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: jQDxbkIuzE
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CountBean.java . FruI#99
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/* zM'-2,
* CountData.java ieI-_]|[
* rQqtejcfx
* Created on 2007年1月1日, 下午4:44 26**tB<
* U}7[8&k1
* To change this template, choose Tools | Options and locate the template under x:x QXjJ
* the Source Creation and Management node. Right-click the template and choose Xx^c?6YM
* Open. You can then make changes to the template in the Source Editor. )t4C*+9<U
*/ AM[:Og S
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package com.tot.count; )\(pDn$W
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/** j{=%~
* 9Dl \S F[
* @author c>g%oE
*/ . ~<+
public class CountBean { _=MWt_A '3
private String countType; >O _
int countId; I?"5i8E
/** Creates a new instance of CountData */ }FXRp=s
public CountBean() {} J3]m*i5A
public void setCountType(String countTypes){ EkX6> mo
this.countType=countTypes; ,&-[$,
} ^kq! /c3r
public void setCountId(int countIds){ 4!jHZ<2Z
this.countId=countIds; FuKNH~MevQ
} F\I^d]#,[
public String getCountType(){ vpDs5tUl
return countType; DkIFvsLK
} X&IY(CX
public int getCountId(){ f"Iyo:Wt
return countId; ?<;<#JN
} b<n)`;
} m%&B4E#3T
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CountCache.java p!ErH]lH
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/* Zux2VepT
* CountCache.java V'.|IuN
* #7=LI\
* Created on 2007年1月1日, 下午5:01 je-s%kNlJ
* U4gwxK
* To change this template, choose Tools | Options and locate the template under Vz*'^=(o&
* the Source Creation and Management node. Right-click the template and choose n&]w* (,
* Open. You can then make changes to the template in the Source Editor. BXY'%8q _a
*/ sYpogFfV
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package com.tot.count; `vw.~OBl
import java.util.*; In&vh9Lw
/** OT i3T1&
* `t6L'%\
* @author ]Ho`*$dD
*/ 8H?AL
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public class CountCache { -cgukl4Va
public static LinkedList list=new LinkedList(); SO/]d70HG
/** Creates a new instance of CountCache */ R`q!~8u
public CountCache() {} {9
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public static void add(CountBean cb){ qgNK!(kWpr
if(cb!=null){ )v~]lk,o
list.add(cb); L:-lqag!
} 'QF>e
} 7g9 ^Jn
} T*yveo&j
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CountControl.java *.g?y6d
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/* +ctv]'P_
* CountThread.java K8Zk{on
* |m- `,
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* Created on 2007年1月1日, 下午4:57 Oy$BR
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* W?-BT >#s
* To change this template, choose Tools | Options and locate the template under xQap44KPZ
* the Source Creation and Management node. Right-click the template and choose >N-%
* Open. You can then make changes to the template in the Source Editor. +_P
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*/
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package com.tot.count; RCXSz
import tot.db.DBUtils; z D<9A6AB
import java.sql.*; !`o:+Gg@
/** om?CFl
* 0!`7kZrN
* @author .N&}<T[
*/ /g'-*:a
public class CountControl{ *J5RueUG
private static long lastExecuteTime=0;//上次更新时间 GK?R76d
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 %+a@|Z
/** Creates a new instance of CountThread */ j9'XZq}
public CountControl() {} 389.&`Q%Ut
public synchronized void executeUpdate(){ a] =\h'S
Connection conn=null; L]N2rMM
PreparedStatement ps=null; 5l0rw)
try{ O7'3}P;
conn = DBUtils.getConnection(); 2EwWV0BS
conn.setAutoCommit(false); gecT*^
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); jMui+G(h
for(int i=0;i<CountCache.list.size();i++){ NP'Ke:
CountBean cb=(CountBean)CountCache.list.getFirst(); t<,p-TM]
CountCache.list.removeFirst(); g4a X
ps.setInt(1, cb.getCountId()); ?0<INS~
ps.executeUpdate();⑴ FNCLGAiZ
//ps.addBatch();⑵ UQ])QTrZFi
} zB"
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//int [] counts = ps.executeBatch();⑶ EZQ+HECpK
conn.commit(); ~PW}sN6ppG
}catch(Exception e){ iCRw}[[
e.printStackTrace(); '8kjTf#g<l
} finally{ Sx9:$"3.X
try{ =^y{@[p`(
if(ps!=null) { Z !25xqNCd
ps.clearParameters(); p6*a1^lU6
ps.close(); U9.=Ik
ps=null; jI`To%^Y
} Kx185Q'W
}catch(SQLException e){} 0nq}SH
DBUtils.closeConnection(conn); p6Dv;@)Yn
} wx%nTf/Oa
} ^@lg5d3F
public long getLast(){ m:fouMS
return lastExecuteTime; 124L3AG
} ivz9R'
public void run(){ {-N90Oe
long now = System.currentTimeMillis(); pkf OM"5'
if ((now - lastExecuteTime) > executeSep) { A2:){`Mw
//System.out.print("lastExecuteTime:"+lastExecuteTime); .4re0:V
//System.out.print(" now:"+now+"\n");
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// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 8G l5)=2
lastExecuteTime=now; ZQ' z
executeUpdate(); C=aj&
} NwlRPyt
else{ *R\/#Y|
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); xT?} wF
} _q$LrAT
} 6+nMH
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} 8<wuH#2<y
//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 GHC?Tp
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类写好了,下面是在JSP中如下调用。 <ivqe"m
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<% 8
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CountBean cb=new CountBean(); *tfDXQ^mN
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 1;kG[z=A
CountCache.add(cb); PBww
out.print(CountCache.list.size()+"<br>"); pY!dG-;
CountControl c=new CountControl(); )
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c.run(); j)tCr Py
out.print(CountCache.list.size()+"<br>"); JlDDM
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