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: }+3IM1VTW{
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CountBean.java p#6V|5~8
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/* o*}--d?S
* CountData.java ZA!yw7~
* /N?vVp
* Created on 2007年1月1日, 下午4:44 v<SCh)[-p
* d(>
* To change this template, choose Tools | Options and locate the template under )?qH#>mD6
* the Source Creation and Management node. Right-click the template and choose tMQz'3,X
* Open. You can then make changes to the template in the Source Editor. Qk_`IlSd
*/ $Afw]F$
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package com.tot.count; %J%ZoptY:
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/** &:MfLDJ
* $4Ko
* @author F>!gwmn~
*/ Mq[|w2.
public class CountBean { `E4OgO
private String countType;
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int countId; <xpHlLc
/** Creates a new instance of CountData */ xO nW~Z
public CountBean() {} ( /):
public void setCountType(String countTypes){ (RtjD`e}
this.countType=countTypes; Y\pRk6,
} z')zVoW,
public void setCountId(int countIds){ /H m),9NN
this.countId=countIds; v?S~ =$.
} _8;)J
public String getCountType(){ #{]Yw}m
return countType; UvPD/qu$8D
} 3Q-[)Z )
public int getCountId(){ gJv;{;%
return countId; y5AJ1A6?E
} w6w'Jx
} cHO8%xu`
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CountCache.java {?zbrgQ<Z
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/* rt5eN:'qY
* CountCache.java P
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* ^3:y<{J
* Created on 2007年1月1日, 下午5:01 5f'<0D;K
* 3jG
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* To change this template, choose Tools | Options and locate the template under yk<$XNc
* the Source Creation and Management node. Right-click the template and choose PiTe/
* Open. You can then make changes to the template in the Source Editor. YKZk/m&H
*/ c'8a)j$$+
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package com.tot.count; eJm7}\/6`
import java.util.*; EDkxRfY2/
/** 14,Pf`5Sz
* 9^5D28y
* @author aTx*6;-PH
*/ 3>I
public class CountCache { /j0zb&
public static LinkedList list=new LinkedList(); zJJ6"9sl
/** Creates a new instance of CountCache */ w`?Rd
public CountCache() {} ]|y]?7
public static void add(CountBean cb){ tgX},OU^
if(cb!=null){ H^e0fm
list.add(cb); kQY+D1
} E*F)jP,yo
} 4\6-sL?rW
} hDf|9}/UQd
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CountControl.java 5v
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/* I
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* CountThread.java mm5y'=#
* 3nJd0E
* Created on 2007年1月1日, 下午4:57 k'd(H5A
* 7wU$P
* To change this template, choose Tools | Options and locate the template under 4[eQ5$CB<u
* the Source Creation and Management node. Right-click the template and choose b35Z1sfD
j
* Open. You can then make changes to the template in the Source Editor. (^ Q:zU
*/ 3hrODts
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package com.tot.count; O73 /2=1V
import tot.db.DBUtils; fzVU9BU
import java.sql.*; K[XFJ 9
/** )E2^G)J$W
* {_]'EK/w
* @author 5"]t{-PD
*/ jr9/
public class CountControl{ y+PiH
private static long lastExecuteTime=0;//上次更新时间 t#0/_tD
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 dK45&JHoW^
/** Creates a new instance of CountThread */ HcrI3v|6
public CountControl() {} ]-D;t~
public synchronized void executeUpdate(){ 1;4]
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Connection conn=null; F9|\(St &
PreparedStatement ps=null; +[DL]e]@U
try{ bS9<LQ*
conn = DBUtils.getConnection(); 0K&\5xXM
conn.setAutoCommit(false); x\
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); v.ftfL!
for(int i=0;i<CountCache.list.size();i++){ &!kr&g#]
CountBean cb=(CountBean)CountCache.list.getFirst(); =eXJZPR
CountCache.list.removeFirst();
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ps.setInt(1, cb.getCountId()); mu(EmAoenQ
ps.executeUpdate();⑴ 2eOde(K+
//ps.addBatch();⑵ u{o!j7
} /
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//int [] counts = ps.executeBatch();⑶ Wy'H4Rg8
conn.commit(); ;'B\l@U\
}catch(Exception e){ f8DF>]WW
e.printStackTrace(); UO&
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} finally{ .i7bI2^
try{ Nz,8NM]
if(ps!=null) { T|h/n\fx)a
ps.clearParameters(); I#]$H#}Av
ps.close(); QX*HvT
ps=null; DJtKLG0
} mkCv
f
}catch(SQLException e){} nr#DE?
DBUtils.closeConnection(conn); kW#{[,7r
} "))G|+tz
} 0ang^v;q
public long getLast(){ %EZG2J jO)
return lastExecuteTime; @+v;B:
} [>'P
public void run(){ 1!x-_h}
long now = System.currentTimeMillis(); dJh T}"x
if ((now - lastExecuteTime) > executeSep) { WheJ 7~
//System.out.print("lastExecuteTime:"+lastExecuteTime); b ;Vy=f
//System.out.print(" now:"+now+"\n"); S >P TD@
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); Lmy ^/P%
lastExecuteTime=now; O MEPF2:
executeUpdate(); H-Uy~Ry*T
} WH.5vrY Z
else{ }NMkL l]J
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); B}.G(-u?7
} rmCrP(
} k-LB %\p
} Tm8c:S^uq)
//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 ^oFg5
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类写好了,下面是在JSP中如下调用。 S.9ki<
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<% lg0iNc!
CountBean cb=new CountBean(); C^@~
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); R~,*W1G6sF
CountCache.add(cb); gJNp]I2R
out.print(CountCache.list.size()+"<br>"); kq[*q-:"x
CountControl c=new CountControl(); d1c_F~h<
c.run(); W*q[f!@
out.print(CountCache.list.size()+"<br>"); [TPr
%>