http断点续传简单实现（java)

/* )]A9~H  
**SiteFileFetch.java \[k%)_  
*/ l% |cB93  
package NetFox; C.HYS S  
import java.io.*; k<,u0  
import java.net.*; kdBV1E+:C  
/p}{#DLB  
*]'qLL7d  
public class SiteFileFetch extends Thread { F(E<,l2[  
V{FE[v_  
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SiteInfoBean siteInfoBean = null; //文件信息Bean #|ddyCg2  
long[] nStartPos; //开始位置 cdN/Qy  
long[] nEndPos; //结束位置 #Jv43
L H  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 }\4p3RQrz  
long nFileLength; //文件长度 p6[#f96^u  
boolean bFirst = true; //是否第一次取文件 GY7s  
boolean bStop = false; //停止标志 w~{| S7/  
File tmpFile; //文件下载的临时信息 >3+FZ@.iT  
DataOutputStream output; //输出到文件的输出流 V*~423  
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//负责整个文件的抓取，控制内部线程（FileSplitterFetch类） R|H[lbw  
public SiteFileFetch(SiteInfoBean bean) throws IOException = uk`pj  
{ lY->ucS %P  
siteInfoBean = bean; 1XGG.+D  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 3!bK d2"  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); u&tFb]1@)  
if(tmpFile.exists ()) +:!ScG*  
{ ~xE=mg4le  
bFirst = false; N)P((>S;  
read_nPos(); e^Aa!  
} %GS\1 Q%  
else yFi6jN#~  
{ n_u`B|^Pj  
nStartPos = new long[bean.getNSplitter()]; j,4,zA1j|  
nEndPos = new long[bean.getNSplitter()]; `>\4"`I  
} }<.7xz|V  
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} m'SmN{(t  
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public void run() o|+E+l9\  
{ FXeV6zfrE  
//获得文件长度 =Iy/cHK  
//分割文件 Dw*Arc+3V  
//实例FileSplitterFetch -}<d(c  
//启动FileSplitterFetch线程 :;q>31:h  
//等待子线程返回 &q"'_4
 
try{ R|$[U  
if(bFirst) xHm/^C&px  
{ 0FTRm2(  
nFileLength = getFileSize(); ]u;GNz}?  
if(nFileLength == -1) 90?,-6  
{ V8\$`NEP  
System.err.println("File Length is not known!"); m:b^,2"g  
} 6TY){Pw  
else if(nFileLength == -2) -!i;7[N  
{ ~~U<  
System.err.println("File is not access!"); 6#fOCr;f7  
} T7^ulG1'  
else  YN4"O>  
{ \m%J`{Mt  
for(int i=0;i<nStartPos.length;i++) g%X&f_@  
{ ~c!Rx'  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ot]>}[  
} x3gwG)Sf  
for(int i=0;i<nEndPos.length-1;i++) \ibCR~
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{ 32s5-.{c/f  
nEndPos = nStartPos[i+1]; Is<x31R  
} >1m)%zt  
nEndPos[nEndPos.length-1] = nFileLength; xnT3^
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} " \`BPN  
} W0C{~|e  
o*-h%Z.  
N4A&"1d&  
//启动子线程 Sy4 mZ}:  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length];
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for(int i=0;i<nStartPos.length;i++) W^003*m~~K  
{ Q^[e/U,  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), FPvuzBJ
 
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (%6(5,   
nStartPos,nEndPos,i); Z@;jIH4 (  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \>4v?\8o  
fileSplitterFetch.start(); Akv(} !g  
} lj4%(rB=  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bd,Uz%o_  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1);
]bs+:  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ht2 f-EKf{  
nEndPos = " + nFileLength); Xg,0/P~  
// fileSplitterFetch[nPos.length-1].start(); 7WgIhQ~  
n?zbUA#  
$Z,i|K;  
//等待子线程结束 3fm;r5  
//int count = 0; '`9%'f)  
//是否结束while循环 aB=vu=hF  
boolean breakWhile = false; U)u\1AV5  
a#YuKh?  
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while(!bStop) :!(YEF#}  
{ dVPq%[J
2  
write_nPos(); lr-12-D%-  
Utility.sleep(500); 2T//%ys=  
breakWhile = true;  AQB1gzE  
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&/
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for(int i=0;i<nStartPos.length;i++) oK#\HD4U  
{ LKIW*M  
if(!fileSplitterFetch.bDownOver) C(EYM$  
{ z\e>DdS  
breakWhile = false; XyvZ&d6(d  
break; caGML|DeI  
} c:3@[nF~  
} 1P(%9
 
if(breakWhile) $7msL#E7  
break; XC*uz  
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17WNJ  
//count++; 7vii9Am7  
//if(count>4) h9w@oRp`~  
// siteStop();
<P|`7wfxE  
} Ko1AaX(I'+  
N|UBaPS|
o  
0q:(-z\S4  
System.err.println("文件下载结束！"); t9?R/:B%  
} [SCw<<l<  
catch(Exception e){e.printStackTrace ();} hO^&0
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} hZp=BM"bJ  
8]sTX9  
`%FIgE^  
//获得文件长度 }V\P,ck  
public long getFileSize() di8W2cwz  
{ ]cx"  
int nFileLength = -1; /d{glOk  
try{ QN)/,=#  
URL url = new URL(siteInfoBean.getSSiteURL()); 8W19#?7>B  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); T[i7C3QS  
httpConnection.setRequestProperty("User-Agent","NetFox"); M,.b`1-w  
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int responseCode=httpConnection.getResponseCode(); (! xg$Kz@  
if(responseCode>=400) )$ ofl%+  
{ aEcktg6h  
processErrorCode(responseCode); P3+)pOE-SI  
return -2; //-2 represent access is error aeG#: Ln+{  
} ML=hKwCA  
9 eSN+q  
t7{L
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String sHeader; RnMBGxa  
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for(int i=1;;i++) y3&Tv  
{ c'4>D,?1  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); @?<N +qdH>  
//Utility.log(in.readLine()); &/B2)l6a  
sHeader=httpConnection.getHeaderFieldKey(i); yf `.%  
if(sHeader!=null) 3S[w'  
{ Fv?R\`52u  
if(sHeader.equals("Content-Length")) 8vz_~p9%j  
{ r!{w93rPX  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); SRA|7g}7W  
break; 1Pud,!\%q  
} qWRNHUd  
} %00k1*$  
else Jo6~r-  
break; ]I{qp~^#n  
} 844tXMtPB\  
} vDu0  
catch(IOException e){e.printStackTrace ();} tb-OKZq  
catch(Exception e){e.printStackTrace ();} uB5h9&57  
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](B&l{V  
Utility.log(nFileLength); [47K7~9p  
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v YRt2({}Z  
return nFileLength; +zFV~]b  
} , aRJ!AZ  
r*X}3t*  
jOoIF/So  
//保存下载信息（文件指针位置） )'BJ4[aq\  
private void write_nPos() E
e t+
 
{ MZUF! B  
try{ dD/29b(  
output = new DataOutputStream(new FileOutputStream(tmpFile)); s,UN'~e1  
output.writeInt(nStartPos.length); l|@/?GaH  
for(int i=0;i<nStartPos.length;i++) ;4-pupK~%  
{ m[g< K  
// output.writeLong(nPos); |QAeQWP+1  
output.writeLong(fileSplitterFetch.nStartPos); &=s|  
output.writeLong(fileSplitterFetch.nEndPos); 6e$sA (a=i  
} 9B!im\]O  
output.close(); veYsctK~  
} 4b3F9  
catch(IOException e){e.printStackTrace ();} 'k-u9  
catch(Exception e){e.printStackTrace ();} <|KKv5[  
} ^7ea6G"  
%nDPM? aO  
7]M,yIwc  
//读取保存的下载信息（文件指针位置） G1#Bb5q:  
private void read_nPos() &xGfkCP.]  
{ z:r
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try{ <B]i80.  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile));
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int nCount = input.readInt(); Z]7;u>2  
nStartPos = new long[nCount]; \U)2 Tg  
nEndPos = new long[nCount]; VgFF+Eg  
for(int i=0;i<nStartPos.length;i++) Se^/V
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{ GvZac  
nStartPos = input.readLong(); RvyBg:Aj5  
nEndPos = input.readLong(); l6&v}M  
} Ie^Dn!0S  
input.close(); 1K? & J2  
} !^>LOH>j  
catch(IOException e){e.printStackTrace ();} LH3N}J({  
catch(Exception e){e.printStackTrace ();} }%o+1 <=  
} c:?#zX  
%vf2||a$BS  
v GR \GFm  
private void processErrorCode(int nErrorCode) 'K;4102\  
{ |l6<GWG+  
System.err.println("Error Code : " + nErrorCode); O]Ry3j  
}
5O;a/q8"  
uhC=  
Ww'TCWk@  
//停止文件下载 dPH! V6r  
public void siteStop() u/!mN2{Rd  
{ !\&7oAs=I  
bStop = true; )MD*)O  
for(int i=0;i<nStartPos.length;i++) }Ll3AR7\  
fileSplitterFetch.splitterStop(); <iXS0k  
b2}QoJ@`  
#czyr@  
} ga{25q}"  
} 6PzN>+t^y  
//负责部分文件的抓取 7/^TwNsv  
**FileSplitterFetch.java ~q8V<@?  
*/ 9?g]qy,1)  
package NetFox; 8CnI%_Su  
7+D'W7Yx  
7?Qt2tr  
import java.io.*; h87L8qh9  
import java.net.*;  0'V-  
pE(<XD3Q  
L6rs9su=7  
public class FileSplitterFetch extends Thread { {x&jh|f`g  
*&hXJJ[+  
7G>0,'XC  
String sURL; //File URL `G ;Lz^  
long nStartPos; //File Snippet Start Position ArmL,  
long nEndPos; //File Snippet End Position \[IdR^<YM  
int nThreadID; //Thread's ID +%Bf y4F6  
boolean bDownOver = false; //Downing is over +9Hk+.
 
boolean bStop = false; //Stop identical vHI"C %  
FileAccessI fileAccessI = null; //File Access interface Top#u  
9s\i
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U7*VIRibv+  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3h D2C'KD  
{  &aevR^f+  
this.sURL = sURL; 1VjeP *  
this.nStartPos = nStart; /SqFP L]  
this.nEndPos = nEnd; -9H!j4]T?  
nThreadID = id; DX%8.@  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 S,`Sq8H  
} q*RaX 4V  
ltr;pc*)  
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public void run() 3f:1D=f  
{ Iu1Sj`A  
while(nStartPos < nEndPos && !bStop) 3|83
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{ t0asW5f  
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try{ eX l%Qs#Y  
URL url = new URL(sURL); zW"3K  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); MR)KLM0  
httpConnection.setRequestProperty("User-Agent","NetFox"); *v:,rh  
String sProperty = "bytes="+nStartPos+"-"; #nc@!+  
httpConnection.setRequestProperty("RANGE",sProperty); }*}`)rj,  
Utility.log(sProperty); z[lRb]:i[  
m|ERf2-  
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InputStream input = httpConnection.getInputStream(); Y8`))MeD  
//logResponseHead(httpConnection); ZTBFV/{  
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byte[] b = new byte[1024]; vU$O{|J
 
int nRead; qs c-e,rl  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >nIcFm  
{ 0m+5Zn  
nStartPos += fileAccessI.write(b,0,nRead); ~g4rGz  
//if(nThreadID == 1) Q5Ghki  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "PX3%II  
} XM@-Y&c$A  
.f92^lu9  
}_kI>  
Utility.log("Thread " + nThreadID + " is over!"); 5k%N<e``  
bDownOver = true;
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//nPos = fileAccessI.write (b,0,nRead); 6rN5Xf cS  
} dT,m{[+  
catch(Exception e){e.printStackTrace ();} S~a:1 _Wl  
} WH*=81)zp  
} X_sG6Q@  
h&k^l,  
t!=~5YgKs  
//打印回应的头信息 #g`cih=QL  
public void logResponseHead(HttpURLConnection con) 0Li'a{n2  
{ ;DgX"Uzm  
for(int i=1;;i++) c7nk~K[6  
{ +} !F(c  
String header=con.getHeaderFieldKey(i); z7Rcnr;  
if(header!=null) ,?~UpsUx  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); dT@SO  
Utility.log(header+" : "+con.getHeaderField(header)); SE}RP3dF!  
else sO4}kxZ  
break; ! ?U^+)^$  
} Mevyj;1t  
} Pl5NHVr  
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public void splitterStop() zUUxxS_?  
{ _~S^#ut+  
bStop = true; UVBw;V  
} }zS&H-8K  
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} E=_B@VJknW  
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iJKm27 ">  
/* io?{ew  
**FileAccess.java s
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*//文件访问(定位，写) gl7vM  
package NetFox; "1`i]Y\'  
import java.io.*;
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public class FileAccessI implements Serializable{ :-WCW);N  
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//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -2na::<K  
RandomAccessFile oSavedFile; bZ22O"F  
long nPos; QGz3id6  
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& Dl
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public FileAccessI() throws IOException J
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{ ND9>`I5  
this("",0); rIWN!@.J  
} h`;F<PFW  
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public FileAccessI(String sName,long nPos) throws IOException KsU&<eQ  
{ {_X1&&>8/  
oSavedFile = new RandomAccessFile(sName,"rw"); "O1*u
wm  
this.nPos = nPos; 6p]R)K>wS  
oSavedFile.seek(nPos); 79B`w #  
} |`;1p@w"  
6M vRR  
7 }MJK)  
public synchronized int write(byte[] b,int nStart,int nLen) -0IFPL8  
{ V45Udwp^  
int n = -1; yY-t4WeXP  
try{ =qR7-Q8B  
oSavedFile.write(b,nStart,nLen); DHNii_w4v  
n = nLen; lGHu@(n<  
} K2o0L5Lke  
catch(IOException e) -[7,ph  
{ #.L0]Uqcp  
e.printStackTrace (); 3)Awj++  
} T0"0/{5-_  
pW^ ?g|_}  
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return n; I4X+'fW,  
} G@<lwnvD*J  
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{,C8}8a W  
} %ih7Jt  
#`)-$vUv^f  
hRZS6" #  
/* j{-7Pf8A  
**SiteInfoBean.java ;OCI.S8  
*/ +X(^Q@  
package NetFox; 3pjYY$'  
Jas|P}{=fT  
{)gd|JV*  
public class SiteInfoBean { l3#dfW{  
M9jo<+  
-/2$P  
private String sSiteURL; //Site's URL 3b[+m}UWQ  
private String sFilePath; //Saved File's Path D
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private String sFileName; //Saved File's Name Vyq<T(5  
private int nSplitter; //Count of Splited Downloading File ,u^0V"hJ  
[qMO7enu#  
8=o5;]Cg  
public SiteInfoBean() [QN7+#K,  
{//nSplitter的缺省值为5 8*~:gZ7:  
//default value of nSplitter is 5 BW-P%:B1!R  
this("","","",5); D!T4k]^  
} /IW=+ri  
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public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Q|z06_3i  
{ p#BvlS=D  
sSiteURL= sURL; =(5GU<}  
sFilePath = sPath; i[^lJ)[>N  
sFileName = sName; =&/a\z!  
this.nSplitter = nSpiltter; p[cL#fBz  
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} }w^ T9OC  
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public String getSSiteURL() Cj9O[  
{ 'wnY>hN  
return sSiteURL; O36r ,/X  
} C|@k+^S  
Z?aR9OTP  
w*P4_= :%Y  
public void setSSiteURL(String value) yBh"qnOT  
{ sq|@9GS0T  
sSiteURL = value; 9<c4y4#y  
} `v2l1CQ:^  
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public String getSFilePath() rAw1g,&  
{ NKhR%H  
return sFilePath; u0hbM9U>  
} z n8ig/C  
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OmbKx&>YGz  
public void setSFilePath(String value) "$cT*}br  
{ 24/~gft  
sFilePath = value; 6="&K_Q7  
} .p~;U|h"  
Vy~$%H94  
f
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public String getSFileName() q=i<vcw  
{ |aJ6363f.  
return sFileName; N;pr:  
} 7[0k5-  
[E1|jcmQ  
o"M^sKz47  
public void setSFileName(String value) :I(gz~u6  
{ )nxIxr0d-  
sFileName = value; kzpbs?<;  
} ts!aKx  
w=o m7%J@l  
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public int getNSplitter() Qnx92
 
{ o xu9
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return nSplitter; K05Y;URbd  
} b/Q"j3
 
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public void setNSplitter(int nCount) .: ;Hh~  
{ e"mfJY  
nSplitter = nCount; >g0@ Bk  
} 'X<uG x  
} U2nRgd  
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<r3n?w8  
/* x99 Oq!  
**Utility.java ^V]DY!@k3_  
*/ k T>}(G||  
package NetFox; :E`l(sI7J}  
h l'k_<a*  
6ng g*kE<  
public class Utility { j&GK
pt  
K):sq{  
:#jv4N  
public Utility() .cog9H'  
{ 'p]qN;`'O$  
0\*<k`dY  
%$?Q%  
} d's`~HOU2  
*3Z#r  
//线程睡眠 tTp`e0L*m  
public static void sleep(int nSecond) XhV"<&v  
{ O#Hz5A5  
try{ 8}T3Fig,q  
Thread.sleep(nSecond); bkIA:2HX  
} /2cOZ1G;  
catch(Exception e) ) <~7<.0  
{ W78-'c  
e.printStackTrace (); !,uw./8@Ku  
} `Db}q^mQ  
} zZiVBUmE<  
JdEb_c3S  
//日志 _'a4I;  
public static void log(String sMsg) sH: &OaA  
{ {v 0(0  
System.err.println(sMsg); H`@7o8oj1  
} &H{>7q#r  
O0YGjS|d  
4q8%!\A+  
public static void log(int sMsg) $dw;Kj'\  
{ '8 #*U  
System.err.println(sMsg); N3RwcM9+;  
} - [j0B|cwG  
} {v(|_j&:o  
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S3cQC`^  
/* ~zRd||qv  
**TestMethod.java 8!Kfe  
*/ N6'Y N10  
package NetFox; ;\.&F
Mi  
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!/j|\_O  
public class TestMethod { -E"o)1Pj6C  
c[q3O**  
WLH2B1_):  
public TestMethod() R8*4E0\br  
{ ///xx/weblogic60b2_win.exe XW:(FzF  
try{ 5w3'yA<vE  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); $=R\3:j  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); cG6+'=]3<  
SiteFileFetch fileFetch = new SiteFileFetch(bean); \v Go5`  
fileFetch.start(); 4+:u2&I  
} v)EJ|2`  
catch(Exception e){e.printStackTrace ();} 5GP'
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pUx@QyrI  
AWcPOU  
} #*@Yil=1  
'"a8<7  
 tvILLR  
public static void main(String[] args) <o}t-Bgg  
{ *L_wRhhk  
new TestMethod(); '#?hm-Ga  
} p9J(,}  
} l[Oxf|  
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