http断点续传简单实现（java)

/* UvMkL  
**SiteFileFetch.java FzOWM7+\  
*/ {KDN|o+%  
package NetFox; h[Sd3Z*  
import java.io.*; 4'3;{k$z  
import java.net.*; ?(zCv9Pg  
X}G$ON  
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public class SiteFileFetch extends Thread { ;HYEJ3  
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SiteInfoBean siteInfoBean = null; //文件信息Bean @gqZiFM)  
long[] nStartPos; //开始位置 wIAH,3!  
long[] nEndPos; //结束位置 |) cJ  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 k:7Gb7\  
long nFileLength; //文件长度 AJ}m2EH  
boolean bFirst = true; //是否第一次取文件 P3!@}!r8  
boolean bStop = false; //停止标志 6jm?d"9  
File tmpFile; //文件下载的临时信息 ho6hjhS|u  
DataOutputStream output; //输出到文件的输出流 #c'B2Jn  
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//负责整个文件的抓取，控制内部线程（FileSplitterFetch类） JXRU9`3)A  
public SiteFileFetch(SiteInfoBean bean) throws IOException u,:hT] ~+  
{ iEI#J!
~  
siteInfoBean = bean; ml|FdQ  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); R<I#. KD  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ]5@n`;&#.  
if(tmpFile.exists ()) t%e<]2-8  
{ `zq+Xl  
bFirst = false;  /s^42  
read_nPos(); Is6}VLbB  
} i/C% 1<  
else aso8,mpZuA  
{ 569p/?  
nStartPos = new long[bean.getNSplitter()]; o,?G(  
nEndPos = new long[bean.getNSplitter()]; SAitufS  
} +-),E.  
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} {U>N*&_`  
IS!OO<  
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public void run() XUVj<U  
{ S,5>/'fy0  
//获得文件长度 <@GO]vY  
//分割文件 m3o -p  
//实例FileSplitterFetch J2 )h":2  
//启动FileSplitterFetch线程 F7j/Zuj  
//等待子线程返回 rp"5176  
try{ uD?G\"L i  
if(bFirst) e T;@pc  
{ =#pYd~  
nFileLength = getFileSize(); ?Be}{Qqlg  
if(nFileLength == -1) }6.@  
{ l"+8>Mm  
System.err.println("File Length is not known!"); n6t@ e^  
} <FU?^
*~  
else if(nFileLength == -2) k]$oir  
{ VJTO:}Q  
System.err.println("File is not access!"); | ?vm.zp  
} 8kdJtEW3  
else Y-y yg4JH  
{ .QKyB>s  
for(int i=0;i<nStartPos.length;i++) flC%<V
%'-  
{ !Tv3WQ@  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); rq!
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} x>##qYT  
for(int i=0;i<nEndPos.length-1;i++) ;>5`Y8s6  
{ 2'-"&d+O  
nEndPos = nStartPos[i+1]; (?t}S.>g  
} gELG/6l  
nEndPos[nEndPos.length-1] = nFileLength; A&Aj!#  
} 7mdd}L^h Z  
} #>bj6<  
v ;}s`P\"  
MA:5'n  
//启动子线程 LOi}\O8  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #I453  
for(int i=0;i<nStartPos.length;i++) yCN_vrH>  
{ M:
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fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r)}U 'iv*%  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +ppA..1  
nStartPos,nEndPos,i); bz#]>RD  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `a MU2  
fileSplitterFetch.start(); ^O+(eA7E  
} 1]~w?)..'  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $+7uB-KsU  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); *QiQ,~Ep  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 7LVG0A2>7  
nEndPos = " + nFileLength); zX&SnT1~  
// fileSplitterFetch[nPos.length-1].start(); qJdlZW<  
Yjjh}R#  
m]AT-]*f  
//等待子线程结束 ^ UmYW  
//int count = 0; ^r&)@R$V  
//是否结束while循环 _#:/ ~Jp  
boolean breakWhile = false; \$wkr  
/v+)#[]>  
s4"OsgP+  
while(!bStop) DpgTm&}-  
{ >UaQ7CRo  
write_nPos(); HTOr  
Utility.sleep(500); /!?LBtqy  
breakWhile = true; ~x9]?T  
rR#Ditn^  
RTm/-6[N  
for(int i=0;i<nStartPos.length;i++) 22CET9iCe  
{ $QC1l@[sM  
if(!fileSplitterFetch.bDownOver) PVo7Sy!'H  
{ 06S R74  
breakWhile = false; *i]?J  
break; 3x0t[{l  
} XnQR(r)pR2  
} lhGJ/By- -  
if(breakWhile) sCFxn  
break; #0P_\X`E   
?q:|vt  
3#>W\_FY*D  
//count++; 5G f@n/M"  
//if(count>4) S<"Fp1#"l  
// siteStop(); vQljxRtW  
} 4 O!2nP  
^viabkf C  
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System.err.println("文件下载结束！"); 0gd`W{YP  
} 7~Y\qJ4b  
catch(Exception e){e.printStackTrace ();} $DL}jH^S  
} 'hpOpIsHa  
q+?<cjVg  
iW5cEI%tb  
//获得文件长度 u m
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public long getFileSize() n i#jAwkN5  
{ F]aoTy  
int nFileLength = -1; vK',!1]y  
try{ w% %q/![uy  
URL url = new URL(siteInfoBean.getSSiteURL()); mUBy*
.  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bA^uzE  
httpConnection.setRequestProperty("User-Agent","NetFox"); F9fLJol  
'f5 8Jwql  
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int responseCode=httpConnection.getResponseCode(); ?I}RX~Tgg  
if(responseCode>=400) 7v5]%%E/  
{ >q
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processErrorCode(responseCode); h `Lr5)B'  
return -2; //-2 represent access is error J @Hg7Faz  
} &jE\D^>ko  
cOVj @z  
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String sHeader; D=e*rrL7a  
z`{sD]  
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for(int i=1;;i++) j4~(
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{ -xn-Af!v  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); CMj =4e  
//Utility.log(in.readLine()); OX_y"]utU  
sHeader=httpConnection.getHeaderFieldKey(i); R"B{IWQi  
if(sHeader!=null) q0.!T0i  
{ 6S`_L  
if(sHeader.equals("Content-Length")) sxNf"C=-.  
{ nWd!ovd  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); nBy-/BU&  
break; }z`x-(V  
} $qNF /rF  
} "Z.6@ c7  
else .n8R%|C5  
break; \c_g9Iqa  
} 6.@.k  
} (?z?/4>7<  
catch(IOException e){e.printStackTrace ();} *C_A(n5"V  
catch(Exception e){e.printStackTrace ();} , $7-SN  
~74Sq'j9Wt  
kckRHbeU  
Utility.log(nFileLength); (0{Dn5MH  
0D5Z#iW>1  
Ip t;NlR  
return nFileLength; ;4 ;gaf  
} \BHZRytQF  
SU0SsgFB  
-.D?Z8e  
//保存下载信息（文件指针位置） Cl0kR3Y  
private void write_nPos() J!C \R
5\  
{ 7
2l:[5ccR  
try{ Xu-~j!  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8m0*89HEu  
output.writeInt(nStartPos.length); -Q? i16pM  
for(int i=0;i<nStartPos.length;i++) RP~nLh3=\  
{ A@?0(  
// output.writeLong(nPos); "Q@m7j)(  
output.writeLong(fileSplitterFetch.nStartPos); tddwnpnSw  
output.writeLong(fileSplitterFetch.nEndPos); <X*oW".  
} 4Sh8w%s  
output.close(); g4+K"Q/M  
} qc(e3x  
catch(IOException e){e.printStackTrace ();} q^xG%YdPz+  
catch(Exception e){e.printStackTrace ();} V Rv4p5  
} C@a I*+@-"  
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lJ3VMYVrUP  
//读取保存的下载信息（文件指针位置） #M!u';bZ  
private void read_nPos() n
n F  
{ b36{vcs~  
try{ \PS]c9@,rc  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); U*+-#  
int nCount = input.readInt(); ^:/c<(DQD  
nStartPos = new long[nCount]; 4A+g-{d  
nEndPos = new long[nCount]; /)[-5n{  
for(int i=0;i<nStartPos.length;i++) $6m@gW]N  
{ ]sEuh~F  
nStartPos = input.readLong(); +mjwX?yF  
nEndPos = input.readLong(); YWU@e[  
} 4- QlIIf  
input.close(); 6"iNh)  
} Rir0^XqG  
catch(IOException e){e.printStackTrace ();} kb 74:  
catch(Exception e){e.printStackTrace ();} #_^p~:  
} u.q3~~[=  
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private void processErrorCode(int nErrorCode) 1tTP;C l#  
{ dWzf C@]  
System.err.println("Error Code : " + nErrorCode); (}wPu&Is,C  
} 2XL^A[?   
sDs.da#*2  
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//停止文件下载 {;Hg1=cm  
public void siteStop() ^/Hf$tYI!`  
{ 1PxRj  
bStop = true; kYCm5g3u  
for(int i=0;i<nStartPos.length;i++) i-w<5pGnf  
fileSplitterFetch.splitterStop(); V}TPt6C2  
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xY)eU;*  
} i|<wnJu  
} <VU-ja*(J  
//负责部分文件的抓取 o_\vudXK  
**FileSplitterFetch.java (XR}U6^v]  
*/ u gRyUny  
package NetFox; aNM*=y`  
/T qbl^[  
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import java.io.*; +z9BWo!{I  
import java.net.*; A'![*O  
W|{!0
w  
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public class FileSplitterFetch extends Thread { m.6uLaD"!}  
j/O9LygB  
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String sURL; //File URL Z  OAg7  
long nStartPos; //File Snippet Start Position Z 9cb  
long nEndPos; //File Snippet End Position sMAH;'`!Eu  
int nThreadID; //Thread's ID G~_eBy  
boolean bDownOver = false; //Downing is over LDw.2E  
boolean bStop = false; //Stop identical L4+R8ojG  
FileAccessI fileAccessI = null; //File Access interface I|bX;l  
ve a$G~[%6  
3bLOT#t  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }|-8-;  
{ 3>5gh8!-  
this.sURL = sURL; _;BNWH  
this.nStartPos = nStart; <b4} B   
this.nEndPos = nEnd; zB7^L^Y  
nThreadID = id; D}{]5R  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 oN83`Z  
} Z[RifqaBby  
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m-[xrVV  
public void run() lZ"C~B}9:I  
{ }f{5-iwD}  
while(nStartPos < nEndPos && !bStop) L`:V]p  
{ I8W9Kzf  
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try{ D!)h92CIDm  
URL url = new URL(sURL); IAmMO[9H  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bLggh]Fh  
httpConnection.setRequestProperty("User-Agent","NetFox"); {)Zz4  
String sProperty = "bytes="+nStartPos+"-"; frQ=BV5%6  
httpConnection.setRequestProperty("RANGE",sProperty); PJKxh%J  
Utility.log(sProperty); j9%vw.3b  
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InputStream input = httpConnection.getInputStream(); DM,;W`|6%  
//logResponseHead(httpConnection); 4/x.qoj  
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)  
ye {y[$#3  
byte[] b = new byte[1024]; JV;VR9-l  
int nRead; >G0ihhVt  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) g1UQ6Oa  
{ TYxi&;w  
nStartPos += fileAccessI.write(b,0,nRead);  
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//if(nThreadID == 1) 4l{La}Aj  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q~\[P4m  
} *:chN' <  
M7gqoJM'Q  
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Utility.log("Thread " + nThreadID + " is over!"); ,y7X>M2  
bDownOver = true; ;[,#VtD  
//nPos = fileAccessI.write (b,0,nRead); X*r?@uK
5  
} 5)4?i p  
catch(Exception e){e.printStackTrace ();} 8L))@SA+uJ  
} ${UH!n{  
} !NhVPb,  
U,`F2yD/!  
4d-"kx3X  
//打印回应的头信息 {RH)&k&%  
public void logResponseHead(HttpURLConnection con) *^%ohCUi  
{ !;U}ax;AF  
for(int i=1;;i++) 1i|5ii*vc  
{ I\6^]pi,  
String header=con.getHeaderFieldKey(i); e5sQl1  
if(header!=null) Or()AzwE@  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); OFlY"OS[  
Utility.log(header+" : "+con.getHeaderField(header)); ,xC@@>f  
else `[4{]jX+<  
break; z0tm3ovp  
} 5bprhq-7  
} <(o) * Zmo  
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public void splitterStop() iC<qWq|S_m  
{ hzy#%FaB  
bStop = true; wb-_CQ  
} }$'T=ay&  
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} +C[%^
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7brC@+ZD  
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/* BP0*`TY  
**FileAccess.java /:aY)0F0<&  
*//文件访问(定位，写) vHx[:vuq:  
package NetFox; *Ag,/Cm]  
import java.io.*; m2PI^?|e  
4#wZ#}  
MJI`1*(  
public class FileAccessI implements Serializable{ @L5s.]vg=  
6^"Spf]  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 j q1|`:  
RandomAccessFile oSavedFile; 18gApRa  
long nPos; 59M\uVWR  
jB%aHUF;  
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public FileAccessI() throws IOException 4:Id8rzz  
{ c R6:AGr  
this("",0); y` 6!Vj l  
} |#`qP^E  
5?1:RE(1  
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public FileAccessI(String sName,long nPos) throws IOException <e@+w6Kp'7  
{ 2N[/Cc2Tg/  
oSavedFile = new RandomAccessFile(sName,"rw"); o0:RsODl  
this.nPos = nPos; 'yR)z\)  
oSavedFile.seek(nPos); cCbZ*  
} wOs t).  
yJ?S7+b  
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public synchronized int write(byte[] b,int nStart,int nLen) .*Ylj2nM  
{ YzVhNJ
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int n = -1; _%:$sAj  
try{ ~l"]J'jF"H  
oSavedFile.write(b,nStart,nLen); R-J^%4U`7  
n = nLen; EohvP[i  
} r: M>/Z/  
catch(IOException e) )4e?-?bK!  
{ EE$\8Gx']!  
e.printStackTrace (); P:&X1MC  
} jcL%_of  
4Be'w`Q {  
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return n; S^T ><C  
} d=d*:<Zx  
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} jIi:tO9G^,  
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/* fs\A(]`$  
**SiteInfoBean.java O_\%8*;  
*/ 2mEvoWnJ  
package NetFox; Oe ~g[I;  
<\EJ:  
vb`R+y@  
public class SiteInfoBean { LY;FjbyU  
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private String sSiteURL; //Site's URL we8aqEomr  
private String sFilePath; //Saved File's Path "fu:hHq  
private String sFileName; //Saved File's Name JIPBJ
 
private int nSplitter; //Count of Splited Downloading File /V GI@"^v  
@ Fkhida  
}`.d4mm  
public SiteInfoBean() 8PR\a!"  
{//nSplitter的缺省值为5 '^)}"sZ@G  
//default value of nSplitter is 5 lhC hk7l  
this("","","",5); ! k 1 Ge+  
} $b(CN+#  
9l(T>B2a  
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public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) :V1j*)  
{ 1mD)G55Ep  
sSiteURL= sURL; +PS jBO4!  
sFilePath = sPath; "T9UedZ  
sFileName = sName; =f!clhO  
this.nSplitter = nSpiltter; #q4uS~  
!Au#j^5K-o  
Q':hmulT!  
} H@1}_d  
jD${ZIv  
@{W"mc+  
public String getSSiteURL() SL-;h#-y 4  
{ )2_[Ww|.  
return sSiteURL; 0(*L)s,5  
} Uo71C4ev  
FgL892[  
sM+~x<}0  
public void setSSiteURL(String value) Q;J( 5;  
{ 7B)1U_L0H  
sSiteURL = value; }opw_h+/F  
} a|"Uw `pX+  
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public String getSFilePath() JJM<ywPGp  
{ ZXGi> E
 
return sFilePath; r*]pL<  
} +D:8r|evH  
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?:ZB'G{%E  
public void setSFilePath(String value) marZA'u%B1  
{ I{jvUYrKH  
sFilePath = value; EG;E !0  
} tKeTHj;jO  
Yu>DgMW
 
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public String getSFileName() ~y2zl  
{ !7 dct#4  
return sFileName; V@!)Pw  
} dniU{v  
}}{n|l+R5  
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public void setSFileName(String value) pX ^^0  
{ !6T"J!F#  
sFileName = value; PmRvjSIG  
} <"J]u@|  
k(l2`I4V  
8~]D!c8;a  
public int getNSplitter() WXl+w7jr  
{ "(^XZAU#W  
return nSplitter; IB/3=4n^|  
} 2t-w0~O  
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]:
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public void setNSplitter(int nCount) Aw |;C  
{ GWnIy6TH l  
nSplitter = nCount; LdV&G/G-#D  
} TZAd{EZa  
} t?W}=%M[  
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//q(v,D%Q  
/* mll:rWC)  
**Utility.java amu;grH  
*/ !Rn6x $_  
package NetFox; d;Vy59}eY  
wA=r]BT  
$J`O-"M  
public class Utility { z-5`6aE9<  
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public Utility() $KiCs]I+  
{ <'a~Y3B"o  
H}^
'  
:v&[!  
} $MQ}+*Wr  
>lQo _p(;  
//线程睡眠 Zv u6/#  
public static void sleep(int nSecond) Z*%;;&?  
{ yB b%#GW  
try{ Td=4V,BN  
Thread.sleep(nSecond); #~*v##^vFH  
} lvs XL  
catch(Exception e) c/;;zc  
{ m>@hh#kBg  
e.printStackTrace (); rhJ&* 0M  
} [{znwK@  
} Jh26!%<Bl  
D*XrK0#Z`  
//日志 D'" T'@  
public static void log(String sMsg) $ V^gFes  
{ n ~t{]if"  
System.err.println(sMsg); O\5%IfB'"  
} lSj gN~:z  
l
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( ;FxKm<P@  
public static void log(int sMsg) $@g]?*L:  
{ 8:ubtB  
System.err.println(sMsg); ?bTfQH vX  
} 44]s`QyG  
} %()d$.F  
DeO-@4+qKd  
%pC<T*f  
/* j6 wFks  
**TestMethod.java i'>6Qo  
*/ ^_7|b[Bt  
package NetFox; twT/uBQ4a  
3]
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+C(-f  
public class TestMethod { |{(<A4W  
S|85g1}t  
T(J'p4  
public TestMethod() !Sc"V.o@!  
{ ///xx/weblogic60b2_win.exe ?=u?u k<-  
try{ inP2y?j  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +8Xjk\Hi  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Q$%apL  
SiteFileFetch fileFetch = new SiteFileFetch(bean); q<3nAE$?=  
fileFetch.start();  Nx}nOm  
} _`$Q6!Z)l  
catch(Exception e){e.printStackTrace ();}
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j=WxtMS  
X5
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} u3T-U_:jSV  
1w,_D.1'  
+! 1_Mt6  
public static void main(String[] args) 3efOgP=L  
{ \)PB p  
new TestMethod(); &<&tdShI  
} ]OAU&t{  
} ]RVu[k8  
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