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: 056yhB
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CountBean.java M[b~5L+S
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/* A+Je?3/.
* CountData.java ocW`sE?EED
* 9|>y[i
* Created on 2007年1月1日, 下午4:44 3H"F~_H
* p(4Ek"
* To change this template, choose Tools | Options and locate the template under G@ybx[_[@
* the Source Creation and Management node. Right-click the template and choose +A,cdi9z
* Open. You can then make changes to the template in the Source Editor. z&GGa`T"
*/ mNe908Yw
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package com.tot.count; 3s:)CXO
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/** gcX
* ]]V=\.y
* @author h;K9}w
*/ :1iXBG\
public class CountBean { <9=RLENmY"
private String countType; .
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int countId; Jl"DMUy[kW
/** Creates a new instance of CountData */ t@cBuV`9c
public CountBean() {} :i?c
public void setCountType(String countTypes){ Qw%0<~<
this.countType=countTypes; Z#%77!3
} )Knsy
public void setCountId(int countIds){ 8v;T_VN
this.countId=countIds; n!b*GXb\
} $[=`*m
public String getCountType(){ f}FJR6VO
return countType; R<h0RKiM@
} OK}8BY
public int getCountId(){ gJOswN;([
return countId; U8g?
} q|D*H9[ke
} ;NJM3g0I
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CountCache.java 4P24ySy9F
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/* 9qZ|=r]y'
* CountCache.java 1^;&?E
* <* PjG}Z.
* Created on 2007年1月1日, 下午5:01 xi\uLu?i
* hi]\M)l&x
* To change this template, choose Tools | Options and locate the template under v#sx9$K T
* the Source Creation and Management node. Right-click the template and choose ^T@-yys
* Open. You can then make changes to the template in the Source Editor. QPF[D7\
*/ |4Q><6"G
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package com.tot.count; JY>I
import java.util.*; P|)SXR
/** C$B?|oUJc
* ;#"`]khd
* @author gD fVY%[Z
*/ pm;g)p?
public class CountCache { 7@VR:~n}k
public static LinkedList list=new LinkedList(); JeCEj=_Z
/** Creates a new instance of CountCache */ X_|} b[b
public CountCache() {} }fxH>79g
public static void add(CountBean cb){ `[1]wV5(5@
if(cb!=null){ [
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list.add(cb);
})w5`?Y
} a-DE-V Uls
} &9g#Vq%
} *KV]MdS
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CountControl.java d{GXFT;0
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/* 4 ]8PF
* CountThread.java z#*GPA8Em:
* CUw
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* Created on 2007年1月1日, 下午4:57 1r w>gR
* %s)E}cGH
* To change this template, choose Tools | Options and locate the template under ~GY;{
* 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. ^jhHaN]G^
*/ bmddh2
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package com.tot.count; f%auz4CZz
import tot.db.DBUtils; /3Gv51'
import java.sql.*; Qg oXOVo6
/** eaiz
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* ~d5{Q?T)
* @author IX3U\_I#
*/ x[oYN9O
public class CountControl{ >"nk}@
private static long lastExecuteTime=0;//上次更新时间 j+ys&pDczm
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 Pr/&p0@aV
/** Creates a new instance of CountThread */ CC87<>V
public CountControl() {}
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public synchronized void executeUpdate(){ !kKKJ~,;
Connection conn=null; )DLK<10
PreparedStatement ps=null; y! 1NS
try{ P?uKDON
conn = DBUtils.getConnection(); V+K.'
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conn.setAutoCommit(false); ,[hJi3xM
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); +yea}uUE
for(int i=0;i<CountCache.list.size();i++){ Rx<pV_|H,
CountBean cb=(CountBean)CountCache.list.getFirst(); ]ogy`O >
CountCache.list.removeFirst(); BR%: `uiQ<
ps.setInt(1, cb.getCountId()); (c_hX(
ps.executeUpdate();⑴ p]g/iLDZ
//ps.addBatch();⑵ 2I4P":q
} lJ,s}l7
//int [] counts = ps.executeBatch();⑶ |O+binq
conn.commit(); \%^3Izsc
}catch(Exception e){ gR>#LM&dG
e.printStackTrace(); 6%xl}z]o
} finally{ e
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try{ &\K#UVDyhh
if(ps!=null) { t-Fl"@s
ps.clearParameters(); wIiT
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ps.close(); *ZEs5`x
ps=null; pV+;/y_
} Kj>_XaFCg!
}catch(SQLException e){} 8ksDXf`.
DBUtils.closeConnection(conn); d16PY_
} \ d;Ow8%d/
} }R'oAE}$
public long getLast(){ yI;Qb7|^
return lastExecuteTime; 0nd<6S+fs
} MLb\:Ihy
public void run(){ TP^0`L
long now = System.currentTimeMillis(); \dMsv1\
if ((now - lastExecuteTime) > executeSep) { [)=FZF6kG
//System.out.print("lastExecuteTime:"+lastExecuteTime); P$QfcJq&c*
//System.out.print(" now:"+now+"\n"); ouI0"R&@
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); &Gt9a-ne
lastExecuteTime=now; +Snjb0
executeUpdate(); :4Vt
} g<-cHF
else{ }A;Xd/,'r
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 334*nQ
} wDG4rN9x
} KKzvoc?Bt
} 'huLv(Uu
//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 RPWYm
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类写好了,下面是在JSP中如下调用。 x1et,&,
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<% J5"*OH:f
CountBean cb=new CountBean(); S'e2~-p0F
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); k4P.}SJ?
CountCache.add(cb); _V?Q4}7d/
out.print(CountCache.list.size()+"<br>"); x@ O:
CountControl c=new CountControl(); ^b#E%Rd
c.run(); Kna'5L5"
out.print(CountCache.list.size()+"<br>"); `xr%LsNn
%>