http断点续传简单实现（java)

/* Zqp<8M2  
**SiteFileFetch.java .[Hv/?L  
*/ !et[Rdbu  
package NetFox; Fcp8RBq  
import java.io.*; <H]1 6  
import java.net.*; +G.F'  
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+`(,1L1  
public class SiteFileFetch extends Thread { $qp,7RW  
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SiteInfoBean siteInfoBean = null; //文件信息Bean HLruZyN4  
long[] nStartPos; //开始位置 I_aSC4  
long[] nEndPos; //结束位置 gX'nFGqud  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 \v,mr|  
long nFileLength; //文件长度 %=PGvu  
boolean bFirst = true; //是否第一次取文件 "TQ3{=j{  
boolean bStop = false; //停止标志 T+knd'2V6  
File tmpFile; //文件下载的临时信息 _oU}>5  
DataOutputStream output; //输出到文件的输出流 k6(9Rw8bCk  
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//负责整个文件的抓取，控制内部线程（FileSplitterFetch类） >c
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public SiteFileFetch(SiteInfoBean bean) throws IOException \J?l7mG  
{ QE\t}>  
siteInfoBean = bean; } N$soaUs  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); y]YUuJ9a  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); tUr
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if(tmpFile.exists ()) %=G*{mK  
{ 15)y]N={^  
bFirst = false; OtsW>L@ O(  
read_nPos(); O\z]1`i*o  
} 2<X.kM?N{B  
else ?z/ )Hkw  
{ %9HL
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nStartPos = new long[bean.getNSplitter()]; $p?TE8G  
nEndPos = new long[bean.getNSplitter()]; C%LXGMt  
} p2)563#RS
 
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} muZ6}&4  
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public void run() %]iE(!>3oy  
{ ,JVWn>s  
//获得文件长度 q2U8]V U)  
//分割文件 g UAx8=h  
//实例FileSplitterFetch )_-EeH  
//启动FileSplitterFetch线程 KhFw%Z0s<  
//等待子线程返回 gOSFvH8FU  
try{ P-25]-  
if(bFirst) KJQW))%e  
{ #|ILeby  
nFileLength = getFileSize(); R4x!b`:i  
if(nFileLength == -1) K4`)srd  
{ nS$_VJ]~  
System.err.println("File Length is not known!"); `(Eiu$h6V-  
} {OBV+}#  
else if(nFileLength == -2) ?ZS/`P0}[  
{ ]Lz:oV^%  
System.err.println("File is not access!"); -w3KBlo  
} )B1gX>J\8  
else BnwYyh  
{ or)v:4PXW  
for(int i=0;i<nStartPos.length;i++) ^v+3qm@,  
{ s/cclFji]  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); =IC cN|  
} ynQ+yW74Z  
for(int i=0;i<nEndPos.length-1;i++) 83[gV@LW0m  
{ k __MYb  
nEndPos = nStartPos[i+1]; Fr{}~fRW<  
} L';b908r2  
nEndPos[nEndPos.length-1] = nFileLength; POl_chq  
} g)/#gyT4Y  
} AJWV#J%nB  
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:u4q.^&!e  
//启动子线程 <Z:Fnp
 
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )u67=0s2i+  
for(int i=0;i<nStartPos.length;i++) $(A LxC  
{ mQiVTIP3[O  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), eX0ASI9  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 1v2pPUH\  
nStartPos,nEndPos,i); zc4l{+3  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6%Ws>H4@|  
fileSplitterFetch.start(); qy$1+>f1  
} |u5Xi5q.f  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(),
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siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \fjr`t]  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", P"k`h=>!4  
nEndPos = " + nFileLength); x } X1 O)  
// fileSplitterFetch[nPos.length-1].start(); VQe@H8>3  
5U[bn=n  
7~H.\4HB  
//等待子线程结束 YuVg/ '=  
//int count = 0; 48p< ~#<W\  
//是否结束while循环 8-clL\bm  
boolean breakWhile = false; Uk0Fo(HY  
u ^}R]:n  
+ia N[F$  
while(!bStop) 4w<4\zT_U}  
{ J\fu6Ti  
write_nPos(); FsTl@zN  
Utility.sleep(500); J~=tR1k  
breakWhile = true; 23_\UTM}1  
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 FKpyD  
for(int i=0;i<nStartPos.length;i++) ^PrG5|,s  
{ *v6 j7<H  
if(!fileSplitterFetch.bDownOver) r@v_hc  
{ YI!@
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breakWhile = false; 0n
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break; _4lhwKYU  
} {DVu* %|  
} H7&bUt/  
if(breakWhile) '3'*VcL(  
break; _1EWmHZ?  
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//count++; Sn~h[s_(  
//if(count>4) sY*iR
q  
// siteStop(); UP?]5x>  
} Q/u1$&1  
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System.err.println("文件下载结束！");
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} %*Aq%,.={  
catch(Exception e){e.printStackTrace ();}
+GDT@,/  
} l2[{T^  
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}+3v5Nz;  
//获得文件长度 tJgo%P1  
public long getFileSize() #lo1GoL\  
{ Zwm2T3@e
 
int nFileLength = -1; [L4s.l_#  
try{ |WMP_sGn  
URL url = new URL(siteInfoBean.getSSiteURL()); `Ir{ax&H.e  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); sPoH12?AL  
httpConnection.setRequestProperty("User-Agent","NetFox"); =bDy :yY}  
}2CVA.Qm!  
?Gr2@,jlD  
int responseCode=httpConnection.getResponseCode(); 6Q}WX[| tQ  
if(responseCode>=400) Dqh rg;  
{ =U)e_q  
processErrorCode(responseCode); .e|VW)  
return -2; //-2 represent access is error J3P)oM[  
} rM5{R}+;  
/_g-w93   
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String sHeader; +D&aE$<  
Q xg)Wb#  
J~,Ny_L  
for(int i=1;;i++) *~H\#
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{ W2 p&LP  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); b0n " J`  
//Utility.log(in.readLine()); %M KZ':m  
sHeader=httpConnection.getHeaderFieldKey(i); I%qZMoS1h  
if(sHeader!=null) Kp.d#W_TX
 
{ 0'Y'K6hG`  
if(sHeader.equals("Content-Length")) L28DBjE)A  
{ 64jFbbd-/  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +;*dFL  
break; Tu*"+*r>s  
} o1B8_$aYgc  
} hJsYKd8g  
else FvTc{"w /  
break; W!.vP~>  
} x.ZW%P1  
} $lYy`OuC  
catch(IOException e){e.printStackTrace ();} qo^PS  
catch(Exception e){e.printStackTrace ();} X6`F<H`
 
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Utility.log(nFileLength); gLGu#6YVu  
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return nFileLength; ZT'VF~  
} !da[#zK  
']]5xH*U  
sH_5.+,`  
//保存下载信息（文件指针位置） Z&w/JP?  
private void write_nPos() `<3xi9  
{ /yhGc}h  
try{ Jq8CII  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 'L1=:
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output.writeInt(nStartPos.length); tITx+i  
for(int i=0;i<nStartPos.length;i++) @_ Q  
{ +^0Q~>=VD  
// output.writeLong(nPos); y53f73Cg  
output.writeLong(fileSplitterFetch.nStartPos); :e|[gEA  
output.writeLong(fileSplitterFetch.nEndPos); :1/K$A)^{  
} =mWr8p-H  
output.close(); 40ZHDtIu<  
} QhqXd  
catch(IOException e){e.printStackTrace ();} V% PeZ.Xv  
catch(Exception e){e.printStackTrace ();} dd{pF\a  
} oI2YJ2?Je8  
5OS|Vp||
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9+!1jTGSkf  
//读取保存的下载信息（文件指针位置） |yT-N3H@  
private void read_nPos() AXmW7/Sj"  
{ ,-[e{=Cz  
try{ ja1WI  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %;0l1X  
int nCount = input.readInt(); I]dt1iXu_{  
nStartPos = new long[nCount]; I0v$3BQ4  
nEndPos = new long[nCount]; G,]%dZHe  
for(int i=0;i<nStartPos.length;i++) k_$9cVA  
{ OwJZ?j&)  
nStartPos = input.readLong(); f5p:o}U*  
nEndPos = input.readLong(); wE*jN~  
} ;3 |Z}P  
input.close(); "B9aJo  
} l{u2W$8  
catch(IOException e){e.printStackTrace ();} 3\~ RWoB0u  
catch(Exception e){e.printStackTrace ();} ud}B#{6  
} !rwe|"8m?u  
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private void processErrorCode(int nErrorCode)
b{WEux{)  
{ Gs7#W:e7  
System.err.println("Error Code : " + nErrorCode); ]`S35b  
} 7 g2@RKo  
tOQura
 
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//停止文件下载 2wKW17wj,  
public void siteStop() =Y;w O8  
{ &Fxw19[G  
bStop = true; 'c")]{  
for(int i=0;i<nStartPos.length;i++) _h7qS  
fileSplitterFetch.splitterStop(); H7=[sL^  
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} 0 jszZ_  
} O5;$cP:  
//负责部分文件的抓取 luYa+E0  
**FileSplitterFetch.java LBs:O*;  
*/ afJ`1l  
package NetFox; rElbzL"&<  
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import java.io.*; NE'4atQ|  
import java.net.*; B"9/+Yj  
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public class FileSplitterFetch extends Thread { x9&{@ ?o  
:^Ouv1!e1  
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String sURL; //File URL k- ?:0  
long nStartPos; //File Snippet Start Position 'Itsu~fza  
long nEndPos; //File Snippet End Position 6,D)o/_  
int nThreadID; //Thread's ID R"0fZENTG  
boolean bDownOver = false; //Downing is over 9*"Ae0ok1  
boolean bStop = false; //Stop identical .S{Q }S  
FileAccessI fileAccessI = null; //File Access interface #UO#kC<2(B  
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@fML.AT  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -5_[m@Vr  
{ |KM<\v(A{  
this.sURL = sURL; p?q~.YY  
this.nStartPos = nStart; T{VdlgL  
this.nEndPos = nEnd; qit D{;  
nThreadID = id; 2d`:lk%\  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 N
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} /J-:?./  
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public void run() H+VKWGmfG  
{
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while(nStartPos < nEndPos && !bStop) s?j` _B  
{ C6-71`C0  
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try{ ~sd+ch*  
URL url = new URL(sURL); D8b~-#  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DV,rh83.ip  
httpConnection.setRequestProperty("User-Agent","NetFox");
:Ur=}@Dj  
String sProperty = "bytes="+nStartPos+"-"; ]nEZQ+F  
httpConnection.setRequestProperty("RANGE",sProperty); U6R"eQUTV  
Utility.log(sProperty); m^O9G?  
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}.uB6&!:  
InputStream input = httpConnection.getInputStream(); hkh b8zS  
//logResponseHead(httpConnection); JMnk~8O  
\8I>^4t'/  
?2#v`Z=L;  
byte[] b = new byte[1024]; K1F,M9 0]  
int nRead; !E0zj9 [ R  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) -}h+hS50F  
{ le*1L8n$'  
nStartPos += fileAccessI.write(b,0,nRead); NvZ )zE  
//if(nThreadID == 1) cP4K9:k  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); k>N >_{\  
} Pd,+= ML  
NVTNjDF%s  
-RSPYQjz  
Utility.log("Thread " + nThreadID + " is over!"); <NLor55.]  
bDownOver = true; #..-!>lY  
//nPos = fileAccessI.write (b,0,nRead); -\.'WZo`  
} A=v^`a03I  
catch(Exception e){e.printStackTrace ();} 5g{L -8XwI  
} `3v!i   
} I^5T9}>Q  
RawK9K_1  
1>doa1  
//打印回应的头信息 x}w"2[fL  
public void logResponseHead(HttpURLConnection con) *acN/
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{ (Oc[j{6q  
for(int i=1;;i++) R"au8f.  
{ 2hjR'6h"Y  
String header=con.getHeaderFieldKey(i); GQNs:oRJ'  
if(header!=null) t5%\`Yo?  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *mc]Oa  
Utility.log(header+" : "+con.getHeaderField(header)); &*}NN5Sv  
else [I`r[u  
break; ;FO1b*  
} nbnbG0r:  
} o4)^U t+  
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?:Y0#Btj  
public void splitterStop() 3lyk/',  
{ N}Ol`@@#h  
bStop = true; hLVS}HE2  
} h48JpZ"  
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jb  
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} nt/+?Sj  
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/* kKFSCl/g  
**FileAccess.java hSgfp  
*//文件访问(定位，写) ZWC-<QO"<  
package NetFox; 6,"fH{Bd  
import java.io.*; ^lqcF.  
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public class FileAccessI implements Serializable{ $B6"fYiDk  
00') Ol&  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节  [69[
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RandomAccessFile oSavedFile; C+r<DC3  
long nPos; 5Rv6+d  
{iP^51fy  
73$^y)A
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public FileAccessI() throws IOException `laaT5G\y  
{ xw*T?!r=V  
this("",0); x%ZgLvdp,  
} qll)  
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public FileAccessI(String sName,long nPos) throws IOException `;7
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{ u,:GJU  
oSavedFile = new RandomAccessFile(sName,"rw"); (C#9/WO?  
this.nPos = nPos; {:&t;5qz^  
oSavedFile.seek(nPos); DiK@>$v  
} _y}]j;e8>{  
Azx4+`!-  
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public synchronized int write(byte[] b,int nStart,int nLen) IqK??KSC  
{ aU]A#g   
int n = -1; (F$V m  
try{ l`L}*Q- 5  
oSavedFile.write(b,nStart,nLen); ]8(_{@/  
n = nLen; *r
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} V#?GDe}[  
catch(IOException e) r;`6ML[5Vx  
{ ;d1\2H  
e.printStackTrace (); D6,rb 9  
} 4@PH5z  
!>B|z=  
,?GEL>F  
return n;  {g?$u  
} _B`'1tNx  
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} &?mH[rG"  
BN&^$1F((  
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/* #C1u~db  
**SiteInfoBean.java B./Lp_QK  
*/ 6P=6E  
package NetFox;  k%V#{t.  
Z~^)B8  
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public class SiteInfoBean { kP9DCDO`[5  
.P\wE";  
+Zu*9&Cx  
private String sSiteURL; //Site's URL `}gjfu -'\  
private String sFilePath; //Saved File's Path vn@9Sqk  
private String sFileName; //Saved File's Name SMVn2H@  
private int nSplitter; //Count of Splited Downloading File fu3/n@L  
w-?_U7'  
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public SiteInfoBean() MtC\kTW  
{//nSplitter的缺省值为5 V6Kw71'9  
//default value of nSplitter is 5 oLEqy  
this("","","",5); q/,>UtRr  
} 53d8AJ_@X  
Qvh:
hkR  
y^:!]-+  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) S6gg(nNe  
{ bX%9'O[-  
sSiteURL= sURL; 7A|n*'[T>  
sFilePath = sPath; PSz|I8 c  
sFileName = sName; /t`s.!k  
this.nSplitter = nSpiltter; dieGLA<5_X  
:R+}[|FV  
Uk=jQfA*J  
} b: UTq 7^  
tW;1  
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public String getSSiteURL() H%`Ja('"p  
{ ;^nN!KDjR  
return sSiteURL; /k3v\Jq{  
} F$P8"q+  
]6NpHDip1  
1
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public void setSSiteURL(String value) eO#Kn'5  
{ 6m_ fEkS[  
sSiteURL = value; ].=&^0cg  
} ?4Z`^uy  
8SII>iL{  
!L4Vz7C  
public String getSFilePath() [F4]pR(  
{ fQcJyX  
return sFilePath; m[6?v;w  
} S%zn
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public void setSFilePath(String value) c8!q_H~  
{ T:&  
sFilePath = value; {/SUfXq  
} o.IJ4'}aN  
e E:J  
WPT0=Hqp7  
public String getSFileName() R&Y+x;({  
{ ._j9^Ll  
return sFileName; r
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} -0rc4<};h  
+~b@W{  
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public void setSFileName(String value) 9<BC6M_/  
{ X}*\/(fzl  
sFileName = value; 8UiRirw  
} o NX-vN-  
2fIHFo\8  
/<7'[x<  
public int getNSplitter() ?7>G\0G  
{ KITC,@xE_O  
return nSplitter; ,TL8`  
} ,.;q[s8  
zvjp]yTx"  
*Ii_dpJ  
public void setNSplitter(int nCount) 8i:E$7etH  
{ qzD<_ynA  
nSplitter = nCount; %mKM9>lf#  
} *9J>3  
} wq$+m(  
?:DeOBAb  
KQGdV{VFs  
/* BZHba8c(  
**Utility.java ,*_=w^;Rr  
*/ 6 axe  
package NetFox; yOHVL~F  
\\w<.\Yh  
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public class Utility { oPP`)b$x  
?wM{NVt#-  
cQM_kV??!  
public Utility() E6+c{41B  
{ wD+4#=/j  
&c[.&L,w4  
k# -u!G  
} ndW]S7  
_{$eOwB  
//线程睡眠 r"HQ>Wn  
public static void sleep(int nSecond) "u29| OY  
{ pjG/`  
try{ f_\,H|zco)  
Thread.sleep(nSecond); yhTC?sf<  
} >JOEp0J  
catch(Exception e) ,j3Yvn W  
{ >~_oSC)E
 
e.printStackTrace (); {\:"OcP #  
} |.]sL0;4Z  
} GnTCq_\  
Ow
d{;  
//日志 _#;UXAi  
public static void log(String sMsg) wz[Xay9jW  
{ rnNB!T  
System.err.println(sMsg); 4v[Zhf4JM  
} z[vHMJ
0  
@J~hi\&`  
LR`]C]  
public static void log(int sMsg) MKiP3kt
8  
{ C[X2]zr  
System.err.println(sMsg); M%{,?
a0V  
} y6#AL<W@=  
} 2g0_[$[m  
xlKg0&D  
mCb1^
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/* PCqE9B)l  
**TestMethod.java J_-K"T|f  
*/ {KQ]"a 6  
package NetFox; 85e!)I_  
{pJf~  
|f+`FOliP  
public class TestMethod { AQ)DiH  
Sv#S_jh  
b=$(`y  
public TestMethod() UiE 1TD{  
{ ///xx/weblogic60b2_win.exe Bjc<d,]  
try{ wf`e3S  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Y'&rSHI"  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ,#V}qSKUS  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 1#Q~aY  
fileFetch.start(); 4QZ|e{t  
} pB;8yz=  
catch(Exception e){e.printStackTrace ();} woyn6Z1JQ  
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*xV  
} 9YQYg@+R  
k]"DsN$
  
][?@))  
public static void main(String[] args) d,XNok{  
{ k=&UV!J  
new TestMethod(); UD0#Tpd7  
} cLm|^j/  
} ;${_eab]  
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