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http断点续传简单实现(java)

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/* h;n\*[fDc  
**SiteFileFetch.java 91;HiILgT  
*/ (@?eLJlT  
package NetFox; |4xo4%BQ>  
import java.io.*; P7>IZ >bw  
import java.net.*; %AgA -pBp  
:1BM=_WwI  
{h^c  
public class SiteFileFetch extends Thread { f=oeF]=I"  
4Bo<4 4-,  
104!!m  
SiteInfoBean siteInfoBean = null; //文件信息Bean AgI>  
long[] nStartPos; //开始位置 qhwoV4@f  
long[] nEndPos; //结束位置 !Ud:?U  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 :tlE`BIp  
long nFileLength; //文件长度 /yt7#!tm+  
boolean bFirst = true; //是否第一次取文件 ;r@!a!NLB  
boolean bStop = false; //停止标志 X4 Y  
File tmpFile; //文件下载的临时信息 /b+;: z  
DataOutputStream output; //输出到文件的输出流 THr8o V5  
]F_r6*<  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) wzxdVn 'S  
public SiteFileFetch(SiteInfoBean bean) throws IOException Lv3XYZgW~  
{ 2mLUdx~c  
siteInfoBean = bean; $"1pws?d  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); _2; ^v`[  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); a G@nErdW  
if(tmpFile.exists ()) 9[,s4sxH  
{ @bY?$fj_u  
bFirst = false; T(&kXMaB  
read_nPos(); y-<$bA[K~  
} ,y%ziay  
else -3\7vpcdN  
{ ?Oqzd$-  
nStartPos = new long[bean.getNSplitter()]; !+=Zjm4L  
nEndPos = new long[bean.getNSplitter()];  ?;+^  
} d<_NB]V&F  
PM8Ks?P#u  
}D Z)W0RDe  
_o&94&  
} {&0mK"z_  
6SV7\,2M  
k*OvcYL1A  
public void run() %`eJ66T  
{ /Ht/F)&P  
//获得文件长度 e& p_f<  
//分割文件 @~s~/[  
//实例FileSplitterFetch KjBOjD'I  
//启动FileSplitterFetch线程 jp% +n  
//等待子线程返回 RrKfTiK H  
try{ U>in2u 9  
if(bFirst) v7L"`  
{ rNZO.qij z  
nFileLength = getFileSize(); T0YDfo  
if(nFileLength == -1) ^DzL$BX  
{ 64h_1,U  
System.err.println("File Length is not known!"); ))p$vU3  
} -.^3;-[  
else if(nFileLength == -2) ):^ '/e  
{ Ny.*G@&  
System.err.println("File is not access!"); _yNT=#/  
} LSSW.Oz2L  
else %V31B\]Nz7  
{ IX"ZS  
for(int i=0;i<nStartPos.length;i++) 6$;L]<$W>  
{ Zd8drT'@#  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); E2kW=6VO>|  
} {K<uM'ww>  
for(int i=0;i<nEndPos.length-1;i++) DCt\E/  
{ 1B6C<cL:sU  
nEndPos = nStartPos[i+1]; *}>Bkq9h  
} Q! Kn|mnN  
nEndPos[nEndPos.length-1] = nFileLength; ^p$1D  
} <b6s&"%=  
} |3 ;u"&(P  
v#iFQVBq  
bo&\3  
//启动子线程 &S<? 07Z  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `'*F 1F  
for(int i=0;i<nStartPos.length;i++) +mivqR~{{  
{ kNRyOUy  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nrF%wH/5  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), "|F. 'qZrm  
nStartPos,nEndPos,i); {cmo^~[L$  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jo<>Hc{g>  
fileSplitterFetch.start(); tB GkRd!  
} {EOn r1  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xR *5q1j  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); lr`?yn1D(  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 7X(rLd 6#  
nEndPos = " + nFileLength); wDB)&b  
// fileSplitterFetch[nPos.length-1].start(); tDEXm^B2Sv  
chKF6n  
Y=5!QLV4  
//等待子线程结束 8rGl&  
//int count = 0; \H,V 9!B  
//是否结束while循环 5tN%a>D%  
boolean breakWhile = false; C]yvK}  
Y*`:M(  
01&*`0?  
while(!bStop) W3FymCI  
{ ,@}W@GGP)  
write_nPos(); JCM)N8~i  
Utility.sleep(500); 'wCS6_K  
breakWhile = true; dD[v=Z_  
E^oEG4 X@  
bq c;.4$  
for(int i=0;i<nStartPos.length;i++) @:S$|D~  
{ lf?Z{^  
if(!fileSplitterFetch.bDownOver) \B*k_W/r@  
{ (nkUeQQN  
breakWhile = false; vs5 D:cZ}  
break; z zulVj*  
} D /,|pC  
} o%vIkXw  
if(breakWhile) /IGrp.}  
break; Ytl:YzXCi  
V_NjkyI  
3c1o,2  
//count++; vS~AxeW/7R  
//if(count>4) .a 'ETNY:>  
// siteStop(); k$9Gn9L%  
} @)aXNQY  
vG'vgUo  
^% ~Et>C  
System.err.println("文件下载结束!"); -=-x>(pRW7  
} e1f^:C  
catch(Exception e){e.printStackTrace ();} N&R '$w  
} :d!i[W*  
OlD7-c2L]  
?TL2'U|M  
//获得文件长度 sRkz WMl  
public long getFileSize() +=n x|:no  
{ |YG)NO  
int nFileLength = -1; X}65\6  
try{ S&4w`hdD>~  
URL url = new URL(siteInfoBean.getSSiteURL()); ,Ut!u)  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); '^P*F9  
httpConnection.setRequestProperty("User-Agent","NetFox"); Y\Fuj)  
kMwIuy  
6E*Zj1KX  
int responseCode=httpConnection.getResponseCode(); EvGUj$  
if(responseCode>=400) Og&0Z)%  
{ = y,yQO  
processErrorCode(responseCode); \K4CbZ,.  
return -2; //-2 represent access is error  6Dr$*9  
} PuUon6bZ  
2uI`$A:  
<.y^  
String sHeader; 1*c0\:BQ;z  
x~3>1Wr#M  
} (GQDJp  
for(int i=1;;i++) 8V53+]c$Y  
{ i?P]}JENM  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); h!JjN$  
//Utility.log(in.readLine()); 0X S' v,|  
sHeader=httpConnection.getHeaderFieldKey(i); ~gzpX,{ n  
if(sHeader!=null) q)zu}m  
{ RY'\mt"W2  
if(sHeader.equals("Content-Length")) 0SGczgg  
{ ( .6tz  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Wb}0-U{S'  
break; hQW#a]]V:  
} %]P@G^Bv  
} .DV#-tUh  
else ND99 g  
break; +kdU%Sm  
} TF ([yZO'  
} sN[@mAoH  
catch(IOException e){e.printStackTrace ();} |L~gNC  
catch(Exception e){e.printStackTrace ();} .q;RNCUt  
5p>]zij>  
=f{Z~`3  
Utility.log(nFileLength);  }@Ll!,  
0,i+  
JY,l#?lM{  
return nFileLength; hzf}_1  
} 1>O0Iu  
YJtOdgG|q  
^!s}2GcS`  
//保存下载信息(文件指针位置) w|U@jr*H]  
private void write_nPos() f"}14V  
{ W3{5Do.h  
try{ -<VF6k<  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 0%L$TJ.''  
output.writeInt(nStartPos.length); Yhv`IV-s  
for(int i=0;i<nStartPos.length;i++) :-jP8X  
{ JeSkNs|vB  
// output.writeLong(nPos); C(Ba r#  
output.writeLong(fileSplitterFetch.nStartPos); I{P$B-  
output.writeLong(fileSplitterFetch.nEndPos); 0z2R`=)  
} I7-PF?  
output.close(); \=: g$_l  
} (Gb{ckzs  
catch(IOException e){e.printStackTrace ();} ]r{ #268  
catch(Exception e){e.printStackTrace ();} oeqJ?1=!  
} (fjXp75  
j?` D\LZhf  
.dq.F#2B;  
//读取保存的下载信息(文件指针位置) UqQZ A0e  
private void read_nPos() uX 5B>32  
{ %L,,  
try{ 9~ .BH;ku  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Mh@ylp+q  
int nCount = input.readInt(); U";Rp&\3;  
nStartPos = new long[nCount]; Lm2cW$s  
nEndPos = new long[nCount]; '{_tDboY  
for(int i=0;i<nStartPos.length;i++) kJ:5msKwC  
{ !c;p4B)  
nStartPos = input.readLong(); ,}xC) >  
nEndPos = input.readLong(); OaVL NA^{  
} ZkG##Jp\>  
input.close(); =:T:9Y_i  
} :zTj"P>"I  
catch(IOException e){e.printStackTrace ();} +/^q"/f F  
catch(Exception e){e.printStackTrace ();} 9#ay(g  
} !{- 3:N7  
$TUC?e9"h  
{ l~T~3/i  
private void processErrorCode(int nErrorCode) "PM:&v  
{ u(Q(UuI  
System.err.println("Error Code : " + nErrorCode); ]7ZC>.t  
} ?q8g<-?  
A^jm<~  
_J#Hq 'K  
//停止文件下载 5 BG&r*U  
public void siteStop() I(eR3d:  
{ *^m.V=  
bStop = true; gnK!"!nL  
for(int i=0;i<nStartPos.length;i++) 7 @Qlp$[F  
fileSplitterFetch.splitterStop(); cnO4N UDv  
Y2~{qY  
=|^W]2W$  
} Rf$6}F  
} *8HxJ+[,[  
//负责部分文件的抓取 }|,\ ?7,  
**FileSplitterFetch.java X=}0+W  
*/ biuo.OG]  
package NetFox; k3eN;3#&  
;^SgV   
Xm+3`$<  
import java.io.*; LA3,e (e  
import java.net.*; `t"Kq+  
Ft>8 YYyU  
BuO J0$  
public class FileSplitterFetch extends Thread { e 2&i  
%zVv3p:  
DEuW'.o>  
String sURL; //File URL PhdL@Mr  
long nStartPos; //File Snippet Start Position T+( A7Qrx%  
long nEndPos; //File Snippet End Position a,\u|T:g  
int nThreadID; //Thread's ID TW? MS em  
boolean bDownOver = false; //Downing is over ;0{*V5A  
boolean bStop = false; //Stop identical 2o}FB\4^i  
FileAccessI fileAccessI = null; //File Access interface $fG/gYvI\  
:O=Vr]Y8K  
tV%\Jk),  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException U}TQXYAg  
{ mSp7H!  
this.sURL = sURL; :36^^Wm  
this.nStartPos = nStart; !7|9r$  
this.nEndPos = nEnd; !I$RE?7eY  
nThreadID = id; 1@Gv`{v  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 x=+H@YO\  
} Qk?Jy<Ra  
J?DyTs3 Z  
Z k_&Kw|  
public void run() g*9>z)  
{ fQ) ;+  
while(nStartPos < nEndPos && !bStop) 7qp|Msf},  
{ n\,W:G9AR7  
WVFy ZpB  
oZw#Nd   
try{ ~<-h# B  
URL url = new URL(sURL); 8=VX` X  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); SesO$=y  
httpConnection.setRequestProperty("User-Agent","NetFox"); eGg#=l=  
String sProperty = "bytes="+nStartPos+"-"; HX^ P9jXT  
httpConnection.setRequestProperty("RANGE",sProperty); Ews Ja3 `  
Utility.log(sProperty); "[ ,XS`  
wVX0!y6  
^hJ ,1{o  
InputStream input = httpConnection.getInputStream(); vN+!l3O  
//logResponseHead(httpConnection); K>~l6  
*O2j<3CHf  
~{{:-XkVB  
byte[] b = new byte[1024]; $tJJ >"  
int nRead;  }P#gXG  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ':@qE\(  
{ iddT.   
nStartPos += fileAccessI.write(b,0,nRead); v'=APl+_  
//if(nThreadID == 1)  (w fZ!  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )k Uw,F=6  
} 7v_e"[s~  
^W*/!q7H  
oB@C-(M  
Utility.log("Thread " + nThreadID + " is over!"); sa($3`d  
bDownOver = true; A |B](MW%O  
//nPos = fileAccessI.write (b,0,nRead); i)ctrdP-  
} ~gD'up@$/  
catch(Exception e){e.printStackTrace ();} 6fiJ' j@  
} [z9i v~  
} _!ed.h.r:  
/r6DPR0\  
2I  
//打印回应的头信息 L $~Id  
public void logResponseHead(HttpURLConnection con) wl4yNC  
{ qJsEKuOs  
for(int i=1;;i++) Nx"?'-3Hm  
{ iGIaZ!j aW  
String header=con.getHeaderFieldKey(i); YH9BJ  
if(header!=null) j(rFORT  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); -JK+{<  
Utility.log(header+" : "+con.getHeaderField(header)); 6{6tg>|L)  
else l)Hu.1~  
break; IM+PjYJ  
} n9%rjS$  
} BeRn9[  
wFD .3!  
9/Ls3U?  
public void splitterStop() RB!g,u  
{ ]KmYPrCl0  
bStop = true; =J,:j[D(  
} 711 z-  
p5*Y&aKj  
Wd7*sa3T  
} >HDK< 1>  
3 f3?%9  
ZO,]h9?4  
/* _> *"6  
**FileAccess.java `fH6E8N  
*//文件访问(定位,写) @RjLDj+)S  
package NetFox; mxIEg?r(  
import java.io.*; n1QO/1} :  
C-M op,w  
jH8F^KJM[  
public class FileAccessI implements Serializable{ l}m@9 ~oC  
#pZ3xa3R  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~Oq(JM $M  
RandomAccessFile oSavedFile; m4EkL  
long nPos; (efH>oY[  
UwLa9Dn^  
w$pv  
public FileAccessI() throws IOException oyUf/ Sl  
{ h:|aQJG5  
this("",0); X/Ae-1!  
} #pIb:/2a_  
(qaY,>je]D  
'b-}KDP  
public FileAccessI(String sName,long nPos) throws IOException ?vXy7y&4  
{ H)5]K9D  
oSavedFile = new RandomAccessFile(sName,"rw"); P%1s6fjU  
this.nPos = nPos; | 2mEowAd  
oSavedFile.seek(nPos); L"IdD5`7T  
} =KX:&GU  
:5ji.g* 0  
Ij" `pdp  
public synchronized int write(byte[] b,int nStart,int nLen) J<'4(}^|  
{ j}y"  
int n = -1; +Ta7b)  
try{ @6\8&(|  
oSavedFile.write(b,nStart,nLen); =ahD'*R^A  
n = nLen; E0GpoG5C  
} U5" C"+ 3  
catch(IOException e) BsxQW`>^y  
{ <h(tW  
e.printStackTrace (); <jxTI%'f59  
} 8NpQ"0X  
LdA&F& pI  
BwbvZfV|  
return n; 7dAa~!/(  
} NJ3b Oq  
4PNl3N3,n  
B&"fPi  
} @;pTQ 5 I  
0rF{"HM~  
@dGj4h.  
/* pm^[ve  
**SiteInfoBean.java r6"t`M  
*/ 3rs=EMz:w  
package NetFox; i: 1V\q%  
Bisht%]^  
rqifjsv  
public class SiteInfoBean { JWC{"6  
e)O6k7U$  
!x[ +rf  
private String sSiteURL; //Site's URL xCGvLvFn  
private String sFilePath; //Saved File's Path hmQD-E{Ab  
private String sFileName; //Saved File's Name @va6,^)  
private int nSplitter; //Count of Splited Downloading File #VtlXr>G  
_.zW[;84b  
;4%^4<+3  
public SiteInfoBean() .Q4EmpByCg  
{//nSplitter的缺省值为5 4?;1cXXA  
//default value of nSplitter is 5 VcA87*pel  
this("","","",5); nx8 4l7<  
} X]M)T  
]hc.cj`\W&  
Vf,t=$.[Q  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) J1hc :I<;  
{ M{1't  
sSiteURL= sURL; "2$C_aE  
sFilePath = sPath; UJ2Tj+  
sFileName = sName; !'[f!vsyM{  
this.nSplitter = nSpiltter; Bzw~OB{!=J  
AKejWh  
9H`Q |7g(5  
} 7&qunK'  
['Hl$2 j  
3t)07(x_B  
public String getSSiteURL() ULNU'6  
{ h:}oUr8   
return sSiteURL; $b QD{ {  
} mY+J ju1  
$~75/  
TW" TgOfd  
public void setSSiteURL(String value) #"|</*% >  
{ E.R,'Y;x  
sSiteURL = value; g:7S/L0]  
} D37N*9}  
Usx8  U  
7jQOwzj  
public String getSFilePath() 9@9(zUS|  
{ s3Pr$h  
return sFilePath; m0DD|7}+  
} @G@,)`p4?  
ycz6-kEp  
E_[|ZrIO&*  
public void setSFilePath(String value) wuR Q H]N  
{ JK) )Cuh  
sFilePath = value; G>& Tap>  
} 1qp<Fz[  
x1VBO.t=*  
N_Q)AXr)  
public String getSFileName() |`B*\\1  
{ bFD vCF  
return sFileName; w\ 4;5.$  
} ux`)jOQ`Y]  
O9?t,1  
7}>Zq`]~  
public void setSFileName(String value) #bc$[%_  
{ a|?&  
sFileName = value; t.Q}V5t{g  
} Fjch<gAofS  
(c AWT,  
-!V+>.Oh  
public int getNSplitter() z=%&?V  
{ .,[ NJ:l  
return nSplitter; 3>asl54  
} a@4 Z x  
utOATjB.z  
WRrCrXP  
public void setNSplitter(int nCount) {x_SnZz&  
{ Jy<hTd*q  
nSplitter = nCount; kd55y  
} ~C M%WvS  
} R. :~e  
E/+H~YzO  
Rn?Yz^ 1q  
/* 3<F\ 5|  
**Utility.java tV.qdy/]}  
*/ 8[v9|r  
package NetFox; W3Gg<!*Uo  
v\lhbpk  
]]Bq te  
public class Utility { w1 ;:B%!H  
J n>3c  
}Br=eaY  
public Utility() vtx3a^  
{ 80m<OW1  
+9gI^Gt  
+|0f7RB+R  
} 7+]+S`p  
WzinEo{ f  
//线程睡眠 TwfQq`  
public static void sleep(int nSecond) [p Y1\$,  
{ 9!XXuMWU<  
try{ fI<|]c}P&J  
Thread.sleep(nSecond); [KcF0%a  
} WR|n>i@m  
catch(Exception e) xxy (#j$  
{ v 79k{<Ln  
e.printStackTrace (); +jD*Jtb<  
} sOVbz2 \yb  
} LC>bZ!(i#  
simD<&p  
//日志 !#[B#DZc(  
public static void log(String sMsg) I@/s&$H`l  
{ ;6)Onwx  
System.err.println(sMsg); /`kM0=MMa  
} B+VD53 V  
?z pN09e  
M7`iAa.}  
public static void log(int sMsg) y1 qJ  
{ C<B+!16  
System.err.println(sMsg); 'g5 Gdn  
} c3__=$)'kP  
} [ !<  
vk><S|[n  
O3JBS^;V2  
/* ?mi1PNps#  
**TestMethod.java OF1fS\P<>  
*/ 'kb|!  
package NetFox; FW@(MIH  
Lk8[fFa4  
"3;b,<0  
public class TestMethod { |& Pa`=sp  
,9.-A-Yw  
Dg=!d)\  
public TestMethod() ISDeLUihY  
{ ///xx/weblogic60b2_win.exe $! R]!s  
try{ 5jey%)=  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); WKvG|YRDq  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); o;"Phc.  
SiteFileFetch fileFetch = new SiteFileFetch(bean); V4 8o+O  
fileFetch.start(); elDt!9Pu  
} FzzV%  
catch(Exception e){e.printStackTrace ();} 1yd}F`{8UF  
E[a|.lnV  
Qq{>]5<  
} %8c2d  
2A(?9 R9&h  
#V-0-n,`  
public static void main(String[] args) mx=2lL`  
{ Ad)::9K?J  
new TestMethod(); vp4NH]fJ  
} X:kr$  
} I3hN7  
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