http断点续传简单实现（java)

/* yo\N[h7  
**SiteFileFetch.java 4$ Dt8!p0  
*/ YV/>8*i  
package NetFox; v7i^O`{eD?  
import java.io.*; d,c8Hs8  
import java.net.*; K8HIuQ!=  
#l*a~^dhqC  
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public class SiteFileFetch extends Thread { 3CR@' qG-  
;,1=zhKU.  
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SiteInfoBean siteInfoBean = null; //文件信息Bean D]IBB>F  
long[] nStartPos; //开始位置 &5\^f?'b7  
long[] nEndPos; //结束位置 8Y2xW`  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 l0gY~T/#3  
long nFileLength; //文件长度 qWsylC23  
boolean bFirst = true; //是否第一次取文件 >Z+"`"^o}  
boolean bStop = false; //停止标志 Q [rj  
File tmpFile; //文件下载的临时信息 q0,kDM66   
DataOutputStream output; //输出到文件的输出流 O: ,$%  
<9P4}`%)3  
//负责整个文件的抓取，控制内部线程（FileSplitterFetch类） G' Blp  
public SiteFileFetch(SiteInfoBean bean) throws IOException D.'h?^kA  
{ OT%0{2c"]  
siteInfoBean = bean; C5P$&s\  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); w8O" =},  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); IY=/`g  
if(tmpFile.exists ()) AXwaVLEBQ  
{ NS`07#z^  
bFirst = false; n(g)UNx  
read_nPos(); T~BA)![  
} YT>KJ  
else )
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{ '|A|vCRCG  
nStartPos = new long[bean.getNSplitter()]; E2@`d6  
nEndPos = new long[bean.getNSplitter()]; ^+ZgWS^
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} lDN"atSf  
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} TZ[Zm  
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public void run() JVtQ,oZ  
{ =#qZ3 Qz_  
//获得文件长度 L!t@-5~  
//分割文件 ,CP5~4u  
//实例FileSplitterFetch zh\p  
//启动FileSplitterFetch线程 :0$a.8Y\++  
//等待子线程返回 
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try{ Ck\7F?S  
if(bFirst) RK[D_SmS  
{ F^QQ0h]2  
nFileLength = getFileSize(); {~SaRB2<'  
if(nFileLength == -1) E<>*(x/\e  
{ A{# Nwd>  
System.err.println("File Length is not known!"); "(v%1tGk  
} iPq &Y*  
else if(nFileLength == -2) hoa7   
{ H&#{l)  
System.err.println("File is not access!"); ^$v3
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} rL

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else -KH)J  
{ T*?s@$)m4  
for(int i=0;i<nStartPos.length;i++) V A<5uk04K  
{ FmEc`N9\v  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); }bH
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}
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for(int i=0;i<nEndPos.length-1;i++) 3iRA$C-p  
{ "13"`!m  
nEndPos = nStartPos[i+1]; }pVTTs`  
} @@@=}!<H=  
nEndPos[nEndPos.length-1] = nFileLength;  ~*M$O&  
} aTd D`h  
} qFco3  
hn.bau[  
$Az^Y0[D  
//启动子线程 'fx UV<K&  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9i5tVOhE  
for(int i=0;i<nStartPos.length;i++) K{@3\5<  
{ N|mJg[j@7  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Xd<t5{bD!  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), S4N(cn&  
nStartPos,nEndPos,i); ('O}&F1  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D-2.fjo9!  
fileSplitterFetch.start(); 7Vu?  
} qH>`}/,P  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %dMqpY7"  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); L[g0&b%%-  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >5hhd38  
nEndPos = " + nFileLength); %ft &Q  
// fileSplitterFetch[nPos.length-1].start(); eg/<[ A:  
MP^ d}FL  
AH#4wPxF  
//等待子线程结束 :XG;ru%i  
//int count = 0; 3*ixlO:qGk  
//是否结束while循环 [kV;[c}  
boolean breakWhile = false; fpWg R4__  
oR .cSGh  
b| M3`  
while(!bStop) J-xS:Ha'l  
{ Es5f*P0  
write_nPos(); S0d~.ah30  
Utility.sleep(500); 2f>PO +4S{  
breakWhile = true; GsQ*4=C  
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for(int i=0;i<nStartPos.length;i++) OFk8>"|  
{ WIr2{+#  
if(!fileSplitterFetch.bDownOver) 'G&{GVbXY  
{ r%@Lej5+  
breakWhile = false; \f:z+F!6R  
break; 7ZxaPkIu&%  
} urBc=3Rz  
} rH8@69,B  
if(breakWhile) B9R(&<4  
break; ^qG
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kDvc" ,SD#  
0NDftcB]  
//count++; *
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//if(count>4) T
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// siteStop(); =(v^5
 
} j;b42G~p  
p;T{i._iL  
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System.err.println("文件下载结束！"); +Y"r71|A6+  
} *N'K/36;  
catch(Exception e){e.printStackTrace ();} {-3LIO  
} O7d$YB_'  
7hP<f}xL  
({r*=wAP  
//获得文件长度 #LlUxHv #  
public long getFileSize() 3_Cp%~Gi-_  
{ VKp*9%9  
int nFileLength = -1; fhPkEvJ  
try{ Sr?#wev]rn  
URL url = new URL(siteInfoBean.getSSiteURL()); qfY5Ww$8  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o+w;PP)+=  
httpConnection.setRequestProperty("User-Agent","NetFox"); Zxr!:t7  
!pTJ./  
Jn:ZYqc  
int responseCode=httpConnection.getResponseCode(); ;Uc0o!1  
if(responseCode>=400) qgIb/6;xQ  
{ +gd4\ZG  
processErrorCode(responseCode); r={c,i  
return -2; //-2 represent access is error ho8`sh>N  
} l^GP3S  
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5=Xy,hmnC  
String sHeader; 32DbNEk  
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for(int i=1;;i++) 5oEV-6  
{ o#) {1<0vg  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *IgE
)N>  
//Utility.log(in.readLine()); Z4<L$i;/jN  
sHeader=httpConnection.getHeaderFieldKey(i); =4V&*go*\  
if(sHeader!=null) ZkL8
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{ ]]7mlQ  
if(sHeader.equals("Content-Length")) O[tvR:Nh  
{ f-DL:@crU  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Jk@]tAwoM  
break; 3LDS Z1f  
} --;@2:lg{  
} &'cL%.  
else vEf4HZ&w  
break; \(226^|j  
} 8fA_p}wp  
} mxor1P#|  
catch(IOException e){e.printStackTrace ();} !It`+0S b  
catch(Exception e){e.printStackTrace ();} %CWPbk^  
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Utility.log(nFileLength); 9T#;,{VQ  
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return nFileLength; zvABU+{jD  
} fYKOJ5f  
C{TA.\   
hxce\OuU0h  
//保存下载信息（文件指针位置） %ZHP2j %~  
private void write_nPos() "KcA  
{ n>@oBG)!  
try{ >WY#4  
output = new DataOutputStream(new FileOutputStream(tmpFile)); pv|Pm  
output.writeInt(nStartPos.length); 6'\6OsH  
for(int i=0;i<nStartPos.length;i++) %%(R@kh9  
{ ^N8)]F,  
// output.writeLong(nPos); &zs'/xv]  
output.writeLong(fileSplitterFetch.nStartPos); DNGvpKY@  
output.writeLong(fileSplitterFetch.nEndPos); +`3!I  
} UK9@oCIB  
output.close(); +P.+_7+:  
} ^C2\`jLMY  
catch(IOException e){e.printStackTrace ();} U,nEbKJgk  
catch(Exception e){e.printStackTrace ();}  KWLbD#  
} X,9 M"E 2  
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EC
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//读取保存的下载信息（文件指针位置） l5L.5$N  
private void read_nPos() ^vG8#A}]  
{ <uj8lctmP  
try{ pp9Zb.D\  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile));
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int nCount = input.readInt(); wAnb Di{W  
nStartPos = new long[nCount]; !w&kyW?e  
nEndPos = new long[nCount]; re> rr4@  
for(int i=0;i<nStartPos.length;i++) @&[T _l  
{ @A)R_p  
nStartPos = input.readLong(); 2NB L}x  
nEndPos = input.readLong(); qJ0fQI\  
} )BRKZQN  
input.close(); eh"3NRrN  
} |_ua
S  
catch(IOException e){e.printStackTrace ();} \U@rg4  
catch(Exception e){e.printStackTrace ();} ?-1r$31p  
} &=4(l|wcg  
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private void processErrorCode(int nErrorCode) sXNb}gJ  
{ CbN!1E6).  
System.err.println("Error Code : " + nErrorCode); #s!'+|2n  
} ]9\!;Bz^J  
P./VmY'  
{3&|tk!*  
//停止文件下载 QBR=0(giF  
public void siteStop() Rb\6;i8R  
{ fxgr`nC  
bStop = true; mFHH515  
for(int i=0;i<nStartPos.length;i++) `5H$IP1XhA  
fileSplitterFetch.splitterStop(); `"%T=w  
;E'"Ks[GH  
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} q%ow/!\;  
} $0arz{Oh  
//负责部分文件的抓取 +f[ED4E>'(  
**FileSplitterFetch.java !0N7^Z"gtz  
*/ 37;$-cFE  
package NetFox; jM\*A#Jo5  
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`9 {mr<  
import java.io.*; 1T:Y0  
import java.net.*; -,["c9'3  
Iy }:F8F>g  
2.d|G`  
public class FileSplitterFetch extends Thread { |{,KRO0P  
^FnfJ:  
 x]z2Z*  
String sURL; //File URL @BNEiOAZ#  
long nStartPos; //File Snippet Start Position p019)X|vx  
long nEndPos; //File Snippet End Position 1Z,[|wJ  
int nThreadID; //Thread's ID ^Idle*+  
boolean bDownOver = false; //Downing is over C)cwAU|h#  
boolean bStop = false; //Stop identical /Wf^hA  
FileAccessI fileAccessI = null; //File Access interface JsotO
ic%  
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vl}  
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException zq%D/H6J,  
{ frBX{L  
this.sURL = sURL; ,\v91Rp~?  
this.nStartPos = nStart; &7_Qd4=08w  
this.nEndPos = nEnd; Ja ,Cvt  
nThreadID = id; k^OV56  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +}-@@,  
} Zy_V9j[n  
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+&["HoKg}&  
public void run() b=/curl&  
{ H)(:8~c,p  
while(nStartPos < nEndPos && !bStop)
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{ mXXt'_"  
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try{ CA +uKM^"6  
URL url = new URL(sURL); n3sUbs;
 
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *OyHHq|>q  
httpConnection.setRequestProperty("User-Agent","NetFox"); vp.ZK[/`  
String sProperty = "bytes="+nStartPos+"-"; M2U&?V C!  
httpConnection.setRequestProperty("RANGE",sProperty); SvR7eC  
Utility.log(sProperty); E#F/88(  
1LJUr"6]  
v 36%Pj`  
InputStream input = httpConnection.getInputStream(); ^H6<Km l/V  
//logResponseHead(httpConnection); b?eu jxqg  
ooV*I|wcI  
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byte[] b = new byte[1024]; ce6__f5?  
int nRead; EJ`T$JD  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) r `eU~7  
{ Ig5L$bAM~  
nStartPos += fileAccessI.write(b,0,nRead);
q=lAb\i  
//if(nThreadID == 1) J6jwBo2m  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Lq>&d,F06)  
} @ps1Dr4s  
C4NTh}6tT  
]#.]/f >-  
Utility.log("Thread " + nThreadID + " is over!"); R-:fd!3oQ  
bDownOver = true; %2V-~.Ro6  
//nPos = fileAccessI.write (b,0,nRead); N&[D>
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} 0dh=fcb  
catch(Exception e){e.printStackTrace ();} 98.>e  
} sFBneBub  
} d`1I".y  
A0%}v*  
FaBqj1O1  
//打印回应的头信息 nbG/c80  
public void logResponseHead(HttpURLConnection con) MfmACd^3$  
{ q%5eVG  
for(int i=1;;i++) :eZh'-c?  
{ fQP{|+4  
String header=con.getHeaderFieldKey(i); b$eXFi/  
if(header!=null) A*|cdY]HP  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); {vo +gRYYv  
Utility.log(header+" : "+con.getHeaderField(header)); O 1oxZj <  
else B(F,h+ajy  
break; ?2Kt'1s#  
} j w* IO  
} 9 fMau  
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6; Y0a4Ax  
public void splitterStop() >O5m5@GK3a  
{ vLxQ *50v$  
bStop = true; }$\M{#C~  
} d(:3
  
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} 4:9KR[y/  
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MZ+e}|!4,  
/* AfC>Q!-
w  
**FileAccess.java @/&b;s73  
*//文件访问(定位，写)  9dzdrT  
package NetFox; mQ}ny(K'  
import java.io.*; >\w&6i~  
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public class FileAccessI implements Serializable{ 8z5# ]u;  
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//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Y q
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RandomAccessFile oSavedFile; \Ey~3&x9f  
long nPos; -|Kzo_" v5  
_8G>&K3T<  
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public FileAccessI() throws IOException gh6d&ucQ^  
{ U.T|   
this("",0); Iak0 [6Ey  
} [_xyl e  
c<#
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oVCmI"'  
public FileAccessI(String sName,long nPos) throws IOException Lhh;2r/?78  
{ 7~M<cD  
oSavedFile = new RandomAccessFile(sName,"rw"); O3V.^_k;  
this.nPos = nPos;  BGzI  
oSavedFile.seek(nPos); m=qOg>k  
} <5@PWrU?[[  
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n
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public synchronized int write(byte[] b,int nStart,int nLen) "8V{5e!%j'  
{ BKU'`5`  
int n = -1; ( #&|Dp^'  
try{ }%{MPqg  
oSavedFile.write(b,nStart,nLen); mCKk*5ws5"  
n = nLen; \.e4.[%[2-  
} 7 gB{In0  
catch(IOException e) p2x[
p  
{ em2_pq9q  
e.printStackTrace (); EP7AP4  
} 9h
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I_ "Z:v{  
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return n; |sgXh9%x<  
} @kD8^,(oH  
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F  
+
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} "r.2]R3  
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/* e&X>F"z2  
**SiteInfoBean.java #I`ms$j%  
*/ w\|Ei(  
package NetFox; g8pm2o@S  
UCqs}U8  
1(`M~vFDK  
public class SiteInfoBean {  YRB%:D@u  
#w3ru6*W  
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private String sSiteURL; //Site's URL <6N_at3  
private String sFilePath; //Saved File's Path DOm-)zl{|x  
private String sFileName; //Saved File's Name <d$A)S};W  
private int nSplitter; //Count of Splited Downloading File ^>r^3C)_-  
E;-qP)yU  
=v"xmx&4  
public SiteInfoBean() %]Cjhs"v  
{//nSplitter的缺省值为5 ^GXEJU7U  
//default value of nSplitter is 5 'm1.X-$V  
this("","","",5); 
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} ,# "(Z  
rpU/s@%L  
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public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) y' tRANxQ  
{ ,8SWe  
sSiteURL= sURL; kHU"AD}.  
sFilePath = sPath; P%GkcV  
sFileName = sName; *)PG-$6X&  
this.nSplitter = nSpiltter; ZzL@[g  
J@bW^>g*6u  
{^&k!H2  
} )W9_qmYd"  
],?pe  
{,V$*  
public String getSSiteURL() o8D{dS>,PL  
{ U1^l+G^,~  
return sSiteURL; ;nf&c;D  
} ^('cbl  
(@?eLJlT  
<
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public void setSSiteURL(String value) jT"r$""1d  
{ v!!;js^  
sSiteURL = value; '(9YB9 i  
}  [`bZ5*&  
83?1<v0%  
zv9MHC &  
public String getSFilePath() j1Fw U  
{ y$h"ty{g  
return sFilePath; 3B"7VBK{  
} <%rh/r  
'8Qw:fh  
KZi'v
6  
public void setSFilePath(String value) Z%;)@0~f  
{ {tmKCG  
sFilePath = value; _jDS"  
} 4[_L=zD  
NY 4C@@"  
:s-EG;.  
public String getSFileName()
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{ '2wCP EC  
return sFileName; w#
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} DOT=U _  
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@4&, #xo  
public void setSFileName(String value) Y^X:vI  
{ bu&;-Ynb
 
sFileName = value; /Bm#`?(ia  
} >.LgsMRIKi  
"kU>~~y,  
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public int getNSplitter() 'hy?jQ'|e  
{ >KKeV(Ur  
return nSplitter; psu OJ-  
}
jwq\stjD  
n{L:MT9TD  
CQ$::;  
public void setNSplitter(int nCount) ~JAjr(G#o  
{ \a?K?v|8  
nSplitter = nCount; Hw y5G;  
} u7n[f@Eg,%  
} RrKfTiK H  
k)|'JDm  
\hrrPPD1z  
/* "bPCOJ[v9  
**Utility.java &adY  
*/ hEWx.  
package NetFox; Z@}sCZ=#A  
@81-kdTx  
|PI)A`  
public class Utility { A*a7\id!y  
]GQv4-y  
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public Utility() H_Iim[v#  
{ 7Pwg+|  
';&0~[R[  
r|*:9|y{"/  
} sfyBw  
*wViH  
//线程睡眠 cES;bwQ  
public static void sleep(int nSecond) : #3OcD4  
{ mm_^gQ,`  
try{ r@olC7&  
Thread.sleep(nSecond); V_Xy2<V  
} S|~i>  
catch(Exception e)  qe[  
{ MJ1W*'9</W  
e.printStackTrace (); ZEL/Ndk  
} C5>{Q:.`e'  
} T}V7SD.  
4sj9Z:  
//日志 B{;11u  
public static void log(String sMsg) P\,F1N_?r  
{ A *a{  
System.err.println(sMsg); [&1iF1)4  
} g4zT(,ZY  
}Vs~RJM)}  
iPA@<D%  
public static void log(int sMsg) C]yvK}  
{ tU9rCL:P  
System.err.println(sMsg); 8dr0 DF$c  
} _u#/u2<  
} :5r:I[FFy  

\#uqD\DE  
aw%>YrJ  
/* bs:C1j\&  
**TestMethod.java (xucZ  
*/ ' %bj9{(0  
package NetFox; bk/.<Rt  
#rh0r`  
!JT<(I2  
public class TestMethod { ~+nS)4(  
d [\>'>  
mJwv&E  
public TestMethod() vN{vJlpY  
{ ///xx/weblogic60b2_win.exe &@mvw=d  
try{ Gh>
"s#+  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); SlH7-"Ag  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?9o#%?6k  
SiteFileFetch fileFetch = new SiteFileFetch(bean); [{6&.v  
fileFetch.start(); *D,v>(  
} wo,""=l  
catch(Exception e){e.printStackTrace ();} >GdLEE'w  
2jI4V;H8g  
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} [+%p!T  

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Hl%+F0^?  
public static void main(String[] args) iqU.a/~y  
{ [15hci+-  
new TestMethod(); ]pM5?^<~  
} Q1N,^71  
} &5kjjQ*HB  
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