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: sfy}J1xIL
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CountBean.java Czy}~;_Ay
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/* b9v<Jk
* CountData.java $e uI
* Otf{)f
* Created on 2007年1月1日, 下午4:44 )NqRu+j
* i;juwc^n}
* To change this template, choose Tools | Options and locate the template under wAL}c(EHO
* the Source Creation and Management node. Right-click the template and choose *!dA/sid
* Open. You can then make changes to the template in the Source Editor. W|s";EAM
*/ eYu 0")
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package com.tot.count; @Q;s[Kg{!
9}4~3_gv;M
/** kZi/2UA5Z
* h b8L[ 4
* @author _qo\E=E
*/ jCIY(/
public class CountBean { D`KaIqLz
private String countType; &H+n0v
int countId; _8\B~;0
/** Creates a new instance of CountData */ M9Nr/jE
public CountBean() {} Tb8r+~HK
public void setCountType(String countTypes){ TgHUH>k
this.countType=countTypes; f"zmN G'
} ~-R2mAUK
public void setCountId(int countIds){ lWT`y
this.countId=countIds; `82Dm!V
} H/={RuU
public String getCountType(){ |>.</68Z
return countType; ,(f W0d#
} sH >zsc
public int getCountId(){ Ps[#z@5{x
return countId; )+w1nw|m
} KeXt"U
} n+i=Ff
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CountCache.java A
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/* l"jYY3N|h
* CountCache.java *-{|m1P
* )?c,&
* Created on 2007年1月1日, 下午5:01 x;Slv(|M
* g2=PZR$
* To change this template, choose Tools | Options and locate the template under IOY7w"|LW
* the Source Creation and Management node. Right-click the template and choose )S/=5Uc
* Open. You can then make changes to the template in the Source Editor. ?)(-_N&T
*/ }&==;7,O
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package com.tot.count; XrWWV2[
import java.util.*; a ~W
/** fFWi
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* a(ITv roM/
* @author \<09.q<8
*/ H\\FAOj
public class CountCache { r\Yh'cRW{
public static LinkedList list=new LinkedList(); .>P:{''
/** Creates a new instance of CountCache */ Ym!e}`A\F
public CountCache() {} X J)Y-7c
public static void add(CountBean cb){ XoL DqN!
if(cb!=null){ s(J>yd=
list.add(cb); eF9GhwE=
} mtn^+*
} "k{so',7z
} :."oWqb)
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CountControl.java o[fg:/5)A
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/* '%XYJr:H[
* CountThread.java _vDmiIn6K
* f.+1Ubq!5
* Created on 2007年1月1日, 下午4:57 -)VjjKz]8
* ^\?Rh(pu
* To change this template, choose Tools | Options and locate the template under 2A[hMbL
* the Source Creation and Management node. Right-click the template and choose ) ba~7A
* Open. You can then make changes to the template in the Source Editor. 1gbFl/i6T
*/ kLZVTVSJt
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package com.tot.count; @z{SDM
import tot.db.DBUtils; %Uz\P|6PO
import java.sql.*; yb?Pyq.D
/** 'wG1un;t
* 'xGhMgR;
* @author \y]K]iv
*/ =\5WYC
public class CountControl{ )H{1Xjh-
private static long lastExecuteTime=0;//上次更新时间 Y%;X7VxU*
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 :TG;W,`.V
/** Creates a new instance of CountThread */ s(3HZ>qx;
public CountControl() {} Zd>sdS`#r
public synchronized void executeUpdate(){ , 6X;YY
Connection conn=null; wTU$jd1;+
PreparedStatement ps=null; t:fz%IOe
try{ O8A1200
conn = DBUtils.getConnection(); &zX W
conn.setAutoCommit(false); QhJN/v
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); v7wyQx+Q
for(int i=0;i<CountCache.list.size();i++){ 'kt6%d2
CountBean cb=(CountBean)CountCache.list.getFirst(); *u"%hXR
CountCache.list.removeFirst(); WF~BCP$OR
ps.setInt(1, cb.getCountId()); j;]I
-M[
ps.executeUpdate();⑴ ISs&1`Y
//ps.addBatch();⑵ KYm8|]'g
} DX>LB$dy?
//int [] counts = ps.executeBatch();⑶ l!88|~
conn.commit(); c-XO}\?
}catch(Exception e){ ZY`9
e.printStackTrace(); |7c],SHm
} finally{ E2>{se Z
try{ ]A%3\)r
if(ps!=null) { 8$_{R!x
ps.clearParameters(); 1n^N`lD8]6
ps.close(); AYfOETz
ps=null; }'eef"DJ9
} Twa(RjB<
}catch(SQLException e){} hHJvLs>^
DBUtils.closeConnection(conn); @u9L+*F
} -yqgs>R(d
} }2;P`s
public long getLast(){ zG_n x3
return lastExecuteTime; %9>w|%+;U+
} )&O2l
public void run(){ `(HD'f ud3
long now = System.currentTimeMillis(); N[W#wYbH
if ((now - lastExecuteTime) > executeSep) { e&
`"}^X;I
//System.out.print("lastExecuteTime:"+lastExecuteTime); Py
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//System.out.print(" now:"+now+"\n"); Vpg>K #w
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); Qg/FFn^Kg*
lastExecuteTime=now; 2JK
'!Ry)
executeUpdate(); 0L/chP
} MBt\"b#t
else{ L/jaUt[,
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); CPy>sV3Ru0
} 1=J& ^O{W
} &YY`XEG59O
} 3&})gU&a
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 ,]1f)>
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类写好了,下面是在JSP中如下调用。 nBk&+SN
ppz3"5
<% <?B3^z$
CountBean cb=new CountBean(); $(D>v!dp
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 23r(4
CountCache.add(cb); m:)&:Y0 (a
out.print(CountCache.list.size()+"<br>"); n8Qv8
CountControl c=new CountControl(); m,\+RUW'
c.run(); a^l)vh{+
out.print(CountCache.list.size()+"<br>"); NC~?4F[
%>