http断点续传简单实现（java)

/* lt4UNJ3w  
**SiteFileFetch.java W9D)QIqbvW  
*/ p~b$+8#+  
package NetFox; w '"7~uN  
import java.io.*; 3OZ}&[3  
import java.net.*; 2uHp%fv;  
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public class SiteFileFetch extends Thread { CMr`n8M  
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SiteInfoBean siteInfoBean = null; //文件信息Bean dWUu3  
long[] nStartPos; //开始位置 Uoe?5Of(*  
long[] nEndPos; //结束位置 A^7!+1*K+  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 6{~I7!m"  
long nFileLength; //文件长度 f1{ckHAY55  
boolean bFirst = true; //是否第一次取文件 l*u@T|Fc$  
boolean bStop = false; //停止标志 4jW{IGW  
File tmpFile; //文件下载的临时信息 *Tlv'E.M  
DataOutputStream output; //输出到文件的输出流 72 6y
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//负责整个文件的抓取，控制内部线程（FileSplitterFetch类） 40E[cGz$*  
public SiteFileFetch(SiteInfoBean bean) throws IOException neBkwXF!  
{ <*+MBF  
siteInfoBean = bean; O?!"15  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); pDLo`F}A  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); >']H)c'2  
if(tmpFile.exists ()) J\*d4I<(Rt  
{ ]VME`]t`  
bFirst = false; 34=0.{qn  
read_nPos(); .<B1i  
} hTm}j,H  
else I}WJ0
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{ ;'p'8lts  
nStartPos = new long[bean.getNSplitter()]; h]#)41y<  
nEndPos = new long[bean.getNSplitter()]; * y B-N;I  
} K
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} Z7^}G=*  
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public void run() gg(U}L ]:  
{ #<o#kJL  
//获得文件长度 K?4(ou  
//分割文件 n3N"Ax  
//实例FileSplitterFetch YUE[
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//启动FileSplitterFetch线程 qo;\dp1  
//等待子线程返回 8(}sZ)6  
try{ *`#,^p`j b  
if(bFirst) TRZ^$<AG  
{ vF&b|V+,  
nFileLength = getFileSize(); Nz;;X\GI  
if(nFileLength == -1) c0 |p34  
{ tp<VOUa  
System.err.println("File Length is not known!"); [P/gM3*'  
} v(iUo&Ge  
else if(nFileLength == -2) sfa'\6=O  
{ qpl5n'qHUc  
System.err.println("File is not access!"); p2G8
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} .D.Rn/  
else l5FQ!>IM  
{ umzYJ>2t  
for(int i=0;i<nStartPos.length;i++) Pcs@`&}7r  
{ Q-v[O4y~  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); lND[anB!  
} 3p4?-Dd|_$  
for(int i=0;i<nEndPos.length-1;i++) %j@FZ )a[  
{ &}O!l'  
nEndPos = nStartPos[i+1]; jvQ"cs$.  
} }H=OVbQor  
nEndPos[nEndPos.length-1] = nFileLength; (Y([^N q  
} }Kt?0  
} %5%Wo(W'  
8:xo ~Vc  
pC-OZ0  
//启动子线程 =f!M=D  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]aNnY?qW5  
for(int i=0;i<nStartPos.length;i++) nY)Pxahm7  
{
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fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3;NRW+  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7VcVI? ?  
nStartPos,nEndPos,i); n^N]iw{G  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); M-N2>i#  
fileSplitterFetch.start(); ozLJ#eOE9  
} fP58$pwu  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (, "E9.  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $8k_M   
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", P~e$iBH'  
nEndPos = " + nFileLength); NrcCUZ .:N  
// fileSplitterFetch[nPos.length-1].start(); LltguNM$  
pm\X*t}L  
}eM<A$J  
//等待子线程结束 moR2iyO_  
//int count = 0; Ib!rf:  
//是否结束while循环 RWFf-VA?  
boolean breakWhile = false; G:`Jrh  
D}sGBsOW  
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while(!bStop) 5#.\pR{Gd  
{ vc#oALc&  
write_nPos(); Y)}%SP>,  
Utility.sleep(500); OPW"ABJ  
breakWhile = true; PU5mz.&0'  
1 ],, Ar5  
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for(int i=0;i<nStartPos.length;i++) ~qxXou,J  
{ .A)Un/k7  
if(!fileSplitterFetch.bDownOver) !m(L0YH  
{ N+q
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breakWhile = false; "H<#91^|  
break; NxO^VUD  
} xY2_
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} u3mT
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if(breakWhile) -WvgK"k  
break; e8mbEC(AK  
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//count++; Ir"Q%>K0f  
//if(count>4) m\M+p
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// siteStop(); s}9tK
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} dqA[|bV  
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System.err.println("文件下载结束！"); y*h1W4:^-  
} #Jz&9I<OKx  
catch(Exception e){e.printStackTrace ();} 86fK=G:>  
} c[_^bs>k  
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//获得文件长度 heZy 66  
public long getFileSize() 7'i#!5  
{ 6\fMzm  
int nFileLength = -1; RS `9?c:  
try{ U qw}4C/0  
URL url = new URL(siteInfoBean.getSSiteURL()); 8KwCwv  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;'QY<,p[e  
httpConnection.setRequestProperty("User-Agent","NetFox"); e ]o'i;I  
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int responseCode=httpConnection.getResponseCode(); o 7W Kh=  
if(responseCode>=400) 4:&qTY)H  
{ in#]3QGV  
processErrorCode(responseCode); m+2`"1IE[  
return -2; //-2 represent access is error 4bev*[k  
} $KWYe{#  
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String sHeader; 76A>^Bs\/  
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for(int i=1;;i++) '&:1?i)  
{ {XD/8m(hN|  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 2FIR]@MQd  
//Utility.log(in.readLine()); FaE#\Q  
sHeader=httpConnection.getHeaderFieldKey(i); DwmU fZp  
if(sHeader!=null) HXfXb^~  
{ $dh4T";  
if(sHeader.equals("Content-Length")) *Ht*)l?  
{ D"XX920$~  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \!JS7!+  
break; EEs-&  
} KU|BT.o8  
} 0vuKGjK  
else r}0C8(oq  
break; AR~$MCR]"k  
} =v4r M0m,  
} sCtw30BL  
catch(IOException e){e.printStackTrace ();} 7ec0Xh1  
catch(Exception e){e.printStackTrace ();} p/k<wCm6  
poQdI?ed,  
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Utility.log(nFileLength); /pN'K5@  
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return nFileLength; q)V1{B@  
} %U5P}  
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//保存下载信息（文件指针位置） ZEj!jWP2m  
private void write_nPos() ,<$YVXe/  
{ n{^<&GWox  
try{
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output = new DataOutputStream(new FileOutputStream(tmpFile)); q11QAx4p  
output.writeInt(nStartPos.length); uKbHFF  
for(int i=0;i<nStartPos.length;i++) b H"}w$!>r  
{ f `y" a@  
// output.writeLong(nPos); $89ea*k  
output.writeLong(fileSplitterFetch.nStartPos); sB( `[5I  
output.writeLong(fileSplitterFetch.nEndPos); s[3![ "^Y  
} 3WCqKXJ7  
output.close(); jF2[bzY4  
} hqs$yb  
catch(IOException e){e.printStackTrace ();} sq~+1(X  
catch(Exception e){e.printStackTrace ();} ESD<8OR  
} 9p2>`L  
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//读取保存的下载信息（文件指针位置） )WVItqQKV  
private void read_nPos() eu}Fd@GO  
{ B;GxfYj  
try{ |^Ew<
  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); #9$V 08  
int nCount = input.readInt(); +ze}0lrEL  
nStartPos = new long[nCount]; CF|moc:;  
nEndPos = new long[nCount]; m<4s*q0\i  
for(int i=0;i<nStartPos.length;i++) $ZI~8rI~  
{ $5lW)q A  
nStartPos = input.readLong(); =[P%_v``  
nEndPos = input.readLong(); hdd>&?p3  
} @PQrmn6w  
input.close(); 5S%C~iB  
}
,!6M*|  
catch(IOException e){e.printStackTrace ();} R:w%2Y  
catch(Exception e){e.printStackTrace ();} ImWXzg3@{  
} jCTy:q]  
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private void processErrorCode(int nErrorCode) h; 'W :P  
{ F0&~ ?2nG  
System.err.println("Error Code : " + nErrorCode); )L |tn  
} vpm ]9>1[  
*o02!EYge  
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//停止文件下载 vWU%
ST  
public void siteStop() Opv1B2  
{ ':l"mkd+`  
bStop = true; f?%qUD_#  
for(int i=0;i<nStartPos.length;i++) #PPR"w2g  
fileSplitterFetch.splitterStop(); (2z%U  
m|]j'g?{}(  
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} ]3L@$`ys  
} J3;Tm~KJ_  
//负责部分文件的抓取 h/I@_?k+  
**FileSplitterFetch.java 3`58ah  
*/ v%lv8Lar'  
package NetFox; $sEB'>:  
#
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import java.io.*; >P<z |8  
import java.net.*; 2)wAFO6u  
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public class FileSplitterFetch extends Thread { %p0b{P j_p  
I"ca+4]  
Bk@)b`WR  
String sURL; //File URL !|B3i_n  
long nStartPos; //File Snippet Start Position 1"}B]5!  
long nEndPos; //File Snippet End Position br0u
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int nThreadID; //Thread's ID p?Ed- S  
boolean bDownOver = false; //Downing is over \n#]%X5c  
boolean bStop = false; //Stop identical Hqvc7-c6  
FileAccessI fileAccessI = null; //File Access interface >b>MKm>q  
pT4qPta,2  
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 79D=d'eA  
{ E{uf\Fc
 
this.sURL = sURL; !w q4EV  
this.nStartPos = nStart; 42fprt  
this.nEndPos = nEnd; Q[M (Wqg  
nThreadID = id; $+Vmw
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fileAccessI = new FileAccessI(sName,nStartPos);//定位 '!!e+\h#  
} Sv7 i! j  
 bRN
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public void run() ~<n(y-P^  
{ >;)2NrJV  
while(nStartPos < nEndPos && !bStop) h$70H^r  
{ 0Cl,8P  
<B!'3C(P  
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try{ =HVfJ"vK  
URL url = new URL(sURL); R|iEv
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HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &K>cW$h=a  
httpConnection.setRequestProperty("User-Agent","NetFox"); +UzXN
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String sProperty = "bytes="+nStartPos+"-"; q]px(  
httpConnection.setRequestProperty("RANGE",sProperty); lR:?uZ$  
Utility.log(sProperty); t9.,/o,  
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InputStream input = httpConnection.getInputStream(); :q^R `8;(t  
//logResponseHead(httpConnection); ;{
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byte[] b = new byte[1024]; {LP b))  
int nRead; Go1(@  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) eJ)1K  
{ RU0i#suiz  
nStartPos += fileAccessI.write(b,0,nRead); YZ+>\ x  
//if(nThreadID == 1) 6B#('gxO  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F?z
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} U;g S[8,p  
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Utility.log("Thread " + nThreadID + " is over!"); 7rcA[)<'  
bDownOver = true; ^
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//nPos = fileAccessI.write (b,0,nRead); eIg+PuQD]  
} 1 tPVP  
catch(Exception e){e.printStackTrace ();} 87i"   
} f ba&`  
} 0x@A~!MoP  
p* RC  
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//打印回应的头信息 
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public void logResponseHead(HttpURLConnection con) G}VDEC  
{ o@9+mM"B)  
for(int i=1;;i++) g:_hj_1Y M  
{ ;1 |x  
String header=con.getHeaderFieldKey(i); ~^&R#4J  
if(header!=null) II;Te7~  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ~.Cv DJy  
Utility.log(header+" : "+con.getHeaderField(header)); @RGDhwS47  
else CbOCk:,g5  
break; Stxp3\jEn  
} q\Rq!7(  
} */w7?QOv  
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public void splitterStop() 56DoO'  
{ l$a?A[M$  
bStop = true; ! Z;T-3^.  
} (WRMaI72(  
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fN)
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} o
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/* IkDiT63]I  
**FileAccess.java ;~+]! U  
*//文件访问(定位，写) lpy:3`ti  
package NetFox; bb;(gK;F  
import java.io.*; bO3GVc+S  
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9 |
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public class FileAccessI implements Serializable{ |0sPka/u16  
#G#g|x*V  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 f+x;:  
RandomAccessFile oSavedFile; V}" g~=  
long nPos; ;+U<bqL6  
0{+.H_f`  
+q{[\#t5  
public FileAccessI() throws IOException Vr=OYI'A  
{ PD6_)PXn  
this("",0); 6e
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} "AC^ rz~U  
"(`2eXR
n  
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public FileAccessI(String sName,long nPos) throws IOException ^m!_2_q  
{ 1J{fXh  
oSavedFile = new RandomAccessFile(sName,"rw"); <T+!V-Pj*  
this.nPos = nPos; &!L:"]=+  
oSavedFile.seek(nPos); P4k;O?y  
} /_t|Dry015  
$*f?&U]k  
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public synchronized int write(byte[] b,int nStart,int nLen) iWA|8$u4gm  
{ ; s|w{.<:  
int n = -1; eC! #CK  
try{ -*B`]  
oSavedFile.write(b,nStart,nLen); ?9mkRd}c  
n = nLen; (R*j|HAw`X  
} 8'#/LA[uPe  
catch(IOException e) jlqv2V7=/  
{ /,s[#J  
e.printStackTrace (); }Fa%%}  
} J?&l*_m;t  
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return n; ,.tfWN%t\  
} 9Uf j  
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} Y?K{(szo ?  
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/* }V]R+%:w@  
**SiteInfoBean.java b2C`g]ibQ  
*/ #Sh <Ih  
package NetFox; VT%:zf  
k;ZxY"^  
4x;_AN  
public class SiteInfoBean { ABh&X+YD  
7f{=w, U  
\ZI'|Ad  
private String sSiteURL; //Site's URL ;# uZhd  
private String sFilePath; //Saved File's Path 5!X1G8h)uy  
private String sFileName; //Saved File's Name O|kOI?f  
private int nSplitter; //Count of Splited Downloading File !RW `3  
@? c2)0
 
*L4`$@l8  
public SiteInfoBean() Lel|,mc`k2  
{//nSplitter的缺省值为5 NZ0O,}m  
//default value of nSplitter is 5 5PT5#[  
this("","","",5); T>`74B:  
} QHq,/kWY  
72W s K"  
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public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9(4&KZpK  
{ )2IH 5  
sSiteURL= sURL; [ic87
0_  
sFilePath = sPath; O@V%Cu  
sFileName = sName; r!PpUwod  
this.nSplitter = nSpiltter; ^T::-pN*  
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P!G858V(  
} 0Hxmm@X2  
jho**TQ P  
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public String getSSiteURL() 7*5Z  
{ [* ?Awf`  
return sSiteURL; Z;/$niY  
} "pP^*9FrA  
~`M\Ir  
0'YG6(h  
public void setSSiteURL(String value) kE9esC3  
{ !K f#@0E..  
sSiteURL = value; aFz5leD  
} !8NC# s  
G 0%6ch^%  
%w7u]-tR  
public String getSFilePath() C?Bl{4-P}*  
{ #|&Sc_#4)  
return sFilePath; 1i[FY?6`dh  
} }G4ztiuG  
u_(VEfs4  
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public void setSFilePath(String value) [Zei0O  
{ Ms~{
9?  
sFilePath = value; ydRC1~f0  
} nD5 gP  
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public String getSFileName() >Cw<BIF  
{ 'u4<BQVV[  
return sFileName; }by;F
9&B  
} ^?7`;/  
;r_F[E2z  
Dn&D!B  
public void setSFileName(String value) #]nx!*JNZ  
{ r\qj!  
sFileName = value; W`\R%>$H  
} C{gyj}5  
v\m ]A1  
1$M@]7e+!+  
public int getNSplitter() wr[,  
{ At7>V-f}  
return nSplitter; &l3iV88  
} Oo"^%F~%  
Ag{iq(X  
d&ex5CU5
 
public void setNSplitter(int nCount)  J5^'HU3  
{ bFe+m1Q_  
nSplitter = nCount; _?OW0x4  
} DxUKUE  
} |<:vY  
|B?27PD  
Re P|UH  
/* X!e[GJ  
**Utility.java $5Xh,DOg  
*/ #Q2Y&2`yGT  
package NetFox; Y.g59X!Ub2  
J]nohICe  
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public class Utility { n4}Br;%  
?b(=1S\E'^  
g!rQ4#4  
public Utility() .Fdgb4>BXX  
{ N[s}qmPha  
-$\+' \  
b )B?
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} {q"OM*L(  
{NHdyc$  
//线程睡眠 DRcNdO/1E  
public static void sleep(int nSecond) ;kY(<{2  
{ &*+'>UEe5  
try{ "rx-_uK*  
Thread.sleep(nSecond); O^oWG&Y;v  
} z^'gx@YD*v  
catch(Exception e)
S:h{2{  
{ ~`aa5;Ab_  
e.printStackTrace (); .Y&)4+ckL  
} :Zlwp6  
} ;M)QwF1  
z6*X%6,8  
//日志 r"P|dlV-  
public static void log(String sMsg) eAE`#t  
{ 7S}_F^  
System.err.println(sMsg); 0*f)=Q'  
} [ucpd  
'.:z&gSqx0  
6}d.5^7lr  
public static void log(int sMsg) o,_?^'@  
{ < jJ  
System.err.println(sMsg); OX\A|$GS  
} 3yVMXK  
} wOU_*uY@6'  
kM,C3x{A  
9[<)WQe6M  
/* RW<D<5C  
**TestMethod.java \G*0"%!U  
*/ =ALTUV3/q  
package NetFox; bbE!qk;hEP  
?l
9XAWt\  
D]zwl@sRX:  
public class TestMethod { 8X[:j&@  
U/!TKic+  
37s0e;aF  
public TestMethod() 1q7|OWFT  
{ ///xx/weblogic60b2_win.exe f
4fvrL  
try{ N sXHO  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); A1O'|7X  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); YtmrRDQs  
SiteFileFetch fileFetch = new SiteFileFetch(bean); .(K)?r-g5  
fileFetch.start(); ~E17L]ete  
} 3LOdjT J  
catch(Exception e){e.printStackTrace ();} e"|efE  
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 y3@H/U{  
} s~^5kgPA  
;r<^a6B  
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public static void main(String[] args) IxY|>5z  
{ b,7k)ND1F  
new TestMethod(); EJMM9(DQ7  
} =;Au<|  
} `dq,>HdW  
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