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: \ax%I)3
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CountBean.java g1~I*!p
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/* d<'xpdxc
* CountData.java eEQ[^i
* [fp"MPP3
* Created on 2007年1月1日, 下午4:44 5F"?]'*/
* D.(G 9H
* To change this template, choose Tools | Options and locate the template under E0Q"qEvU
* the Source Creation and Management node. Right-click the template and choose ^{:jY, ?]
* Open. You can then make changes to the template in the Source Editor. er0D5f R
*/ BuTIJb+Q\
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package com.tot.count; ozC!q)j
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/** (L$~zw5gr
* 7X(]r1-+\
* @author 2HXKz7da
*/ Nb~dw;t
public class CountBean { K//T}-Uub
private String countType; #OWs3$9
int countId; t1jlxK
/** Creates a new instance of CountData */ = O1;vc}AA
public CountBean() {} s &hA
public void setCountType(String countTypes){ yvCR = C
this.countType=countTypes; U@MP&sdL
} X5Y
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public void setCountId(int countIds){ OZD!#YI
this.countId=countIds; H@E ")@92
} E[.tQ|C
public String getCountType(){ W@,p9=425
return countType; VONAw3k7!
} y?n2`l7f
public int getCountId(){ lt6;*z[
return countId; $-Pqs
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} IzdTXc
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} Xexe{h4t_>
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CountCache.java .3<IOtD=
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/* 8i;)|z7
* CountCache.java
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* oL Vtu5
* Created on 2007年1月1日, 下午5:01 [W$Z60?RR
* ncattp
* To change this template, choose Tools | Options and locate the template under G4Kmt98I
* the Source Creation and Management node. Right-click the template and choose ouVjZF@kS
* Open. You can then make changes to the template in the Source Editor. a4(?]ND~6
*/ EeJqszmH
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package com.tot.count; { ^2W>^
import java.util.*; pEVgJ/>
/** eKVALUw
* ?96-" l
* @author T5Sg2a1&
*/ P:(EU s}0
public class CountCache { ~sU?"V
public static LinkedList list=new LinkedList(); *SkiFEoD
/** Creates a new instance of CountCache */ TcD[Teu
public CountCache() {} !ml_S)
public static void add(CountBean cb){ X#DL/#z k
if(cb!=null){ sr+gD*@h
list.add(cb); +z|UpI
} R6q4 ["
} C~{NKMeC/m
} /e|[SITe
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CountControl.java ],\sRQbv&
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/* 1iJ0Hut}d
* CountThread.java jQ_dw\
{0
* p9AZ9xr
* Created on 2007年1月1日, 下午4:57 mN\%fJ7
* }A1|jY)x
* To change this template, choose Tools | Options and locate the template under SbS$(Gt#Bv
* the Source Creation and Management node. Right-click the template and choose JG@L5f
* Open. You can then make changes to the template in the Source Editor. "Su
b4F`
*/ 5[,+\
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package com.tot.count; d&[iEU
import tot.db.DBUtils; 894r;UA7
import java.sql.*; Y^R?Q'
/** =`qRu
* 'y4zBLY
* @author ]8$#qDS@
*/ R2}kz.
public class CountControl{ uW}Hvj;0a*
private static long lastExecuteTime=0;//上次更新时间 7
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private static long executeSep=60000;//定义更新间隔时间,单位毫秒 /Jxq
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/** Creates a new instance of CountThread */ t_dcV%=
public CountControl() {} &
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public synchronized void executeUpdate(){ { p1lae
Connection conn=null; #V.ZdLo(
PreparedStatement ps=null; -7>^
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try{ EKZA5J7kn
conn = DBUtils.getConnection(); MV:W@)rg
conn.setAutoCommit(false); R'6@n#:
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 5>k>L*5J
for(int i=0;i<CountCache.list.size();i++){ tm(v~L%$>]
CountBean cb=(CountBean)CountCache.list.getFirst(); O(VxMO
CountCache.list.removeFirst(); In
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ps.setInt(1, cb.getCountId()); UTZ776`S&X
ps.executeUpdate();⑴ Hm>-LOCcl
//ps.addBatch();⑵ [6AHaOhR'
} OmB
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//int [] counts = ps.executeBatch();⑶ WgE@8 9
conn.commit(); wJ6_I$>
}catch(Exception e){ (O$}(Tn
e.printStackTrace(); q 75ky1^1:
} finally{ jcE Msc
try{ ?-e7e%
if(ps!=null) { U+-F*$PO+
ps.clearParameters(); qQ^d9EK'?~
ps.close(); 'X9AG6K1
ps=null; tKwn~T
} F8;mYuA
}catch(SQLException e){} Zr=ib
DBUtils.closeConnection(conn); BU`ckK\(
} _ w/_(k
} >-b&v $
public long getLast(){ DKX/W+#a
return lastExecuteTime; -$.0Dc)3!
} U_]=E<el
public void run(){ +jUgx;u,
long now = System.currentTimeMillis(); mjbTy"}"
if ((now - lastExecuteTime) > executeSep) { ymYBm:"
//System.out.print("lastExecuteTime:"+lastExecuteTime); )i;un.
//System.out.print(" now:"+now+"\n"); a"x}b
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); yO00I`5
lastExecuteTime=now; CphFv!k'Z
executeUpdate(); p!_[qs
} ["u#{>(X
else{ yNBv-oe5
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 3A_G=WaED
} S<"oUdkz
} oe9lF*$/
} Vz{>cSz#
//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`4c 4h]I
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类写好了,下面是在JSP中如下调用。 9YD\~v;x
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<% / 2xSNalC
CountBean cb=new CountBean(); l-<`m#/v
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); M diwRi
CountCache.add(cb); M*w' 1fT
out.print(CountCache.list.size()+"<br>"); h$`#YNd'
CountControl c=new CountControl(); J? .F\`N)
c.run(); A
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out.print(CountCache.list.size()+"<br>"); ?F_)-
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