http断点续传简单实现（java)

/* ^ <qrM  
**SiteFileFetch.java vd}*_d  
*/ GS\%mPZ  
package NetFox; |9>*$Fe"  
import java.io.*; 0Injyc*bMF  
import java.net.*; \\jIl3Z  
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public class SiteFileFetch extends Thread { R? O-x9  
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SiteInfoBean siteInfoBean = null; //文件信息Bean Aoj6k\YX  
long[] nStartPos; //开始位置 '_B_&is  
long[] nEndPos; //结束位置 K7IyCcdB  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Kb}MF9?:e  
long nFileLength; //文件长度 K~c^*;F  
boolean bFirst = true; //是否第一次取文件 6Wj@r!u  
boolean bStop = false; //停止标志 U1l0Uke  
File tmpFile; //文件下载的临时信息 fr+@HUOxsl  
DataOutputStream output; //输出到文件的输出流 /b.$jnqL  
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//负责整个文件的抓取，控制内部线程（FileSplitterFetch类） ]}Pl%.  
public SiteFileFetch(SiteInfoBean bean) throws IOException [ S5bj]D  
{ [#p&D~Du&  
siteInfoBean = bean; >DL/..  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ~}BJ0P(VMc  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); _=ugxL #eB  
if(tmpFile.exists ()) UL+E,=  
{ Fse['O~  
bFirst = false; eY T8$  
read_nPos(); 9"~9hOEct  
} (]2<?x*  
else )8;{nqoC  
{ n ]w7Zj  
nStartPos = new long[bean.getNSplitter()]; xw?CMA  
nEndPos = new long[bean.getNSplitter()]; J"-_{)0lD  
} v"rl5x  
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} @7-=zt+f  
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public void run() O@s{uZ|A6  
{ h1#S+k  
//获得文件长度 80Ag  
//分割文件 Y)|~:& tZ  
//实例FileSplitterFetch <yZP|_
  
//启动FileSplitterFetch线程 2B^~/T<\  
//等待子线程返回 R*087X7 N|  
try{ 0h22V$  
if(bFirst) lWbZ=x_0  
{ G]4OFz+  
nFileLength = getFileSize(); ,+se  
if(nFileLength == -1) <;%0T xK|U  
{ E/ijvuO  
System.err.println("File Length is not known!"); \<ZLoy_  
} S_2"7  
else if(nFileLength == -2) (#$$nQj  
{ F"'n4|q4n  
System.err.println("File is not access!"); e&0N
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} `m%:rE,  
else bp#fyG"  
{ u,eZ6  
for(int i=0;i<nStartPos.length;i++) #4><r.v3  
{ &UL_bG}  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); l4KbTKm7  
} fD{II+T  
for(int i=0;i<nEndPos.length-1;i++) tjj^O%SV<  
{ &1_U1  
nEndPos = nStartPos[i+1]; FPF6H puV  
} g`n;R  
nEndPos[nEndPos.length-1] = nFileLength; M'q'$)e  
} G+VD8]!K1  
} ]*3:DU  
sK&,):"]R  
X"j>=DEX  
//启动子线程 JS!*2*Wr  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; nLj&Uf&  
for(int i=0;i<nStartPos.length;i++) @u/H8\.l  
{ yxwWj>c  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /Wu|)tx  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), U'y,YtF@  
nStartPos,nEndPos,i); :I \9YzSs@  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @DuK#W"E u  
fileSplitterFetch.start(); 03([@d6<
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} Bd5+/G=m  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Fnb2.R'+  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $"\O;dp7l  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1{
Jb"  
nEndPos = " + nFileLength);  F~6#LT  
// fileSplitterFetch[nPos.length-1].start();
^ S  
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//等待子线程结束 ]GX \|1L  
//int count = 0; OP%?dh]  
//是否结束while循环 T6Ctf#  
boolean breakWhile = false; &cu!Hx  
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(#|{%4g@>  
while(!bStop) rk|a5-i  
{ fxgU~'  
write_nPos(); \G>ZkgU  
Utility.sleep(500); iY~rne"l  
breakWhile = true; O4L#jBa+  
lZW
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for(int i=0;i<nStartPos.length;i++) ,a0pAj  
{ ;Lo&}U3F,!  
if(!fileSplitterFetch.bDownOver) HI`q1m.  
{ dlDki.  
breakWhile = false; ufrqsv]=  
break; Bu3T/m  
} KKEN'-3  
} >o~Z>lr  
if(breakWhile) \?Mf_  
break; [h&BAR/ 2  
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//count++; v+=k-;-  
//if(count>4) <&<,l58[c  
// siteStop(); [ohBPQO  
} \.#p_U5In  
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]|U-y645  
System.err.println("文件下载结束！"); ECcZz.  
} l&W;b6L  
catch(Exception e){e.printStackTrace ();} y3eHF^K+$  
} >MG(qi  
2(M6(xH>  
B=X,7  
//获得文件长度 V&ot3- Rf  
public long getFileSize() C$9z  
{ fD4ICO@  
int nFileLength = -1; 0Fw6Dq<8-!  
try{ `f9gC3Hk  
URL url = new URL(siteInfoBean.getSSiteURL()); &aG*k*  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BqH]-'1G  
httpConnection.setRequestProperty("User-Agent","NetFox"); c</1  
qAY%nA>jO  
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int responseCode=httpConnection.getResponseCode(); {gsdG-  
if(responseCode>=400) 0F:1\9f5  
{ P"3*lk+w  
processErrorCode(responseCode); bZ 443SG  
return -2; //-2 represent access is error T$+-IAE  
} +4qU>  
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String sHeader; g{:<2xI5P  
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for(int i=1;;i++) wy,p&g)>  
{ )ev<7g9*q  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )]43R   
//Utility.log(in.readLine()); 7~1IO|4t  
sHeader=httpConnection.getHeaderFieldKey(i); Vj?DA5W`'  
if(sHeader!=null) +&|S'7&{  
{ xV\5<7qk5g  
if(sHeader.equals("Content-Length")) $uDqqG(^  
{ TDt
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nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]N{0:Va@D  
break; Anm=*;*M`  
} %|"g/2sF[G  
} k\`S lb1  
else :6{`~=  
break; *G5c|Y  
} 1.U`D\7mb  
} c#/H:?q?a  
catch(IOException e){e.printStackTrace ();} V5`^Y=X(%  
catch(Exception e){e.printStackTrace ();} &M/>tEZ)  
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Utility.log(nFileLength); 3oy~=  
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return nFileLength; 3)=c]@N0  
} u3 0s_\  
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//保存下载信息（文件指针位置） Gi2$B76<  
private void write_nPos() zDTv\3rZ4X  
{ XT>.`, sv  
try{ lB91An  
output = new DataOutputStream(new FileOutputStream(tmpFile)); R&f^+0%f  
output.writeInt(nStartPos.length); E:`v+S_h  
for(int i=0;i<nStartPos.length;i++) rN)V[5R#M  
{ {a(&J6$VE  
// output.writeLong(nPos); "&.S&=FlI  
output.writeLong(fileSplitterFetch.nStartPos); 9=X)ung9  
output.writeLong(fileSplitterFetch.nEndPos); LOy0hN-$b  
} = u[#2!  
output.close(); rjx6Djo>  
} a>O9pX  
catch(IOException e){e.printStackTrace ();} J%lgR  
catch(Exception e){e.printStackTrace ();} e4>"92hX  
} *hLQ  
{LHR!~d}5f  
?:{sH#ua  
//读取保存的下载信息（文件指针位置） RDqFL.-S  
private void read_nPos() . #lsic8]  
{ t"072a  
try{ \daZk/@  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); U?a6D:~G  
int nCount = input.readInt(); y !$alE  
nStartPos = new long[nCount]; VZ& A%UFC  
nEndPos = new long[nCount]; '(GiF  
for(int i=0;i<nStartPos.length;i++) < 0M:"^f  
{ $Fkaa<9;P  
nStartPos = input.readLong(); .iMN,+qP  
nEndPos = input.readLong(); #>=j79~  
} Sq\(pfvo  
input.close(); rKH:[lKm  
} C)'q QvA  
catch(IOException e){e.printStackTrace ();} ` |IUGz  
catch(Exception e){e.printStackTrace ();} w;UqEC V  
} /H7&AiA  
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private void processErrorCode(int nErrorCode) j]|U  
{ \s"U{N-  
System.err.println("Error Code : " + nErrorCode); 4(6b(]G'#  
} PO:"B6  
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,GWNLm\5  
//停止文件下载 k3?rp`V1  
public void siteStop() ;W>Cqg=  
{ c~QS9)=E  
bStop = true; =OIw*L8C"I  
for(int i=0;i<nStartPos.length;i++)  qy)_wM  
fileSplitterFetch.splitterStop(); m7EcnQf  
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} -=s(l.?Hm5  
} ~x#w<0e>  
//负责部分文件的抓取 J^R=dT!  
**FileSplitterFetch.java ~/^5) g_  
*/ _Z5Mw+=19  
package NetFox; =K'cM=WM6  
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import java.io.*; -7J|
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import java.net.*; ^7zu<lX  
}Sy=My89r  
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public class FileSplitterFetch extends Thread { Hbv6_H  
qW:HNEiir  
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String sURL; //File URL 6T 8!xyi-+  
long nStartPos; //File Snippet Start Position DCqY|4Qc  
long nEndPos; //File Snippet End Position .ERO|$fv  
int nThreadID; //Thread's ID Ookh<ES>  
boolean bDownOver = false; //Downing is over f&v9Q97=  
boolean bStop = false; //Stop identical "ju6XdZo  
FileAccessI fileAccessI = null; //File Access interface ;7N{^"r  
AJ#Nenmj  
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException CLvX!O(~  
{ l Va &"  
this.sURL = sURL; r.7$&BCng  
this.nStartPos = nStart; )95f*wte  
this.nEndPos = nEnd; `+6R0Ch  
nThreadID = id; W9NX=gE4  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *
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} dy_:-2S  
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public void run() q, O$ %-70  
{ {s.=)0V  
while(nStartPos < nEndPos && !bStop) w]N!S;<N  
{ %|s+jeUDn|  
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try{
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URL url = new URL(sURL); }&_/PA0j  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); MEB it  
httpConnection.setRequestProperty("User-Agent","NetFox"); RX/hz|  
String sProperty = "bytes="+nStartPos+"-"; vWAL^?HUP  
httpConnection.setRequestProperty("RANGE",sProperty); I`NjqyTW  
Utility.log(sProperty); #g6.Glz3  
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InputStream input = httpConnection.getInputStream(); sr8cYLm5R  
//logResponseHead(httpConnection); ]U"94S U:)  
8OgLn?"P  
H;
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byte[] b = new byte[1024]; N7e"@Ic  
int nRead; 03C0L&  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ]+X@ 7  
{ s[UHe{^T  
nStartPos += fileAccessI.write(b,0,nRead); / m=HG^!  
//if(nThreadID == 1) c38D}k^
):  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4?B\O`sy.  
} AK@9?_D  
c/sC&i;%O  
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Utility.log("Thread " + nThreadID + " is over!"); p5G?N(l  
bDownOver = true; &jmRA';sK  
//nPos = fileAccessI.write (b,0,nRead); K6R.@BMN  
} 41&\mx  
catch(Exception e){e.printStackTrace ();} p,#o<W  
} ob8qe,_'  
} 4:FK;~wM&x  
~@}Bi@*  
5{g?,/(  
//打印回应的头信息 %7|9sQ:  
public void logResponseHead(HttpURLConnection con) e%b6(%  
{ u?C#4  
for(int i=1;;i++) wb0L.'jyR)  
{ WlU0:(d  
String header=con.getHeaderFieldKey(i); VVlr*`  
if(header!=null) z4N*b"QF  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); kGl~GOB a  
Utility.log(header+" : "+con.getHeaderField(header)); .[_L=_.  
else Hj}K{20  
break; 5 sX+~Q  
} X(NLtO w  
} 6Yln,rC  
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public void splitterStop() ~sh`r{
0  
{ 7j-4TY~  
bStop = true; {tWf  
}  qi^7  
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} uLV#SQ=bZN  
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YuO.yh_  
/* tS6qWtE  
**FileAccess.java \2h!aRWR  
*//文件访问(定位，写) F1yqxWHeo  
package NetFox; a^I\ /&aw'  
import java.io.*; " )1V]}+m  
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public class FileAccessI implements Serializable{ 'd9INz.  
)?anOD[  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 p
;>ec:z3M  
RandomAccessFile oSavedFile; @J/K-.r  
long nPos; XwJ7|cB  
"]} bFO7C  
dl.p\t(1  
public FileAccessI() throws IOException 3ca (i/c  
{ %WjXg:R  
this("",0); [DI+~F  
} ?82xdpg  
7fZDsj:  
Wi)_H$KII  
public FileAccessI(String sName,long nPos) throws IOException .[I
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{ 1G^`-ri6  
oSavedFile = new RandomAccessFile(sName,"rw"); Hquc o  
this.nPos = nPos; `r9!zffyS  
oSavedFile.seek(nPos); m+]K;}.}R  
} Fj2BnM3#  
,?^ p(w  
,s"^kFl  
public synchronized int write(byte[] b,int nStart,int nLen) #V~me  
{ a.k.n<  
int n = -1; f*?]+rz  
try{ iP7(tnlW$  
oSavedFile.write(b,nStart,nLen); rX2.i7i,  
n = nLen; {8W'%\!=  
} m
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catch(IOException e)
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{ 0x@6^%^\  
e.printStackTrace (); *Q "wwpl?  
} [1Qo#w1  
+nFu|qM}  
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return n; !Wntd\w  
} n{argI8wF  
-&zZtDd F  
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} Rl?_^dPx  
ia!y!_L\'  
g}1B;zGf  
/* j8^Iz  
**SiteInfoBean.java 52Z2]T c,  
*/ LTQ"8  
package NetFox; &]|?o_p3W  
 iu=7O  
:(P9mt  
public class SiteInfoBean { 8e1UmM
[  
Yi%;|]  
KPKt^C  
private String sSiteURL; //Site's URL
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private String sFilePath; //Saved File's Path l
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private String sFileName; //Saved File's Name y51e%n$  
private int nSplitter; //Count of Splited Downloading File :!WHFB o 8  
];[}:
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public SiteInfoBean() ?N*>*"  
{//nSplitter的缺省值为5 dy%;W%   
//default value of nSplitter is 5 B9jC?I |`  
this("","","",5); vc;$-v$&  
} B"1c  
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|4;Fd9q^m  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,~N/- 5  
{ IL#"~D?
  
sSiteURL= sURL; hF~n)oQ  
sFilePath = sPath; `ts$(u.w  
sFileName = sName; k8&;lgO'  
this.nSplitter = nSpiltter; nv|NQ Tk  
7rc0yB  
&[?\k>  
} 'CM|@Zz%  
Qb-M6ihcc  
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public String getSSiteURL() @<hb6bo,N
 
{ -A^_{4X  
return sSiteURL; +SR+gE\s0  
} P^~yzI  
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] vHF~|/-  
public void setSSiteURL(String value) > PRFWO  
{ JE"x  
sSiteURL = value; p_gm3Q  
} AUG#_HE]k  
c<:-T  
t6"%3#s  
public String getSFilePath() r= `Jn6@  
{ we//|fA<  
return sFilePath; [6Izlh+D  
} q_[o"wq/  
]nn
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A4x]Qh3OO  
public void setSFilePath(String value) f643#1  
{ zZPO&akB"  
sFilePath = value; Y.(PiuG$G  
} _aSxc)?  
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LYTdTP  
public String getSFileName() hR?{3d#x2  
{ Mq156TL  
return sFileName; hn GZ=  
} .5_2zat0H  
2`K=Hby  
gh]cXuph  
public void setSFileName(String value) ZPLm]I\]  
{ AofKw  
sFileName = value; I5p? [  
} R`qFg/S  
2*& ^v  
vm8eZG|  
public int getNSplitter()  ?(1y  
{ rH Lm\3  
return nSplitter; &jJL"gq"  
} 6Pl<'3&  
y'q$|  
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public void setNSplitter(int nCount) 1v27;Q<+Q  
{ k(nW#*N_  
nSplitter = nCount; `Y$4 H,8L  
} _1\v  
} _ ]ipajT  
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$bR~+C  
/* eu-*?]&Di  
**Utility.java 0Th&iA4  
*/ %YscBG  
package NetFox; Czu9o;xr  
194)QeoFw  
CY5Z{qiX  
public class Utility { )mT<MkP  
S9y}  
b2Fe<~S{  
public Utility() K($Npuu]  
{ 6<QQ@5_  
r#p9x[f<Y  
+~$ ]}%  
} EW OVx*l  
sY&IquK^  
//线程睡眠 j</: WRA`]  
public static void sleep(int nSecond) g*_&  
{ %ntRG!  
try{ /$?}YL,  
Thread.sleep(nSecond); Xl#ggub?  
} A?P_DA  
catch(Exception e) r),kDia  
{ IOmfF[  
e.printStackTrace (); K+3=tk]W9u  
} +I|vzz`ZVr  
} 2HA:"v8  
^\=`ed
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//日志 ^jZbo{  
public static void log(String sMsg) m<Dy<((_I  
{ FTUv IbT  
System.err.println(sMsg); LU%E:i|  
} yR{3!{r3(  
:crW9+  
0'C1YvF  
public static void log(int sMsg) 29.h91  
{ ?k{?GtSs  
System.err.println(sMsg); q>+k@>bk@  
} |)v,2  
} ]{@-HTt  
( Erc3Ac8  
Kw ]=  
/* 3F2w-+L  
**TestMethod.java pl?`8@dI  
*/ ?CPahU  
package NetFox; bROLOf4S  
9W2Vo [(  
 x'<X!gw  
public class TestMethod { '\iCP1>+S  
)3EY;  
0aB;p7~&  
public TestMethod() mCVFS=8V  
{ ///xx/weblogic60b2_win.exe W^l-Y%a/o  
try{ 2E'UZ m  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !%c\N8<>GD  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); )Ql%r?(F+  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Vt#.eL)Ee  
fileFetch.start();
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} '~=SzO  
catch(Exception e){e.printStackTrace ();} zQ
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(O3nL.  
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} [7Oe3=  
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83#mB:^R  
public static void main(String[] args) }o`76rDN  
{ (f"4,b^]  
new TestMethod(); _q-*7hCQ`  
} `b$.%S8uj=  
} !+v$)3u9  
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