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: B#R|*g:x
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CountBean.java ~V6D<
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/* 0"SU_jQzv
* CountData.java Iga024KR
* \b>]8Un"
* Created on 2007年1月1日, 下午4:44 U$UIN#
* ?q [T
* To change this template, choose Tools | Options and locate the template under 5:?!=<=
* the Source Creation and Management node. Right-click the template and choose J.%IfN
* Open. You can then make changes to the template in the Source Editor. \{D"
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*/ bI`g|v
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package com.tot.count; 6S{l'!s'
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/** ugBCBr
* _e2=ado
* @author }-`4DHgq
*/ G+m }MOQP7
public class CountBean { u%!@(eKM-
private String countType; W%Fv p;\`
int countId; 1.>m@Slr>
/** Creates a new instance of CountData */ HbIF^LeY|R
public CountBean() {} Alq(QDs
public void setCountType(String countTypes){ @}ZVtrz
this.countType=countTypes; L RF103nw
} *NQ/UXE
public void setCountId(int countIds){ V.2_i*
this.countId=countIds; e}W)LPR!
} phz&zlD
public String getCountType(){ FGkVqZ Y2?
return countType; |l!aB(NW
} 7[wPn`v2
public int getCountId(){ dF2RH)Ud
return countId; D/' dTrR
} +H2Qk4XFB
} 4Po_-4
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CountCache.java c*M}N?|6
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/* "Rl}VeDY
* CountCache.java K<J9~
* DaVa}
* Created on 2007年1月1日, 下午5:01 LIrb6g&xj_
* T^q
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* To change this template, choose Tools | Options and locate the template under L:x-%m%w
* the Source Creation and Management node. Right-click the template and choose : E?V.
* Open. You can then make changes to the template in the Source Editor. #A.@i+Zv
*/ 54qFfN8O
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package com.tot.count; 13wE"-
import java.util.*; 048kPXm`
/** DV{=n C
* M^I(OuRMeI
* @author hv+zGID7
*/ PI<vxjOK`
public class CountCache { 1YMh1+1
public static LinkedList list=new LinkedList(); 2T`!v
/** Creates a new instance of CountCache */ =R\]=cRbg
public CountCache() {} rM"l@3hP
public static void add(CountBean cb){ OrG).^l
if(cb!=null){ 1:wQ.T
list.add(cb); i6N',&jFU
} -$@h1Y
} .e5Mnd%$M
} NEF#
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CountControl.java et+0FF
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/* A)KZa"EX
* CountThread.java |K~Nw&rZ]
* ]%(2hY~i
* Created on 2007年1月1日, 下午4:57 QCJM&
* oXS}IL
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* To change this template, choose Tools | Options and locate the template under H[|~/0?K
* the Source Creation and Management node. Right-click the template and choose ?1".;foZ
* Open. You can then make changes to the template in the Source Editor. Dhv3jg;lq
*/ B1Oq!k
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package com.tot.count; =Runf
+}
import tot.db.DBUtils; LHmZxi?
import java.sql.*; <6=c,y
/** C.QO#b
* mcok/,/
* @author 8r!zBKq2~
*/ nF/OPd
public class CountControl{ ~_ a-E
private static long lastExecuteTime=0;//上次更新时间 $]8Q(/mbK
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 F<w/PMb
/** Creates a new instance of CountThread */ RT5T1K08I
public CountControl() {} MY/}-*|
public synchronized void executeUpdate(){ LIdF 0
Connection conn=null; h1(4Ic
PreparedStatement ps=null; Np)lIGE
try{ J.
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conn = DBUtils.getConnection(); IO> yIU[
conn.setAutoCommit(false); GH
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); DeYV$W
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for(int i=0;i<CountCache.list.size();i++){ |D.ND%K&
CountBean cb=(CountBean)CountCache.list.getFirst(); D3A/l
CountCache.list.removeFirst(); S@sO;-^+
ps.setInt(1, cb.getCountId()); u-C)v*#L
ps.executeUpdate();⑴ s<o7!!c
//ps.addBatch();⑵ iyog`s c
} 39jG8zr=Z[
//int [] counts = ps.executeBatch();⑶ TB^$1C
conn.commit(); w*MpX
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}catch(Exception e){ wdZ/Xp9]
e.printStackTrace(); PxE3K-S)G
} finally{ 4Xv*wB1
try{ KY N0
if(ps!=null) { IIqUZJ
ps.clearParameters(); D
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ps.close(); D,ln)["xm
ps=null; C8 \^#5
} Y4(
}catch(SQLException e){} K4);HJ|=
DBUtils.closeConnection(conn); 8x{'@WCG%
} bYPK h
} Ic4H# w
public long getLast(){ .>nRzgo
return lastExecuteTime; 8sCv]|cn
} sT' 5%4
public void run(){ ]0\MmAJRn
long now = System.currentTimeMillis(); O| hpXkV
if ((now - lastExecuteTime) > executeSep) { +'w3 =2Bo
//System.out.print("lastExecuteTime:"+lastExecuteTime); r"R#@V\'1b
//System.out.print(" now:"+now+"\n"); ri.I pRe
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); zv"Z DRW
lastExecuteTime=now; x$%!U[!3
executeUpdate(); I`p;F!s
} as_PoCoss
else{ 5 u0HI
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); !Rt>xD
} ;({W#Wa
} ]$_NyAoBb
} kSh( u
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 z$xo$R(
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类写好了,下面是在JSP中如下调用。 b%5f&N
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<% &8 x-o,
CountBean cb=new CountBean(); B93+BwN>95
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); vZoaT|3
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CountCache.add(cb); eGHaY4|
out.print(CountCache.list.size()+"<br>");
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CountControl c=new CountControl(); O1mKe%'|
c.run(); VAu&@a`
out.print(CountCache.list.size()+"<br>"); xZv#Es%#
%>