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http断点续传简单实现(java)

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/* t|t#vcB  
**SiteFileFetch.java MX@IHc  
*/ :JlP[I  
package NetFox; 6TP7b|  
import java.io.*; 4Llo`K4  
import java.net.*; lKk/p^:  
d[rv1s>i  
a>\vUv*  
public class SiteFileFetch extends Thread { Ym;*Y !~[  
d1[ZHio2c?  
+r3IN){jz  
SiteInfoBean siteInfoBean = null; //文件信息Bean 8[6o (  
long[] nStartPos; //开始位置 ZiLj=bh  
long[] nEndPos; //结束位置 o1nURJ!  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 (8_\^jJ  
long nFileLength; //文件长度 \EseGgd21  
boolean bFirst = true; //是否第一次取文件 ETs>`#`6o  
boolean bStop = false; //停止标志 r$)w7Gk<  
File tmpFile; //文件下载的临时信息 ">?vir^  
DataOutputStream output; //输出到文件的输出流 % `Z! 4L  
NnVnUgx  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) (sWLhUgRX  
public SiteFileFetch(SiteInfoBean bean) throws IOException phO;c;y}  
{ E*i#?u  
siteInfoBean = bean; _X?^Cy  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); `est|C '+  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); e<r,&U$  
if(tmpFile.exists ()) F;^F+H  
{ $XoQ]}"O  
bFirst = false; o M Zq+>  
read_nPos(); 4Qn$9D+?  
} K98i[,rP  
else )8g(:`w  
{ !ct4;.2 D  
nStartPos = new long[bean.getNSplitter()]; a22XDes=  
nEndPos = new long[bean.getNSplitter()]; uslQ*7S[^  
} +}jJ&Z9 )  
XrZ*1V  
V)}rEX   
v%Wx4v@%SE  
} ,AT[@  
(p%>j0<  
A_KW(;50  
public void run() >M&3Y XC  
{ ](|\whI  
//获得文件长度 0Won9P  
//分割文件 3G kv4,w<  
//实例FileSplitterFetch k5]j.V2f  
//启动FileSplitterFetch线程 nT2)E&U6%  
//等待子线程返回 _UuC,Pl3  
try{ `-LGU7~+  
if(bFirst) Hc`A3SMR  
{ Bj7gQ%>H4  
nFileLength = getFileSize(); irjP>3_e  
if(nFileLength == -1) m#=z7.XrX  
{ $ `7^+8vHV  
System.err.println("File Length is not known!"); _YRE (YZ/  
} 43=,yz2Ef  
else if(nFileLength == -2) ,a#EW+" Z  
{ 5atYOep  
System.err.println("File is not access!"); 8_N]e'WUh  
} ;| 1$Q!4  
else <tioJG{OT  
{  O#I1V K  
for(int i=0;i<nStartPos.length;i++) Sfdu`MQR  
{ *g^x*|f6  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ,i@X'<;y  
} +@r*}  
for(int i=0;i<nEndPos.length-1;i++) f5` g  
{ kwsp9 0)  
nEndPos = nStartPos[i+1]; JfPD}w  
} G}p\8Q}'  
nEndPos[nEndPos.length-1] = nFileLength; ++E3]X|  
} Z@r.pRr'  
} 6^DR0sO  
$q 2D+_  
q:g2Zc'Y~W  
//启动子线程 )vxUT{;sH  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; A`R{m0A  
for(int i=0;i<nStartPos.length;i++) /t(C>$ }p  
{ &iV{:)L  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vhhC> 7  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), h yv2SxP*  
nStartPos,nEndPos,i); 2PG [7u^  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Sf8{h|71  
fileSplitterFetch.start(); `jOX6_z?I  
} P~ &$l2  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TiH) 5  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); b5^OQH{v  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )5 R=Z<  
nEndPos = " + nFileLength); M+x,opl  
// fileSplitterFetch[nPos.length-1].start(); Fgh]KQ/5  
QPq7R  
KZeQ47|  
//等待子线程结束 N\bocMc,X  
//int count = 0; ZWS`\M  
//是否结束while循环 W | o'&  
boolean breakWhile = false; KI+VXH}Y5{  
,GgAsj: K  
MuSUKBhM  
while(!bStop) M %Qt|@O  
{ Sf r&p>{,  
write_nPos(); S.a%  
Utility.sleep(500); iJ~Vl"|m  
breakWhile = true; GQ-Rtn4v  
Km^&<3ch#  
,\@O(; mF  
for(int i=0;i<nStartPos.length;i++) c ;'[W60  
{ Y3=_ec3w  
if(!fileSplitterFetch.bDownOver) CoA6  
{ 8}(]]ayl  
breakWhile = false; oqeSG.1  
break; }C|dyyr  
} )Dz+X9;g+  
} F,'exuZ  
if(breakWhile) b3VS\[p  
break; -! K-Htb-  
/S lYm-uQ+  
=xS+5(  
//count++; hh[jN 7K  
//if(count>4) x@Hc@R<!  
// siteStop(); ~#/hzS  
} b4pm_Um  
=ha{Ziryo  
& :7ZQ1  
System.err.println("文件下载结束!"); k%G1i-] 4  
} Ft!],n-n*  
catch(Exception e){e.printStackTrace ();} Tq~=TSD  
} vz!s~cAt  
h3;bxq!q  
RG4sQ0  
//获得文件长度 /7YF mI/0  
public long getFileSize() YSe.t_K2C  
{ 9tqF8pb7v  
int nFileLength = -1; _x5 3g A  
try{ tq|hPd<C  
URL url = new URL(siteInfoBean.getSSiteURL()); @i*|s~15  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7!N2-6GV  
httpConnection.setRequestProperty("User-Agent","NetFox"); mtj h`  
FeTL&$O  
piZJJYv t  
int responseCode=httpConnection.getResponseCode(); Zg.&V  
if(responseCode>=400) _ :VB}>  
{ :*2ud(  
processErrorCode(responseCode); (!zy{;g|  
return -2; //-2 represent access is error NW&b&o  
} IOV(seEY  
]S5JUAGkE*  
y?q*WUh  
String sHeader; $81*^  
)d>!"JB-  
L:'J Bhg  
for(int i=1;;i++) 5hy""i  
{ J`^I./  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); oo.2Dn6z  
//Utility.log(in.readLine()); }O4^Cc6  
sHeader=httpConnection.getHeaderFieldKey(i); `9b7>Nn<  
if(sHeader!=null) fP `b>]N_  
{ 1N>|yQz  
if(sHeader.equals("Content-Length")) aUtnR<6  
{ uF3qD|I\  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); t0T"@t#c  
break; @$+ecaVW  
} qhz]Wm P   
} QD>"]ap,o  
else >:|q&|x-  
break; <|Pun8j  
} ez6EjUk  
} r'*}TM'8  
catch(IOException e){e.printStackTrace ();} d:U9pC$  
catch(Exception e){e.printStackTrace ();} [`):s= FC  
GHeVp/u  
se>MQM5 )  
Utility.log(nFileLength); .8G@%p{,  
,5*eX  
ksN+ ?E4w  
return nFileLength; }I2@%tt?  
} WpRc)g :  
PuZf/um  
iS<I0\D  
//保存下载信息(文件指针位置)  MEGv}  
private void write_nPos() O~^"  
{ IDG}ZlG  
try{ \9g+^vQg  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1cD! :[  
output.writeInt(nStartPos.length); u9EgdpD  
for(int i=0;i<nStartPos.length;i++) 6 jn3`D  
{ `6xkf&Kt  
// output.writeLong(nPos); lh;:M -b9  
output.writeLong(fileSplitterFetch.nStartPos); >M/V oV  
output.writeLong(fileSplitterFetch.nEndPos); ixT:)|'i  
} )}?#  
output.close(); B,=H@[Fj  
} /x1![$oC0  
catch(IOException e){e.printStackTrace ();} ={xE!"  
catch(Exception e){e.printStackTrace ();} 7 !JQB  
} Yn G_m]  
2mGaD\?K  
[a wjio  
//读取保存的下载信息(文件指针位置) fu]s/'8B  
private void read_nPos() ]3 l9:|  
{ k>g _Z`%<  
try{ !GNBDRr  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); t8+X%-r  
int nCount = input.readInt(); ]@Uq=?%  
nStartPos = new long[nCount]; 0PrLuejz  
nEndPos = new long[nCount]; t?'!$6   
for(int i=0;i<nStartPos.length;i++) ~S7 D>D3S  
{ X'qU*Eo  
nStartPos = input.readLong(); jm Fz51  
nEndPos = input.readLong(); ftF@Wq1f  
} pj?f?.^  
input.close(); $H9%J  
} Q{5kxw1ZF  
catch(IOException e){e.printStackTrace ();} 3skC$mpJHw  
catch(Exception e){e.printStackTrace ();} ,~]tg77  
} < RH UH)I  
57&b:0`p  
u;/ Vyu  
private void processErrorCode(int nErrorCode) VeQg -#&I  
{ N<-gI9_  
System.err.println("Error Code : " + nErrorCode); j4R(B  
} 5X:*/FuS@  
xM&Wgei]10  
8;+B*+%@n  
//停止文件下载 #kaY0M  
public void siteStop() @dPTk"P  
{ K8UP,f2  
bStop = true; %*0^0wz  
for(int i=0;i<nStartPos.length;i++) U5.LDv;  
fileSplitterFetch.splitterStop(); /q`xCS  
0p}D(m2B  
70Wggty  
} ?1K#dC52#  
} 5jgR4a*_v  
//负责部分文件的抓取 #nPQ!NB/  
**FileSplitterFetch.java &b%zQ4%d-`  
*/ PC-"gi =h  
package NetFox; /*X2c6<d  
I ,z3xU  
`yH<E+   
import java.io.*; ne_TIwfw-  
import java.net.*; t~#zMUfac  
mSb#Nn6W  
sWc*5Rt  
public class FileSplitterFetch extends Thread { \Yc'~2n  
"Pu!dJ5[]  
f>UXD  
String sURL; //File URL Xy$3VU*  
long nStartPos; //File Snippet Start Position +>{Y.`a;Jo  
long nEndPos; //File Snippet End Position pw)||Q  
int nThreadID; //Thread's ID P;ci9vk  
boolean bDownOver = false; //Downing is over + |#O@k  
boolean bStop = false; //Stop identical *&^:T~|=!  
FileAccessI fileAccessI = null; //File Access interface g| vNhq0|i  
G(G{RAk>  
|6K+E6H  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException rp!oO>F  
{ 4hTMbS_;  
this.sURL = sURL; YW( Qmo7  
this.nStartPos = nStart; pH"#8O&  
this.nEndPos = nEnd; \ b?" b  
nThreadID = id; JS CZ{v J$  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 j)/nKh4O  
} /7|V+6jV  
; Q3n  
mR?5G: W~R  
public void run() ~nh:s|l6%M  
{ pxCK;]  
while(nStartPos < nEndPos && !bStop) S/e2P|}  
{ C8 xZ;V]  
pu 7{a  
H1QJ k_RL  
try{ iV*q2<>  
URL url = new URL(sURL); 0Tx{3#  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (nlvl?\d  
httpConnection.setRequestProperty("User-Agent","NetFox"); XF;ES3 d  
String sProperty = "bytes="+nStartPos+"-"; ;; C?{  
httpConnection.setRequestProperty("RANGE",sProperty); d9;g]uj`  
Utility.log(sProperty); _lGdUt 2  
o:3dfO%nuM  
iB%gPoDCL@  
InputStream input = httpConnection.getInputStream(); }dWq=)*  
//logResponseHead(httpConnection); o7sT=x9  
ToXki,  
MbZJ;,e?  
byte[] b = new byte[1024]; V@ cM|(  
int nRead; #t: S.A@  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) XBb~\p3y  
{ HUv/ ~^<  
nStartPos += fileAccessI.write(b,0,nRead); C9n?@D;S  
//if(nThreadID == 1) }%'?p<^M  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); M42 Ssn)  
} U |Jo{(Y  
 @Z\,q's  
][9%Kl*%@p  
Utility.log("Thread " + nThreadID + " is over!"); DRp~jW(\y  
bDownOver = true; clL2k8VS  
//nPos = fileAccessI.write (b,0,nRead); _m gHJ0v'  
} YW_Q\|p]M  
catch(Exception e){e.printStackTrace ();} 1m:XR0P  
} Sjyoc<Uo  
} 17oa69G  
Q@<S[Qh[.  
S+atn]eU@  
//打印回应的头信息 VC\S'z  
public void logResponseHead(HttpURLConnection con) \n8] M\<  
{ [<g?WPCcC  
for(int i=1;;i++) u'|4?"uz  
{ ||hb~%JK6  
String header=con.getHeaderFieldKey(i);  PT=2@kH  
if(header!=null) a!< 8\vzg  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); si`A:14R  
Utility.log(header+" : "+con.getHeaderField(header)); 52 fA/sx  
else Crho=RJPR  
break; Sa?ksD2IaB  
} g*e   
} 7hlO#PYZ  
Jq&uF*!  
i|w81p^o  
public void splitterStop() (e!0]Io@  
{ 4'g;TI^  
bStop = true; wVicyiY]  
} >VP= MbN  
^;Y|3)vvB  
vY  }A  
} TZ(cu>  
G-xDN59K  
8S mCpg  
/* H:t$'kb`  
**FileAccess.java E9Np0M<  
*//文件访问(定位,写) zR1^I~ %  
package NetFox; @z4*.S&tz  
import java.io.*; 544X1Ww2  
}XV+gyG=@  
x(etb<!jd  
public class FileAccessI implements Serializable{ #{?PbBE}  
P9^-6;'Y  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 trPAYa}W  
RandomAccessFile oSavedFile; FbaEB RM  
long nPos; }=gx#  
Xjo5v*Pu  
/'].lp  
public FileAccessI() throws IOException "?ucO4d  
{ !;i`PPRwk  
this("",0); DnCP aM4%  
} -8:&>~4`  
Ghx3EVqnx"  
E^ P,*s  
public FileAccessI(String sName,long nPos) throws IOException q|o}+Vr  
{ DoJ\ q+  
oSavedFile = new RandomAccessFile(sName,"rw"); J&[@}$N  
this.nPos = nPos; HJXT9;w  
oSavedFile.seek(nPos); !UG 7Uer  
} 4 N H  
A+SE91m  
Sp@^XmX(S  
public synchronized int write(byte[] b,int nStart,int nLen) <tF9V Jq  
{ hU`wVy  
int n = -1; Gn|F`F  
try{ M m[4yP%  
oSavedFile.write(b,nStart,nLen); 8oUpQcim  
n = nLen; .y_/Uwu  
} +Z7th7W/,  
catch(IOException e) YQ+tDZY8`  
{ #E? (vA1  
e.printStackTrace (); Mr;E<Lj ^K  
} VL% UR{  
~$iIVJ`  
P3cRl']  
return n; _LMM,!f  
} !>{G,\^=pT  
TH; R  
& -{DfNKc  
} ]h>_\9qO  
L\)ZC  
-yE/f2PgQ  
/* ?no fUD.  
**SiteInfoBean.java ? WF/|/  
*/ ]+|~cRQ9I  
package NetFox; Y ;u<GOe  
#w,Dwy  
$FlW1E j  
public class SiteInfoBean { 'oF%,4 !Y  
As3.Q(#Z  
LQ(yScA@  
private String sSiteURL; //Site's URL CN#+U,NZV  
private String sFilePath; //Saved File's Path QW $G  
private String sFileName; //Saved File's Name @y='^DQ*  
private int nSplitter; //Count of Splited Downloading File >TOu|r  
+W:= e,=  
 {Or;  
public SiteInfoBean() %MrWeYd1  
{//nSplitter的缺省值为5 0'V5/W  
//default value of nSplitter is 5 )2V:  
this("","","",5); eoai(&o0$  
} W=#:.Xj[  
}`W){]{k O  
J6U$qi  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \R|4( +]x  
{ HG+%HUO$  
sSiteURL= sURL; ]bj&bk#  
sFilePath = sPath; .q `Hjmg<  
sFileName = sName; Xe<sJ. &Wf  
this.nSplitter = nSpiltter; ]$Yvj!K*Q  
Fs{x(_LOr  
Y%PwktQm  
} ~aMlr6;  
A*2  bA  
_AQb6Nb  
public String getSSiteURL() \ ^ZlG.  
{ 5jd,{<  
return sSiteURL; 4a'N>eDR  
} r<K(jG[:{f  
GliwY_  
k.uMp<)D  
public void setSSiteURL(String value) zaah^.MA|  
{ uT}' Y)m  
sSiteURL = value; 5]n[]FW  
} V}dJ.I /#  
FrTi+& <  
AWP"b?^G|  
public String getSFilePath() ]|MEx{BG-  
{ A%`[mc]4#  
return sFilePath; k\WR  ]  
} 1#.>a$>  
Z @^9PQG$  
J3n-`k8  
public void setSFilePath(String value) Tav*+  
{ H*[ M\gN$  
sFilePath = value; X:6c}p%,!  
} &?q/1vLa  
*MJX?  
 _59huC.  
public String getSFileName() g=QDu7Ux  
{  c|M6 <}  
return sFileName; UD8op]>L  
} kKAP"'v  
 .Nw=[  
W7U2MqQ  
public void setSFileName(String value) #=6E\&NC  
{ W}5xmz  
sFileName = value; kL$!E9  
} B?4boF?~  
xL{a  
>N]7IU[-  
public int getNSplitter() 95YL]3V  
{ %] >KvoA  
return nSplitter; pgOQIzu  
} KO]T<R h<  
eu(:`uu  
+tVaBhd!  
public void setNSplitter(int nCount) So0f)`A  
{ kdl:Wt*4o  
nSplitter = nCount; 5<UVD:~z  
} s (zL   
} gREzZ+([  
my}-s  
:P<]+\m  
/* KU8J bl*   
**Utility.java B5X(ykaX~  
*/ f6p-s y>  
package NetFox; &Rvm>TC=  
1XD,uoxB  
a{R%#e\n  
public class Utility { j!]YNH@  
fZ*+2T>  
vJ'2@f$  
public Utility() s;3={e.  
{ VzY8rI  
K?BOvDW"`  
B]uc<`f  
} !t gi  
> U%gctIg  
//线程睡眠 9D7+[`r(-  
public static void sleep(int nSecond) xO&eRy?%  
{ y~F,0"N\r  
try{ *XT/KxLa7  
Thread.sleep(nSecond); V+VkY3  
} 4<k9?)~(J  
catch(Exception e) /+@p7FqlE  
{ MM (xk  
e.printStackTrace (); X4 A<[&F/  
} q U]gj@R  
} kzt(i Y_6  
<})2#sZO!  
//日志 w-Da~[J  
public static void log(String sMsg) v"#mzd.tW  
{ X22[tqg;&  
System.err.println(sMsg); k +H3Bq  
} (=* cK-3  
R,pX:H&#+  
TrLu~4  
public static void log(int sMsg) U$_xUG  
{ Yy)tmq  
System.err.println(sMsg); `/EGyN6X  
} w+1 |9Y  
} \lZf<f  
bdQ_?S(  
d` jjGEj  
/* qzf!l"bT  
**TestMethod.java %Ti}CwI`  
*/ kPF9Z "l  
package NetFox;  (Q.waI  
T>R0T{A  
1T-8K r  
public class TestMethod { M#As0~y  
9J9)AV  
fjs [f'L  
public TestMethod() f"qga/  
{ ///xx/weblogic60b2_win.exe 6WU(%  
try{ SVO3821  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *Df,Ijh$  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); b\-&sM(W"  
SiteFileFetch fileFetch = new SiteFileFetch(bean); f] J M /  
fileFetch.start(); K }Vv4x1U  
} XqW@rU  
catch(Exception e){e.printStackTrace ();} Aq0S-HKF  
5[* qi?w=  
_Jme!Oaa  
} }Rz3<eON  
eC[$B99\  
kH]yl 2  
public static void main(String[] args) fO0XA"=  
{ +eFFSt  
new TestMethod(); V>A .iim  
} -Xxqm%([71  
} pXJpK@z  
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