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http断点续传简单实现(java)

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/* h\p!J-V  
**SiteFileFetch.java ] s^7c  
*/ \WBO(,]V  
package NetFox; s= ]NKJaQH  
import java.io.*; gD51N()s,  
import java.net.*; 41]a{A7q  
*;)O'|  
7H09\g&  
public class SiteFileFetch extends Thread { &XV9_{Hm  
F b?^+V]9  
$OG){'X  
SiteInfoBean siteInfoBean = null; //文件信息Bean =tbfBK+  
long[] nStartPos; //开始位置 O\ _ro.  
long[] nEndPos; //结束位置  B$6KI  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 X4 ] miUmh  
long nFileLength; //文件长度 {:3\Ms#  
boolean bFirst = true; //是否第一次取文件 Q=8YAiCu  
boolean bStop = false; //停止标志 n807?FORB  
File tmpFile; //文件下载的临时信息 'YB[4Q /0  
DataOutputStream output; //输出到文件的输出流 ?QmtZG.$  
=^GPQ_"  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) Pjk2tf0j`  
public SiteFileFetch(SiteInfoBean bean) throws IOException Pn^`_  
{ q01 L{~>bz  
siteInfoBean = bean; Ufl\ uq3'H  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); [.^ol6  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");  [Q{\Ik  
if(tmpFile.exists ()) ZM})l9_o"  
{ Zj!,3{jX^  
bFirst = false; *1Bq>h:  
read_nPos(); ?IYu"UO<)|  
} *~g*J^R}  
else u.|%@  
{ J/jkb3  
nStartPos = new long[bean.getNSplitter()]; 26g]_Igq  
nEndPos = new long[bean.getNSplitter()]; .n1&Jsey  
} ,|d9lK`"P  
bJetqF6 n  
r@}`Sw]@  
CDM6o!ur3  
} _,!0_\+i  
triU^uvh  
{h|<qfH  
public void run() ']TWWwj$  
{ 7bk77`qWr  
//获得文件长度 )-_^vB  
//分割文件 ,IyQmN y  
//实例FileSplitterFetch #?Kw y  
//启动FileSplitterFetch线程 lwq:0Rj@Q  
//等待子线程返回 pdRM%ug   
try{ S?d<P  
if(bFirst) @JXpD8jn  
{ g}v](Q  
nFileLength = getFileSize(); mA{?E9W  
if(nFileLength == -1) zawu(3?~)5  
{ Tk?uJIS :  
System.err.println("File Length is not known!"); V.&F%(L  
} {6H[[7i  
else if(nFileLength == -2) `=H*4I-"  
{ JY2<ECO  
System.err.println("File is not access!"); YK)m6zW5  
} GMJ4v S  
else x6`mv8~9Db  
{ ;.uYWP|9  
for(int i=0;i<nStartPos.length;i++) &Gjpc>d  
{ ^AH[]sE_  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); e&;e<6l&{  
} i8V\x>9  
for(int i=0;i<nEndPos.length-1;i++) EL`|>/[J  
{ p[JIH~nb  
nEndPos = nStartPos[i+1]; 4j=3'Z|  
} -`I|=lBz{H  
nEndPos[nEndPos.length-1] = nFileLength; U0_)J1Yp  
} d}4NL:=&  
} ;[::&qf  
Sv M\9  
ZU`9]7"87B  
//启动子线程 #"4ioTL2  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; aDdGhB  
for(int i=0;i<nStartPos.length;i++) =\< 7+nv  
{ 3P6O]x<-?  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Bib<ySCre  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), @e)}#kN.  
nStartPos,nEndPos,i); 8X,6U_>#a  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @ !P2f   
fileSplitterFetch.start(); 5`.CzQVb  
} G1z*e.+y  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wtek5C^  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); V O:4wC"7  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", b]]8Vs)'  
nEndPos = " + nFileLength); pJ] Ix *M  
// fileSplitterFetch[nPos.length-1].start(); J,?#O#j  
v8ap"9b  
@PvO;]]%  
//等待子线程结束 *DPX4 P  
//int count = 0; Y6v{eWtSn  
//是否结束while循环 /A7( `l;6  
boolean breakWhile = false; O=2|'L'h!  
!1)aie+p6  
vUpAW[[  
while(!bStop) (L/>LZn|  
{ _= v4Iz0  
write_nPos(); AT"gRCU$4  
Utility.sleep(500); (!nkv^]  
breakWhile = true; uxf,95<g)  
!rUP&DA  
>1s a*Wf  
for(int i=0;i<nStartPos.length;i++) {U=J>#@G  
{ >38>R0k35  
if(!fileSplitterFetch.bDownOver) ?#K.D vGJ  
{ [KK |_  
breakWhile = false; uE's&H  
break; \(Sly&gL  
} 8TP$?8l  
} Nj>6TD81u  
if(breakWhile) 7S{qo&j'  
break; 2`f{D~w  
{zb'Z Yz  
E'LI0fr  
//count++; huC{SzXM  
//if(count>4) FHOw ]"#  
// siteStop(); K}l3t2uk  
} 4eHSAN"$  
|o5eG><  
y74Q(  
System.err.println("文件下载结束!"); DhM=q  
} '8q3ub<\  
catch(Exception e){e.printStackTrace ();} M|DMoi8x  
} &O' W+4FAc  
ukR0E4p  
R:~aX,qR  
//获得文件长度 O)dnr8*  
public long getFileSize() /z-rBfdy^  
{ V+`kB3GV  
int nFileLength = -1; Clum m@z;#  
try{ s>>&3jfM  
URL url = new URL(siteInfoBean.getSSiteURL()); ?Q]&;5o  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); N1'`^ay$  
httpConnection.setRequestProperty("User-Agent","NetFox"); eGEwXza 4  
l?m"o-Gp3  
qd0G sr}j  
int responseCode=httpConnection.getResponseCode(); wsQnjT>  
if(responseCode>=400) Dd?G4xUG  
{ ,%9XG077  
processErrorCode(responseCode); "|3I|#s  
return -2; //-2 represent access is error ZG=]b%  
} tyR?A>F4  
}3*<sxw7<  
^OY$ W  
String sHeader; ^OV; P[  
Dmh$@Uu#F  
| xB`cSu(  
for(int i=1;;i++) rp@:i _]  
{ wC{sP"D  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); p.W7>o,[w  
//Utility.log(in.readLine()); ]ae(t`\l^  
sHeader=httpConnection.getHeaderFieldKey(i); MRpMmu  
if(sHeader!=null) mV^w|x  
{ -m`|Sq  
if(sHeader.equals("Content-Length")) $J6 .0O  
{ fJ Ll-H  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); K&[0`sH!  
break; 1GN^ui a7  
} ]t 0o%w  
} ?\\wLZ  
else ;u2[Ww~k  
break; Y(,RJ&7  
} Q`bXsH  
} s,_+5ukv  
catch(IOException e){e.printStackTrace ();} eCI'<^  
catch(Exception e){e.printStackTrace ();} H>+/k-n-  
goR_\b SU  
.<t{saToU  
Utility.log(nFileLength); (XOz_K6c%K  
I{$suPk  
m'2F#{  
return nFileLength; ;<i u*a  
} mu B Y  
dC6>&@ VX  
1:eWZ]B5"  
//保存下载信息(文件指针位置) O8Mypv/C  
private void write_nPos() j)@W1I]2#  
{ ~|KqG  
try{ @JSWqi>  
output = new DataOutputStream(new FileOutputStream(tmpFile)); /o4_rzR?  
output.writeInt(nStartPos.length); %/2 ` u  
for(int i=0;i<nStartPos.length;i++) B>i%:[-e  
{ r8(oTx  
// output.writeLong(nPos); $@VJ@JAe  
output.writeLong(fileSplitterFetch.nStartPos); <);j5)/  
output.writeLong(fileSplitterFetch.nEndPos); =)bOteWM  
} _L8&.=4]i  
output.close(); )nHMXZ>Td  
} HP*)^`6X  
catch(IOException e){e.printStackTrace ();} yl>^QMmo  
catch(Exception e){e.printStackTrace ();} Y5 E0n(Z  
} bAt!S  
kg Bkwp  
U,b80%k:  
//读取保存的下载信息(文件指针位置) $U,]c  
private void read_nPos() _U}|Le@ e  
{ zDYJe_m ~  
try{ E `N`  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >XZ2w_  
int nCount = input.readInt(); 9ZOQNN<ex  
nStartPos = new long[nCount]; f.ua,,P.  
nEndPos = new long[nCount]; 7_Vd%<:  
for(int i=0;i<nStartPos.length;i++) T \34<+n1N  
{ ]>)}xfL &,  
nStartPos = input.readLong(); p YCMJK-H  
nEndPos = input.readLong(); T72Li"00  
} z .lb(xQ  
input.close(); ';eAaDM  
} o<b  
catch(IOException e){e.printStackTrace ();} tQj=m_  
catch(Exception e){e.printStackTrace ();} [GyPwb-  
} [ GknE#p  
4-O.i\1q  
2s2KI=6  
private void processErrorCode(int nErrorCode) lxTqGwx  
{ (O ;R~Io  
System.err.println("Error Code : " + nErrorCode); f[zKA{R  
} %.[AZ>  
=[4C[s  
@ &c@  
//停止文件下载 [9EL[}  
public void siteStop() #)D$\0ag  
{ +SV!QMIg  
bStop = true; Pd:tRY+t/  
for(int i=0;i<nStartPos.length;i++) 6mZpyt  
fileSplitterFetch.splitterStop(); U&kdR+dB  
#;2mP6a[  
bN*zx)f  
} Qm3 RXO  
} q+YK NXI  
//负责部分文件的抓取 /\jRr7 Cd  
**FileSplitterFetch.java v]drDVJ   
*/ vO{[P# L}  
package NetFox; gO~>*q &  
n-9X<t|*?a  
Ft2 ZZ<As  
import java.io.*; 1 xrmmK  
import java.net.*; #$t93EI  
K<ldl.  
Ky7-6$  
public class FileSplitterFetch extends Thread { $I@. <J*  
kD+B8TrW  
(B+zh  
String sURL; //File URL mnMY)-6C  
long nStartPos; //File Snippet Start Position Q!Dr3x  
long nEndPos; //File Snippet End Position d cht8nX7~  
int nThreadID; //Thread's ID 4pu>f.  
boolean bDownOver = false; //Downing is over ,J-YfL^x6*  
boolean bStop = false; //Stop identical ">I50#bT  
FileAccessI fileAccessI = null; //File Access interface eR1]<Z$W\  
j"+R*H(#  
Xo4K!U>TzZ  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 8-vNXvl  
{ WAw} ?&k  
this.sURL = sURL; FCr>$  
this.nStartPos = nStart; d 7QWK(d  
this.nEndPos = nEnd; *O-si%@]  
nThreadID = id; F[|aDj@q e  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 c;7ekj  
} v/Ei0}e6~  
_1Iw"K49Qx  
l3/?,xn  
public void run() tO QY./I  
{ R75np^  
while(nStartPos < nEndPos && !bStop) b!|c:mE9|  
{ ^$O,Gy)V  
hz+x)M`Y  
b{d@:"  
try{ ?To r)>A'  
URL url = new URL(sURL); \xaK?_hv  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ddjaM/.E  
httpConnection.setRequestProperty("User-Agent","NetFox"); {@[z-)N7\,  
String sProperty = "bytes="+nStartPos+"-"; *FUbKr0  
httpConnection.setRequestProperty("RANGE",sProperty); bjJ212J  
Utility.log(sProperty); wg,w;Gle  
>'lte&  
6d3-GMUQ  
InputStream input = httpConnection.getInputStream(); rOy-6og  
//logResponseHead(httpConnection); pEE.%U  
&P{[22dQ  
_gF )aE  
byte[] b = new byte[1024]; 2^7VDqLc  
int nRead; ',p`B-dw  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) {)0"?$C_H  
{ t1YVE%`w  
nStartPos += fileAccessI.write(b,0,nRead); "M.vu}~>  
//if(nThreadID == 1) e'zG=  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); vN%SN>=L<  
} Hh8)d/D  
LN?W~^gsR  
@nS+!t{  
Utility.log("Thread " + nThreadID + " is over!"); W]rK*Dc  
bDownOver = true; ^J]~&.l  
//nPos = fileAccessI.write (b,0,nRead); dw!cDfT+  
} .5zqpm  
catch(Exception e){e.printStackTrace ();} LMrb 1lg$  
} /r Hd9^Y  
} ~sSlfQWMzy  
=q( ;g]e  
b}9Ry"  
//打印回应的头信息 viT/$7`AI  
public void logResponseHead(HttpURLConnection con) yb#NB)+E@  
{ G~I@'[ur  
for(int i=1;;i++) ^U.8grA  
{ <o";?^0Q  
String header=con.getHeaderFieldKey(i); G.,dP +i  
if(header!=null) A-&C.g  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); m]$!wp  
Utility.log(header+" : "+con.getHeaderField(header)); g,!6, v@  
else Lh6G"f(n  
break; UHYnl ]  
} @""aNKA^r>  
} R*D0A@  
$4y;F]  
Ax4nx!W,   
public void splitterStop() jd|? aK;(  
{ 1O0o18'  
bStop = true; u|.L7 3<j%  
} wG4=[d  
HgP9evz,0  
PYYOC"$  
} F`;oe[wfk  
++Qg5FukR  
+^ n\?!  
/* ~*9 vn Z@  
**FileAccess.java C#`VVtei  
*//文件访问(定位,写) e.%` tK3J  
package NetFox; V^WR(Q}  
import java.io.*; wIIxs_2Q0c  
ML!Z m[I9  
z^to"j  
public class FileAccessI implements Serializable{ 't:|>;Wx  
-(4)lw>U  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Bkvh]k;F8  
RandomAccessFile oSavedFile; @sRUl ,M;Z  
long nPos; #wL}4VN  
\Jr ta  
Z> jk\[  
public FileAccessI() throws IOException R87-L*9B^0  
{ 8_6\>hW&  
this("",0); T> cvV  
} 5_@ u Be~  
fJ_d ,4  
fGDR<t3yiQ  
public FileAccessI(String sName,long nPos) throws IOException 2yk32|  
{ SR@yG:~  
oSavedFile = new RandomAccessFile(sName,"rw"); C~IsYdln  
this.nPos = nPos; E^a He  
oSavedFile.seek(nPos); _Gv[ D  
} hce *G@b  
_zq"<Q c  
&L[7jA'[J  
public synchronized int write(byte[] b,int nStart,int nLen) #gzY _)E  
{ y%A!|aBu  
int n = -1; z yyt`  
try{ 8.4 1EKr2  
oSavedFile.write(b,nStart,nLen); \^O#)&5 V  
n = nLen; .}W#YN$  
}  'k[O?}  
catch(IOException e) .:?X<=!S&t  
{ MYgh^%w:  
e.printStackTrace (); TxL;qZRY ^  
} ?-mDvW  
Gq_rZo(@  
|F _ Z  
return n; G9y 0;br  
} wg<UCmfu!  
%a- *Ku  
H4[];&]xr  
} J ik+t\A  
egcJ@Of  
"iFA&$\  
/* i7g+8 zd8d  
**SiteInfoBean.java 4 [2^#t[  
*/ : tKa1vL  
package NetFox; HPT{83  
u~MD?!LV  
o4I&?d7;"  
public class SiteInfoBean { M{#  
ATq)8Rm\  
. C_\xb  
private String sSiteURL; //Site's URL 3QlV,)}  
private String sFilePath; //Saved File's Path ?' F>DN  
private String sFileName; //Saved File's Name t Dx!m~[  
private int nSplitter; //Count of Splited Downloading File T8|aFoHCK  
6- H81y 3  
E[N5vG<  
public SiteInfoBean() L@> +iZSO  
{//nSplitter的缺省值为5 3,qq\gxB  
//default value of nSplitter is 5 ? U~}uG^  
this("","","",5); -oGJPl{r  
} @o&.]FZs  
rG7S^,5o  
6n9;t\'Gt  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2K/+6t}  
{ B/#tR^R  
sSiteURL= sURL; s':fv[%  
sFilePath = sPath; WH Zz?|^  
sFileName = sName; ('1k%`R%  
this.nSplitter = nSpiltter; slSQ\;CDA  
=Rnx!E  
8ut:cCrmg  
} C:C9swik"5  
)*&I|L<1  
:/e= J  
public String getSSiteURL() " bHeNWZ  
{ cI#2MjL  
return sSiteURL; \VW&z:/*pZ  
} *h ~Y=#`8*  
F_Q,j]0  
~r~~0|=  
public void setSSiteURL(String value) Bsm>^zZ`YU  
{ JM8 s]&  
sSiteURL = value; @&f3zq  
} 6`LC(Nv%-n  
F">>,Oc)U"  
p_hljgOV  
public String getSFilePath() |.D_[QI  
{ o!Vs{RRu}  
return sFilePath; ;0}8vs  
} .F'fBT` $  
j[/'`1tOe  
5[WhjTo  
public void setSFilePath(String value) B!jINOg  
{ z~d\d!u1  
sFilePath = value; #k%3Ag  
} Ed/@&52z0  
dvUBuY^[  
1XZ|}Xz  
public String getSFileName() "i$uV3d  
{ x/$s:[0B#  
return sFileName; (]BZ8GOx  
} :=#*[H  
\mZ\1wzn'{  
+NRn>1]  
public void setSFileName(String value) [P*3ld,,G%  
{ Xq&x<td  
sFileName = value; {aq\sf;i{  
} |Iy55~hK`  
pk'@!|g%=  
0|X!Uw-Q%_  
public int getNSplitter() LX.1]T*m`  
{ eafy5vN[zX  
return nSplitter; vx=I3o  
} 7p}G!]`  
+P6#7.p`Z  
qR<  
public void setNSplitter(int nCount) >Uvtsj#  
{ h Ia{s)  
nSplitter = nCount; 9frx60  
} *qg9~/  
} X|L8s$>  
{Ny\9r  
fmie,[  
/* sZ-]yr\E"  
**Utility.java c< gM  
*/ Kq`Luf  
package NetFox; *Kt7"J  
~nb%w?vv  
xtjTU;T  
public class Utility { /#$bb4  
<C6/R]x#  
bi!4I<E>k  
public Utility() L&ws[8-  
{ 4:cbasy  
w0~iGr}P  
9G_=)8sOV  
} ;JFE7\-mC  
^g[\.Q  
//线程睡眠 W<2%J)N<  
public static void sleep(int nSecond) <E@ 7CG.=  
{ UVu"meZX  
try{ *wp'`3y}  
Thread.sleep(nSecond); .Z&OKWL  
} >^:g[6Sj  
catch(Exception e) &7Ixf?e!K  
{ 0 P/A  
e.printStackTrace (); (Wq9YDD@  
} EyNI]XEj  
} ^yK94U;<Gy  
Vu\|KL|  
//日志 V@>?lv(\  
public static void log(String sMsg) 94APjqV6'  
{ 8tA.d.8  
System.err.println(sMsg); (%#d._j>fZ  
} N/{A ' Wd  
.ET;wK  
no?)GQ  
public static void log(int sMsg) 6xL=JSi~  
{ 'VJMi5Y(-  
System.err.println(sMsg); ?RpT_u  
} #EHBS~^  
} c;U\nC<Y  
9^a>U(,  
+{hxEDz  
/* EE}NA{b  
**TestMethod.java !a~x |pjJ  
*/ WKah$l  
package NetFox; 2zFdKs,  
1r~lh#_8  
c+a f=ac  
public class TestMethod { T@yH. 4D  
\=N tbBL$[  
l42m81x"  
public TestMethod() ik$wS#1+L  
{ ///xx/weblogic60b2_win.exe On'3K+(_  
try{ |Y'$+[TE  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); J`RNik*>  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); H <1?<1^  
SiteFileFetch fileFetch = new SiteFileFetch(bean); _5`M( ;hL2  
fileFetch.start(); E<\\'VF  
} NWAF4i&$  
catch(Exception e){e.printStackTrace ();} BB%(!O4Dl  
(VOKa  
;~1r{kXxA"  
} pRU6jV 6e)  
ESomw  
Hzj*X}X#K  
public static void main(String[] args) c%Gz{':+  
{ /6q/`vx@  
new TestMethod(); ~zm/n,Epb  
} Iyc')\W&  
} `S~u4+y]  
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