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: % O%;\t
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CountBean.java N0lFx?4
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/* fU.hb%m)Q\
* CountData.java P/~dY[6m
* 5r8
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* Created on 2007年1月1日, 下午4:44 G2[2y-Rv
* 0j;|IU\
* To change this template, choose Tools | Options and locate the template under HSG9|}$
* the Source Creation and Management node. Right-click the template and choose #F
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* Open. You can then make changes to the template in the Source Editor. < :eKXH2
*/ PTpCiiA@
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package com.tot.count; T5 pc%%q
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/** 4mBM5Tv
* UlN}SddI9
* @author L}8 }Pns?&
*/ #9"lL1
public class CountBean { b N>Ar
private String countType; rf$[8d
int countId; \2@9k`
/** Creates a new instance of CountData */ J=^5GfM)J
public CountBean() {} $a\X(okx
public void setCountType(String countTypes){ tvzO)&)$
this.countType=countTypes; hhjsg?4uL
} *X|%H-Q:H`
public void setCountId(int countIds){ .q]K:}9!\
this.countId=countIds; FGwgSrXL7
} %iV\nFal>
public String getCountType(){ $\4O r
return countType; z5:3.+M5
} 6x;"T+BSSS
public int getCountId(){ /KvpJ4
return countId; Z#%77!3
} )Knsy
} qj*BV
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CountCache.java z9#jXC#OdN
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/* Ej VB\6,
* CountCache.java 71&`6#
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* Created on 2007年1月1日, 下午5:01 jS/$o ?
* U/(R_U>=
* To change this template, choose Tools | Options and locate the template under yCg>]6B
* the Source Creation and Management node. Right-click the template and choose dnPr2oI?I
* Open. You can then make changes to the template in the Source Editor. ~}~ yR*K%
*/ /s:akLBaD
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package com.tot.count; Y u^ }
import java.util.*; v g tJ+GjN
/** &zP\K~Nt
* m}
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* @author 10/3 -)+
*/
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public class CountCache { oU 8o;zk0
public static LinkedList list=new LinkedList(); HoM8V"8B
/** Creates a new instance of CountCache */ VxAR,a1+n
public CountCache() {} JY>I
public static void add(CountBean cb){ DNM~/Oo
if(cb!=null){ uoBPi[nK
list.add(cb); b;|^62
} eP3 itrH(
} :\1&5Pm]
} :TWHmxch
}S&SL)
CountControl.java `+@%l*TQ
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/* ]gj@r[
* CountThread.java .^1=*j(;
* 6Ue6b$xE
* Created on 2007年1月1日, 下午4:57 t!Av[K
* Vk~}^;`Y
* To change this template, choose Tools | Options and locate the template under G}~b
* the Source Creation and Management node. Right-click the template and choose d{GXFT;0
* Open. You can then make changes to the template in the Source Editor. WI'csM;M#
*/ ma*9O |v^
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package com.tot.count; kQBVx8Uq]
import tot.db.DBUtils; <~8W>Y\m
import java.sql.*; tv|=`~Y
/** )Zm E"
* +V\NMW4d
* @author )'<zC
*/ (/Y
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public class CountControl{ &q` =xF
private static long lastExecuteTime=0;//上次更新时间 QnOa?0HL/
private static long executeSep=60000;//定义更新间隔时间,单位毫秒
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/** Creates a new instance of CountThread */ ~E`A,
public CountControl() {} AAl`bhx'n
public synchronized void executeUpdate(){ "ChBcxvxb:
Connection conn=null; z?YGE iR/}
PreparedStatement ps=null; T
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try{ Ip1QmP
conn = DBUtils.getConnection(); ;[zx'e?!
conn.setAutoCommit(false); ;NPb
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); %r,2ZLZ
for(int i=0;i<CountCache.list.size();i++){ hQ8{
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CountBean cb=(CountBean)CountCache.list.getFirst(); >\p}UPx
CountCache.list.removeFirst(); ,!py
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ps.setInt(1, cb.getCountId()); =O_[9kuJ
ps.executeUpdate();⑴ 02S(9^=
//ps.addBatch();⑵ 2Uk8{d
} <*5D0q#~"
//int [] counts = ps.executeBatch();⑶ 3 \WdA$Wx
conn.commit(); kI;^V
}catch(Exception e){ WK^qYfq|
e.printStackTrace(); 1!NaOfP;@
} finally{ dX3>j{_
try{ 6qA{l_V
if(ps!=null) { p_(hM&>C
ps.clearParameters(); 5Np. &
ps.close(); XZT( :(
ps=null; '}Y8a$(;V
} [E /3&3
}catch(SQLException e){} Mo<p+*8u:
DBUtils.closeConnection(conn); %`\{Nxk
} gR>#LM&dG
} J/*[wj
public long getLast(){ e
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return lastExecuteTime; &\K#UVDyhh
} Bms?`7}N
public void run(){ ,?f(~<Aj
long now = System.currentTimeMillis(); sR0nY8@F
if ((now - lastExecuteTime) > executeSep) { WL~`L!_. A
//System.out.print("lastExecuteTime:"+lastExecuteTime); DpR%s",Q
//System.out.print(" now:"+now+"\n"); i!nl%%
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); %?$"oWmenS
lastExecuteTime=now; JZ7-?
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executeUpdate(); nC Z
} Fy@D&j
else{ %~[F^
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); -
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} 1f:k:Y9i
} vT~ a}
} =w5w=qB
//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 rYqvG
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类写好了,下面是在JSP中如下调用。 hv)($;
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<% <Jk|Bmw;
CountBean cb=new CountBean(); i\'N1S<D
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); #>V;ZV5"
CountCache.add(cb); _8>"&1n
out.print(CountCache.list.size()+"<br>"); wDG4rN9x
CountControl c=new CountControl(); "8X+F%
c.run(); ij),DbWd
out.print(CountCache.list.size()+"<br>"); G#*;3X$
%>