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: 2D`@$)KL
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CountBean.java tu6oa[s
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/* @uz&]~+`
* CountData.java yCkfAx8]
* '-3AWBWI1
* Created on 2007年1月1日, 下午4:44 qC?J`
* ]O',Ei^
* To change this template, choose Tools | Options and locate the template under ntkTrei
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* the Source Creation and Management node. Right-click the template and choose s<'^
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* Open. You can then make changes to the template in the Source Editor. K"Vv=
*/ A/RHb^N
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package com.tot.count; <aa#OX
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/** 4q[C'
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* 5%(J +d
* @author NuI9"I/
*/ EU]{S=T
public class CountBean { H,txbJ
private String countType; X;flA*6V
int countId; /pgfa-<
/** Creates a new instance of CountData */ GdEkA
public CountBean() {} t5N@z
public void setCountType(String countTypes){ 84)$ CA+NX
this.countType=countTypes; 3v;o`Em&
} 62rTGbDbx
public void setCountId(int countIds){ 0!veLXeK!
this.countId=countIds; aUSxy8%
} !uLAW_~
public String getCountType(){ @Ek''a$
return countType; E4[
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} Xhtc0\0"(
public int getCountId(){ 1;3oGuHj8
return countId; [&t3xC,
} "C.'_H!Ex
} CCfuz &
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CountCache.java z %{>d#rw
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/* jVL<7@_*
* CountCache.java ^"v~hjM#
* (f5!36mz
* Created on 2007年1月1日, 下午5:01 J|_&3@r
* ^M6v;8EU
* To change this template, choose Tools | Options and locate the template under im9 B=D
* the Source Creation and Management node. Right-click the template and choose
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* Open. You can then make changes to the template in the Source Editor. pBiC
*/ [J\5DctX;c
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package com.tot.count; :Gqyj_|<
import java.util.*; pez*kU+9
/** >T;"bcb
* 4Ub_;EI>
* @author *$/7;CLq
*/ m'Z233Nt"
public class CountCache { j]rE0Og
public static LinkedList list=new LinkedList(); >4}+\ Q`S
/** Creates a new instance of CountCache */ h'^7xDw
public CountCache() {} 2/=CrK
public static void add(CountBean cb){ 6:>4}WOP
if(cb!=null){ T[U&Y`3g
list.add(cb); N~l(ng9'U
} /ivt 8Uiw
} ,,mkB6;
} GV6!`@<
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CountControl.java 'IP'g,o++
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/* GBtBmV/`
* CountThread.java OJ8W'"`L&
* NSHWs%Zc
* Created on 2007年1月1日, 下午4:57 gg'lb{oG
* 9X,dV7 yW
* To change this template, choose Tools | Options and locate the template under Y oNg3
* the Source Creation and Management node. Right-click the template and choose 8U0y86q>)E
* Open. You can then make changes to the template in the Source Editor. iU9de
*/ d~C
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package com.tot.count; 4pV.R5:
import tot.db.DBUtils; pA='(G
import java.sql.*; X3(:)zUL
/** =+~e44!~D
* bM_Y(TgJ
* @author !jMa%;/
*/ H:#b(&qw2
public class CountControl{ )+wBS3BC
private static long lastExecuteTime=0;//上次更新时间 4LtFv)i
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 K6@QZc5.!
/** Creates a new instance of CountThread */ "@W0Lk[
public CountControl() {} D^=_408\
public synchronized void executeUpdate(){ }XaO~]
Connection conn=null; 1d7oR`qr
PreparedStatement ps=null; PP/M-Jql)
try{ AnU,2[(
conn = DBUtils.getConnection(); WG NuB9R
conn.setAutoCommit(false); ~
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); uTA
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for(int i=0;i<CountCache.list.size();i++){ F)j-D(c4
CountBean cb=(CountBean)CountCache.list.getFirst(); yY4*/w7*j4
CountCache.list.removeFirst(); lDe9(5|)Q
ps.setInt(1, cb.getCountId()); d,iW#,
ps.executeUpdate();⑴ (
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//ps.addBatch();⑵ 5,I'6$J
} @JT9utct
//int [] counts = ps.executeBatch();⑶ ylLQKdcL
conn.commit(); 8/U=~*`_
}catch(Exception e){ T.d+@ZV<#
e.printStackTrace(); Q7&Yy25
} finally{ #R"9(Q&
try{ {\ P$5O{%
if(ps!=null) { ?}m/Q"!1
ps.clearParameters(); <?&GBCe
ps.close(); Tc,Bv7:
ps=null; ;i^p6b j
} T.<eriv
}catch(SQLException e){} 49nZWv48"_
DBUtils.closeConnection(conn); gZ%B9i:
} kwMuL>5
} yTz@q>6s-
public long getLast(){ { r`l
return lastExecuteTime; zwN;CD1
} \U4O*lq
public void run(){ VmF?8Vi4
long now = System.currentTimeMillis(); ?Vb=W)Es
if ((now - lastExecuteTime) > executeSep) { JHwkLAuz
//System.out.print("lastExecuteTime:"+lastExecuteTime); &1%W-&bc6
//System.out.print(" now:"+now+"\n"); |rH;}t|un
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); :t?9$ dL
lastExecuteTime=now; -. L)-%wIV
executeUpdate(); chQt8Ar3
} S6h=}
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else{ &Sj<X`^
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); .S`Ue,H
} R5ZnkPEA
} xAYC%)
} }+nC}A"BC
//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 NO P~?p
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类写好了,下面是在JSP中如下调用。 Ht5 %fcD
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<% ro6|N?'
CountBean cb=new CountBean(); pNcNU[c
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); *SzP7]1m
CountCache.add(cb); +)^F9LPl
out.print(CountCache.list.size()+"<br>"); [N$da=`wv
CountControl c=new CountControl(); `mQY%p|
c.run(); muQH!Q
out.print(CountCache.list.size()+"<br>"); `x lsvK>
%>