http断点续传简单实现（java)

/* AH`15k_i  
**SiteFileFetch.java Kzb@JBIF  
*/ Wy4^mOv  
package NetFox; V\"5<>+O  
import java.io.*; hkJZqUA  
import java.net.*; vo$66A  
/4?`F}7)  
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public class SiteFileFetch extends Thread { =#tQIhX`  
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SiteInfoBean siteInfoBean = null; //文件信息Bean 5avO48;Vc  
long[] nStartPos; //开始位置 u\xm8}A  
long[] nEndPos; //结束位置 `$H  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 M@kZ(Rkv  
long nFileLength; //文件长度 qJA.+q.e$e  
boolean bFirst = true; //是否第一次取文件 CiuN26>  
boolean bStop = false; //停止标志 }#8uXA  
File tmpFile; //文件下载的临时信息
? st#6=M  
DataOutputStream output; //输出到文件的输出流 0I((UA/7Zs  
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//负责整个文件的抓取，控制内部线程（FileSplitterFetch类） b..$5  
public SiteFileFetch(SiteInfoBean bean) throws IOException Z-|C{1}A  
{ \DqxS=o;  
siteInfoBean = bean; vI'>$
 
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ~-`02  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Bs?
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if(tmpFile.exists ()) |esjhf}H>v  
{ fO
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bFirst = false; u`@f~QP0  
read_nPos(); 8~E)gV+v  
} ;#
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else MPbPq3an  
{ (OB8vTRXP  
nStartPos = new long[bean.getNSplitter()]; r6JkoPMh  
nEndPos = new long[bean.getNSplitter()]; pXv[]v  
} %KF:- w  
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z  
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} >8fH5  
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public void run() 9M]"%E!s  
{ W_\L_)^X  
//获得文件长度 J~3T8e#  
//分割文件 (Fzh1#  
//实例FileSplitterFetch lzG;F]  
//启动FileSplitterFetch线程 `HG19_Z  
//等待子线程返回 4QAIQQS  
try{ k!=GNRRZE  
if(bFirst) r)(BT:2m  
{ X'7S|J6s  
nFileLength = getFileSize(); jHH  
if(nFileLength == -1) O/9%"m:i  
{ WG !t!1p  
System.err.println("File Length is not known!"); rs Uw(K^  
} @z
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else if(nFileLength == -2) ""3m!qn#  
{ ^YJA\d@  
System.err.println("File is not access!"); WWW#s gM%  
} { $/Fk6qr  
else >JPJ%~y  
{ }.UI&UZ-  
for(int i=0;i<nStartPos.length;i++) M#]|$\v(  
{ 1L8ULxi_?]  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); !u4Z0!Ll  
} 5`'=Ko,N  
for(int i=0;i<nEndPos.length-1;i++) 9C}aX}`  
{ 4c[)}8\  
nEndPos = nStartPos[i+1]; t!~YO'<dS  
} mqk(UOK`  
nEndPos[nEndPos.length-1] = nFileLength; ' P`p.5nH  
} t"/"Ge#a  
} WG/J4H`Od  
5A$az03y$\  
$;uWj|  
//启动子线程 .xkV#ol  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; KHecc/,,S  
for(int i=0;i<nStartPos.length;i++) 8@yc}~8 *  
{
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fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;Z1U@2./  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), DJYXC,r  
nStartPos,nEndPos,i); QeeC2  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7Sz'vyiz  
fileSplitterFetch.start(); >'-w%H/  
} ix7 e])m(  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]9&q'7*L  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); `3y!XET  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (_qBsng:  
nEndPos = " + nFileLength); gSr}p$N  
// fileSplitterFetch[nPos.length-1].start(); uxC   
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(Ef2 w['  
//等待子线程结束 Mj B<\g>  
//int count = 0; )n}]]^Sc  
//是否结束while循环 4ZJT[zi  
boolean breakWhile = false; )yNw2+ ~5  
>}DjHLTW\  
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while(!bStop) 37O#aJ,K  
{ Uty(sDtu  
write_nPos(); {8#N7(%z  
Utility.sleep(500); `+hy#1]  
breakWhile = true; Md>f  
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for(int i=0;i<nStartPos.length;i++) w <#*O:  
{ ECS<l*i57&  
if(!fileSplitterFetch.bDownOver) ,/?%y\:J  
{ "T{~,'T  
breakWhile = false; 
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break; we\b]  
} 2JA&{c
h  
} %<w
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if(breakWhile) u3M`'YCb  
break; ^\vfos  
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//count++; v$)@AE  
//if(count>4) /=muj9|+s  
// siteStop(); D]pK=247  
} s-GleX<  
b#p~F}qT  
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System.err.println("文件下载结束！"); ayH%  qp  
} !$p2z_n$@.  
catch(Exception e){e.printStackTrace ();} ti{H(;;@  
} ?)?IZ Qj  
V#zhGAMy.  
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//获得文件长度 { OxAY_  
public long getFileSize() JA?,0S  
{ a(}VA|l  
int nFileLength = -1; +q #Xy0u  
try{ GP{$v:RG  
URL url = new URL(siteInfoBean.getSSiteURL());
"rjv5*z^&  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "#-Nqq  
httpConnection.setRequestProperty("User-Agent","NetFox"); mmrW`~-  
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int responseCode=httpConnection.getResponseCode(); nE]~E xr  
if(responseCode>=400) x2j/8]'o  
{ (o x4K{  
processErrorCode(responseCode); 2vqmsl?  
return -2; //-2 represent access is error %A)-m 69  
} oh7#cFZZ0  
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hl6,#2$  
String sHeader; /<(*/P,>  
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for(int i=1;;i++) ?418*tXd  
{ C.yY8?|  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); bK03S Vx  
//Utility.log(in.readLine()); #*yM2H"7,;  
sHeader=httpConnection.getHeaderFieldKey(i); ASzzBR;?_  
if(sHeader!=null) ^8?j
~&u$F  
{ ="3a%\  
if(sHeader.equals("Content-Length")) `a9k!3_L  
{ [cGt  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5
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break; _`bS[%CJ  
} QL)>/%yU  
} 1DEO3p  
else <a8#0ojm  
break; WF ?/GN  
} T!u'V'Ei2  
} zW"~YaO%C  
catch(IOException e){e.printStackTrace ();} a. h?4+^bN  
catch(Exception e){e.printStackTrace ();} xa87xX=a  
o &BPG@n  
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Utility.log(nFileLength); v}7@CP]nV  
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return nFileLength; RGT_}ni  
} 8w)e/*:j  
98ca[.ui  
6#E]zmXO2  
//保存下载信息（文件指针位置） 0s860Kn  
private void write_nPos() 0zeUP{MQ  
{ wzD\8_;6N  
try{ 2}^+]5  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 9 '2=  
output.writeInt(nStartPos.length); GN\8![J  
for(int i=0;i<nStartPos.length;i++) wl7 MfyU  
{ !2GHJHxv]c  
// output.writeLong(nPos); 7<h.KZPc  
output.writeLong(fileSplitterFetch.nStartPos); ixOEdQ  
output.writeLong(fileSplitterFetch.nEndPos); Y3-]+y%l  
} ' 2>l  
output.close(); 84iJ[F
q{  
} Z:I*y7V-  
catch(IOException e){e.printStackTrace ();} 0Vf)Rw1%I  
catch(Exception e){e.printStackTrace ();} B }6Kd  
} ~_ *H)|  
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//读取保存的下载信息（文件指针位置） /VRUz++K  
private void read_nPos() 3H1Pp*PH  
{ .|T2\M  
try{ *Y8XP8u/  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); jMK3T  
int nCount = input.readInt(); CXBzX:T?#  
nStartPos = new long[nCount]; 48wDf_<f5=  
nEndPos = new long[nCount]; YV*b~6{d  
for(int i=0;i<nStartPos.length;i++) j._G7z/LJ  
{ Kn']n91m  
nStartPos = input.readLong(); bX7EO 8  
nEndPos = input.readLong(); [!^cd%l  
} ows^W8-w  
input.close(); '4$lL6ly>  
} R"NGJu9  
catch(IOException e){e.printStackTrace ();} >OT\~C  
catch(Exception e){e.printStackTrace ();} LRWOBD  
} doLkrEm&
 
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private void processErrorCode(int nErrorCode) aIQOs  
{ ;U |NmC+  
System.err.println("Error Code : " + nErrorCode); (G#}*  
} /4yOs@#  
M /"gf;)q>  
6A}eSG3  
//停止文件下载 l$M$o(  
public void siteStop() ~ 9=27p  
{ }xqXd
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bStop = true; 4&|C}  
for(int i=0;i<nStartPos.length;i++) @\ }sb]  
fileSplitterFetch.splitterStop(); d5Qd'  
:ztyxJv1  
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} ^b=XV&{q  
} ?gLAWz  
//负责部分文件的抓取 =qw&dwIQ  
**FileSplitterFetch.java V7P6zAJy  
*/ oB4#J*  
package NetFox; .vK.XFZ8R  
;J'OakeVO  
c)03Ms4 D  
import java.io.*; _D-5}a"  
import java.net.*; eO'xkm  
)`<6taKx@n  
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public class FileSplitterFetch extends Thread { #'C/Gya  
~^x-ym5  
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String sURL; //File URL B3Mx,uXT\  
long nStartPos; //File Snippet Start Position f4 Q( 1(C  
long nEndPos; //File Snippet End Position [g+y_@9s  
int nThreadID; //Thread's ID mk\i}U>`  
boolean bDownOver = false; //Downing is over _e_4Q)z-a  
boolean bStop = false; //Stop identical x:qr\Rz  
FileAccessI fileAccessI = null; //File Access interface H-Pq!9[DB  
6%%PP8
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2% %
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException l]$40 j  
{ U%q:^S%#eG  
this.sURL = sURL; WV2~(/hX&  
this.nStartPos = nStart; v{.\iIg N  
this.nEndPos = nEnd; O] H=s  
nThreadID = id; _#FIay\ahB  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 E3f9<hm  
} TMww  
{ UOhVJy  
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public void run() YN^T$,*  
{ {
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while(nStartPos < nEndPos && !bStop) R4SxFp  
{ _jmkl B  
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try{ *0~M
 
URL url = new URL(sURL); n$YE !D'  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2m\m/O  
httpConnection.setRequestProperty("User-Agent","NetFox"); F@1d%c  
String sProperty = "bytes="+nStartPos+"-"; "<x&pQZ%  
httpConnection.setRequestProperty("RANGE",sProperty); ~0ooRUWU7  
Utility.log(sProperty); $3 4j6;oN  
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InputStream input = httpConnection.getInputStream(); e/>:K' {  
//logResponseHead(httpConnection); @zrNN>  
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# kEOKmO  
byte[] b = new byte[1024]; TP{Gt.e  
int nRead; (Xo

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while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) MRs,l'  
{ G?/c/rG  
nStartPos += fileAccessI.write(b,0,nRead); UiIF6-ZZ!  
//if(nThreadID == 1) _f3 WRyN0  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U CRAw3=  
} _q)!B,y-/N  
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Utility.log("Thread " + nThreadID + " is over!"); {zP#woz2Q  
bDownOver = true; 0[)VO[  
//nPos = fileAccessI.write (b,0,nRead); PrSkHxm  
} DbtF~`3, .  
catch(Exception e){e.printStackTrace ();} 5V@&o`!=h  
} s}ADk-7  
} JKy#j g:#  
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//打印回应的头信息 EZib1g&:R/  
public void logResponseHead(HttpURLConnection con) 7~b!4x|Z  
{ !)c=1EX]"  
for(int i=1;;i++) ],[)uTZc  
{ -CD\+d "  
String header=con.getHeaderFieldKey(i); ^i'y6J  
if(header!=null) K%gP5>y*9>  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); rY,PSK/j  
Utility.log(header+" : "+con.getHeaderField(header)); 7Ms90oE/c  
else etyCrQ ?U  
break; c@(1:,R  
} hH`Jb77L  
} @o#+5P  
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public void splitterStop() %LQ/q3?_  
{ n+;vjVS%  
bStop = true; P+Z\3re  
} JMlV@t7y<  
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cJ
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} //.>>-~1m  
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/* 0pN{y}x,  
**FileAccess.java 3taa^e.  
*//文件访问(定位，写) 3SNL5  
package NetFox; a2yE
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import java.io.*; eN/G i<  
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public class FileAccessI implements Serializable{ l}}UFEA^  
*eUc.MX6x  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~Ltr.ci  
RandomAccessFile oSavedFile; mxJXL":|  
long nPos; u9]1X1wV  
&?+WXL>  
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public FileAccessI() throws IOException } 
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{ %0XvJF)s  
this("",0); "8(U\KaX  
} eH <Jng  

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public FileAccessI(String sName,long nPos) throws IOException Mo^`\/x!  
{ f=aIXhiYU  
oSavedFile = new RandomAccessFile(sName,"rw"); 8_xLl2  
this.nPos = nPos; ;%zC@a~{  
oSavedFile.seek(nPos); oT&m4I  
} `Ko[r R+  
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!/
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public synchronized int write(byte[] b,int nStart,int nLen) 2P9J' L  
{ 8S  U%  
int n = -1; n?E}b$6  
try{ c Zvf"cIs  
oSavedFile.write(b,nStart,nLen); $|a;~m>  
n = nLen; ue0s&WF|  
}
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catch(IOException e) T*CME]  
{ Gt~JA0+C)7  
e.printStackTrace (); nQ=aLV+'  
} Eg8i _s~:  
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return n; '4u v3)P  
} }9&9G%  
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}
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/* <DZcra  
**SiteInfoBean.java yA;W/I4  
*/ YV([2  
package NetFox; 8;n_TMb  
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 `w<J25  
public class SiteInfoBean { QUOKThY?  
sN/+   
l
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private String sSiteURL; //Site's URL `# ^0cW  
private String sFilePath; //Saved File's Path QxpKX_@Q5  
private String sFileName; //Saved File's Name YYUe)j{T  
private int nSplitter; //Count of Splited Downloading File #Ufo)\x  
213\ehhG<  
>Ko[Xb-8^_  
public SiteInfoBean() \=nrt?  
{//nSplitter的缺省值为5 36$[  
//default value of nSplitter is 5 o""~jc~  
this("","","",5); KCtX$XGL  
} u\g,.C0  
.\)A@ua^  
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public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9UD @MA  
{ Q`6i=mB;  
sSiteURL= sURL; P(ZQDTbM :  
sFilePath = sPath; (|u31[  
sFileName = sName; TlRk*/PlJ  
this.nSplitter = nSpiltter; NQLiWz-q  
5Op_*N{V  
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} qnIew?-*  
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i_l+:/+G+  
public String getSSiteURL() M{KW@7j  
{ flnVYQe  
return sSiteURL; 8MF2K6  
} fN[8N$1-  
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public void setSSiteURL(String value) m#H_*L0  
{ TV:<TR  
sSiteURL = value; j _ ;fWBD:  
} z<n-Gzwk  
tXq)nfGe{  
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public String getSFilePath() IXq(jhm8bL  
{ l(:kfR~AC  
return sFilePath; 2\@Z5m3B  
} &/WAZs$2n  
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public void setSFilePath(String value) %ROwr[Dj=  
{ [Z<Z;=t  
sFilePath = value; |NMO__l@  
} w^;DG
   
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public String getSFileName() @d&H]5  
{ ?R'Y?b  
return sFileName; # cFr   
} TFH&(_b  
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public void setSFileName(String value) q7Es$zjX  
{ _vl}*/=Hc  
sFileName = value; 4JMiyiW&  
} X0uJNHO  
yyP-=Lhmo=  
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public int getNSplitter() };katqzEg  
{
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return nSplitter; z2 hFn&  
}
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public void setNSplitter(int nCount) k`VM2+9h'^  
{ $c9k*3{<+A  
nSplitter = nCount; Tlsa%pn  
} %oof}=MxCL  
} mP^SS Je  
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/* ?IW_O~Js  
**Utility.java pJ^NA2  
*/ }iww:H-1  
package NetFox; Mi0sC24b|  
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S
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public class Utility { 63&^BW  
Lp&k3?W  
:qj<p3w~}  
public Utility() q,l)I+  
{ X.#oEmA,P  
(03pJV&K  
8]"(!i_;)  
} r4{<
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|g&ymFc  
//线程睡眠 [EZYsOr.  
public static void sleep(int nSecond) %&+59vq   
{ HuI`#.MpWE  
try{ \8v91g91
f  
Thread.sleep(nSecond); h*l&RR:i  
} W!la-n  
catch(Exception e) 1mgLX_U9  
{ Op}ZB:  
e.printStackTrace (); GDhM<bVqM*  
} U@-2Q=  
} M\2"gT-LV  
WxUxc75  
//日志 %dttE)oH?  
public static void log(String sMsg) cxyM\@QB3  
{ FxW&8 9G  
System.err.println(sMsg); B$a-og(  
} 8OFj0S1r`  
\:_3i\2p  
4^Rd{'mt  
public static void log(int sMsg)
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{ nHst/5dA  
System.err.println(sMsg); < n?=|g  
} cy3Td28,  
} EbK0j?  
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\~DM  
/* gPXa>C  
**TestMethod.java :E_a0!'  
*/ j,-C{ K  
package NetFox; /iQ(3
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m VxO$A,  
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public class TestMethod { 0Y+FRB]u  
${r[!0|  
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public TestMethod() "&o,yd%  
{ ///xx/weblogic60b2_win.exe 2xxB\J  
try{ 9Sg<K)Mc  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >hsuAU.UOR  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); )N!>=  
SiteFileFetch fileFetch = new SiteFileFetch(bean); =JO^XwUOo  
fileFetch.start(); Paf%rv2  
} |%7cdMC  
catch(Exception e){e.printStackTrace ();} `:|@Zln  
tY/vL^mi  
+pmu2}E.3  
} L'A)6^d@S  
+}kgQ^  
#/-_1H  
public static void main(String[] args) ;`j/D@H  
{ X
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new TestMethod(); 1y"3  
} ^Z,q$Gp~P  
} l* dV\ B  
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