http断点续传简单实现（java)

/* TpA\9N#$  
**SiteFileFetch.java mAk{"65V  
*/ .qk]$LJF7  
package NetFox; eMRar<)+#*  
import java.io.*; `.y}dh/+0W  
import java.net.*; d--y  
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public class SiteFileFetch extends Thread { bqanFQj  
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SiteInfoBean siteInfoBean = null; //文件信息Bean 50dGBF  
long[] nStartPos; //开始位置 P;PQeXKw  
long[] nEndPos; //结束位置 iR$<$P5  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 K^r)CCO  
long nFileLength; //文件长度 7u\*_mrv  
boolean bFirst = true; //是否第一次取文件 x\2?y
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boolean bStop = false; //停止标志 Y^%T}yTtq  
File tmpFile; //文件下载的临时信息 bVmAtm[  
DataOutputStream output; //输出到文件的输出流 ~.%K/=wK@  
`V[!@b:  
//负责整个文件的抓取，控制内部线程（FileSplitterFetch类） _= #zc4U  
public SiteFileFetch(SiteInfoBean bean) throws IOException ;Ut+yuy  
{ gn5)SP8  
siteInfoBean = bean; K;7f?52  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); o;b0m;~   
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); H' T  
if(tmpFile.exists ()) ?muzU.h"z  
{ k%[3Q>5iM  
bFirst = false; (wc03,K^  
read_nPos(); N8KQz_]9I  
} @`FCiHM  
else fAZiC+  
{ sBv>E}*R  
nStartPos = new long[bean.getNSplitter()]; A?G IBjs  
nEndPos = new long[bean.getNSplitter()]; 4`#F^2r!  
} vi@Lz3}::  
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OdMO=Hy6d  
} ?Z\Yu'  
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PiFD^w  
public void run() UR(-q  
{ W~_t~Vg5  
//获得文件长度 1GEK:g2B  
//分割文件 R];Oxe  
//实例FileSplitterFetch

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//启动FileSplitterFetch线程 FZB~|3eq{  
//等待子线程返回 $ _8g8r}  
try{ \yrisp#`  
if(bFirst) :hGPTf  
{ _wb0'xoK"  
nFileLength = getFileSize(); H7i$xWs  
if(nFileLength == -1) k {-  
{ H1!iP$1#V  
System.err.println("File Length is not known!"); SM[
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} HxK$4I`  
else if(nFileLength == -2) 8\<jyJ  
{ \qsw"B*tv`  
System.err.println("File is not access!"); dBO@6*N4c  
} VC5_v62&.  
else KlK`;cr?  
{ U=bEA1*@0  
for(int i=0;i<nStartPos.length;i++) @|yeqy_:  
{ 2?Ye*-  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ry};m_BY  
} TJ?g%  
for(int i=0;i<nEndPos.length-1;i++) =Nz0.:  
{ !gwjN_ZJ^  
nEndPos = nStartPos[i+1]; -
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} 4!`bZ`_Bw  
nEndPos[nEndPos.length-1] = nFileLength; \EbbkN:D  
} Hy{ Q#fq  
} $]aBe !  
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s  
3#wcKv%>&_  
//启动子线程 A5#y?Aq  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; v"+k~:t*  
for(int i=0;i<nStartPos.length;i++) OEd
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{ ujW1+Oj=~  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), fpM#XFj  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (_* wt]"'  
nStartPos,nEndPos,i); A`O<6   
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +.[\g|G  
fileSplitterFetch.start(); _9:@Vl]Q@  
} Vbh6HqAHxJ  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `,wu}F85  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); PXP`ZLF  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ')+0nPV  
nEndPos = " + nFileLength); h%d^Gq~  
// fileSplitterFetch[nPos.length-1].start(); &O[s:  
7#;vG>]  
_RMQy~&b  
//等待子线程结束 ~ aZedQc  
//int count = 0; {TXOQ>gY  
//是否结束while循环
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boolean breakWhile = false; JM0I(%Z%  
kfC0zd+  
>KGE-Yzj  
while(!bStop) B1N)9%  
{ >5~7u\#9  
write_nPos(); ]TO/
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Utility.sleep(500); }:iBx  
breakWhile = true; NTs;FX~g[  
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lQPqcZd  
for(int i=0;i<nStartPos.length;i++) 4C~UcGMv\  
{ " oy\_1|  
if(!fileSplitterFetch.bDownOver) %XhfXd'  
{ Ft%hh|$5y  
breakWhile = false; HN5W@5m: .  
break; lp&!lb`  
} 5/ecaAB2  
} ;mm!0]V  
if(breakWhile) s #:%x#  
break; k
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\hk/1/siyF  
[2$4|;7  
//count++; g=]&A  
//if(count>4) L3y5a?G  
// siteStop(); 
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} A,i()R'I  
t> Q{yw  
?`sy%G  
System.err.println("文件下载结束！"); !MZw#=D`  
} -Q$nA>trKA  
catch(Exception e){e.printStackTrace ();} q/@dR{-  
} 6=|
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t\U$8l_;  
ka7uK][  
//获得文件长度 y<r}"TAf-  
public long getFileSize() Uku5wPS  
{ C77D{@SM  
int nFileLength = -1; ESQ!@G/n  
try{ g%J./F=@3  
URL url = new URL(siteInfoBean.getSSiteURL()); V: p)m&y6  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); gqiXmMm:9  
httpConnection.setRequestProperty("User-Agent","NetFox"); B5=3r1Ly  
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8q_0,>w%  
int responseCode=httpConnection.getResponseCode(); 4-4?IwS  
if(responseCode>=400) G^h_YjR`*  
{ QrjDF>   
processErrorCode(responseCode); Rm
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return -2; //-2 represent access is error F+=urc>w  
} P9#)~Zm
}]  
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cFfTYP9  
String sHeader; p]LnE`v  
7s>a2  
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for(int i=1;;i++) ?A=b6Um  
{ tbj=~xYf  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ());  .Oo/y0E^  
//Utility.log(in.readLine()); i*tv,f.(  
sHeader=httpConnection.getHeaderFieldKey(i); XDmbm*~i  
if(sHeader!=null) ~^o=a?L`<  
{ _,;%mK  
if(sHeader.equals("Content-Length")) 'Tf9z+0;  
{ xe:' 8J6L  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); N)OCSeh  
break; #qL9{P<}  
} [STj
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} L=A\ J^%  
else X\2_;zwf  
break; @@pq'iRn  
} ~ l )t|'6  
} *re 44  
catch(IOException e){e.printStackTrace ();} Dt}dp_  
catch(Exception e){e.printStackTrace ();} ??xlA-E  
2;(W-]V?  
N=fz/CD)I  
Utility.log(nFileLength); -q2MrJ*  
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return nFileLength; X\A]"su  
} v&0d$@6/U  
|^5/(16  
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//保存下载信息（文件指针位置） E2:D(7(;l  
private void write_nPos() qzdaN5  
{ vo;5f[>4i  
try{ 3"i%{  
output = new DataOutputStream(new FileOutputStream(tmpFile)); fEiJ~&{&  
output.writeInt(nStartPos.length); _Xh=&(/8@  
for(int i=0;i<nStartPos.length;i++) sco uO$
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{ [\HQPo'S  
// output.writeLong(nPos); )+GX<2_  
output.writeLong(fileSplitterFetch.nStartPos); }MZan" cfo  
output.writeLong(fileSplitterFetch.nEndPos); Q]i[.ME  
} QT}iaeC1i  
output.close(); &-F"+v,+  
} 0VG=?dq  
catch(IOException e){e.printStackTrace ();} )1z4q`  
catch(Exception e){e.printStackTrace ();} Q;gQfr"c7  
} @ R'E?|  
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//读取保存的下载信息（文件指针位置） 02M7gBS  
private void read_nPos() &t[|%c*D&  
{ &wGg6$  
try{ rt;gC[3\  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); iPFL"v<#J  
int nCount = input.readInt(); NKh,z& _5-  
nStartPos = new long[nCount]; u[[/w&UV.,  
nEndPos = new long[nCount]; &!#2ZJ}{  
for(int i=0;i<nStartPos.length;i++) [f(uqLdeM  
{ #_p  
nStartPos = input.readLong(); ![H
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nEndPos = input.readLong(); 7K !GK  
} lm &^tjx  
input.close(); Em9my2oE  
} ScHlfk p  
catch(IOException e){e.printStackTrace ();} nOuN|q=C  
catch(Exception e){e.printStackTrace ();} 2mOfsn d@  
} >C^/,/%v  
0# UAjT3  
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private void processErrorCode(int nErrorCode) ?1DUNZ6  
{ %JaE4&  
System.err.println("Error Code : " + nErrorCode); 8>v7v&Bh|  
} !h/
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wy\o*P9mG)  
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//停止文件下载 EFNdiv$wF  
public void siteStop() wLSjXpP8  
{ 3DI^y`av  
bStop = true; G4);/#  
for(int i=0;i<nStartPos.length;i++) ;>/
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fileSplitterFetch.splitterStop(); /MqP[*L  
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} hgif]?:C<  
} af^@ .$ |  
//负责部分文件的抓取 YiBOi?h9  
**FileSplitterFetch.java XWf7"]%SX  
*/ @2|G|C/]O}  
package NetFox; *|CLO|B)  
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import java.io.*;  3:"AFV  
import java.net.*; kFnUJM$r  
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public class FileSplitterFetch extends Thread { a(g$ d2H  
k$?&]! <o  
!yk7HaP  
String sURL; //File URL 7j95"mI  
long nStartPos; //File Snippet Start Position :(RL8  
long nEndPos; //File Snippet End Position <EOg,"F  
int nThreadID; //Thread's ID 5bF5~D(E  
boolean bDownOver = false; //Downing is over JN)"2}SE  
boolean bStop = false; //Stop identical TA<hj[-8  
FileAccessI fileAccessI = null; //File Access interface y8}"DfU.  
w[M5M2CF  
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException BMe72  
{ myffYK,  
this.sURL = sURL; T+3k$G[e/  
this.nStartPos = nStart; a\Tr!Be,  
this.nEndPos = nEnd; bL#sn_(m  
nThreadID = id; =cknE=  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 m_~y  
} !__D}k,  
@gY'YA8m  
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public void run() fg< (bXC  
{ +-'`Q Ae  
while(nStartPos < nEndPos && !bStop) |zg=+  
{ XZ!cW=bqS  
7-(>"75Q|  
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try{ EOofa6f&l  
URL url = new URL(sURL); +6wx58.B&  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6@i|Kw(:  
httpConnection.setRequestProperty("User-Agent","NetFox"); SG1&a:c+.  
String sProperty = "bytes="+nStartPos+"-"; es{cn=\s  
httpConnection.setRequestProperty("RANGE",sProperty); z`;&bg\8  
Utility.log(sProperty); S/KVN(Z  
`f2W;@V0  
;}n|,g>  
InputStream input = httpConnection.getInputStream();
'[ @F%  
//logResponseHead(httpConnection); ,K`E&hS  
<tGI]@Nwk  
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byte[] b = new byte[1024]; (cu'  
int nRead; !7ph,/P$7  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;sm"\.jF  
{ !XkymIX~O.  
nStartPos += fileAccessI.write(b,0,nRead); k{zs578h2  
//if(nThreadID == 1) b*@&c9I;q  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0@JilGk1u  
} EaJDz`T}  
~r{\WZ.  
U#OWUZ  
Utility.log("Thread " + nThreadID + " is over!"); X!7czt  
bDownOver = true; +"TI_tK,S  
//nPos = fileAccessI.write (b,0,nRead); M9g~lKs'  
} cH+h=E=  
catch(Exception e){e.printStackTrace ();} _K*\}un2  
} &?}kL= h  
} )w^GPlh  
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dcV,_  
//打印回应的头信息 {d&X/tT  
public void logResponseHead(HttpURLConnection con) CM+F7#T?n  
{ nNd`]F^U  
for(int i=1;;i++) j;$6F/g  
{ ]J8KCjq@  
String header=con.getHeaderFieldKey(i); G5y]^P  
if(header!=null) 82G lbd)  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); u^j8 XOT  
Utility.log(header+" : "+con.getHeaderField(header)); ^D%}V-"  
else *#ob5TBq[  
break; 9;>@"e21R  
} 6M O|s1zk  
} 3ybK6!g`[  
@&!=m]D*  
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public void splitterStop() <XkkYI(  
{ ,6S_&<{  
bStop = true; o|z
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} JL}hOBqfI  
{mCKTyN+  
+#de8/x  
} ~0'_K1(H  
zgEr,nF  
vkDZv@  
/* 3I(dC|d  
**FileAccess.java f}Ne8]U/Hc  
*//文件访问(定位，写) jsZiARTZRl  
package NetFox; /Bg6z m  
import java.io.*; l(3'Re  
se^NQ=  
{ar5c&<  
public class FileAccessI implements Serializable{ zN?$Sxttx  
!mpMa]G3  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~#HH;q_7m  
RandomAccessFile oSavedFile; GFASF,+  
long nPos; X+?Il)Bv  
knNhN=hG+  
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public FileAccessI() throws IOException \]L::"![?  
{ ;PP_3`  
this("",0); X]3l| D  
} =hZ&66  
P;HVLflu  
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public FileAccessI(String sName,long nPos) throws IOException +
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{ }"g21-T^  
oSavedFile = new RandomAccessFile(sName,"rw"); i?&4SG+2~K  
this.nPos = nPos; rzYobOKd#  
oSavedFile.seek(nPos); XudH
 
} FOlA* U4U  
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-@gJqoo>  
public synchronized int write(byte[] b,int nStart,int nLen) 1`2);b{@  
{ Tb!B!m  
int n = -1; hB2s$QS  
try{ iECC@g@a  
oSavedFile.write(b,nStart,nLen); q>D4m
a^  
n = nLen; &F<J#cfe8  
} " kE:T.,  
catch(IOException e) BCa90  
{ 1{\,5U&  
e.printStackTrace (); BM=V,BZy  
} P0`>{!r6@  
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Xj})?{FP  
return n; X1 0"G~0  
} )$lSG}WD  
&dwI8@&  
~q'w),bE"Q  
} t9$AvE#a!=  
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/* cW~6@&
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**SiteInfoBean.java ]$?zT`>(F  
*/ m"?'hR2  
package NetFox; \U<F\i  
A^= Hu,"
e  
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public class SiteInfoBean { fRv S@  
C,VqT6E<  
O_s9  
private String sSiteURL; //Site's URL x]%4M\T``  
private String sFilePath; //Saved File's Path ,,wyydG  
private String sFileName; //Saved File's Name N#-kk3!Z;  
private int nSplitter; //Count of Splited Downloading File $&n240(  
FgHB1x4;  
=A6u=  
public SiteInfoBean() '^.=gTk  
{//nSplitter的缺省值为5 V5hlG =V  
//default value of nSplitter is 5
>r4Y\"/j  
this("","","",5); 8Jib|#!  
} XCqfAcNQ  
=xlYQ}-(a  
gR_b~^  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {%+3D,$)  
{ 1Hk<_no5  
sSiteURL= sURL; dZ]\1""#H  
sFilePath = sPath; ^$&"<  
sFileName = sName; c@ZkX]g  
this.nSplitter = nSpiltter; 0
=(-8vwd  
WO \lny!  
I%zo>s6  
} yw3U"/yw  
tUAY]BJ*s  
(8m\#[T+R  
public String getSSiteURL() w'!}(Z5X?  
{ [r~rIb%Zj  
return sSiteURL;  \3y=0  
} #`6OC)1J  
HS5Ug'\446  
;hfG${l;  
public void setSSiteURL(String value) |+4E 8;4_  
{ 31o7R &v  
sSiteURL = value; [}xIg
8  
} 9>$%F;JP44  
g:HbmXOBpj  
\A~I>x  
public String getSFilePath() |"tV["a  
{ L[[H&#\  
return sFilePath; A0N ;VYv  
} ~_l:b  
BGh8\2  
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public void setSFilePath(String value) 1WA""yb  
{ EK-bvZ  
sFilePath = value; l`5}i|4KTW  
} o y%g{,V  
\
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as!|8JE`  
public String getSFileName() Kjca>/id  
{ in;+d~
?  
return sFileName; `v/tf|v6  
} ~E:/oV:4 >  
i7w}
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3bI|X!j  
public void setSFileName(String value) ~BYEeUo;%v  
{ 3z/O`z  
sFileName = value; ?'$. -z:  
} N(({2'Rr  
+[l{C+p  
I}Gl*@K&O  
public int getNSplitter() )*L?PT  
{ cX=b q_  
return nSplitter; @}rfY9o'  
} dU04/]modD  
[Xo J7  
gu.))3D9  
public void setNSplitter(int nCount) &MGgO
\|6  
{ Z`1o#yZ  
nSplitter = nCount; D<L{Z[  
} h|/*yTuN.y  
} VT~ ^:-]  
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QX~72X=(  
/* Hd@T8 D*A  
**Utility.java cJE>;a  
*/ []fj~hj  
package NetFox; W!9f'Yn  
r@V(w`  
 D]>
86&  
public class Utility { T6?d`i i1  
6V_5BpXt  
Pc:'>,3!V3  
public Utility() !
\|@{UJk/  
{ FUv)<rK  
$YO]IK$  
6I.+c
 
} '~6CGqU*  
ojs/yjvx  
//线程睡眠 [`nyq)  
public static void sleep(int nSecond) PT*@#:MA  
{ +z/73s0~  
try{ <h>fip3o  
Thread.sleep(nSecond); E6IL,Iq9  
} WAXrA$:3J  
catch(Exception e) { dxyBDK  
{ _"e( ^yiK  
e.printStackTrace (); KB-#):'  
} HQ#L |LN  
} ha'm`LiX  
tp3N5I  
//日志
|`9zE]  
public static void log(String sMsg) a{YVz\?d}  
{ I)4|?tb?  
System.err.println(sMsg); z&G3&?Z  
} v?'k)B  
#[rFep  
u6&Ixi/s'  
public static void log(int sMsg) j:<T<8.o  
{ sU3V)7"  
System.err.println(sMsg); Yy:sZJ  
} =|zyi|  
} 3mn-dKe((  
$R}iL  
:r+ 1>F$o  
/* ^\t">NJ^  
**TestMethod.java |vE#unA  
*/ ]V7hl#VO  
package NetFox; *>H'@gS  
4>eg@sN  
pv.),Iv-68  
public class TestMethod { |"&4"nwa  
Olrw>YbW  
?fwr:aP~  
public TestMethod() t-{OP?c
E1  
{ ///xx/weblogic60b2_win.exe jS)-COk  
try{ 9CSz<[  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); c^UM(bW  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Tfs9<k>G#  
SiteFileFetch fileFetch = new SiteFileFetch(bean); j[ YTg]  
fileFetch.start(); 9_^V1+   
} 78A4n C  
catch(Exception e){e.printStackTrace ();} $w}aX0dK&  
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m`6`a|Twp$  
} 5w%9b  
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public static void main(String[] args) _C\ d^a(  
{ o[*ih\d  
new TestMethod(); eh=bClk  
} nr%^:u  
} ,$*klod  
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