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http断点续传简单实现(java)

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/* &_9YLXtMi;  
**SiteFileFetch.java v Zb|!#I  
*/ -c+>j  
package NetFox; >-5td=:Z  
import java.io.*; .!yWF?T8  
import java.net.*; 1mHwYT+  
]6{(Hjt  
qGnPnQc  
public class SiteFileFetch extends Thread { &so-O90  
-RG8<bI,  
P>*Fj4 Z~  
SiteInfoBean siteInfoBean = null; //文件信息Bean }+Rgx@XZ\  
long[] nStartPos; //开始位置 . [T'yc:=  
long[] nEndPos; //结束位置 /!=U +X  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 @up&q  
long nFileLength; //文件长度 7 9Qc`3a  
boolean bFirst = true; //是否第一次取文件 2J;kD2"!  
boolean bStop = false; //停止标志 D:wnO|:  
File tmpFile; //文件下载的临时信息 onnI !  
DataOutputStream output; //输出到文件的输出流 t_jyyHxoZ:  
& u$(NbK  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) vG]GQ#  
public SiteFileFetch(SiteInfoBean bean) throws IOException bz{^h'  
{ 3ty4D2y  
siteInfoBean = bean; [ rQMD^:M$  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); I&L.;~  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); U^%9 )4bj  
if(tmpFile.exists ()) rO/a,vV  
{ w4\BD&7V  
bFirst = false; P<%v +O  
read_nPos(); -xJX_6}A  
} Ci~f#{  
else tm(v~L%$>]  
{ (VgNb&Yo9  
nStartPos = new long[bean.getNSplitter()]; 7:n?PN(p6a  
nEndPos = new long[bean.getNSplitter()]; (y1$MYZ Q  
} SQ}S4r  
5;W\2yj  
7MY)\aH  
{7vgHutp  
} P}HC(S1  
Y!SE;N&  
vqq6B/r@Fu  
public void run() Y [W6Sc  
{ >s&XX, w  
//获得文件长度 >n]oB~P%  
//分割文件 A-Mj|V  
//实例FileSplitterFetch -i#J[>=w{C  
//启动FileSplitterFetch线程 @-0Fe9 n=  
//等待子线程返回 9Ei5z6Vk/+  
try{ N99[.mErU  
if(bFirst) ^_@r.y]  
{ :<L5sp  
nFileLength = getFileSize(); /@VsqD  
if(nFileLength == -1) {'NBp0i  
{ -*?p F_*w  
System.err.println("File Length is not known!"); R"@7m!IA  
} ]k[x9,IU\y  
else if(nFileLength == -2) E W`W~h[  
{ jDR')ascn  
System.err.println("File is not access!"); F8;mYuA  
} 6DB0ni  
else <mL%P`Jj  
{ C 8N%X2R  
for(int i=0;i<nStartPos.length;i++) @B?FE\  
{ _ w/_(k  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); tl|ijR  
} .}o~VT:!?Y  
for(int i=0;i<nEndPos.length-1;i++)  Nj+a2[  
{ T/ik/lFI  
nEndPos = nStartPos[i+1]; -$. 0Dc)3!  
} sa*g  
nEndPos[nEndPos.length-1] = nFileLength; gNqAj# m  
} >?z:2@Q)B  
} H nK!aa  
{@3z\wMK$  
vd`O aM}#U  
//启动子线程 h\(B#SN  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6 Ew@L<v  
for(int i=0;i<nStartPos.length;i++) RT,:hH  
{ eH %Ja[  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), GWhE8EDT  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?=<~^Lk  
nStartPos,nEndPos,i); ]% K' fXj$  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1B 5:s,Oyj  
fileSplitterFetch.start(); \wYc1M@7V  
} qe<Hfp/p  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ioxbf6{  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ,]ga[  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =NadAyv  
nEndPos = " + nFileLength); ?-f,8Z|h  
// fileSplitterFetch[nPos.length-1].start(); =J](.78  
* r;xw  
w8p8 ;@  
//等待子线程结束 GF*>~_Yr  
//int count = 0; @o6R[5(  
//是否结束while循环 p}uncIod  
boolean breakWhile = false; pr_>b`p6  
28a$NP\KW  
sf$o(^P9\A  
while(!bStop) >TY6O.]  
{ R::zuv  
write_nPos(); 'S*k_vuN  
Utility.sleep(500); L_~8"I_  
breakWhile = true; (-,>qMQs  
;r.EC}>m  
Lkn4<'un  
for(int i=0;i<nStartPos.length;i++) KFU%DU G  
{ TkRmV6'w  
if(!fileSplitterFetch.bDownOver) ziiwxx_  
{ 49AW6H.JT  
breakWhile = false; dxK9:IX  
break; (,B#t7ka  
} Ird|C[la  
} 2s\BY%XY  
if(breakWhile) d1c0l{JV3  
break; ;'0=T0\  
D/CIA8h3  
.fp&MgiQ  
//count++; 5pfYEofK[  
//if(count>4) D<>@ %"%  
// siteStop(); XRxj  W  
} `:p1&OS  
5wv fF.v  
BEUK}T K4  
System.err.println("文件下载结束!"); uH:YKH':/  
} V%*b@zv  
catch(Exception e){e.printStackTrace ();} x6W `hpL  
} ~E)fpGJ  
9%tobo@J~n  
F'FP0t!S  
//获得文件长度 O6X"RsI}  
public long getFileSize() C h19h8M  
{ v+xB7w  
int nFileLength = -1; '#.#$8l  
try{ Ls}7VKl'   
URL url = new URL(siteInfoBean.getSSiteURL()); qtMD CXZ^n  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Rko M~`CT  
httpConnection.setRequestProperty("User-Agent","NetFox"); .UQE{.?  
2' ] KTHm  
<CZgQ\Mt  
int responseCode=httpConnection.getResponseCode(); , jU5|2  
if(responseCode>=400) e2cP *J  
{ 6;iJ*2f5V  
processErrorCode(responseCode); ;wHCj$q  
return -2; //-2 represent access is error l1'6cLT`  
} 3I  $>uR  
Z"y=sDO{  
bm# (?  
String sHeader; YlF%UPp  
H,y4`p 0  
-oP'4QVb  
for(int i=1;;i++) \+ 0k+B4a  
{ R[jEvyD>(  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &%mXYj3y5  
//Utility.log(in.readLine()); ?!'Zf Q:zK  
sHeader=httpConnection.getHeaderFieldKey(i); iM]o"qOQm  
if(sHeader!=null) Nd@~>&F  
{ Ef)yQ  
if(sHeader.equals("Content-Length")) 4a''Mi`u  
{ h@ )  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); NxA)@9Q  
break; Hy_;nN+e  
} 4vWkT8HQ  
} .i Hn5SGA  
else >V$ Gx>I  
break; Vsnuy8~k  
} <hx+wrv  
} Ig6T g ?  
catch(IOException e){e.printStackTrace ();} :j^FJ@2_  
catch(Exception e){e.printStackTrace ();} x@KZ ]  
i'#Gy,R  
4 %W:  
Utility.log(nFileLength); bZ1 78>J]  
yuhnYR\`m  
~Z'w)!h  
return nFileLength; sN6N >{  
} {Ui =b+  
eq4C+&O&  
4\M.6])_   
//保存下载信息(文件指针位置) 9DQa PA6  
private void write_nPos() vVl; |  
{ tmUFT  
try{ Z\}K{#   
output = new DataOutputStream(new FileOutputStream(tmpFile)); {0"YOS`3AX  
output.writeInt(nStartPos.length); *%/~mSx  
for(int i=0;i<nStartPos.length;i++) ^-z=`>SrS"  
{ W ~f(::  
// output.writeLong(nPos); H<EQu|f&x  
output.writeLong(fileSplitterFetch.nStartPos); k%]=!5F  
output.writeLong(fileSplitterFetch.nEndPos); GL{57  
} /3B $(  
output.close(); uocHa5J  
} }a AH  
catch(IOException e){e.printStackTrace ();} ig}A9j?]  
catch(Exception e){e.printStackTrace ();} \p{5D`HY  
} !V 2/A1?  
?L&|Uw+  
$-}e; VZb  
//读取保存的下载信息(文件指针位置) z7GTaX$d  
private void read_nPos() \;u@"  
{ qt%D'  
try{ b` Hz$8  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )B,|@ynu  
int nCount = input.readInt(); 1K,1X(0rL8  
nStartPos = new long[nCount]; \^7C0R-hX  
nEndPos = new long[nCount]; U-/{0zB  
for(int i=0;i<nStartPos.length;i++) K"j_>63)  
{ Ig]iT  
nStartPos = input.readLong(); kVK/9dy-F  
nEndPos = input.readLong(); OCZaQ33  
} s, k  
input.close(); LJk%#yV|_  
} &F STpBu  
catch(IOException e){e.printStackTrace ();} %1}K""/  
catch(Exception e){e.printStackTrace ();} D(-yjY8aG  
} w }Uhd ,  
o*U]v   
s*U1  
private void processErrorCode(int nErrorCode) Wjhvxk  
{ &nBa=Enf  
System.err.println("Error Code : " + nErrorCode); AdRX`[ik  
} <\kr1qH H  
iu&wO<)+?  
[ i#zP  
//停止文件下载 >SPh2[f  
public void siteStop() ~ .;<  Bj  
{ M9zfT !-  
bStop = true; {pM?5"M MJ  
for(int i=0;i<nStartPos.length;i++) hW!)w  
fileSplitterFetch.splitterStop(); q[`j`8YY!R  
b& 1`NO  
y6]vl=^L  
} cuy1DDl  
} zg-2C>(6a  
//负责部分文件的抓取 34\(7JO  
**FileSplitterFetch.java p-.n3AL  
*/ !uQPc   
package NetFox; ( Jz;W<E  
pPd#N'\*  
i[wb0yL  
import java.io.*; yR(x+ Gs{]  
import java.net.*; T)r9-wOq  
a!O0,y  
Q0EiEX)  
public class FileSplitterFetch extends Thread { ~ vqa7~}m  
>jD[X5Y  
4Y[1aQ(%  
String sURL; //File URL Y>'|oygHA  
long nStartPos; //File Snippet Start Position cM&{+el  
long nEndPos; //File Snippet End Position E[Cb|E  
int nThreadID; //Thread's ID EkziAON  
boolean bDownOver = false; //Downing is over jH_JmYd  
boolean bStop = false; //Stop identical $56,$K`H  
FileAccessI fileAccessI = null; //File Access interface xyI}y(CN1  
7jdb)l\p=  
As>_J=8} 3  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?lP':'P  
{ 9K1oZ?)_z  
this.sURL = sURL; %2v4<icvq  
this.nStartPos = nStart; yn#X;ja-  
this.nEndPos = nEnd; l ok=  
nThreadID = id; \L"kV!>  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =UV`.d2[  
} u*hSj)vr1  
>$4d7.^hb/  
o}ZdTf=  
public void run() 812$`5l  
{ t.;LnrY  
while(nStartPos < nEndPos && !bStop) G;YrF)\  
{ r?/'!!4  
Fi0GknQ+  
i-6 Z"b{  
try{ ~c\e'&sc;  
URL url = new URL(sURL); Qjb:WC7he  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .0es 3Rj  
httpConnection.setRequestProperty("User-Agent","NetFox"); p|!  
String sProperty = "bytes="+nStartPos+"-"; #'y#"cmQ.  
httpConnection.setRequestProperty("RANGE",sProperty); 4ecP*g  
Utility.log(sProperty); NX}<*b/  
R6(oZph  
9g<7i  
InputStream input = httpConnection.getInputStream(); EKO[!,  
//logResponseHead(httpConnection); 5k.oW=  
w4gJoxY-`  
' ET~  
byte[] b = new byte[1024]; v d[0X;  
int nRead; 4M2j!Sw  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *6 >.!&  
{ RN e^; B  
nStartPos += fileAccessI.write(b,0,nRead); 76`8=!]R  
//if(nThreadID == 1) }9FSO9*&}  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .nVa[B |.  
} BBev<  
T \_ ]^]>  
}R{ts  
Utility.log("Thread " + nThreadID + " is over!"); \pVXimam  
bDownOver = true; r4SXE\ G  
//nPos = fileAccessI.write (b,0,nRead); lz?$f4TzA  
} | AozR ~  
catch(Exception e){e.printStackTrace ();} N(Tz%o4  
} 2%_vXo=I  
} WHj'dodS  
tIuCct-  
.?loO3 m  
//打印回应的头信息 :s7m4!EF  
public void logResponseHead(HttpURLConnection con) \hx1o\  
{ i uF*.hc,%  
for(int i=1;;i++) IhVO@KJI  
{ vwxXgk  
String header=con.getHeaderFieldKey(i); GJ_7h_4  
if(header!=null) QD0"rxZJ  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?M\{&mlF  
Utility.log(header+" : "+con.getHeaderField(header)); *=V~YF:Qb  
else # mV{#B=  
break; 9[.8cg*  
} ,)vDeU  
} _I:/ZF5  
A\HxDIU  
`ojoOB^L  
public void splitterStop() u=`L )  
{ !1$])VQWI  
bStop = true; 4b98Ks Yg  
} $\X[@E S0  
s T}. v*  
rustMs2p  
} Z$/xy"  
o!kbK#k  
~f$|HP}  
/* SAy=WV  
**FileAccess.java e&&53?  
*//文件访问(定位,写) BRgXr  
package NetFox; Z{]0jhUyNh  
import java.io.*; 7$CBx/X50)  
HTX?,C_  
E2R&[Q"%  
public class FileAccessI implements Serializable{ &L'Dqew,*  
{xXsBh Y  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >n'o*gZM  
RandomAccessFile oSavedFile; t/VD31  
long nPos; onz?_SAW  
x!5'`A!W%  
S[PE$tYT#t  
public FileAccessI() throws IOException 0jy2H2  
{ >0ow7Uw;  
this("",0); 8%A#`)fb  
} '>-gi}z7  
m qMHL2~  
A%KDiIA  
public FileAccessI(String sName,long nPos) throws IOException CDQW !XHc  
{ 0IBhb(X  
oSavedFile = new RandomAccessFile(sName,"rw"); Lr$go6s  
this.nPos = nPos; dfKF%27  
oSavedFile.seek(nPos); ,!#*GZ.ix  
} C~2F9Pg  
haK3?A,"_A  
gG<~-8uQ  
public synchronized int write(byte[] b,int nStart,int nLen) M2OIBH4!  
{ pwL ;A3$|  
int n = -1; < $J>9k  
try{ 49GkPy#]L=  
oSavedFile.write(b,nStart,nLen); .F   
n = nLen; "{@A5A  
} 9K{%vK  
catch(IOException e) 47+&L   
{ u0|8Tgf  
e.printStackTrace (); }B\a<0L/  
} X' H[7 ^W  
RJ  8+h  
dCi?SIN  
return n;  HN=V"a  
}  oM2l-[-  
Wh+{mvu#  
8 OY3A  
} ]zE;Tw.S  
>,gg5<F-E  
x@P y>f2  
/* $PTP/^  
**SiteInfoBean.java m0ER@BXRn  
*/ {o_X`rgrL  
package NetFox; $WyD^|~SF  
Qu?R8+"KS  
%7zuQ \w  
public class SiteInfoBean { _}lZ,L(w  
qE&v ;  
YVQN&|-  
private String sSiteURL; //Site's URL BLfTsNzmt  
private String sFilePath; //Saved File's Path *scVJ  
private String sFileName; //Saved File's Name JD)(oK%C  
private int nSplitter; //Count of Splited Downloading File <*16(!k0  
tItX y  
[I '0,y  
public SiteInfoBean() nw-xSS{  
{//nSplitter的缺省值为5 _<k\FU r  
//default value of nSplitter is 5 dgR g>)V  
this("","","",5); {MtpkUN  
} 1C}NQ!.  
]zj9A]i:a  
$?Yry. 2  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^U `[(kz=  
{ Ixb=L (V  
sSiteURL= sURL; 2|3)S`WZl  
sFilePath = sPath; R Q vft  
sFileName = sName; ;&< {ey  
this.nSplitter = nSpiltter; "+kL )]  
iHeN9 cl  
z:8eEq3w  
} 3h;{!|-3  
Y2a5bc P  
h1B? 8pD  
public String getSSiteURL() qaiNz S@q  
{ &+Z,hs9%  
return sSiteURL; !\zWF  
} ?5C!<3gM)  
LPZF)@|`  
V=R 3)GC  
public void setSSiteURL(String value) P\yDa*m  
{ {P*pk c  
sSiteURL = value; ah+~y,Gl  
} C7rNV0.Fq  
x'+T/zw  
|jI#"LbF  
public String getSFilePath() 3LAIl913  
{ o< |cA5f\  
return sFilePath; I8wXuIN_  
} {@eJtF+2  
l)G^cSHF.3  
>p)MawT]  
public void setSFilePath(String value) l1T m`7}  
{ g[1gF&  
sFilePath = value; F~T]u2qt  
} $G8E 3|k  
S{]x  
SX<` {x&L  
public String getSFileName() iP =V8g?L  
{ d74d/l1*{  
return sFileName; 2)G %)'  
} -e_hrCW&9  
3kw,(-'1  
Ja,wfRq  
public void setSFileName(String value) s3~lT.  
{ &M46&^Jho  
sFileName = value; kStnb?nk  
} 5Sm}n H  
GR&z,  
.:@Ykdm4I  
public int getNSplitter() fKeT,U`W  
{  'C`U"I  
return nSplitter; BzkooJ  
}  3L< wQ(  
7op`s5i  
&+cEV6vb+  
public void setNSplitter(int nCount) iIMd!Q.)@  
{ lpQSup  
nSplitter = nCount; =y [M\m  
} .n#@$ nGZ  
} N*"p|yhd]  
s %qF/70'  
tX5"UQA  
/* g l^<Q  
**Utility.java CLRiJ*U  
*/ 48:>NW  
package NetFox; wLi4G@jJ  
+ fC=UAZ  
@LS@cCC,a  
public class Utility { wfNk=)^$  
RX>xB  
tmv&U;0Z  
public Utility() Fpm|_f7  
{ @Fluc,Il  
 `7 vHt`  
B|R@5mjm  
} Sx708`/Ep  
I%r{]-Obr-  
//线程睡眠 JG" R\2  
public static void sleep(int nSecond) R@/"B8H  
{ 5 xppKt  
try{ d9B]fi}  
Thread.sleep(nSecond); I/a/)No  
} z2MWN\?8  
catch(Exception e) eFaO7mz5V%  
{ "]"|"0#i  
e.printStackTrace (); 1M}5>V{  
} /.3}aj;6  
} G f,`  
,24p%KJ*X  
//日志 }@;ep&b*  
public static void log(String sMsg) ix([mQg  
{ q#T/  
System.err.println(sMsg); Hc>m;[M)l  
} gG]Eeu+z   
: ]sUpO  
$K]m{  
public static void log(int sMsg) [#l*_0  
{ MXw hxk#E  
System.err.println(sMsg);  Q?nN!e T  
} U* i{5/$  
} qu-B| MuOa  
~tBYIkvWT  
)CuZDf@  
/* ]!I7Y.w6  
**TestMethod.java $* AYcy7  
*/ o$#G0}yn  
package NetFox; P,xKZ{(  
q?4p)@#   
-n=^U  
public class TestMethod { %e-7ubW  
zb k q   
uW30ep'  
public TestMethod() .$qnZWcgG  
{ ///xx/weblogic60b2_win.exe O!P H&;H  
try{ y`F3Hr c  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); U&Wt%U{  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); '^No)n\`  
SiteFileFetch fileFetch = new SiteFileFetch(bean); O_ChxX0KP  
fileFetch.start(); QWD'!)Zb  
} -*$HddD  
catch(Exception e){e.printStackTrace ();} L\@I*QP  
G_0( |%  
n;@bLJ$W  
} d Vj_8>  
z2g3FUTX)b  
tKuVQH~D  
public static void main(String[] args) yKa{08X:  
{ 4Uphfzv3D  
new TestMethod(); (BTVD,G  
} Y&S24aql  
} #:[t^}  
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