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http断点续传简单实现(java)

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/* 'g8~uP  
**SiteFileFetch.java nyZUf{:  
*/ [jD.l;jF  
package NetFox; pZu2[  
import java.io.*; pq"3)+3:  
import java.net.*; , qj  
3H0~?z_  
9Bl c  
public class SiteFileFetch extends Thread { IH;+pN  
D Hkmn  
-Mb`I >=  
SiteInfoBean siteInfoBean = null; //文件信息Bean H0Q.; !^  
long[] nStartPos; //开始位置 R "S,&  
long[] nEndPos; //结束位置 Z|YiYQl[)  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 A9_)}  
long nFileLength; //文件长度 3Z *'  
boolean bFirst = true; //是否第一次取文件 ;:JTb2xbb  
boolean bStop = false; //停止标志 v2>.+Eh#  
File tmpFile; //文件下载的临时信息 pPUv8, %  
DataOutputStream output; //输出到文件的输出流 SBBDlr^P  
87P.K Yy  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) lNcXBtwK@#  
public SiteFileFetch(SiteInfoBean bean) throws IOException OPp>z0p%6X  
{ VO|2  
siteInfoBean = bean; /dU-$}>ZI  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 69U[kW&  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); q M( n]{H  
if(tmpFile.exists ()) k%iZ..  
{ C:77~f-+rQ  
bFirst = false; 9/rX%  
read_nPos(); #>m#i1Nu  
} w<?v78sT  
else Hq.ys>_  
{ 26fbBt8nP  
nStartPos = new long[bean.getNSplitter()]; rBv  
nEndPos = new long[bean.getNSplitter()]; S!0ocS!t  
} >&K1+FSmyJ  
<lHelX=/  
4{Vw30DZ  
,t4g^67R{  
} Sri,sZv  
7/.-dfEK  
<<@vy{*Hg  
public void run() eMPk k=V  
{ gl/n*s#r_  
//获得文件长度 *5$$C&@o9  
//分割文件 eGrC0[SH  
//实例FileSplitterFetch Sb=cWn P  
//启动FileSplitterFetch线程 qRMH[F$`  
//等待子线程返回 t'@1FA!)  
try{ {'W\~GnZ  
if(bFirst) *@J  
{ <(Ub(  
nFileLength = getFileSize(); mmrx*sr=  
if(nFileLength == -1) =W1`FbR  
{ 3lc'(ts %  
System.err.println("File Length is not known!"); xU/Eu;m  
} w(kN0HD  
else if(nFileLength == -2) ;m{*iKL6{  
{ yM%,*VZ  
System.err.println("File is not access!"); F&}>2QiL  
} uJ<sa;  
else ;H5H7ezV  
{ 3%Jg' Tr+  
for(int i=0;i<nStartPos.length;i++) d[+xLa  
{ g>h5NrD N  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); jHPJk8@y  
} #/'5N|?  
for(int i=0;i<nEndPos.length-1;i++) sidSY8j  
{ ar.w'z  
nEndPos = nStartPos[i+1]; 7dl]f#uZU  
} Fx']kn9  
nEndPos[nEndPos.length-1] = nFileLength; ^E&':6(  
} FHVZ/ e  
} "R-1 G/  
yBKkx@o#z  
yZ t}Jnv  
//启动子线程 "|{O%X  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; pqPhtWi%PJ  
for(int i=0;i<nStartPos.length;i++) =T$-idx1l  
{ k36%n *4  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >&h#t7<  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 45l/)=@@B  
nStartPos,nEndPos,i); 4C2JyP3  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^|DI9G(Bs  
fileSplitterFetch.start(); ($^XF:#5  
} RG=!,#X  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), g+gHIb7{  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); kd9rvy0oK  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", B@Zed Xi  
nEndPos = " + nFileLength); *9}2Bmojv  
// fileSplitterFetch[nPos.length-1].start(); {uEu ^6a5  
J2 _DP  
T_CYSS|fX  
//等待子线程结束 s$e0;C!D  
//int count = 0; L 0k K'n?  
//是否结束while循环 !n4p*<Y6  
boolean breakWhile = false; kQXtO)  
1P&XG@  
3IHya=qN  
while(!bStop) aF4vNUeG  
{ hA)tad]  
write_nPos(); }YHoWYR  
Utility.sleep(500); z5Hz-.  
breakWhile = true; Two$wL/  
g:MpN^l  
ot P7;l  
for(int i=0;i<nStartPos.length;i++) `As.1@  
{ IpQ51  
if(!fileSplitterFetch.bDownOver) 5-O[(b2O  
{ j;eR9jI$T  
breakWhile = false; [i24$UT  
break; UahFs  
} 4-efnB  
} NZ`W`#{  
if(breakWhile) az3rK4g  
break; \M M(w&  
;3NA,JA#Y  
)|f!}( p  
//count++; rk W*C'2fz  
//if(count>4) -?n|kSHX  
// siteStop(); V}ZF\SG(K  
} DWDL|4 og  
Q}ho Y  
A][\L[8X  
System.err.println("文件下载结束!"); jJ86Ch  
} Pb=J4Lvz(d  
catch(Exception e){e.printStackTrace ();} 31-%IkX+k  
}  lTsl=  
Qy |*[  
@%@uZqQ4  
//获得文件长度 ;cIs$  
public long getFileSize() ;Ad$Q9)EE  
{ bJ~]nj 3  
int nFileLength = -1; GYYk3\r  
try{ k0.|%0?K  
URL url = new URL(siteInfoBean.getSSiteURL()); dC;@ Fn  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -xtj:UO  
httpConnection.setRequestProperty("User-Agent","NetFox"); w$UWfL(  
,dK<2XP  
g83]/s+  
int responseCode=httpConnection.getResponseCode(); x7 jE Ns )  
if(responseCode>=400) qazM@  
{ \"i2E!  
processErrorCode(responseCode); ^yiRrcOo  
return -2; //-2 represent access is error [_ESR/&N  
} u$d T^c  
mjG-A8y  
* 3mF.^  
String sHeader; ) 2C`;\/:  
" cx\P,<  
QcG4~DEX4  
for(int i=1;;i++) PO5/j  
{ <m"Zk k  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); mu0ER 3o  
//Utility.log(in.readLine()); "<x%kD  
sHeader=httpConnection.getHeaderFieldKey(i); /qA\|'~  
if(sHeader!=null) <)+9PV<w  
{ D_@WB.e L  
if(sHeader.equals("Content-Length")) AjB-&Z  
{ -4{sr| lm  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +s.r!?49+  
break; WjtmV2b<7  
} 8@ck" LUzD  
} w$4fS  
else }7E2,A9_"  
break; GL'zs8AKf  
} !},_,J~(|  
} 0|n1O)>J  
catch(IOException e){e.printStackTrace ();} 0dA'f0Uy\X  
catch(Exception e){e.printStackTrace ();} sI/Jhw)  
zl\mBSBx"  
(gZKR2hO  
Utility.log(nFileLength); b&X- &F  
>8+:{NW  
}2;~':Mklz  
return nFileLength; fEF1&&8^  
} lAz.I  
i/`N~r   
ntE;*F yH  
//保存下载信息(文件指针位置) Q)S0z2  
private void write_nPos() 0q(}nv  
{ ZW n j-  
try{ JlJy3L8L  
output = new DataOutputStream(new FileOutputStream(tmpFile)); + DFG762  
output.writeInt(nStartPos.length); >.N?y@  
for(int i=0;i<nStartPos.length;i++) XhjH68S(  
{ cLn&b}8'  
// output.writeLong(nPos); IY2ca Xu  
output.writeLong(fileSplitterFetch.nStartPos);  +T02AS  
output.writeLong(fileSplitterFetch.nEndPos); hDI_qZ  
} 0@ []l{N  
output.close(); oA`'~~!  
} uH S)  
catch(IOException e){e.printStackTrace ();} B B*]" gT  
catch(Exception e){e.printStackTrace ();} wB~Ag$~  
} 4`Qu+&4J  
$Kn{x!,"(  
aaW(S K  
//读取保存的下载信息(文件指针位置) 6tBL?'pG  
private void read_nPos() C;#vW FE  
{ C5GO?X2  
try{ Ge=+ 0W)&  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `b 6j7  
int nCount = input.readInt(); ,,vl+Z <&  
nStartPos = new long[nCount]; YNV4w{>FD  
nEndPos = new long[nCount]; 1:5jUUL8  
for(int i=0;i<nStartPos.length;i++) #]pFE.o  
{ -@f5d  
nStartPos = input.readLong(); eSNi6RvE  
nEndPos = input.readLong(); v {E~R  
} J P'|v"  
input.close(); &y"e|aE  
} !2>MaV1,  
catch(IOException e){e.printStackTrace ();} ^3?]S{1/#  
catch(Exception e){e.printStackTrace ();} 1 i # .h$  
} +HvEiY  
^6tGj+D9  
U {Xg#UN  
private void processErrorCode(int nErrorCode) x TEDC,B  
{ F3j#NCuO=z  
System.err.println("Error Code : " + nErrorCode); N9 yL(2  
} gOaL4tu  
[O92JT:li  
| wuUH  
//停止文件下载 YD1 :m3l!  
public void siteStop() X,dOF=OJL  
{ V*HkF T  
bStop = true; w4w[qxV>  
for(int i=0;i<nStartPos.length;i++) GqB]^snh  
fileSplitterFetch.splitterStop(); R+Q..9 P  
!*#2~$:  
I[u%k ir  
} $2N)m:X0  
} AB92R/  
//负责部分文件的抓取 HAJK%zLc  
**FileSplitterFetch.java $A"C1)d;  
*/ t/xWJW2  
package NetFox; w+c%Y\:  
 vU(2[  
<pzCpF<  
import java.io.*; /~RY{ c@#L  
import java.net.*; _)AX/%^%  
##Jg>HL'  
xfYDjf :<  
public class FileSplitterFetch extends Thread { %DH2]B? 0  
e%_2n=p~)%  
RQ}0f5~t  
String sURL; //File URL ; C/:$l  
long nStartPos; //File Snippet Start Position q5<'pi   
long nEndPos; //File Snippet End Position BVAxeXO  
int nThreadID; //Thread's ID (/6~*<ZGT  
boolean bDownOver = false; //Downing is over 8XFs)1s[  
boolean bStop = false; //Stop identical q^5j&jx Vl  
FileAccessI fileAccessI = null; //File Access interface tB-0wD=PR  
Se*o{V3s$  
N,N9K  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException BWRM gN'.  
{ vhe[:`=a  
this.sURL = sURL; R0|dKKzS  
this.nStartPos = nStart; h$3o]~t  
this.nEndPos = nEnd; a'3|EWS ?  
nThreadID = id; K1i@.`na/$  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 B.)!zv\{  
} 53>y<  
DL$O274uZ  
RE~9L5i5  
public void run() Z]U"i1lA  
{ dV_ClH &)  
while(nStartPos < nEndPos && !bStop) ECq(i(  
{ _J' _9M?>  
/1A3 Sw  
NrQGoAOw  
try{ -2Bkun4Pt  
URL url = new URL(sURL); NF9fPAF%;  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [=f(u wY>g  
httpConnection.setRequestProperty("User-Agent","NetFox"); O"%b@$p\L  
String sProperty = "bytes="+nStartPos+"-"; pGS!Nn;K2  
httpConnection.setRequestProperty("RANGE",sProperty); ,+LX.f&/8!  
Utility.log(sProperty); V $'~2v{_  
=gSa?pd  
0^?:Zds  
InputStream input = httpConnection.getInputStream(); U7GgGMw  
//logResponseHead(httpConnection); L-J 7z+{  
$Sz@u"ig%  
fjD/<`}v  
byte[] b = new byte[1024]; YVSAYv_ZG}  
int nRead; SxyXz8+e[  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^t X}5i`P  
{ }2@Aj  
nStartPos += fileAccessI.write(b,0,nRead); |a||oyrN  
//if(nThreadID == 1) &~9'7 n!  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e+`LtEve0  
} .x6c.Y.S  
#J4{W84B  
'E_M, Y  
Utility.log("Thread " + nThreadID + " is over!"); v2Lx4:dzi  
bDownOver = true; l~_] k  
//nPos = fileAccessI.write (b,0,nRead); e+'PRVc  
} gXrXVv<)yw  
catch(Exception e){e.printStackTrace ();} qIXo_H&\C  
} ,gag_o{*a  
} x}\_o< d  
32#|BBY  
Vr%>'XN>"  
//打印回应的头信息 Gcu[G]D  
public void logResponseHead(HttpURLConnection con) by*?PhfF  
{ V?_:-!NJ(  
for(int i=1;;i++) 3 VNPdXsh  
{ ]'  ck!eG  
String header=con.getHeaderFieldKey(i); c~,OU7[  
if(header!=null) %8U/!(.g  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); aHhr_.>X  
Utility.log(header+" : "+con.getHeaderField(header)); | DB7o+4  
else i!AFXVX  
break; $-x@P9im  
} }MW7,F  
} 2=?:(e9  
fv;3cxQp  
F0Nl,9h('  
public void splitterStop() )\xDo<@  
{ 06)B<  
bStop = true; QB3vp4pBg@  
} =x_~7 Xc{  
rzl0*CR  
]H%S GQPn  
} -}_X'h&"  
,RA;X  
jUtFDw  
/* VXfp=JE  
**FileAccess.java qwf97pg$  
*//文件访问(定位,写) G6*P]<  
package NetFox; |o6g{#1  
import java.io.*; ET2^1X#j  
^/"[jq3F  
"W"2 Y(  
public class FileAccessI implements Serializable{ #L3heb&9  
obRYU|T  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 t@_MWF  
RandomAccessFile oSavedFile; =qg;K'M5  
long nPos; ?.*^#>-  
84X/=l-c=  
By&ibN),  
public FileAccessI() throws IOException v@qU<\Y>  
{ c3L)!]kB  
this("",0); @2X{e7+D  
} o+}>E31a  
o.o$dg(r!  
w6Owfq'v  
public FileAccessI(String sName,long nPos) throws IOException *_qLLJg  
{ R&v V! d  
oSavedFile = new RandomAccessFile(sName,"rw"); YA?46[:  
this.nPos = nPos; $;k2b4u  
oSavedFile.seek(nPos); 2#y-3y<G  
} Qp?+G~*  
9/yE\p .  
KscugX*x  
public synchronized int write(byte[] b,int nStart,int nLen) hxT{!g  
{ Hv3<gyD  
int n = -1; ;Z asK0  
try{ y;$ !J  
oSavedFile.write(b,nStart,nLen); j0X Jf<  
n = nLen; u#Z#NP ~F0  
} Z<Rhn  
catch(IOException e) u`ezQvrcy  
{ o*r 2T4 8  
e.printStackTrace (); "/#=8_f  
} .)Wqo7/Gx  
.%x1%TN  
W Z_yaG$U  
return n; 'zUWO_(  
} fzk^QrB  
Zf,9 k".'C  
3$~oQC  
} 2jT2~D.U1  
grs~<n|o\  
F\Z|JCA  
/* SQS PdR+  
**SiteInfoBean.java VfFXH,j  
*/ flXDGoW  
package NetFox; V Kw33  
57S!X|CE  
pWm==Ds|  
public class SiteInfoBean { 141G~@-  
8TE2q Pm  
0Mo?9??  
private String sSiteURL; //Site's URL }2!=1|}  
private String sFilePath; //Saved File's Path JtbwY@R  
private String sFileName; //Saved File's Name <rbzsn"a  
private int nSplitter; //Count of Splited Downloading File 0rA&Q0  
zHg1K,t:  
"NM SLqO  
public SiteInfoBean() gK#G8V-,  
{//nSplitter的缺省值为5 "C~Zl&3  
//default value of nSplitter is 5 <J o\RUx  
this("","","",5); ],l}J'.8<V  
} eKv{N\E  
u$MXO].Q  
4\pUA4  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?]]7PEee*  
{ p* Q *}V  
sSiteURL= sURL; '[zy%<2sL  
sFilePath = sPath; VZ1u/O?ub  
sFileName = sName; fgW>~m.W  
this.nSplitter = nSpiltter; Yp@i{$IUW  
`iQ9 9  
] v8.ym  
} ~2L]K4Z^  
= ;z42oS  
"T~ce@  
public String getSSiteURL() cxB{EH,2Um  
{ |.~0Ulk,  
return sSiteURL; )1ct%rue  
} \-Ipa59U  
6}"t;4@$x  
Ty5}5)CRZ  
public void setSSiteURL(String value) vd FP ^06  
{ Q^@z]Sc[  
sSiteURL = value; wticA#mb  
} >&?k^nI}J  
[IRWm N-  
^)%TQ.  
public String getSFilePath() o'*7I|7a  
{ g?1! /+  
return sFilePath; wyC1M  
} _!:*&{  
4.&hV?Kxz  
C'S&  
public void setSFilePath(String value) DRy,n)U&  
{ x:0nK,  
sFilePath = value; e:T8={LU2W  
} CGCI3Z'  
Gi 7p`F.  
LO@='}D=  
public String getSFileName() ,5Nf9z!hk(  
{ P7|x=Ew;`  
return sFileName; b!gvvg<  
} g7g^iLU  
tEl_a~s*3?  
a`E1rK'  
public void setSFileName(String value) =&-+{txs  
{ iRsK; )<  
sFileName = value; '^ob3N/Y [  
} xL#UMvZ>;h  
@";zM&  
upefjwm  
public int getNSplitter() Bf+7;4-  
{ svj0;x5  
return nSplitter; u~7 ,v  
} UWIw/(Mv/]  
l0@+ &Xj  
d>k"#|  
public void setNSplitter(int nCount) >oasA2S  
{ t{g7 :A  
nSplitter = nCount; +-d)/h.7  
} 96]!*}  
} 3{FUFx  
En:/{~9{ F  
|9x H9@^f  
/* >og- jz  
**Utility.java 0hoi=W6AQ  
*/ q-5U,!!W/  
package NetFox; E,$5 V^ 9  
qrt2BT)  
$`'Xb  
public class Utility { R A^-Pa.O  
"+k^8ki  
HTw7l]]  
public Utility() kY.3x# w  
{ *c{X\!YBh  
# *)X+*  
:}{,u6\  
} @q<F_'7is  
m |%ly  
//线程睡眠 Api<q2@R  
public static void sleep(int nSecond)  /gUD!@  
{ T/Fj0'  
try{ ;lU]ilYv  
Thread.sleep(nSecond); ")i>-1_H  
} "4[8pZO/  
catch(Exception e) i-E/#zni  
{ FAbl5VW'  
e.printStackTrace (); L.R4 iN  
} R0DWjN$j  
} 'A)r)z {X  
#}|g8gh  
//日志 V0/O T~gS8  
public static void log(String sMsg) KXvBJA$  
{ EN/e`S$)  
System.err.println(sMsg); SM1[)jZ-  
} 9n!IdqKN  
C[IY9s:Pf  
SQ0t28N3h  
public static void log(int sMsg) #dEMjD  
{ &* 1iW(x  
System.err.println(sMsg); GAY f.L"  
} de$0DfK  
} ,d~6LXr<fM  
R(dOQ. ;  
\ N;%  
/* rQM$lJ[x  
**TestMethod.java o{I]c#W  
*/ HI%#S&d  
package NetFox; 9}*<8%PSt,  
dSq3V#Q  
.Mz'h 9@  
public class TestMethod { X|wg7>kh*`  
%9Y3jB",2  
dRu|*s  
public TestMethod() G ;fc8a[X  
{ ///xx/weblogic60b2_win.exe {-Q=YDR  
try{ <WCTJ!Z  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); REc+@;B  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); A$;"9F@  
SiteFileFetch fileFetch = new SiteFileFetch(bean); F!pgec%]'  
fileFetch.start(); v>oWk:iJP  
} 6 ~LCj"  
catch(Exception e){e.printStackTrace ();} KE*8Y4#9  
7,:$, bL  
pxgVYr.  
} j$mCU?  
lOJ3_8  
f' 28s*n  
public static void main(String[] args) h.WvPZ2U  
{ Ka|, qkb  
new TestMethod(); C<u<:4^H  
} ObIL  w  
} w/UZ6fu  
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