http断点续传简单实现（java)

/* //\ORJ
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**SiteFileFetch.java t*<.^+Vd  
*/ m]+g[L?-  
package NetFox; Xp
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import java.io.*; ,Zb]3  
import java.net.*; *;(
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public class SiteFileFetch extends Thread { L=Fm:O'#2  
# h]m8  
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SiteInfoBean siteInfoBean = null; //文件信息Bean ,g#=pdX;  
long[] nStartPos; //开始位置 1 +O- g  
long[] nEndPos; //结束位置 l];,)ddD9  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 hUcG3IOBf  
long nFileLength; //文件长度 ot]E\g+!  
boolean bFirst = true; //是否第一次取文件 A{Z=[]r1`E  
boolean bStop = false; //停止标志 /,f*IdB  
File tmpFile; //文件下载的临时信息 O$E3ry+?  
DataOutputStream output; //输出到文件的输出流 ^UZEdR;  
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//负责整个文件的抓取，控制内部线程（FileSplitterFetch类） +g<2t,  
public SiteFileFetch(SiteInfoBean bean) throws IOException cnXIE{9M  
{ Fa,a)JY>  
siteInfoBean = bean; v-3In\T=^  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); jmmm0,#D  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); bg*4Z?[dd  
if(tmpFile.exists ()) !uii|"  
{ @3K)VjY7  
bFirst = false; YW}q@AY7  
read_nPos(); (!&cf
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} _y#t[|}w  
else h-=3b  
{ =da_zy  
nStartPos = new long[bean.getNSplitter()]; >;dMumX  
nEndPos = new long[bean.getNSplitter()]; { ,/mQ3  
} 3 ~0Z.!O  
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} n|Iy  
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public void run() n
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{
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//获得文件长度 `=RJ8u  
//分割文件 Qa~o'  
//实例FileSplitterFetch 6&S;Nrg9  
//启动FileSplitterFetch线程 E'?yI'~=  
//等待子线程返回 t?L;k+sMM  
try{ %kS+n_*  
if(bFirst) U,yU-8z/  
{ $(H%|Oyn  
nFileLength = getFileSize(); -~~"}u  
if(nFileLength == -1) -tAdA2?G  
{ 2i;G3"\  
System.err.println("File Length is not known!"); |G~LJsXW!v  
} p [4/Nq,c  
else if(nFileLength == -2) yjaX\Wb[z[  
{ 4P(Y34j  
System.err.println("File is not access!"); H-~V:OCB~  
} %<CahzYc6  
else W
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{ _(&^M[O  
for(int i=0;i<nStartPos.length;i++) QU_O9 BN  
{ N W :_)1  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); oJ\UF S  
} '3O@Nxof4  
for(int i=0;i<nEndPos.length-1;i++) .$y}}/{j?[  
{ d&4]?8}=.  
nEndPos = nStartPos[i+1]; w7cciD|  
} !Low%rP  
nEndPos[nEndPos.length-1] = nFileLength; r5h}o)J  
} $NC1>83  
} X}Bo[YoY$  
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//启动子线程  d!5C$C/x  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; x+x6F  
for(int i=0;i<nStartPos.length;i++) +!6aB|-  
{ l69&-Nyg  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ml<X92Y  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ,4zwd@&O  
nStartPos,nEndPos,i); w$WN` =  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9"Oz-!Y4  
fileSplitterFetch.start(); >j5) MF{"  
} i\lur ET  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), eVyXh>b*  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 4n @}X-)  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", zV_U/]y  
nEndPos = " + nFileLength); fNNkc[YTZI  
// fileSplitterFetch[nPos.length-1].start(); ^I=c]D]);  
!qsk;Vk7Z  
?Y7'OlO  
//等待子线程结束 q(4W/y  
//int count = 0; Z{s&myd  
//是否结束while循环 \Y&*sfQ  
boolean breakWhile = false; `,gGmh  
o4,fwPkB  

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while(!bStop) 6!bp;iLKy  
{ ifTMoC%  
write_nPos(); s+&Ts|c#  
Utility.sleep(500); e>vV8a\  
breakWhile = true; ?piv]Z  
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for(int i=0;i<nStartPos.length;i++) SIv8EMGo  
{ "jqC3$DKI  
if(!fileSplitterFetch.bDownOver) ^-?5=\`5  
{ LW<DhMV  
breakWhile = false; 7^7Rk  
break; g+;)?N*j  
} 47>IT  
} /` 891(f,  
if(breakWhile) L1A0->t  
break; ?muI8b  
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1ThONrxu  
//count++; GxE"q-G  
//if(count>4) X~|P  
// siteStop(); @FVan  
} ):OGhW
q  
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System.err.println("文件下载结束！"); B?`n@/  
} rqbX9M^  
catch(Exception e){e.printStackTrace ();} q
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} N=FU>qbz  
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l*_%K}%?V  
//获得文件长度 M\O6~UFq!  
public long getFileSize() bh9
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{ r \+&{EEG  
int nFileLength = -1; /+2;".  
try{ &~VWh}=r  
URL url = new URL(siteInfoBean.getSSiteURL()); ]v
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HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v$c*3H.seM  
httpConnection.setRequestProperty("User-Agent","NetFox"); fq(r,h=|  
4Kjrk7GAx  
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int responseCode=httpConnection.getResponseCode(); 9s\(yC8h  
if(responseCode>=400) V\Oe]w  
{ ;/+VHZP;  
processErrorCode(responseCode); +]Ca_`  
return -2; //-2 represent access is error Y2709LWmP  
} 7|4hs:4mD  
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i(R&Q;{E^  
String sHeader; q] g'rO'  
vJ5`:4n"  
w#.Tp-AZ;\  
for(int i=1;;i++) \pI)tnu6'U  
{ .BN~9w  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); N!Dc\d=8q]  
//Utility.log(in.readLine()); BzBij^h  
sHeader=httpConnection.getHeaderFieldKey(i); %\6ns  
if(sHeader!=null) P'f0KZL;  
{ #;FHyKx  
if(sHeader.equals("Content-Length")) F7$x5h@  
{ mUW|4zl i}  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); uim4,Zm{  
break; }YUUCq&  
} \Y.&G,?  
} %qA@)u53  
else Pw:(X0@  
break; Hik8u!#P  
} <[{Ty+  
} ^Q!qJav  
catch(IOException e){e.printStackTrace ();} 3`sM/BoA  
catch(Exception e){e.printStackTrace ();} F02S(WWo;  
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Utility.log(nFileLength);
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return nFileLength; <hlH@[7!  
} wn*<.s  
0l-m:6
 
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//保存下载信息（文件指针位置） mNkS!(L6  
private void write_nPos()
LB`=+FD  
{ ]jo^P5\h>  
try{ bg.f';C  
output = new DataOutputStream(new FileOutputStream(tmpFile)); X
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output.writeInt(nStartPos.length); ?DPNa  
for(int i=0;i<nStartPos.length;i++) 2 mM0\ja  
{ :NB|r  
// output.writeLong(nPos); v%RcwVt|  
output.writeLong(fileSplitterFetch.nStartPos); 9^l[d<  
output.writeLong(fileSplitterFetch.nEndPos); ;0*T7l  
} 9y=$|"<(  
output.close(); K07SbL7g!p  
} _nw=^zS  
catch(IOException e){e.printStackTrace ();} {SH+lX0]{  
catch(Exception e){e.printStackTrace ();} ZUGuV@&-T  
} mq~rD)T  
6GVj13Nr  
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//读取保存的下载信息（文件指针位置） qc^u%  
private void read_nPos() {2kw*^,l  
{
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try{ 0{|ib !  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); b|U
48j1A  
int nCount = input.readInt(); z9mmZqhK\  
nStartPos = new long[nCount]; &sbA:xZBA  
nEndPos = new long[nCount]; (lv|-Phc.  
for(int i=0;i<nStartPos.length;i++) GCx1lm  
{ Jp)>Wd  
nStartPos = input.readLong(); n]&/?6}  
nEndPos = input.readLong(); GRpS^%8i@  
} F@Bh>Vb  
input.close(); d;(&_;  
} O+Z[bis`  
catch(IOException e){e.printStackTrace ();} h
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catch(Exception e){e.printStackTrace ();} yjCY2T E  
} (QQ/I;  
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private void processErrorCode(int nErrorCode) lhZWL}l  
{ 1B~H*=t4h  
System.err.println("Error Code : " + nErrorCode); F 7+Gt Ed  
} |a@$K
F$  
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1M&n=s _  
//停止文件下载 12)~PIaF  
public void siteStop() ju8mO&  
{ _2{i}L  
bStop = true; .S/W_R  
for(int i=0;i<nStartPos.length;i++) dP0!?J Y  
fileSplitterFetch.splitterStop(); /|] %0B  
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} "kyy>H9)  
} (:3rANY|  
//负责部分文件的抓取 |6LC>'  
**FileSplitterFetch.java ;w1?EdaO  
*/ S3nA}1R  
package NetFox; F?2(U\k#  
vPuPSE%M  
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import java.io.*; ?! dp0<  
import java.net.*; @Tmqw(n{  
` c~:3^?9d  
*LJN2;  
public class FileSplitterFetch extends Thread { BBw]>*  
kJIKULf  
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String sURL; //File URL P\bW kp0  
long nStartPos; //File Snippet Start Position <~# ZtD$G  
long nEndPos; //File Snippet End Position `+]9+:tS  
int nThreadID; //Thread's ID !?B9 0(  
boolean bDownOver = false; //Downing is over fx|$(D@9  
boolean bStop = false; //Stop identical l= 5kd.{  
FileAccessI fileAccessI = null; //File Access interface xy`aR< L  
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =g'7 xA  
{ c0ET]  
this.sURL = sURL; *ie#9jA  
this.nStartPos = nStart; m;o \.s  
this.nEndPos = nEnd; $oK,&_  
nThreadID = id; .(Q3M0.D  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^!H8"CdC3  
} Er} xB~<t  
'3=[xVnv  
Uxx=$&#  
public void run() ]t_AXKd  
{ (_-<3)q4  
while(nStartPos < nEndPos && !bStop) qNER 6  
{ oPRvd_~  
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try{ >L#&L?#  
URL url = new URL(sURL); ~]?Q'ER  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &s_O6cqgh  
httpConnection.setRequestProperty("User-Agent","NetFox"); `9b/Q  
String sProperty = "bytes="+nStartPos+"-"; $A6'YgK  
httpConnection.setRequestProperty("RANGE",sProperty); VR5$[-E3  
Utility.log(sProperty); bnLvJ]i)  
&k(t_~m>  
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InputStream input = httpConnection.getInputStream(); dUeM+(s1  
//logResponseHead(httpConnection); Y1EN|!WZ  
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[La=z7*  
byte[] b = new byte[1024]; +jzpB*@  
int nRead; 1g{`1[.QO  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0rY<CV;fZ  
{ MdT'xYomzQ  
nStartPos += fileAccessI.write(b,0,nRead); tDFN *#(  
//if(nThreadID == 1) x:=Kr@VP  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6d"dJV.\  
} KZeRbq2jJ  
\p1H" A  
A:[La#h|p  
Utility.log("Thread " + nThreadID + " is over!"); DIodQkF  
bDownOver = true; iOm1U_S  
//nPos = fileAccessI.write (b,0,nRead); wG2lCv`
d  
} ON _uu]=  
catch(Exception e){e.printStackTrace ();} G\tTwX4  
} Rj9ME,u  
} 0wXfu"E{  
^Qz8`1`;Z  
vjaIFyj  
//打印回应的头信息 GEfX,9LF&  
public void logResponseHead(HttpURLConnection con) bmna*!l^M  
{ 3(%hHM7DM  
for(int i=1;;i++) !cT#G  
{ N5csq(  
String header=con.getHeaderFieldKey(i); Zu:cF+hl  
if(header!=null) Wcn3\v6_  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Y&`Vs(  
Utility.log(header+" : "+con.getHeaderField(header)); $bh2zKB)  
else 2fTkHBhn&  
break; %yJL-6U  
} &$jg *Kr  
} hf0G-r_ow  
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}
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public void splitterStop() A_T-]YQ  
{ zMt"ST.  
bStop = true; g"
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} Y'Sxehx  
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} &M=12>ah]  
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o %A4wEye  
/* lYT}Nc4"="  
**FileAccess.java CjORL'3  
*//文件访问(定位，写) :2Qm*Y&_$V  
package NetFox; `23&vGk}  
import java.io.*; )y'`C@ijI  
r0l ud&_9  
hE-`N,i}  
public class FileAccessI implements Serializable{
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$&nF1HBI4  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 =#n05*^  
RandomAccessFile oSavedFile; e"hm|'  
long nPos; Yi&;4vC  
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public FileAccessI() throws IOException #>O,w0<qM  
{ Wra*lQb/B  
this("",0); #nX0xV5=  
} _)p@;vGV  
n99:2r_  
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public FileAccessI(String sName,long nPos) throws IOException r^_8y8&l  
{ HD?z  
oSavedFile = new RandomAccessFile(sName,"rw"); SG |!wH^  
this.nPos = nPos; t*zve,?}  
oSavedFile.seek(nPos); BqP:]  
} Hx2UDHF  
y.JAtsxD  
aoz+g,1 //  
public synchronized int write(byte[] b,int nStart,int nLen) ~YO')  
{ "v/^nH  
int n = -1; )FT~gl%  
try{ 5H:NY|  
oSavedFile.write(b,nStart,nLen); u9"b,].b  
n = nLen; 'IFbD["r  
} je9[S_Z:Y  
catch(IOException e) _a8^AG  
{ EK_NN<So#  
e.printStackTrace (); TgJx%  
} %MU<S9k  
1sYwFr5  
HB{w:  
return n; (<s7X$(]e  
} R+P,kD?  
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C"k8M\RW?  
} k7>*fQ89@  
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.hn{m9|U  
/* pnca+d  
**SiteInfoBean.java )"|'=  
*/ (k6=o';y  
package NetFox; /],:sS7  
- 4'yp  
G~a;q+7v'$  
public class SiteInfoBean { *y5d&4G2  
&E.0!BuqV  
*W y0hnr;]  
private String sSiteURL; //Site's URL D(Zux8l  
private String sFilePath; //Saved File's Path &at>pV3_  
private String sFileName; //Saved File's Name KArf:d  
private int nSplitter; //Count of Splited Downloading File M ioS  
)J<Li!3  
"'94E,W  
public SiteInfoBean() aW
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{//nSplitter的缺省值为5 .^I,C!O#  
//default value of nSplitter is 5 u]@``Zb|  
this("","","",5); JMuUj_^}7  
} ^USj9HTK  
Au#(guvm  
(-(,~E  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) tNjb{(eO\h  
{ ]?#f=/  
sSiteURL= sURL; uZz^>*b  
sFilePath = sPath; 8*=N\'m],  
sFileName = sName; eqD%Qd
x  
this.nSplitter = nSpiltter; ?T7`E q  
Lx8^V7X  
L:%ek3SOz  
} PQWo<Uet  
v[e$
RH  
&sR{3pC}  
public String getSSiteURL() 7`6n]4e  
{ J^hj R%H  
return sSiteURL; S-gL]r3G8  
} ?#ndMv!$  
aN).G1  
L;Nz\sJ  
public void setSSiteURL(String value) #?}k0Y  
{ yf*MG&}  
sSiteURL = value; ~d/Doi  
}  v#IW;Rj8  
%g5weiFM  
E+dr\Xhv  
public String getSFilePath() DvF`KHsy  
{ Z?oFee!4
 
return sFilePath; 4FQU$f  
} Q5;Km1(  
}KCXo/y  
VeA;zq  
public void setSFilePath(String value) _p?lRU8  
{ 2fO ~%!.G  
sFilePath = value; BEg%u)"([  
} `8xmMA_l  
3xsC"c>  
'-D-H}%;}M  
public String getSFileName()  X4BDl  
{ 0+P_z(93?  
return sFileName; {K*l,U  
} ZajQ B  
AQ32rJT8c`  
1jh^-d5  
public void setSFileName(String value) NVS U)#  
{ )$P!7$C-  
sFileName = value; r5(OH3  
} `dMOBYV  
g`y >)N/  
}LM^>M%  
public int getNSplitter() KAjKv_6=g  
{ F04`MY"  
return nSplitter; j{7_p$JM  
} W6K]jIQ  
KOV^wSwS  
@0A0\2  
public void setNSplitter(int nCount) O1JGv8Nr  
{ wS%I.  
nSplitter = nCount; ] \4-e2N`\  
} +&O[}%W  
} 5
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<&8cq@<  
2"'0OQN0\  
/* +@cf@}W6QC  
**Utility.java
X@JDfn?A  
*/ Fw!5hR`,  
package NetFox; *=MC+4E  
@=K> uyB  
xRv1zHZ  
public class Utility { {p9y{$  
I=D`:u\H  
> 9JzYI^  
public Utility() jX
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{ BpDf4
)|  
yh]#V"
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X3!btxa%t  
} Fng":28o  
*Mg=IEu-6[  
//线程睡眠 jzI\Q{[m'  
public static void sleep(int nSecond) ~~;fWM '  
{ X z2IAiAs'  
try{ f>\?\!  
Thread.sleep(nSecond); ro}plK(<WQ  
} >J3N,f  
catch(Exception e) w]"Y1J(i  
{ >LgV[D#=&o  
e.printStackTrace (); s)375jCga  
} 9C-F%te7  
} (vz)GrH>  
d7It}7@9  
//日志 W2%(a0p  
public static void log(String sMsg) 5;>M&qmN  
{ kzLj1Ix2  
System.err.println(sMsg);  _"%d9B  
}
kkyn>Wxv  
V*5:V
t7N  
RT)0I
;  
public static void log(int sMsg) @-kzSm  
{ iq5h[  
System.err.println(sMsg); +m:U9K(\h  
} !b rN)b)f  
} =XQ3sk6U  
n6O1\}YB  
!g=
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/* UmiW_JB  
**TestMethod.java ^^jF*)DT@  
*/ @2CYv>  
package NetFox; l"IBt:  
%Q1v8l.}  
R@=ve %a-  
public class TestMethod { qk~QcVg  
[jDO8n/  
#ZCgpg$wM  
public TestMethod() 67 7p9{:  
{ ///xx/weblogic60b2_win.exe 0w8Id . ,  
try{ <rRmbFH#  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 15iCJ p  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); qq[2h~6
P]  
SiteFileFetch fileFetch = new SiteFileFetch(bean); }!Qo wG  
fileFetch.start(); .3{S
6#  
} d+fmVM?p  
catch(Exception e){e.printStackTrace ();} -R~;E[ {%  
 O7s0M?4  
#T#&qo#  
} z.e%AcX  
1 YMaUyL 1  
&^ =t%A%#  
public static void main(String[] args) Tl8S|Rg  
{ e1~C>  
new TestMethod(); wy&VClT  
} : 60PO  
} xb8fV*RO8A  
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