"  
Thread.sleep(nSecond); q_5hKipd\b  
} hKG)* Q  
catch(Exception e) =/ b2e\  
{ -E*VF{IG1  
e.printStackTrace (); kOu C@~,  
} \`FpBE_e)  
} !$q *~F"S  
+prr~vgE  
//日志 3RwDIk?>%  
public static void log(String sMsg) rA=iBb3`  
{ nUp, %z[  
System.err.println(sMsg); ~\UH`_83[  
} anM]khs?  
E< 57d,3l  
P(n_eIF-f  
public static void log(int sMsg) OMl<=;^:|  
{ yvQRr75  
System.err.println(sMsg); NCid`a$  
} il=:T\'U9  
} E46+B2_~zk  
JO|%Vpco  
xI'sprNa_1  
/* HDV@d^]-  
**TestMethod.java 4#dS.UfI  
*/ ( 04clU^F  
package NetFox; qs9q{n-Aj  
 T:~c{S4&  
|8DMj s()*  
public class TestMethod { u\&F`esQ2  
| Ns-l (l  
E`M, n ,  
public TestMethod() n`W7g@Sg#I  
{ ///xx/weblogic60b2_win.exe Rxl )[\A*  
try{ n7CwGN%  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 1N3qMm^  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); h$[tEmD%  
SiteFileFetch fileFetch = new SiteFileFetch(bean); sQIzcnKB  
fileFetch.start(); Vo G`@^s  
} 8p91ni'  
catch(Exception e){e.printStackTrace ();} bL6, fUS  
w &b?ze{  
:u ruC  
} _J N$zZ{  
B&bQvdp  
"8BZj;yS  
public static void main(String[] args) u{Rgk:bn  
{ AA&5wDMV>  
new TestMethod(); i_[nW  
} E1"H( m&6  
} Xb/W[rcs  
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