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+p?J.+
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CountBean.java Z<z(;)?c
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/* ^_KHw
* CountData.java -gH1`*YL
* 3t[2Bd
* Created on 2007年1月1日, 下午4:44 f&B&!&gZ
* U$6N-q
* To change this template, choose Tools | Options and locate the template under w<N[K>
* the Source Creation and Management node. Right-click the template and choose mZJ"e,AY
* Open. You can then make changes to the template in the Source Editor. LnvC{#TFO
*/ s$J0^8Q~i
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package com.tot.count; HS]|s':
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/** 95>(NwST4
* (F~i
* @author #/!a=0
*/ D#508{)
public class CountBean { $/nU0W
private String countType; B|gyr4]
int countId; uG&xtN8
/** Creates a new instance of CountData */ 8a|p`)lT
public CountBean() {} j*<H18^G
public void setCountType(String countTypes){ v7T05
this.countType=countTypes; #rqLuqw
} &(-+?*A`E
public void setCountId(int countIds){ !6\{q
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this.countId=countIds; BdB/`X*
} zn&NLsA
public String getCountType(){ >y"V%
return countType; aGx`ec*t
} 5`*S'W}\>
public int getCountId(){ K+TRt"W8&s
return countId; $fV47;U'*
} ]$!-%pNv
} q5YgKz?IC
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CountCache.java C^XJE1D.
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/* 0sto9n3
* CountCache.java _a"5[sG
* ])egke\!
* Created on 2007年1月1日, 下午5:01 o X )r4H?
* 6:i{_YX(.S
* To change this template, choose Tools | Options and locate the template under QNJ )HNLp
* the Source Creation and Management node. Right-click the template and choose SaMg)s~B
* Open. You can then make changes to the template in the Source Editor. Ly/"da
*/ 4!,x3H'
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package com.tot.count; ~~,\BhG?
import java.util.*; E$=!l{Ms
/** lNowH0K!D
* z{Z'2 ,#
* @author 4*d$o=wa
*/ {<o_6 z`$
public class CountCache { yNi/JM
public static LinkedList list=new LinkedList(); p)RASIB
/** Creates a new instance of CountCache */ fI;6!M#
public CountCache() {} T?{"T/
public static void add(CountBean cb){ 7'z{FSS
if(cb!=null){ w`&~m:R
list.add(cb); "detDB
} k?3NF:Yy7
} d4t%/ Uh
} }&Ngh4/
}p$>V,u
CountControl.java w,> ceu/
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/* [U.3rcT"N
* CountThread.java zMxHJNQ\D
* &eKnLGKD
* Created on 2007年1月1日, 下午4:57 _so\h.lt
* w2_$>z
* To change this template, choose Tools | Options and locate the template under ~cQ./G4
* the Source Creation and Management node. Right-click the template and choose 4*< x0
* Open. You can then make changes to the template in the Source Editor. Y^Y|\0
*/ 2'Cwx-_G`
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package com.tot.count; Pky/fF7e
import tot.db.DBUtils; b^_#f:_j
import java.sql.*; A^nB!veh
/** \]dx;,T
* 3&:Us|}
* @author X|fl_4NC>
*/ $!%/Kk4M
public class CountControl{ o8;>E>;
private static long lastExecuteTime=0;//上次更新时间 fT.18{'>
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 pyYm<dn
/** Creates a new instance of CountThread */ ^0py
public CountControl() {} dc.9:u*w
public synchronized void executeUpdate(){ C?m2R(RF
Connection conn=null; `w';}sQA7
PreparedStatement ps=null; bYQvh/(J
try{ GcaLP*%>B
conn = DBUtils.getConnection(); I },.U&r
conn.setAutoCommit(false); #pO=\lJ,
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); $_ IvzbOh
for(int i=0;i<CountCache.list.size();i++){ smaPZ^;; j
CountBean cb=(CountBean)CountCache.list.getFirst(); Fv$5Zcf
CountCache.list.removeFirst(); L"{qF<@V7&
ps.setInt(1, cb.getCountId()); 4v9jGwnz t
ps.executeUpdate();⑴ O?5uCh$H
//ps.addBatch();⑵ Cl#PYB{1Y
} ~Gm<F .(+
//int [] counts = ps.executeBatch();⑶ BC*62m
conn.commit(); o~<Xc
}catch(Exception e){ l{ <+V)
e.printStackTrace(); 7.mY@
} finally{ 5IE3[a%X
try{ dJxdrs
if(ps!=null) { qM78s>\-h
ps.clearParameters(); Yw @)0%G
ps.close(); g<U\7Vp\1
ps=null; "g27|e?y
} NV\t%/ ?
}catch(SQLException e){} nMm4fns
DBUtils.closeConnection(conn); 9MP_#M7
} 55Z)*JMv
} Nc;cb
public long getLast(){ d1CQ;,Df<
return lastExecuteTime; @9#l3
} ~+DPq|-O
public void run(){ j"=F\S&!
long now = System.currentTimeMillis(); c"D%c(:4|
if ((now - lastExecuteTime) > executeSep) { ?1Os%9D*
//System.out.print("lastExecuteTime:"+lastExecuteTime); DS;,@$N_N
//System.out.print(" now:"+now+"\n"); @A32|p}
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); fk%W07x!
lastExecuteTime=now; mD@*vq
executeUpdate(); r{\c.\
} R(p`H}^
else{ 'kBg3E$y
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); A1>fNilC9
} wr);+.T9R
} ]M3V]m
} $fifx>!
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 h pf,44Kg
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类写好了,下面是在JSP中如下调用。 >u?m
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<% (4]M7b[S$
CountBean cb=new CountBean(); RTC;Wj
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); <c'0-=
CountCache.add(cb); .cks){\
out.print(CountCache.list.size()+"<br>"); `>ppDQaS)W
CountControl c=new CountControl(); H!SFSgAu
c.run(); IQZ/8UwB
out.print(CountCache.list.size()+"<br>"); o6bT.{8\
%>