有时要为每一篇文章统计其点击次数,如果每一次浏览都要更新一次库的话,那性能在访问量很大的情况下,服务器的压力就会很大了,比较好一点的方法就是先将要更新的数据缓存起来,然后每隔一段时间再利用数据库的批量处理,批量更新库。源码如下: g)D_!iz
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CountBean.java yIMqQSt79z
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/* WjV15\,
* CountData.java K2
* ]MbPivM
* Created on 2007年1月1日, 下午4:44 I=Y>z^4
* (i1JRn-f
* To change this template, choose Tools | Options and locate the template under K=g</@L6R
* the Source Creation and Management node. Right-click the template and choose t}EMX9SQ
* Open. You can then make changes to the template in the Source Editor. qe~x?FO_>
*/ wp[Ug2;G
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package com.tot.count;
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/** okNo-\Dh!
* ?1e{\XW
* @author ;JW_4;-
*/ QTV*m>D
public class CountBean { .n-#A
private String countType; JKfG/z|
int countId; FL0uY0K
/** Creates a new instance of CountData */ %u -x9
public CountBean() {}
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public void setCountType(String countTypes){ E8Dh;j
this.countType=countTypes; yU? jmJ
} ; *
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public void setCountId(int countIds){ ~Bd=]a$mj
this.countId=countIds; $o^Z$VmL
} ,Kit@`P%
public String getCountType(){ 8`Ya7c>
return countType; cNs'GfD}
} !3v&+Jrf6
public int getCountId(){ (~T*yH ~
return countId; tYS4"Nfb+
} iCt.rr~;V
} ZzT=m*tQ&
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CountCache.java 5of3&
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/* I<SgKva;c
* CountCache.java k$EVr([
* K|& f5w
* Created on 2007年1月1日, 下午5:01 zmMc*|
* Mf}M/Fh
* To change this template, choose Tools | Options and locate the template under wBPo{
* the Source Creation and Management node. Right-click the template and choose ITu19WG
* Open. You can then make changes to the template in the Source Editor. YFKE>+
*/ G)3I+uxn
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package com.tot.count; *Ak .KBg
import java.util.*; f0<zK!
/** ~MpikBf
* IG-\&
* @author N^^0j,
*/ :5d>^6eoB?
public class CountCache { K%^n.
public static LinkedList list=new LinkedList(); BHXi g~d
/** Creates a new instance of CountCache */ ^5mc$~1`
public CountCache() {} L9x-90'q,
public static void add(CountBean cb){ v
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if(cb!=null){ n,la<N]
list.add(cb); Bq0 \T
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} /--p#G h'
} bOY;IB
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} gk ]QR.
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CountControl.java @=J|%NO
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/* 4s\spvJ
* CountThread.java (IJNBJb
* _|HhT^\P
* Created on 2007年1月1日, 下午4:57 3v* ~CQy9
* QYJ
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* To change this template, choose Tools | Options and locate the template under cHFi(K]|1
* the Source Creation and Management node. Right-click the template and choose 8*ZsR)!
* Open. You can then make changes to the template in the Source Editor. rIb+c=|F
*/ Vej$|nF
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package com.tot.count; O5\r%&$xd
import tot.db.DBUtils; _z5/&tm_H
import java.sql.*; pO]gf$
/** zF&VzNR2
* %36x'Dn?
* @author }xZi Ct
*/ :yay:3qv
public class CountControl{ h8rW"8Th
private static long lastExecuteTime=0;//上次更新时间 6&3,fSP
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 !,4ag1
/** Creates a new instance of CountThread */ V0ze7tSG[f
public CountControl() {} 8^mE<
public synchronized void executeUpdate(){ |rm elQ-
Connection conn=null; kmB!NxF>)F
PreparedStatement ps=null; !^J;S%MB:K
try{ !iXRt" )
conn = DBUtils.getConnection(); \1EuHQ?
conn.setAutoCommit(false); lU
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 7Z-j'pq
for(int i=0;i<CountCache.list.size();i++){ Z%T Ajm
CountBean cb=(CountBean)CountCache.list.getFirst(); 9tiZIm93]
CountCache.list.removeFirst(); g40Hj Y
ps.setInt(1, cb.getCountId()); OATdmHW
ps.executeUpdate();⑴ jm0p%%z
//ps.addBatch();⑵ _=v#"l
} ]5!3|UYS
//int [] counts = ps.executeBatch();⑶ OG\i?N
conn.commit(); lFBdiIw
}catch(Exception e){ Aq i:h]x
e.printStackTrace(); +X?ErQm
} finally{ ~ELY$G.xl
try{ =w2 4(S
if(ps!=null) { XN<SKW(H3
ps.clearParameters(); K+g[E<x\=
ps.close(); #A63?kDE&&
ps=null; 8-$t7bV5
} _0H oJ
}catch(SQLException e){} 0zt]DCdY
DBUtils.closeConnection(conn); dj gk7
} ZR.k'
} !\4x{Wa]
public long getLast(){ &(F
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return lastExecuteTime; g` rr3jP
} 4;`z6\u9-
public void run(){ ~/OY1~c
long now = System.currentTimeMillis(); w$2q00R>
if ((now - lastExecuteTime) > executeSep) { F!z0N
//System.out.print("lastExecuteTime:"+lastExecuteTime); .ZXoRT
//System.out.print(" now:"+now+"\n"); 1 $E(8"l
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); g?j)p y
lastExecuteTime=now; FaHOutP
executeUpdate(); 5Rqdo\vE
} /Vlc8G
else{ "k zKQ~
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); *D5 xbkH=.
} I16FVdUun4
} ;Iu _*U9)
} Met?G0[
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 K.tNV{OL
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类写好了,下面是在JSP中如下调用。 dwj?;
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<% $H:!3-/
CountBean cb=new CountBean(); ?d')#WnC
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); EOPx4+o
CountCache.add(cb); V"Q\7,_k.
out.print(CountCache.list.size()+"<br>"); GT{4L]C
CountControl c=new CountControl(); 72HA.!ry
c.run(); D%SOX N
out.print(CountCache.list.size()+"<br>"); #~0Nk6*u
%>