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: p 3`odmbN
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CountBean.java 0pW?v:!H
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/* mN^/
* CountData.java '.$va<
* hO?RsYJ.F
* Created on 2007年1月1日, 下午4:44 h+d \u
* u&-Zh@;Q7
* To change this template, choose Tools | Options and locate the template under ?7| 6jTIs
* the Source Creation and Management node. Right-click the template and choose ]ucz8('
* Open. You can then make changes to the template in the Source Editor. X}5}M+'~
*/ LkK# =v
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package com.tot.count; a9%^Jvm"
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/** UB9n7L(@c
* Ms61FmA4
* @author ZvVrbj&
*/ JlMD_p A
public class CountBean { -F338J+J24
private String countType; 5J vrQGvL
int countId; bf*VY&S-T
/** Creates a new instance of CountData */ @gM>Lxj
public CountBean() {} S`t@L}
public void setCountType(String countTypes){ z4B-fS]
this.countType=countTypes; 3;-P (G@
} @!np
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public void setCountId(int countIds){ iD"9,1@~n
this.countId=countIds; .$~zxd#zo
} NW%u#MZ[h
public String getCountType(){ dd>
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return countType; 4Rv.m*^ B
} 3@*orm>em
public int getCountId(){ +$SJ@IH[<
return countId; *p !F+"
} 4n5r<?rY
} G[4$@{
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CountCache.java 6a MG!_jC
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/* :d{-"RAG"
* CountCache.java !M*$pQi}
* XI/LVP,.
* Created on 2007年1月1日, 下午5:01 kaG@T,pH(
* &CcUr#|
* To change this template, choose Tools | Options and locate the template under s%OPoRE
* the Source Creation and Management node. Right-click the template and choose D.;iz>_}Y
* Open. You can then make changes to the template in the Source Editor. RASPOc/]
*/ \.l8]LH
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package com.tot.count; W[4 V#&Z
import java.util.*; |Ym3.hz
/** umJ!j&(
* 41oXOB
* @author Op>l~{{{
*/ +>*! 3x+sE
public class CountCache { J&w'0
public static LinkedList list=new LinkedList(); 1Vi3/JM@
/** Creates a new instance of CountCache */ D\CjR6DE
public CountCache() {} u+_6V
public static void add(CountBean cb){ 6aq=h`Y
if(cb!=null){ [,?5}'we
list.add(cb); XtP5IN\S
} *74VrAo
} lD41+x7
} i+XHXpk
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CountControl.java M:/)|fk
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/* tH^]`6"QUa
* CountThread.java i[7<l&K]
* 2M$^|j:[
* Created on 2007年1月1日, 下午4:57 s+a} _a:
* }Y`D^z~
* To change this template, choose Tools | Options and locate the template under ?j^:jV
* the Source Creation and Management node. Right-click the template and choose [==x4Nb
* Open. You can then make changes to the template in the Source Editor. K?$|Y-_D^M
*/ j.O+e|kxU
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package com.tot.count; chs] ,7R
import tot.db.DBUtils; QTLGM-Z
import java.sql.*; ww#]i&6
/** H$44,8,m
* "xxt_
* @author S|pf.l
*/ 7Bs:u
public class CountControl{ (Ee5Af,4
private static long lastExecuteTime=0;//上次更新时间 *i,@d&J y]
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 Wfp>BC
/** Creates a new instance of CountThread */ TRzL":
public CountControl() {} $z
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public synchronized void executeUpdate(){ )8@|+'q
Connection conn=null; O+ghw1/
PreparedStatement ps=null; <4%cKW0
try{ ;,7/> Vt
conn = DBUtils.getConnection(); K|V<e[X[V
conn.setAutoCommit(false); 2Sb68hJIE
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); cD JeYduK
for(int i=0;i<CountCache.list.size();i++){ `c.P`@KA
CountBean cb=(CountBean)CountCache.list.getFirst(); ;t\oM7J|
CountCache.list.removeFirst(); Je &O
ps.setInt(1, cb.getCountId()); #C#*yE
ps.executeUpdate();⑴ h*B7UzCg
//ps.addBatch();⑵ {"WfA
} hRaX!QcG3
//int [] counts = ps.executeBatch();⑶ oUNuM%g9Dy
conn.commit(); p"tCMB
}catch(Exception e){ Wz&[cj
e.printStackTrace(); Rn9e#_ Az
} finally{ H7?Sd(U
try{ q<Z`<e
if(ps!=null) { c5- 56Q
ps.clearParameters(); {NTMvJLm
ps.close(); D&-cNxh
ps=null; a%XF"*^v
} 6z2W N|78
}catch(SQLException e){} /L^pU-}Z0
DBUtils.closeConnection(conn); <1eD*sC?g
} _2~+%{/m,
} 5lrjM^E|
public long getLast(){ ,?oC+9w
return lastExecuteTime; \PL0-.t,
} 'aqlNBG*
public void run(){ q#_<J1)z
long now = System.currentTimeMillis(); YMr2Dv\y
if ((now - lastExecuteTime) > executeSep) { 7w5C
NV
//System.out.print("lastExecuteTime:"+lastExecuteTime); opv<r*!
//System.out.print(" now:"+now+"\n"); a?1lj,"~R
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 8{DW$ZtR
lastExecuteTime=now; f~P~%
executeUpdate(); 34c+70x7
} .
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else{ _ZHDr[
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); GAU7w"sE
} :zp9L/eh
} ,"U|gJn|^
} k<A|+![
//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 moCr4*jDX,
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类写好了,下面是在JSP中如下调用。 ZO8r8
[
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<% D $&6 8
CountBean cb=new CountBean(); .g>0FP
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); XE($t2x,M
CountCache.add(cb);
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out.print(CountCache.list.size()+"<br>"); [pX cKN
CountControl c=new CountControl(); w:h([q4X
c.run(); MHQM'
out.print(CountCache.list.size()+"<br>"); ZfVw33z
%>