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: ^]^Y~$u
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CountBean.java $zbm!._~DA
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/* !NK8_p|X
* CountData.java EUmQn8
* .Ff;St
* Created on 2007年1月1日, 下午4:44 XCoN!~
* R>BI;IcX
* To change this template, choose Tools | Options and locate the template under =El.uBz{
* the Source Creation and Management node. Right-click the template and choose ^%|{>Mz;c
* Open. You can then make changes to the template in the Source Editor. f8_5.vlw
*/ YMad]_XOP
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package com.tot.count; d4/snvq
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/** 3>yb$ZU"-
* fyT:I6*
* @author *-T3'beg
*/ ()v[@"J
public class CountBean { /"tVOv#
private String countType; $}2m%$vJO
int countId; o5mt7/5[i
/** Creates a new instance of CountData */ .?CDWbzq
public CountBean() {} -#j-Zo+<
public void setCountType(String countTypes){ cIK-VmO
this.countType=countTypes; 7EOn4I2@[
} 2sjV*\Udf
public void setCountId(int countIds){ 1$?O5.X:
this.countId=countIds; 5W>i'6*
} ypwVzCUG
public String getCountType(){ Duj9PV`2
return countType; 8fTuae$^
} Yq4_ss'nB
public int getCountId(){ G9:[W"P
return countId; prb;q~
} 20d[\P(.
} f8+($Ys
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CountCache.java ~EW
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/* nYY@+%`]z
* CountCache.java \gki!!HQ
* Nj*J~&6G
* Created on 2007年1月1日, 下午5:01 U:~O^
* !FZb3U@
* To change this template, choose Tools | Options and locate the template under
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* the Source Creation and Management node. Right-click the template and choose YMj
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* Open. You can then make changes to the template in the Source Editor. ueDG1)
*/ k]lM%
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package com.tot.count; *5hg}[n2
import java.util.*; !h}x,=`z/
/** ]}i_Nq W)
* V9I5/~0c
* @author @sav8]
*/ 3%|LMX]M5_
public class CountCache { 2Prr:k
public static LinkedList list=new LinkedList(); ~A}"s-Kq5
/** Creates a new instance of CountCache */ 0diQfu)Fi
public CountCache() {} ;XSV}eLu
public static void add(CountBean cb){ }ARWR.7Cc
if(cb!=null){ us"SM\X#
list.add(cb); uNxR#S
} hvQOwA;e
} \,!FL))yC
} B<xBuW
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CountControl.java fBR,Oneo
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/* ~zi6wu(3
* CountThread.java @ >%I\
* &=nwb4
* Created on 2007年1月1日, 下午4:57 dMCV
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* =PP]LDlJs
* To change this template, choose Tools | Options and locate the template under 0yfmQ=,X
* the Source Creation and Management node. Right-click the template and choose &7,Kv0j}
* Open. You can then make changes to the template in the Source Editor. CSRcTxH
*/ z,87;4-
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package com.tot.count; $T8Ni!#/C
import tot.db.DBUtils; <oS2a/Nd
import java.sql.*; #b4`Wcrj
/** K8XX O "
* ;}#tm9S;
* @author ]t\fw'
*/ WO/;o0{d\9
public class CountControl{ |#^u%#'[2
private static long lastExecuteTime=0;//上次更新时间 "KcSOjvJ
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 Z=|:D,&
/** Creates a new instance of CountThread */ 8RVNRV@g%
public CountControl() {} 2shr&Mfp[
public synchronized void executeUpdate(){ m@;X%wf<U
Connection conn=null; ZtlF]k:MV
PreparedStatement ps=null; 67+ K
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try{ gs_"H
conn = DBUtils.getConnection(); &1ASWllD
conn.setAutoCommit(false); kn 5q1^
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); m4<8v
for(int i=0;i<CountCache.list.size();i++){ usZmf=p-r
CountBean cb=(CountBean)CountCache.list.getFirst(); UtIwrR[
CountCache.list.removeFirst(); QzT )PtX
ps.setInt(1, cb.getCountId()); 'vgw>\X(
ps.executeUpdate();⑴ ?y>xC|kt
//ps.addBatch();⑵ Se9I1~mX
} :aV(i.LW
//int [] counts = ps.executeBatch();⑶ O _yJR
conn.commit(); 9IIQon
}catch(Exception e){ <:-|>R".
e.printStackTrace(); lj/?P9
} finally{ i*:lZ eU61
try{ $2A%y14
if(ps!=null) { HTao)`.
ps.clearParameters();
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ps.close(); ,}2M'DSWa
ps=null; x|<rt966A
} 36`aG Y
}catch(SQLException e){} 12gcma}
DBUtils.closeConnection(conn); Vl5}m
} B=%cXW,
} :J`:Q3@
public long getLast(){ l}j5EWe
return lastExecuteTime; oZHsCQ %
} sw6]Bc
public void run(){ A-aukJg9
long now = System.currentTimeMillis(); /k|y \'<
if ((now - lastExecuteTime) > executeSep) { 'uGn1|Pvy
//System.out.print("lastExecuteTime:"+lastExecuteTime); \9geDX9A
//System.out.print(" now:"+now+"\n"); [?r`8K2!,
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ? ;i O
lastExecuteTime=now; z\*ii<-@
executeUpdate(); +yiGZV/X
} rBye%rQRq
else{ 1/c7((]7(,
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); mg[=~&J^
} PEW^Vl-6q
} W&q]bi@C
} ` :eXXE
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 %k_R;/fjW
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类写好了,下面是在JSP中如下调用。 <%#M&9d)E
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<% G4{ zt3{
CountBean cb=new CountBean(); PCF!Y(l
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); B4bC6$Lg
CountCache.add(cb); *>h"}e41
out.print(CountCache.list.size()+"<br>"); p 2It/O
CountControl c=new CountControl(); wqx@/--E(
c.run(); 8G;
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out.print(CountCache.list.size()+"<br>"); ?DzKqsS'
%>