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http断点续传简单实现(java)

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/* "#`c\JuR ]  
**SiteFileFetch.java Q$2^m(?;  
*/ |)Sx"B)  
package NetFox; tA9(N>[ *  
import java.io.*; 1;9  %L@  
import java.net.*; CYC6:g|)  
4Jj O.H  
qzu%Pp6If  
public class SiteFileFetch extends Thread { ++0xa%:  
l7GLN1#m  
^i~'aq  
SiteInfoBean siteInfoBean = null; //文件信息Bean O[#B906JB  
long[] nStartPos; //开始位置 <*&2b  
long[] nEndPos; //结束位置 cWL 7gv\|  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 {%z}CTf#  
long nFileLength; //文件长度 hH@pA:`s  
boolean bFirst = true; //是否第一次取文件 bq` 0$c%hN  
boolean bStop = false; //停止标志 h>K%Ox R  
File tmpFile; //文件下载的临时信息 LL=nMoS  
DataOutputStream output; //输出到文件的输出流 Jx= v6==7  
"a >a "Ei  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 6b#J!:?  
public SiteFileFetch(SiteInfoBean bean) throws IOException 610hw376B  
{ \JEI+A PY*  
siteInfoBean = bean; Gex%~';+q  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ( j~trpe,  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ]6EXaf#  
if(tmpFile.exists ()) 5>[ j^g+@  
{ >a1 ovKF  
bFirst = false; g,cl|]/\d  
read_nPos(); ~0@+8%^>;  
} g3uI1]QXLg  
else EYF]&+ 9  
{ %j?<v@y  
nStartPos = new long[bean.getNSplitter()]; a=3{UEi'o  
nEndPos = new long[bean.getNSplitter()]; &tE#1<k  
} OQh(qa  
zos#B30  
5%6r,?/7KM  
lGP'OY"Q  
} D>Ph))QI  
IT0*~WMZ  
c\pPwG  
public void run() H@xIAL  
{ g:nU&-x#R  
//获得文件长度 VR9C< tMSi  
//分割文件 ua vv  
//实例FileSplitterFetch }nJG<rY  
//启动FileSplitterFetch线程 qjp<_aw  
//等待子线程返回 :V#W y  
try{ x?|   
if(bFirst) p#dpDjh  
{ Wc)f:]7  
nFileLength = getFileSize(); +Ss|4O}'  
if(nFileLength == -1) (P N!k0Y  
{ `Z0#IeX=  
System.err.println("File Length is not known!"); ,HdFE|  
} ]%5DuE\M8\  
else if(nFileLength == -2) W=EvEx^?%  
{ 3QrYH @7zx  
System.err.println("File is not access!"); X pd^^  
} U ]6 Hml;l  
else yegTKoY  
{ jE{2rw$ZJ?  
for(int i=0;i<nStartPos.length;i++) l`R/WC  
{ }Ik{tUS$  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); >_$DKY>$`  
} &~7b-foCq  
for(int i=0;i<nEndPos.length-1;i++) A@0%7xm  
{ -3<5,Q{G+  
nEndPos = nStartPos[i+1]; Y?z@)cL  
} J$?*qZ(oO  
nEndPos[nEndPos.length-1] = nFileLength; 8vcV-+x  
} {>c O&eiCt  
} `MtPua\_  
O`hOVHD Q  
rE bC_<  
//启动子线程 @M-+-6+  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2|)3Ly9  
for(int i=0;i<nStartPos.length;i++) FPu"/4v&  
{ =,~h]_\_  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :,=no>mMx  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), D`lTP(] y  
nStartPos,nEndPos,i); /)PD+18  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )vK %LmP  
fileSplitterFetch.start(); B&`hvR  
} B{SzC=4f}  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), G8lR_gD"!  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~Cj55S+  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?*z#G'3z1  
nEndPos = " + nFileLength); rQbL86+  
// fileSplitterFetch[nPos.length-1].start(); t,.MtU>K@  
& ;+u.X  
5B? >.4R  
//等待子线程结束 wvm`JOP:A  
//int count = 0; i(JBBE"  
//是否结束while循环 5xi f0h-`  
boolean breakWhile = false; _e=R[  
tw]RH(g+#  
?s("@dz_  
while(!bStop) d"|XN{  
{ V>j6Juh  
write_nPos(); lV-7bZ  
Utility.sleep(500); _n(NPFV  
breakWhile = true; }xHoitOD  
~:f9,  
%zs 1v]  
for(int i=0;i<nStartPos.length;i++) ` =!&9o  
{ *Ri?mEv hF  
if(!fileSplitterFetch.bDownOver) .foM>UOY  
{ ' @M  
breakWhile = false; dm&F1NkT  
break; 9LGJ-gL  
} Wr7^  
} a'ViyTBo  
if(breakWhile) A:EF#2) g  
break; DA@YjebP'  
PY.c$)az>  
$Tt@Xu  
//count++; 8ltHR]v  
//if(count>4) AyKaazm]9  
// siteStop(); #{GUu ',?&  
} Z xLjh  
l,*v/95h  
3C8'0DB  
System.err.println("文件下载结束!"); rO/mK$  
} lkV% k1w  
catch(Exception e){e.printStackTrace ();} y5.Z<Y  
} gO?+:}!  
/b20!3  
pK#Ze/!  
//获得文件长度 SG8H~]CO)  
public long getFileSize() hNXPm~OK\  
{ YZf<S:  
int nFileLength = -1; 1<^"OjQ  
try{ b1jh2pG(V  
URL url = new URL(siteInfoBean.getSSiteURL()); 0i9y-32-  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jN V2o  
httpConnection.setRequestProperty("User-Agent","NetFox"); #JGy2Hk$^  
W?G4\ubM3<  
abUn{X+f~  
int responseCode=httpConnection.getResponseCode(); l'VgS:NT  
if(responseCode>=400) wYhWRgP  
{ y>u+.z a|  
processErrorCode(responseCode); BUv;BzyV  
return -2; //-2 represent access is error ~ -Rr[O=E  
} >/EmC3?b!  
_h7+.U=  
*"0Yr`)S  
String sHeader; ,qpn4`zE~  
m~#S76!w  
'!Vn  
for(int i=1;;i++) BG"~yyKA  
{ Tn/T :7C  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); t-lWvxXe  
//Utility.log(in.readLine()); %$I\\q q>{  
sHeader=httpConnection.getHeaderFieldKey(i); Vf*!m~]Vqi  
if(sHeader!=null) y%=\E  
{ +M (\R?@gr  
if(sHeader.equals("Content-Length")) Fm{Ri=X<:  
{ <dDGV>n4;  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); s'ntf  
break; T.!GEUQ  
} M'W@K  
} SZ~Ti|^  
else LDW":k|  
break; R,/?p  
} ()K%Rn  
} =lS~2C  
catch(IOException e){e.printStackTrace ();} 0[xum  
catch(Exception e){e.printStackTrace ();} FJv=5L  
&7T0nB/)  
._=Pa)T  
Utility.log(nFileLength); 6 EE7<&  
?)7uwJsH  
RP7e)?5$s  
return nFileLength; XY1NTo. =  
} ${KDGJ,^  
z}s0D]$+x  
?.IT!M}DR  
//保存下载信息(文件指针位置) 2;5EH 0  
private void write_nPos() !k||-Q &  
{ 6t TLyI$+  
try{ r`i<XGPJ%  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]OM|Oo  
output.writeInt(nStartPos.length); 06pLa3oi  
for(int i=0;i<nStartPos.length;i++) s9~W( Wi  
{ c&3 ]%urL  
// output.writeLong(nPos); P`5@$1CJ  
output.writeLong(fileSplitterFetch.nStartPos); \)DP(wC  
output.writeLong(fileSplitterFetch.nEndPos); u1ggLH!U  
}  e1S |&W8  
output.close(); /lm;.7_J+  
} K-)_1  
catch(IOException e){e.printStackTrace ();} q>%KIBh(  
catch(Exception e){e.printStackTrace ();} Yp./3b VO  
} n%3rv?m7  
/P5w}n  
a =*(>=  
//读取保存的下载信息(文件指针位置) %z J)mOu  
private void read_nPos() NM/?jF@j*  
{ II)\rVP5  
try{ PLKp<kg  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); IBf&'/ 8\  
int nCount = input.readInt(); WHqp7NPl  
nStartPos = new long[nCount]; s,"<+80%  
nEndPos = new long[nCount]; Bra>C  
for(int i=0;i<nStartPos.length;i++) ly}6zOC\  
{ ?2%d;tW  
nStartPos = input.readLong(); .Hl]xI$;+  
nEndPos = input.readLong(); -B9C2  
} mgL~ $  
input.close(); #c'yAa  
} Y;p _ff  
catch(IOException e){e.printStackTrace ();} C&,&~^_F  
catch(Exception e){e.printStackTrace ();} x<"1T w5e  
}  ^vYH"2  
]=2Ba<)m  
b~Op1p  
private void processErrorCode(int nErrorCode) d47b&.v8e  
{ 5.]+K<:h"A  
System.err.println("Error Code : " + nErrorCode); \^iJv ~d  
} E08FUAth]#  
VThcG( NF  
uo_Y"QiKEH  
//停止文件下载 L|qQZ=  
public void siteStop() Tw)nFr8oF]  
{ `Ff3H$_*  
bStop = true; kTAb <  
for(int i=0;i<nStartPos.length;i++) ixw3Z D(>+  
fileSplitterFetch.splitterStop();  &xgMqv2/  
Q$Ga.fI  
JWr:/?  
} wXMKQ)$(  
} KF|+# qCN  
//负责部分文件的抓取 >t)vQ&:;u  
**FileSplitterFetch.java U>IllNd  
*/ !Sy._NE`z  
package NetFox; Y _m4:9p  
P \tP0+at  
=GL}\I  
import java.io.*; cZ k? o  
import java.net.*; xKWqDt  
2xhwi.u  
Sf B+;i'D  
public class FileSplitterFetch extends Thread { \-0@9E<D  
`L`qR,R  
w0)V3  
String sURL; //File URL 4[ M!x  
long nStartPos; //File Snippet Start Position MGfDxHg]  
long nEndPos; //File Snippet End Position @HxEp;*NH"  
int nThreadID; //Thread's ID 6b~Zv$5^Y-  
boolean bDownOver = false; //Downing is over =dHM)OXD"  
boolean bStop = false; //Stop identical wOOBW0tj  
FileAccessI fileAccessI = null; //File Access interface dQYb)4ir  
$HF. 02{|  
+wXrQV  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,=O`'l >K  
{ AV Gu*  
this.sURL = sURL; +(x^5~QX  
this.nStartPos = nStart; O%H_._#N`  
this.nEndPos = nEnd; l9lBhltOH  
nThreadID = id; MIo<sJuv  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 k*(c8/<.d  
} u pg?  
gS_)(  
vp? 87h  
public void run() t 9&xk?%{  
{ '3 w=D )  
while(nStartPos < nEndPos && !bStop) "^F#oo%L  
{ :6S!1roi  
1 !bODd  
B]L5K~d  
try{ U&yXs'3a&  
URL url = new URL(sURL); .+MJ' bW  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); QG*=N {% 5  
httpConnection.setRequestProperty("User-Agent","NetFox"); 'A;G[(SYy  
String sProperty = "bytes="+nStartPos+"-";  H;s  
httpConnection.setRequestProperty("RANGE",sProperty); CnSfGsE>  
Utility.log(sProperty); hEi]-N\X  
7Ab&C&3  
4 sasf94  
InputStream input = httpConnection.getInputStream(); ,;)Y 1q}Q  
//logResponseHead(httpConnection); }l~|c{WH`  
&PVos|G  
7yD=~l\Bbs  
byte[] b = new byte[1024]; /x,gdZPX  
int nRead; e:fp8 k<  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 91qk0z`N  
{ PElC0 qCn[  
nStartPos += fileAccessI.write(b,0,nRead); <cNXe4(  
//if(nThreadID == 1) WSi`)@.X O  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); J( JsfU4  
} u~[HC)4(0  
fuSfBtLPR#  
^e:C{]S=  
Utility.log("Thread " + nThreadID + " is over!"); 59!yz'feF  
bDownOver = true; 4e~^G  
//nPos = fileAccessI.write (b,0,nRead); i]J*lM7'  
} R*a5bKr  
catch(Exception e){e.printStackTrace ();} d9>*a$x;/  
} k"D6Vyy`  
} 5Ds/^fA  
0D/u`-  
(|)`~z  
//打印回应的头信息 c[\ :^w^I6  
public void logResponseHead(HttpURLConnection con) 4 YDK`:4I~  
{ ~XN--4%Q  
for(int i=1;;i++) =}>wxO  
{ x=T`i-M  
String header=con.getHeaderFieldKey(i); ma9q?H#X  
if(header!=null) ?j;e/r.  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); (MhC83|?  
Utility.log(header+" : "+con.getHeaderField(header)); &IsQgS7R  
else =M'M/vKD  
break; PLU8:H@X  
} nlmc/1C  
} bP\0S@1YL  
A'r 3%mC  
E9z^#@s  
public void splitterStop() =y -L'z&r  
{ CF"$&+s9  
bStop = true; rCfr&>nn  
} <6QG7 i  
uMVM-(g%  
s3qWTdM  
} nfpkWyIu{  
`q|&;wP.  
mAMi-9  
/* **_`AM~  
**FileAccess.java D,q=?~  
*//文件访问(定位,写) g?` g+:nug  
package NetFox; .w2QiJ  
import java.io.*; i)9}+M 5  
BC*vG=a  
h07Z.q ;  
public class FileAccessI implements Serializable{ {6{y"8  
&7Frg`B&:  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 2{;&c  
RandomAccessFile oSavedFile; ?#; oqH<  
long nPos; ^2f'I iE  
7jvy]5y8&~  
8 2qf7`  
public FileAccessI() throws IOException NbOeF7cq+  
{ \{r-e  
this("",0); Ft%HWGE  
} !w iW#PR  
U |I>CDp  
2WQKj9iyN  
public FileAccessI(String sName,long nPos) throws IOException 5v"r>q[ X  
{ @(>XSTh9  
oSavedFile = new RandomAccessFile(sName,"rw"); Gt#Jr!N~  
this.nPos = nPos; pRI<L'  
oSavedFile.seek(nPos); @P=St\;VP  
} OS8 ^mC  
I)#=#eI* :  
iEx.BQ+  
public synchronized int write(byte[] b,int nStart,int nLen) &:}e`u@5|  
{ L9tjH C]  
int n = -1; L%](C  
try{ kwxb~~S}h(  
oSavedFile.write(b,nStart,nLen); dxqVZksg(9  
n = nLen; @X`~r8&  
} b3(pRg[Fp  
catch(IOException e) BiGB<Jr  
{ p@epl|IZp  
e.printStackTrace (); 50!/%  
} w-2&6o<n-  
QZy+`  
|GuIp8~  
return n; we'<Y  
} D|-^}I4  
x._IP,vRx^  
sYV7t*l  
} []HMUL]"  
!iKR~&UpAL  
u] C/RDTH  
/* TymE(,1  
**SiteInfoBean.java hUirvDvX  
*/ q6A!xQs<  
package NetFox; 9pPb]v,6  
>55c{|"@L  
_;mN1Te  
public class SiteInfoBean { O%)@> 5#S  
RjS;Ck@;  
)"?6EsSF  
private String sSiteURL; //Site's URL qz7:jq3N-{  
private String sFilePath; //Saved File's Path [8*Ovd  
private String sFileName; //Saved File's Name cBf9-k  
private int nSplitter; //Count of Splited Downloading File ;t!n%SnK9!  
,h21 h?6  
' Cy^G;  
public SiteInfoBean() /lAB  
{//nSplitter的缺省值为5 ?pgdj|"a  
//default value of nSplitter is 5 =`2nv0%2  
this("","","",5); CU =}]Y  
} P.*J'q 28  
nb(4"|8}  
RZ)sCR  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) B5J!&suX  
{ mhnjY K9  
sSiteURL= sURL; 2m. RM&TdB  
sFilePath = sPath; AH`n  
sFileName = sName; @rs(`4QEh  
this.nSplitter = nSpiltter; #.O,JG#H  
:T~Aa(%(  
/UeLf $%ZW  
} f.V;Hl,  
qh Ezv~  
A^7!:^%K  
public String getSSiteURL() VlKy6PSIg  
{ 1|Y(XB^os(  
return sSiteURL; 8f>=.O*)  
} }qfr&Ffh@  
8Ml&lfn_8  
'Z2:u!E  
public void setSSiteURL(String value) r}) 2-3ZA9  
{ g-'y_'%0G  
sSiteURL = value; zx^]3}  
} h}xUZ:  
#1R_* Uh  
0 eZfHW&  
public String getSFilePath() Hh @q;0ni  
{ n<MMO=+bg  
return sFilePath; XfA3Ez,}  
} ~ `2w ul  
 {ZFa +  
$,08y   
public void setSFilePath(String value) \V@SCA'  
{ *Yv"lB8  
sFilePath = value; 2&91C[da0  
} $;un$ko6%  
E [JXQ76  
m1_?xU  
public String getSFileName() N_<sCRd]9  
{ /H.QGPr  
return sFileName; >JT{~SRB|Y  
} U`q[5U"  
^B@4 w\t  
zjgK78!<  
public void setSFileName(String value) gd<8RVA  
{ oTZ?x}Z1  
sFileName = value; Sp)KtMV  
} SCeZt [  
RAKQ+Y"nl  
ANSvZqKh  
public int getNSplitter() aKs!*uo0H  
{ FtN1ZZ"<*  
return nSplitter; []Cvma 1\  
} 6h>8^l  
\Ekez~k{`  
Qu]0BVIe  
public void setNSplitter(int nCount) z.1 6%@R  
{ H%7V)"  
nSplitter = nCount; )hk=wu6  
} b{)('C$  
} ;a!o$y  
[rqe;00]  
qx 3.oU  
/* k/l@P  
**Utility.java 4,9AoK)yp  
*/ =f@O~nGm  
package NetFox; tYIHsm\b  
#%VprcEK  
T Uhp  
public class Utility { x6HebIR+  
nzy =0Ox[  
LoHWkNZ5:  
public Utility() uuj"Er31  
{ gT @YG;  
IcL3.(!]l  
Wy#`*h,  
} ->wY|7  
;]fpdu{  
//线程睡眠 hgj#VY$B  
public static void sleep(int nSecond) j>&n5?  
{ 567ot|cc  
try{ 5!#"8|oY  
Thread.sleep(nSecond); el!Bi>b9c!  
} E E?v~6"&  
catch(Exception e) A`(p6 H"s  
{ V$ 38  
e.printStackTrace (); *wt yyP@  
} /iif@5lw{  
} +Smv<^bW  
|}Mkn4  
//日志 sxL;o >{  
public static void log(String sMsg) ]wne2WXE  
{ d1e'!y}R5  
System.err.println(sMsg); &o"Hb=k<  
} }=A6Jv(j  
T.ub! ,Y  
:&yRvu  
public static void log(int sMsg) qIjC-#a=m  
{ |L;'In  
System.err.println(sMsg); :EgdV  
} CW\o>yh  
} OpxVy _5,  
yD1*^~loJ  
2DQ'h}BI  
/* yE9JMi 0  
**TestMethod.java ?^BsR  
*/ 1@)]+* F*z  
package NetFox; gbpm::  
k6JB%m\E  
$pk3d+0B  
public class TestMethod { i`&yPw  
]kb%l"&  
"EEE09~l\  
public TestMethod() b]RCe^E1  
{ ///xx/weblogic60b2_win.exe 344,mnAd  
try{ j,/o0k,  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); W\.f:"2qr  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6}iIK,Om  
SiteFileFetch fileFetch = new SiteFileFetch(bean); OD\x1,E)I  
fileFetch.start(); sbK 0OA  
} ccD+o$7LT  
catch(Exception e){e.printStackTrace ();} `m2F.^qrr  
DDAqgx  
$#R.+B  
} W\eB   
w2{k0MW  
/2'\ya4B  
public static void main(String[] args) F!]UaEmV  
{ eg(xN/D  
new TestMethod(); {h9#JMIA  
} );))kYr  
} zN5i}U=|r  
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