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: !A>VzW
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CountBean.java j\w>}Pc
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/* I0\}S [+H
* CountData.java -"L)<J@gQ?
* D7Y5q*F
* Created on 2007年1月1日, 下午4:44 <&'Y e[k
* QC:/xP
* To change this template, choose Tools | Options and locate the template under \Yv<TzJ9
* the Source Creation and Management node. Right-click the template and choose W68d"J%>_
* Open. You can then make changes to the template in the Source Editor. A:"J&TbBx
*/ G>hmVd
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package com.tot.count; %9|=\#
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/** G@Dw
* 0`X%&
* @author 1\d$2N"
*/ \FOX#|i)
public class CountBean { W'{q
private String countType; g%w@v$
int countId; #80*3vi~F
/** Creates a new instance of CountData */ zT}Q rf~
public CountBean() {} :=#*[H
public void setCountType(String countTypes){ >/Z#{;kOz
this.countType=countTypes; Meh?FW||5
} qL^}t_>
public void setCountId(int countIds){ W%]sI n
this.countId=countIds; 6p/gvpZ
} 7lpd$Y
public String getCountType(){ aE^tc'h~
return countType; ?v2OoNQ
} 3Lwl~h!
public int getCountId(){ dG{`Jk
return countId; pk'@!|g%=
} w $7J)ngA9
} ?U0iHg{
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CountCache.java t"1'B!4
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/* u!2.[CV
* CountCache.java lv}U-vK
* "r0z(j
* Created on 2007年1月1日, 下午5:01 1QRE-ndc
* P9J3Ii!
* To change this template, choose Tools | Options and locate the template under 8|[\Tp:;
* the Source Creation and Management node. Right-click the template and choose 78tWzO
* Open. You can then make changes to the template in the Source Editor. amf=uysr
*/ 5Ah-aDBj
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package com.tot.count; =K2Dxu_:
import java.util.*; uPe4Rr
/** lh*m(
* =5&)^
* @author \S;%
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*/ wxZnuCO%H8
public class CountCache { fiTMS:
public static LinkedList list=new LinkedList(); fmie,[
/** Creates a new instance of CountCache */ jG{}b6
public CountCache() {} S>7Zq5*
public static void add(CountBean cb){ my")/e
if(cb!=null){ $JmL)r
list.add(cb); 7|6tH@4Ub
} O#A1)~
} (7
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} PK C``+Ki
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CountControl.java >c7/E
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/* bi!4I<E>k
* CountThread.java <Q=ES,M
* ^e8R43w:!
* Created on 2007年1月1日, 下午4:57 5h[u2&;G
* p)tac*US
* To change this template, choose Tools | Options and locate the template under QN-n9f8
* the Source Creation and Management node. Right-click the template and choose CzzG
* Open. You can then make changes to the template in the Source Editor. +nd'Uf
*/ lf|e8kU\f
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package com.tot.count; 'KQ]7
import tot.db.DBUtils; W<2%J)N<
import java.sql.*; K_`*ZV{r
/** w;QDQ
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* $E|W|4N
* @author #`GW7(M
*/ 5 LX3.
public class CountControl{ z$G?J+?J
private static long lastExecuteTime=0;//上次更新时间 p%IR4f
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 >^:g[6Sj
/** Creates a new instance of CountThread */ D4'?
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public CountControl() {}
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public synchronized void executeUpdate(){ 0P/A
Connection conn=null; O(
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PreparedStatement ps=null; w0SzK-&
try{ YO!,m<b^u
conn = DBUtils.getConnection(); =
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conn.setAutoCommit(false); q~trn'X>
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); |!%A1 wp#
for(int i=0;i<CountCache.list.size();i++){ *U54x
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CountBean cb=(CountBean)CountCache.list.getFirst(); QVn0!R{
CountCache.list.removeFirst(); {r&M
ps.setInt(1, cb.getCountId()); -xXNzC
ps.executeUpdate();⑴ d(wqKiGwe
//ps.addBatch();⑵ wt2S[:!p
} 3N+P~v)T'
//int [] counts = ps.executeBatch();⑶ /F;*[JZIb
conn.commit(); . F#mT h
}catch(Exception e){ Q77qrx3
e.printStackTrace(); 8kJ k5
} finally{ ` N(.10~
try{ 8<n8joO0
if(ps!=null) { 9,`mH0jP
ps.clearParameters(); 2+=|!+f
ps.close(); HC{|D>x.
ps=null; />ob*sk/Y
} YGWb!|Z$
}catch(SQLException e){} +1d\ZZA|6&
DBUtils.closeConnection(conn); V"$t>pAG
} Sa,N1r
} C2<y(GU[Bh
public long getLast(){ NYP3uGH]
return lastExecuteTime; -&)^|Atm
} ,;+\!'lS
public void run(){ 7Wb.(` a<
long now = System.currentTimeMillis(); A^ ,(Vyd
if ((now - lastExecuteTime) > executeSep) { "fpj"lf-
//System.out.print("lastExecuteTime:"+lastExecuteTime); ]nX.zE|F
//System.out.print(" now:"+now+"\n"); >.{
..~"K
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); (X!/tw,.
lastExecuteTime=now; p~8~EQFj
executeUpdate(); X3W)c&Pr
} @1]<LQ\\
else{ +ypG<VBx%
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); \=N
tbBL$[
} SOK2{xCG
} 9Biw!%a
} >t D-kzN
//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 ik$wS#1+L
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类写好了,下面是在JSP中如下调用。 =R>Sxaq
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<% p1?}"bHk
CountBean cb=new CountBean(); 3~cOQ%#]4
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); A^K,[8VX
CountCache.add(cb); M%B[>pONb7
out.print(CountCache.list.size()+"<br>"); l m
CountControl c=new CountControl(); e-e{-pB6
c.run(); NPoXz
out.print(CountCache.list.size()+"<br>"); }qKeX4\-
%>