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http断点续传简单实现(java)

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/* |#@7$#j  
**SiteFileFetch.java WR)=VE   
*/ %xg+UW }  
package NetFox; Plp.\N%f3  
import java.io.*; R@\}iyM  
import java.net.*;  l(?B0  
_]`7et\=  
ep"[; $Eb  
public class SiteFileFetch extends Thread { J:m/s9r  
JXK\mah  
f8]sjeY  
SiteInfoBean siteInfoBean = null; //文件信息Bean #{8I FA  
long[] nStartPos; //开始位置 \X8b!41  
long[] nEndPos; //结束位置 *y*tI}  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 zFq%[ X  
long nFileLength; //文件长度 !4vb{AH  
boolean bFirst = true; //是否第一次取文件  VGV-t  
boolean bStop = false; //停止标志 4!/JN J  
File tmpFile; //文件下载的临时信息 UphTMyn3  
DataOutputStream output; //输出到文件的输出流 7AV{ h[J  
6{y7e L3!  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 5naFnm7%  
public SiteFileFetch(SiteInfoBean bean) throws IOException 1Z# $X`  
{ gJ6`Kl985O  
siteInfoBean = bean; @V%\Gspv  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); qT$k%(  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); :\OSHs<M  
if(tmpFile.exists ()) q-JTGCFl  
{ #d-({blo<  
bFirst = false; 1>J.kQR^  
read_nPos(); RV~fml9c  
} P}@AH02  
else ~Ru\Z-q1  
{ f^$,;  
nStartPos = new long[bean.getNSplitter()]; Hf`i~6  
nEndPos = new long[bean.getNSplitter()]; c{=Sy;i@  
} $o[-xNn1  
Bu{Kjv  
}>xwiSF?  
,X?/FAcb  
} P1eSx#3bR  
9F/I",EA  
Cr5ND\  
public void run() 4[gmA  
{ +0pI}a\  
//获得文件长度 BsQ;`2  
//分割文件 3oCI1>k  
//实例FileSplitterFetch o1.~g'!^  
//启动FileSplitterFetch线程 4D?h}U /  
//等待子线程返回 +U o NJ   
try{ o<Zlm)"%1  
if(bFirst) | &X<-  
{ ;kgP:n  
nFileLength = getFileSize(); 8rsc@]W  
if(nFileLength == -1) _?c.m*)A  
{ VgH O&vU  
System.err.println("File Length is not known!"); 'c35%? ]  
} P@7>R7gS  
else if(nFileLength == -2) <0CjEsAB]  
{ rnIj pc F  
System.err.println("File is not access!"); #A/OGi  
} OyTK,i<n  
else -r\jIO_  
{ +4?Lwp'q  
for(int i=0;i<nStartPos.length;i++) {iD/0q  
{ C >*z^6Gz  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); `OfhzOp  
} .vu7$~7  
for(int i=0;i<nEndPos.length-1;i++) \o>-L\`O  
{ kKyU?/aj  
nEndPos = nStartPos[i+1]; b"I#\;Ym  
} M)bQvjj  
nEndPos[nEndPos.length-1] = nFileLength; cgb>Naa<  
} h.\I tK{)  
} "DW~E\Y  
l9.`2d]o  
46C%at M0}  
//启动子线程 ._}}@V_/  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; u[GZ~L  
for(int i=0;i<nStartPos.length;i++) WcN4ff-  
{ Af|h*V4Xu  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -<g9 ) CV5  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (p{X.X+  
nStartPos,nEndPos,i); )d3 09O  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0+>g/ >  
fileSplitterFetch.start(); `d_T3^ayu  
} T)! }Wvv  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), dSGdK $XA  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #w{`6}p  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", I{IB>j}8  
nEndPos = " + nFileLength); '.|}  
// fileSplitterFetch[nPos.length-1].start(); uN%Cc12  
vpu#!(N  
Ik:G5m<ta  
//等待子线程结束 v$}^$8`  
//int count = 0; I-#!mFl  
//是否结束while循环 u+)!C*ho  
boolean breakWhile = false; ?@"@9na  
=Vg~ VD   
5{! fa  
while(!bStop) r^,_m,s'<  
{ b<u\THy#  
write_nPos(); L=<xTbY  
Utility.sleep(500); Thggas,  
breakWhile = true; /uw@o9`~2-  
5U?O1}P  
QV[&2&&^<<  
for(int i=0;i<nStartPos.length;i++) yX&# rI  
{ ZX_QnSNZ?  
if(!fileSplitterFetch.bDownOver) mI lg=8:  
{ ?_]Y8f  
breakWhile = false; LK h=jB^bT  
break; nDrRK  
} iA[T'+.Y  
} fG2)r  
if(breakWhile) Y9abRr K  
break; +R~]5Rxd  
}u^bTR?3  
:DH@zR  
//count++; `gl?y;xC  
//if(count>4) !&U75FpN}:  
// siteStop();  <$nPGz)}  
} ]TrJ*~  
30h[&Oc  
+k=*AQt^8  
System.err.println("文件下载结束!"); 8r( Vz  
} lO@-*m$  
catch(Exception e){e.printStackTrace ();} Vz mlKVE  
} ]y OM  
2^XmtT  
ev&l=(hY  
//获得文件长度 ]D6<6OB  
public long getFileSize() kH 9k<{  
{ }w f8y  
int nFileLength = -1; sX?arI=_U  
try{ S1r{2s&  
URL url = new URL(siteInfoBean.getSSiteURL()); '&CZ%&(Gw  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0hS&4nW  
httpConnection.setRequestProperty("User-Agent","NetFox"); N<#J!0w  
k7Nx#%xx  
4W>DW`{  
int responseCode=httpConnection.getResponseCode(); LsR<r1KDJ  
if(responseCode>=400) 2[w9#6ly  
{ {A}T^q!m]  
processErrorCode(responseCode); <(E)M@2  
return -2; //-2 represent access is error (s'xO~p  
} P0UR{tK  
&tOo[U?  
9^Xndo]y  
String sHeader; RlfI]uCDM  
{r&r^!K;  
 ZPf&4#|  
for(int i=1;;i++) <@7j37,R7V  
{ CX#d  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !d##q)D f?  
//Utility.log(in.readLine()); 6UIS4 _   
sHeader=httpConnection.getHeaderFieldKey(i); ^ iu)vED  
if(sHeader!=null) 8z93ETv7`  
{ -dMH>e0  
if(sHeader.equals("Content-Length")) $;g*s?F*  
{ ceg\lE:8  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); d^'_H>x  
break; ygTfQtN  
}  WDNj 7  
} f TmJDUv+  
else r%: :q^b3  
break; Xp;'Wa"@  
} 6~ET@"0uK  
} i(A `'V8GY  
catch(IOException e){e.printStackTrace ();} <,Gjo]z  
catch(Exception e){e.printStackTrace ();} [?z;'O}y  
['(qeS@5O  
d Np%=gIj  
Utility.log(nFileLength); hbXmIst  
>u%Bn \G  
KMT$/I{p,  
return nFileLength; uJ"#j X  
} UHJro9  
ZV Ko$q:F  
65B&>`H~  
//保存下载信息(文件指针位置) Ds=d~sNu  
private void write_nPos() w[2E:Nj  
{ 4gZR!J  
try{ E2hML  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Q8TR@0d  
output.writeInt(nStartPos.length); .t ^1e  
for(int i=0;i<nStartPos.length;i++) qPu?rU{2  
{ W&A^.% 2l  
// output.writeLong(nPos); + fvVora  
output.writeLong(fileSplitterFetch.nStartPos); HmXxM:[4;  
output.writeLong(fileSplitterFetch.nEndPos); pDC`Fi  
} i{g~u<DH)Q  
output.close(); dsEvpa$?  
} F, =WfM\  
catch(IOException e){e.printStackTrace ();} xqT} 9,  
catch(Exception e){e.printStackTrace ();} r 8N<<^  
} |$8N*7UD  
"+Ks#  
Xe}I;sKrB  
//读取保存的下载信息(文件指针位置) = CXX.%N  
private void read_nPos() gC6Gm':c  
{ yFo8 x[  
try{ a;i} <n7  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); tm;\m!^X{  
int nCount = input.readInt(); TPJuS)TU9  
nStartPos = new long[nCount]; p@$92> '  
nEndPos = new long[nCount]; mv<cyWp  
for(int i=0;i<nStartPos.length;i++) ?zo7.R-Vac  
{ c3fd6Je5  
nStartPos = input.readLong(); x}C$/7^  
nEndPos = input.readLong(); (>Sy,  
}  LWo)x  
input.close(); JpQV7}$  
} ^b&hy&ag  
catch(IOException e){e.printStackTrace ();} hzV%QDUpe  
catch(Exception e){e.printStackTrace ();} Mt4`~`6  
} *{fZA;<R  
}Ej^"T:H_;  
j%!xb><  
private void processErrorCode(int nErrorCode) IFSIQ q  
{ 7vqE @;:dt  
System.err.println("Error Code : " + nErrorCode); yr zyus  
} 'mU\X!- 4<  
=+e;BYD#!  
F0xm% ?  
//停止文件下载 "t{D5{q|[k  
public void siteStop() V" 5rIk  
{ 2$Z4 >!  
bStop = true; ZB}zT9JaE  
for(int i=0;i<nStartPos.length;i++) rp-.\Hl/a  
fileSplitterFetch.splitterStop(); 3qfQlqJ&3  
7n#Mh-vq  
k DKfJp&a  
} ]{-ib:f~  
} Si;eBPFH  
//负责部分文件的抓取 kKQD$g.z6  
**FileSplitterFetch.java `C:J{`  
*/ )q7!CG'oY  
package NetFox; ZYl*-i&~?  
QswFISch  
!&8B8jHqA  
import java.io.*; !;PKx]/&  
import java.net.*; 0@!-+}i  
=rNI&K_<  
S?H qrf7<  
public class FileSplitterFetch extends Thread { Yu9(qRK  
c"'JMq  
$+ \JT/eG9  
String sURL; //File URL 4m9]d)  
long nStartPos; //File Snippet Start Position ds+0y;vc  
long nEndPos; //File Snippet End Position =sXk,I;  
int nThreadID; //Thread's ID ]gb?3a}A  
boolean bDownOver = false; //Downing is over uQkFFWS  
boolean bStop = false; //Stop identical [MM`#!K%  
FileAccessI fileAccessI = null; //File Access interface uY )|   
j&?@:Zg v  
0bIhP,4&  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException q-0( Wx9|  
{ CwzDkr&QC_  
this.sURL = sURL; |A u+^#:;  
this.nStartPos = nStart; j|WN!!7  
this.nEndPos = nEnd; 2K(zYv54  
nThreadID = id; -[lOf  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 DTV"~>@  
} 5 .b U2C  
r/ LgmVRn  
/9u12R*<  
public void run() \g;-q9g;O  
{ A3e83g~L  
while(nStartPos < nEndPos && !bStop) XuW>GT/  
{ Pu]Pp`SP  
XgZ.UT  
9&KiG* .  
try{ /`B:F5r  
URL url = new URL(sURL); y}lqF8s  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v+2t;PJd2  
httpConnection.setRequestProperty("User-Agent","NetFox"); 7gbu7"Qc  
String sProperty = "bytes="+nStartPos+"-"; Pu|3_3^  
httpConnection.setRequestProperty("RANGE",sProperty); >^KO5N-:4  
Utility.log(sProperty); r7:4| 6E  
bu r0?q  
&qFy$`"  
InputStream input = httpConnection.getInputStream(); Z:%~Al:  
//logResponseHead(httpConnection); <bOi}  
$~.'Tnk)  
|rk4,NG.  
byte[] b = new byte[1024]; -6>T0-  
int nRead; r`CsR0[  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) OM7EmMa;  
{ ~@Eu4ip)F  
nStartPos += fileAccessI.write(b,0,nRead); Hk|wO:7Be  
//if(nThreadID == 1) Y]{~ogsn$:  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |"EQyV  
} \ssqIRk  
KP]{=~(  
2~*.X^dR  
Utility.log("Thread " + nThreadID + " is over!"); S_56!  
bDownOver = true; (E?X@d iu  
//nPos = fileAccessI.write (b,0,nRead); m&8'O\$  
} ^NiS7)FX  
catch(Exception e){e.printStackTrace ();} niJtgK:H^  
} Tf?|*P  
} 3It9|Y"6[  
&,~Oi(SX5  
aRF}F E,u  
//打印回应的头信息 G$$y\e$  
public void logResponseHead(HttpURLConnection con) 4brKAqg.  
{ dJD8c 2G  
for(int i=1;;i++) 4XXuj  
{ loFApBD=$^  
String header=con.getHeaderFieldKey(i); sDnXgCcS!  
if(header!=null) \$[S=&E  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); N1i%b,:3  
Utility.log(header+" : "+con.getHeaderField(header)); etWCMR  
else iqP MCOPZ  
break; zU,Qph ,<  
} V0!$k.Wk  
} :NPnwX8w  
Rz9IjL.Z  
;/g Bjp]H  
public void splitterStop() wm/=]*jpK  
{ h"DxgG  
bStop = true; 1x~dsM;q  
} a6i%7Om  
z 8\z`#g!  
GY,HEe]2r  
} &!5S'J %  
Sr?2~R0&  
HTU?hbG(  
/* ev;R; 0<  
**FileAccess.java (^).$g5Hg  
*//文件访问(定位,写) e${Cf  
package NetFox; ~*Kk+w9H<  
import java.io.*; ij+)U`  
;X XB^,  
of k@.TmO  
public class FileAccessI implements Serializable{ R9`37(c9+  
' (1`iQ;  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 iy\ 6e k1  
RandomAccessFile oSavedFile; .~t.B!rVSB  
long nPos; {gwJ>]z"e  
Xe7/  
YA[\|I33  
public FileAccessI() throws IOException 0<C]9[l  
{  &@h(6  
this("",0); QlCs ,bT  
} VuWBWb?0Q  
.>Fy ]Cqoh  
r0 fxEYze&  
public FileAccessI(String sName,long nPos) throws IOException yO`HL'SMo  
{ 85GU~.  
oSavedFile = new RandomAccessFile(sName,"rw"); C=>IJ'G  
this.nPos = nPos; [uD G;We=  
oSavedFile.seek(nPos); I@/+=  
} Ri mz~}+  
TKBW2  
Q' qz(G0  
public synchronized int write(byte[] b,int nStart,int nLen) =AIeYUh  
{ M6o"|\  
int n = -1; $vK(Qm  
try{ +XP9=U*g  
oSavedFile.write(b,nStart,nLen); 2j <Y>Y  
n = nLen; n3Q Rn^  
} LW '3m5  
catch(IOException e) 1 ms(03dp  
{ oW \k%Vj  
e.printStackTrace (); &K.js  
} yrVk$k#6}  
vQ",rP%  
7U, [Ruu  
return n; \]=''C=J  
} M\rZr3  
kt;uB X3  
}a?(}{z-  
} F2:nL`]b[  
g<(\#F}/  
JRYCM}C]  
/* Yfd0Np~  
**SiteInfoBean.java #Li6RSeW  
*/ <*F!A' w2o  
package NetFox; v%$c_'d  
n/Fx2QC{  
l}MVk%[  
public class SiteInfoBean { {GP#/5$=  
Qf#=Y j  
wX Kg^%t\  
private String sSiteURL; //Site's URL ZD;1{  
private String sFilePath; //Saved File's Path x@*!MC #  
private String sFileName; //Saved File's Name ?)V?6"fFP  
private int nSplitter; //Count of Splited Downloading File Xdtyer%  
O=;}VZ<9  
_my!YS5n  
public SiteInfoBean() .Gq]Mrim9G  
{//nSplitter的缺省值为5 +Cg[!6[#  
//default value of nSplitter is 5 =Y`e?\#`  
this("","","",5); 0wnC"2GUX  
} 7Z[6_WD3  
)N'rYS' 9  
sRK oM  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) e[l#r>NT  
{ (R|Ftjs .  
sSiteURL= sURL; MlH0  
sFilePath = sPath; 6O0CF}B*  
sFileName = sName; VteMsL/H  
this.nSplitter = nSpiltter; YM.Q?p4g  
>%1mx\y^  
Oz-;2   
} 6h9Hf$'  
/|#";QsPN  
6TkV+\  
public String getSSiteURL() 'S#D+oF(1~  
{  ;U<}2M!g  
return sSiteURL; cl1>S3  
} Or<OmxJg  
oj%(@6L  
GX0S9s  
public void setSSiteURL(String value) K$kI%eGZA  
{ :xy4JRcF  
sSiteURL = value; i!u:]14>  
} mGP&NOR0^y  
>\4"k4d}  
R8N*. [  
public String getSFilePath() O f.%rpgy  
{ Mp,aQ0bNS  
return sFilePath; %ki^XB86  
} !si}m~K!_  
Q.i_?a  
Tx:S{n7&  
public void setSFilePath(String value) ]gjB%R[.m  
{ EAZLo;  
sFilePath = value; Z%$ tV3a?  
} 7;r Jr&.)  
h;DLD8L  
w tSX(LN Y  
public String getSFileName() n =qu?xu  
{ iOXsj  
return sFileName; hZwJ@ Vm#  
} %Rm`+  
!cNw 8"SIU  
N.F //n  
public void setSFileName(String value) ]o2jS D  
{ 5-2#H?:U  
sFileName = value; MN<uIqG  
} /v8yE9N_  
Yc p<N>)  
P TMJ.;  
public int getNSplitter() s ~>0<3{5  
{ W'"p:Uh q  
return nSplitter; #M@Ki1  
} |*v w(  
@ebSM#F?  
k@}g?X`8  
public void setNSplitter(int nCount) L=9 ^Y/8Q  
{ &e)V!o@wJV  
nSplitter = nCount; P&sYS<9q  
} B2T=O%  
} 2#)z%K6T  
ioJ|-@! #o  
#,CK;h9jy!  
/* "|nh=!L  
**Utility.java ( 8Q*NZ  
*/ Zonr/sA~  
package NetFox; IutU ~%wv  
/zg|I?$>Z4  
8>AST,  
public class Utility { V(wANvH  
'dJ(x  
0HPqoen$  
public Utility() bwyj[:6l  
{ T )!k J;vc  
uy rS6e0  
w^E$R  
} HyC826~-rI  
@&9, 0 x  
//线程睡眠 )QAS7w#k  
public static void sleep(int nSecond) l|sC\;S  
{ g]Z@_  
try{ O#n=mJ  
Thread.sleep(nSecond); dM)x|b3z  
} ;5&=I|xqe  
catch(Exception e) S+7u,%n/  
{ Z3O_K  
e.printStackTrace (); Lq]t6o ]  
} LO@o`JF  
} bzyy;`;6Q~  
6<Txkk  
//日志 A@ZsL  
public static void log(String sMsg) Wa<SYJ  
{ Lk2;\D>  
System.err.println(sMsg); "U|u-ka8B  
} :wY(</H  
v{;^>"5o  
P2 fiK  
public static void log(int sMsg) "5@\"L  
{ se*!OiOt  
System.err.println(sMsg); a\*_b2 ^n  
} (d*~Qpi{7  
} % 8P8h%%Z  
C`["4  
Qb#iT}!p%  
/* vVf%wei^#  
**TestMethod.java TpRI+*\  
*/ MQMc=Z4d  
package NetFox; ,A[NcFdCB  
W.nr&yiQ  
l#&\,T  
public class TestMethod { D_M73s!U  
Kb~i9x&  
#k|f%!-Vo  
public TestMethod() -0>s`ruor  
{ ///xx/weblogic60b2_win.exe ->)0jZax  
try{ Jvr`9<`  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); En{< OMg  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5 51p* B2  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Y*0j/91  
fileFetch.start(); 6kHuKxY,  
} hxkwT  
catch(Exception e){e.printStackTrace ();} ~; vt{pk  
IVso/!   
$f AZ^   
} ?X@uR5?{  
@dc4v_9  
\[<8AV"E-'  
public static void main(String[] args) n'8 3P%x  
{ `{H!V~42  
new TestMethod(); Ntlbn&lc;D  
} i|!W;2KL5  
} 0?*":o30  
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