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http断点续传简单实现(java)

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/* 1Jt5|'tl  
**SiteFileFetch.java 6Wl+5 a6V  
*/ PE0A`  
package NetFox; (]1n!  
import java.io.*; Ovh[qm?Z  
import java.net.*; \IIR2Xf,K  
I!~5.  
'`I&g8I\  
public class SiteFileFetch extends Thread { x8w455  
CM_FF:<tn  
;mu^WIj  
SiteInfoBean siteInfoBean = null; //文件信息Bean O$+0 .  
long[] nStartPos; //开始位置 O)n"a\LD  
long[] nEndPos; //结束位置 gh#9<  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 xx_]e4  
long nFileLength; //文件长度 g?qm >X  
boolean bFirst = true; //是否第一次取文件 1ve %xF  
boolean bStop = false; //停止标志 HTA Jn_  
File tmpFile; //文件下载的临时信息 D:4Iex9$F"  
DataOutputStream output; //输出到文件的输出流 (w}iEm\b  
)[i0~o[  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) LY(YgqL  
public SiteFileFetch(SiteInfoBean bean) throws IOException W{<_gD9  
{ r>+\9q1  
siteInfoBean = bean; r3*0`Rup  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); A}W) La\  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); !RN(/ &%y  
if(tmpFile.exists ()) j#rjYiYKy  
{ B agO0#  
bFirst = false; u1R_u9  
read_nPos(); x\T 9V~8a  
} Q/xT>cUd  
else /_rEI,[k  
{ JHC 6l  
nStartPos = new long[bean.getNSplitter()]; 7.`Fe g.  
nEndPos = new long[bean.getNSplitter()]; ]3nka$wA*  
} .5 Sw  
`7[z%cuK  
yY+)IU.  
|uf{:U)  
} xM"k qRZ  
pUi|&F K">  
m^I+>Bp/:  
public void run() F%M4i`Vh  
{ )RG@D\t,  
//获得文件长度 0]p! Bscaf  
//分割文件 46OYOa  
//实例FileSplitterFetch +uZ,}J  
//启动FileSplitterFetch线程 ]?tC+UKb  
//等待子线程返回 e=e^;K4  
try{ N8S !&*m  
if(bFirst) 9.)*z-f$  
{ '#pY/,hVB  
nFileLength = getFileSize(); Myaj81  
if(nFileLength == -1) o_R<7o/d|  
{ 7L)edR [  
System.err.println("File Length is not known!"); Oh)s"f\N  
} ++1<A& a  
else if(nFileLength == -2) vkUXMMuf+e  
{ ?tx%K U\3  
System.err.println("File is not access!"); >U .  
} $=3&qg"!  
else 7/C,<$Ep  
{ /Y| y0iK  
for(int i=0;i<nStartPos.length;i++) lOB*M!8   
{ ,41Z_h  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); wiHGTaR  
} >v--R8I*  
for(int i=0;i<nEndPos.length-1;i++) M uz+j.0  
{ @/jLN  
nEndPos = nStartPos[i+1]; j=c=Pe"?u  
} 7m='-_w)?w  
nEndPos[nEndPos.length-1] = nFileLength; r?Q`b2Q  
} xgeDfpF'  
} 4u0\|e@a  
NEp )V'  
z 3((L  
//启动子线程 d+DdDr  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; CWKN0HB  
for(int i=0;i<nStartPos.length;i++) Zfwhg4G~  
{ vfBIQfH  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T .#cd1b  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), k_ d)  
nStartPos,nEndPos,i); f 0"N  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9NzK1V0X  
fileSplitterFetch.start(); ;6+e!h'1  
} =T7lv%u  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), P}kBqMM  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5@c/,6l  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (h&XtFul}  
nEndPos = " + nFileLength); #WE"nh9f|z  
// fileSplitterFetch[nPos.length-1].start(); <7  
ct o+W}k  
e8E*Urtz  
//等待子线程结束 w2 %u;D%  
//int count = 0; fyHFfPEE  
//是否结束while循环 '?$N.lj$d  
boolean breakWhile = false; /w[B,_ZKTk  
o}^/K m+t  
@bfW-\ I  
while(!bStop) R{6~7<m.  
{ Ei$?]~ &  
write_nPos(); M( eu wy  
Utility.sleep(500); 4DLp +6zP  
breakWhile = true; 3jeB\  
A8|DB@ Bi  
X1wlOE  
for(int i=0;i<nStartPos.length;i++) s<#["K*_  
{ Ku 'OM6D<  
if(!fileSplitterFetch.bDownOver) I| V yv  
{ nf%"7y{dd  
breakWhile = false; +F>9hA  
break; ^jph"a C  
} ioJ~k[T  
} %1JN%  
if(breakWhile) @'5*u~M  
break; gC/~@Z8W]  
yW@0Q:  
5Yxs_t4  
//count++; &PE/\_xD_  
//if(count>4) NI<;Lm  
// siteStop(); &<Iyb}tA?  
} `qXCY^BH2  
E\$7tXQK6  
o x|K2A  
System.err.println("文件下载结束!"); S`w_q=-^8  
} n PAl8  
catch(Exception e){e.printStackTrace ();} ?@@BIg-  
} DA9-F  
At t~N TL  
QXaE2}}P  
//获得文件长度 th :I31  
public long getFileSize() n7A %y2  
{ {.r jp`39  
int nFileLength = -1; [c`u   
try{ G d%X> ~  
URL url = new URL(siteInfoBean.getSSiteURL()); B)L=)N  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {?+dVLa^;  
httpConnection.setRequestProperty("User-Agent","NetFox"); E\_Wpk  
Q:v9C ^7  
wO-](3A-8P  
int responseCode=httpConnection.getResponseCode(); {p90   
if(responseCode>=400) 7>@g)%",  
{ H Z)an  
processErrorCode(responseCode); 9y$"[d27;+  
return -2; //-2 represent access is error L!>EW0  
} HxE`"/~.7k  
RX"~m!26  
<w1# 3Mu'  
String sHeader; TXH9BlDn  
g %e"KnU  
5eL_iNqJM  
for(int i=1;;i++) Qnr7Qnb  
{ 1s"/R  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); R3dt-v  
//Utility.log(in.readLine()); Yw!(]8PYdU  
sHeader=httpConnection.getHeaderFieldKey(i); >}I BPC  
if(sHeader!=null) Ho^rYz  
{ Fv!KLw@  
if(sHeader.equals("Content-Length")) USDqh437  
{ o6b\ w  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader));  f3E%0cg  
break; >Nho`m(  
} f7du1k3  
} H)5V \  
else MJ% gF=$X  
break; {>]7xTpwZ  
} Qzh`x-S  
} ;ND)h pD+  
catch(IOException e){e.printStackTrace ();} 8lJMD %Df:  
catch(Exception e){e.printStackTrace ();} )=9EShz!  
O_~vl m<#  
C)H1<Br7  
Utility.log(nFileLength); +\D?H.P  
$LXz Q>w9  
BIK^<_?+ZU  
return nFileLength; ;zpSyyp@  
} lk[BS*  
iC`mj  
s9\HjK*+  
//保存下载信息(文件指针位置) jb'A Os  
private void write_nPos() No(p:Snbo  
{ q33Z.3R  
try{ $Y3mO ~  
output = new DataOutputStream(new FileOutputStream(tmpFile)); +<TnE+>j  
output.writeInt(nStartPos.length); cy%S5Rz  
for(int i=0;i<nStartPos.length;i++) }b$W+/M\  
{ F,)\\$=,  
// output.writeLong(nPos); U%qE=u-  
output.writeLong(fileSplitterFetch.nStartPos); +jv&V%IL  
output.writeLong(fileSplitterFetch.nEndPos); ?z/ )Hkw  
} EWZ?q$  
output.close(); \|wUxijJ*,  
} 2sXNVo8`w"  
catch(IOException e){e.printStackTrace ();} >vny9^_  
catch(Exception e){e.printStackTrace ();} v "Yo  
} id=:J7!QU  
$ KAOJc4<  
0^G5 zQlj  
//读取保存的下载信息(文件指针位置) xkPH_+4i8  
private void read_nPos() JsY|Fv  
{ !o{>[  
try{ (;(P3h  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g=q1@)  
int nCount = input.readInt(); &?wNL@n  
nStartPos = new long[nCount]; ] l@Mo7|w  
nEndPos = new long[nCount]; 'G|M_ e  
for(int i=0;i<nStartPos.length;i++) )^q7s&p/  
{ !7fL'  
nStartPos = input.readLong(); 1SY`V?cu  
nEndPos = input.readLong(); =,HxtPJ  
} mDB?;a>  
input.close(); :Y\!~J3W  
} NW AT"  
catch(IOException e){e.printStackTrace ();} L^b /+R#  
catch(Exception e){e.printStackTrace ();} R32A2Ml  
} KN\*|)  
NJqjW  
!\(j[d#  
private void processErrorCode(int nErrorCode) BK/~2u  
{ f?[0I\V[$  
System.err.println("Error Code : " + nErrorCode); J6s@}@R1  
} ZPO+ #,  
wx]r{  
[.[|rnil  
//停止文件下载 X 8#Uk}/  
public void siteStop() f?P>P23  
{ 67]kT%0  
bStop = true; ;+6TZqklQ  
for(int i=0;i<nStartPos.length;i++) ("!P_Q#  
fileSplitterFetch.splitterStop(); .9'bi#:Cw  
7{fOo%(7  
POl_chq  
} J}M_Ka  
} G-#]|)  
//负责部分文件的抓取 A6faRi703  
**FileSplitterFetch.java :rcohzfa  
*/ W}0cM9 g  
package NetFox; ~REP@!\r^  
FQp@/H^  
7JL*y\'  
import java.io.*; D&C83^m  
import java.net.*; \:[J-ySJ  
^W)h=49PN  
"u=U@1 ^  
public class FileSplitterFetch extends Thread { qbZY[Q+F  
:3h'Hr  
]\ DIJ>JZ  
String sURL; //File URL M>m+VsJV  
long nStartPos; //File Snippet Start Position NBaXfWh  
long nEndPos; //File Snippet End Position 7sglqf>  
int nThreadID; //Thread's ID {S*:pG:+q  
boolean bDownOver = false; //Downing is over X`' @ G  
boolean bStop = false; //Stop identical C(jUM!m  
FileAccessI fileAccessI = null; //File Access interface 7!kbe2/]'  
t,4'\nv*  
}u9wD08x  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 'qt+.vd  
{ sQ05wAv  
this.sURL = sURL; ;mtv  
this.nStartPos = nStart;  )o\U4t  
this.nEndPos = nEnd; ?K>=>bS^h  
nThreadID = id; TLWU7aj&!  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 IJzPWs5W:  
} 1O@y >cV  
;:l>Kac  
1*vt\,G  
public void run() wB0K e  
{ 2nsW)bd  
while(nStartPos < nEndPos && !bStop) q?TI(J+/  
{ %!HBPLk  
4Y!_tZ>  
66jL2XU<  
try{ HgfeSH  
URL url = new URL(sURL); xmp^`^v*  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); E3`&W8  
httpConnection.setRequestProperty("User-Agent","NetFox"); `k.Nphx~%  
String sProperty = "bytes="+nStartPos+"-"; )(`HEl>-9c  
httpConnection.setRequestProperty("RANGE",sProperty); n+qa/<  
Utility.log(sProperty); _G1C5nkDl4  
?loP18S b  
xzrA%1y  
InputStream input = httpConnection.getInputStream(); s;NPY  
//logResponseHead(httpConnection); XkE'k;AEx  
m:4Ec>?e  
c*:H6(u  
byte[] b = new byte[1024]; $Il:Yw_  
int nRead; ek9Y9eJ"  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) uL1$yf'  
{ |o0?u:  
nStartPos += fileAccessI.write(b,0,nRead); ,LpGE>s  
//if(nThreadID == 1) P S [ifC  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1,pg7L8H  
} ;VlA~tv  
tuWJj^  
9X%H$>s  
Utility.log("Thread " + nThreadID + " is over!"); pjaDtNb  
bDownOver = true; JrhDqyk*  
//nPos = fileAccessI.write (b,0,nRead); klON6<w  
} {S 2? }  
catch(Exception e){e.printStackTrace ();} KB6'sj  
} o n+:{ad  
} u?-X07_  
PY{])z3N  
/QT"5fxKJ  
//打印回应的头信息 8O='Q-& 8  
public void logResponseHead(HttpURLConnection con) %g+*.8;"b  
{  jcVK4jW  
for(int i=1;;i++) N sNk  
{ v$_YZm{!<  
String header=con.getHeaderFieldKey(i); :^H#i:4  
if(header!=null) c(5r  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); RV{'[8gM   
Utility.log(header+" : "+con.getHeaderField(header)); n(.U>_ P  
else @Fs2J_v  
break; U5!T-o;3}  
} BL?Bl&p(  
} s4uYp  
>56I`[)  
f 3t&Bcw$  
public void splitterStop() c u:1|gt  
{ Ed$;#4  
bStop = true; y/d/#}\:  
} }k7t#O  
+;*dFL  
,'0Zd(s  
} !caY  
o1B8_$aYgc  
hJsYKd8g  
/* vD@ =V#T  
**FileAccess.java L%sskV(  
*//文件访问(定位,写) YKtF)N;m]  
package NetFox; F-SD4a  
import java.io.*; z&x3":@u<  
q o^PS  
b!hs|emo;  
public class FileAccessI implements Serializable{ {6,  l#z  
;5TQH_g  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 m(6SiV=D9  
RandomAccessFile oSavedFile; ?9I=XTR  
long nPos; c"H59 jE  
d} {d5-_a  
!da [#zK  
public FileAccessI() throws IOException ']]5xH*U  
{ sH_5.+,`  
this("",0); G+dQ" cI9  
} |MEu"pY)  
g E#4 3  
Sh(Ws2b7  
public FileAccessI(String sName,long nPos) throws IOException 'L1=:g.\i  
{ P g{/tM Y  
oSavedFile = new RandomAccessFile(sName,"rw"); A.@/~\  
this.nPos = nPos; yR|Beno  
oSavedFile.seek(nPos); Mb0l*'ZF  
} YrRD3P.P  
7F!(60xY  
l]wjH5mz=i  
public synchronized int write(byte[] b,int nStart,int nLen) 2qQG  
{ n9p_D  
int n = -1; W7 iml|WV0  
try{ +q NX/F  
oSavedFile.write(b,nStart,nLen); BXx0Z %e.3  
n = nLen; t!S ja  
} 9+!1jTGSkf  
catch(IOException e) w,/&oe5M+  
{ E` O@UW@  
e.printStackTrace (); C % d  
} d \[cFe1d  
/j|Rz5@ =  
F[HMX4  
return n; yCt,-mz!z  
} RD1N@sHDKc  
#;*0 Pwe`  
qC;1ND  
} ]u\K}n6[q  
GI ~<clhf  
yi-S^  
/* FR%u1fi  
**SiteInfoBean.java PRo;NE  
*/ Uw:gJ 9  
package NetFox; SmR"gu  
Y%"6  
nS`DI92I  
public class SiteInfoBean { N=hhuKt]  
n@ rphJb  
oI/jGyY;  
private String sSiteURL; //Site's URL LEJ8 .z6$  
private String sFilePath; //Saved File's Path 9"%ot=)  
private String sFileName; //Saved File's Name [ S_8;j  
private int nSplitter; //Count of Splited Downloading File T+9#&  
b7nER]R  
&F xw19[G  
public SiteInfoBean() 'c")]{  
{//nSplitter的缺省值为5 :% o32  
//default value of nSplitter is 5 `_*NFv1_  
this("","","",5); K@DK4{  
} (sHvoE^q-  
3$E\B=7/U  
luYa+E0  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) LBs:O*;  
{ afJ`1l  
sSiteURL= sURL; rEl bzL"&<  
sFilePath = sPath; icnc5G  
sFileName = sName; NDt +m  
this.nSplitter = nSpiltter; NE'4atQ|  
B"9/+Yj  
Xgs 31#K  
} K.{:H4_  
Z\@m_ /g  
4Em$L]7   
public String getSSiteURL() +d=cI  
{ |i-d#x8  
return sSiteURL; '&<T;V%  
} ?cF-w!>o8  
|x[zzx# >-  
5m e|dvk  
public void setSSiteURL(String value) Ba]J3Yp,z  
{ uBPxMwohR  
sSiteURL = value; l-GQ AI8  
} @aX$}  
@&7|Laa  
U <|h4'(@L  
public String getSFilePath() P<1ZpL  
{ }/{G  
return sFilePath; BRu/pyxG  
} w N-np3k  
[`u3SN/P  
^{vf|zZ _  
public void setSFilePath(String value) GG KD8'j]  
{ pjh o#yP  
sFilePath = value; Tn'_{@E;  
} Gxj3/&]^Y  
13X0LN  
3Xun>ZQ-  
public String getSFileName() IQz:D J  
{ +/L "A  
return sFileName; qq)Dh'5*e,  
} x-Cy,d:YX  
l_Ffbs_6t  
qBkI9H  
public void setSFileName(String value) t mCm54  
{ |6mDooTy  
sFileName = value; :Y AxL J  
} KG5h$eM'  
=h#3D?b0n  
m ^O9G?  
public int getNSplitter() WrS|$: 0  
{ }.uB6&!:  
return nSplitter; U!0 Qf7D  
} JMnk~8O  
%Q0J$eC  
Bx>)i8P7i0  
public void setNSplitter(int nCount) yLo{^4a.  
{ ##6_kcL:6G  
nSplitter = nCount; R-8/BTls7  
} \U1fUrw$*  
} s /? &H-  
cP4K9:k  
k>N >_{\  
/* PhS`,I^Z  
**Utility.java NVTNjDF%s  
*/ cvf@B_iN9  
package NetFox; YRkp(}*!\  
#..-!>lY  
]T3dZ`-(  
public class Utility { ZW]Q|vPh4U  
sw(dd01a 7  
OYWW<N+R2  
public Utility() _Gpq=(q)  
{ $7#N@7  
Bhy:" r%#  
$9}z^sGIM  
} P&ig.Og*  
78s:~|WB<{  
//线程睡眠 d" "GG/  
public static void sleep(int nSecond) IQZBH2R  
{ ]aqHk  
try{ ; FO1b*  
Thread.sleep(nSecond); k{fCU%  
} z)Y<@2V*C  
catch(Exception e) &IQp&  
{ $uA?c& e  
e.printStackTrace (); )-_NtMr~`!  
} sGf\!w  
} iaqhP7!  
\LFRu  
//日志 FN#6pM']|  
public static void log(String sMsg) T:$zNX<f  
{ *3yeMxa  
System.err.println(sMsg);  Yfk){1  
} 5$r`e+Nf'  
I[~EQ {Iz  
6AZJ,Q\E@  
public static void log(int sMsg) ]7QRelMiz+  
{ B%v2)+?@  
System.err.println(sMsg); X(-e-:B4;  
} Y* #'Gh,  
} kAbkhZ1^  
z2m%L0  
1_Um6vS#  
/* TJ:B_F*bSk  
**TestMethod.java OHqc,@a;+  
*/ $J/Z~ (=JT  
package NetFox; $c-h'o  
dbkkx1{>Y  
Q0K4_iN)&  
public class TestMethod { 00') Ol&  
)`RF2Y-A7  
`"0#lZ`n  
public TestMethod() C+r<DC3  
{ ///xx/weblogic60b2_win.exe Y",Fs(  
try{ z$3 3NM  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Kilq Jg1%C  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Lm kv .XF  
SiteFileFetch fileFetch = new SiteFileFetch(bean); RVFQ!0 C  
fileFetch.start(); `laaT5G\y  
} <a-I-~  
catch(Exception e){e.printStackTrace ();} or_x0Q  
XE_|H1&j  
tHSe>*eC  
} {x $H# <Y  
^X6fgsjz  
tJ>OZ  
public static void main(String[] args) DWB.dP *8  
{ G<kslTPyq  
new TestMethod(); r5b5`f4  
} JM5 w`=  
} i|X ;n  
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