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: g-'y_'%0G
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CountBean.java CG'NC\x5
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/* M ,V+bt
* CountData.java <B6@q4Q
* Rf@D]+v
* Created on 2007年1月1日, 下午4:44 U
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* g+/%r91hZ
* To change this template, choose Tools | Options and locate the template under $;un$ko6%
* the Source Creation and Management node. Right-click the template and choose '|^LNAx
* Open. You can then make changes to the template in the Source Editor. $w%oLI@kl
*/ >JT{~SRB|Y
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package com.tot.count; zjgK78!<
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/** iU^ 4a
* -Nmf}`_
* @author 7=XQgbY/
*/ aKs!*uo0H
public class CountBean { q3Umqvl)oe
private String countType;
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int countId; UCYhaD@sP
/** Creates a new instance of CountData */ _dqjRhu
public CountBean() {} &QE^i%6>\
public void setCountType(String countTypes){ g$VcT\X
this.countType=countTypes; pH#&B_S6z=
} k/l@P
public void setCountId(int countIds){ 6A M,1
this.countId=countIds; ?97MW a
} ^7q=E@[e
public String getCountType(){ x6HebIR+
return countType; cb&y8!ci~
} e<5+&Cj
public int getCountId(){ oSNB\G<
return countId; Ga f/0/|
} hgj#VY$B
} fEs957$
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CountCache.java ^FgNg'"[3
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/* *p?b "{_a
* CountCache.java ;TSnIC)c
* 3FUZTX]Q1
* Created on 2007年1月1日, 下午5:01 UEo,:zeN[
* ,<hXNN
* To change this template, choose Tools | Options and locate the template under js`zQx'
* the Source Creation and Management node. Right-click the template and choose S
!c/"~X+
* Open. You can then make changes to the template in the Source Editor. #BS]wj2#
*/ +^YV>;
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package com.tot.count; >&^w\"'
import java.util.*; xHsH .f_{
/** u4VQx,,
* d\;M F
* @author @PwEom`a
*/ C*Ws6s>+z
public class CountCache { vlIdi@V
public static LinkedList list=new LinkedList(); &8"a 7$
/** Creates a new instance of CountCache */ @<vDR">
public CountCache() {} /l(:H
public static void add(CountBean cb){ #*S/Sh?Q
if(cb!=null){ gp-wlu4
list.add(cb); gY0*u+LF
} o*p7/KvoT
} A!^K:S:@
} )\mklM9Z
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CountControl.java uzp!Y&C
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/* qgZ(o@\
* CountThread.java 9k 7|B>LT
* 9q* sR1
* Created on 2007年1月1日, 下午4:57
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* AL|fL
* To change this template, choose Tools | Options and locate the template under *otJtEI>6
* the Source Creation and Management node. Right-click the template and choose "Wi`S;
* Open. You can then make changes to the template in the Source Editor. ; UrwK
*/ ?rBj{]=
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package com.tot.count; R63"j\0
import tot.db.DBUtils; D<xP x
import java.sql.*; z[t$[Qg
/** O')Ivm,E
* ZlO@PlZ)
* @author L7D'wf
*/ 9,y&?GLP
public class CountControl{ yvH:U5%
private static long lastExecuteTime=0;//上次更新时间 _|A)ueY
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 m@zxjIwT
/** Creates a new instance of CountThread */ W:5m8aE\
public CountControl() {} =HoiQWQs`
public synchronized void executeUpdate(){ e'\I^'`!M
Connection conn=null; f2{4Y)
PreparedStatement ps=null; $ng\qJ"HF
try{ 3I"&Qp%2
conn = DBUtils.getConnection(); -q+Fj;El
conn.setAutoCommit(false); <CA
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); a?JU(
for(int i=0;i<CountCache.list.size();i++){ M/1Q/;0P
CountBean cb=(CountBean)CountCache.list.getFirst(); ahV_4;yF
CountCache.list.removeFirst(); ~(%G;fZ?x
ps.setInt(1, cb.getCountId()); .5dZaI)
ps.executeUpdate();⑴ -Q$$2QW!
//ps.addBatch();⑵ gcv,]v8
} C62<pLJf
//int [] counts = ps.executeBatch();⑶ 8AefgjE
conn.commit(); !o.g2
}catch(Exception e){ &rNXn?>b
e.printStackTrace(); LG,RF:
} finally{ ax3:rl
try{ Mb<KZ_wYOX
if(ps!=null) { @8CD@SDv
ps.clearParameters(); @x=CMF15
ps.close(); ikxSWO_Y=
ps=null; 9s7B1Pf
} c3
wu&*p{
}catch(SQLException e){} J@Orrz2q#
DBUtils.closeConnection(conn); )E4COw+
} w1KQ9H*
} i5AhF\7F9
public long getLast(){ *=sU+x&X
return lastExecuteTime; ]7VK&YfN
} #Kh`ATme
public void run(){ ~(&xBtg:}
long now = System.currentTimeMillis(); zc2,Mn2
if ((now - lastExecuteTime) > executeSep) { &c\8`# 6
//System.out.print("lastExecuteTime:"+lastExecuteTime); C u?$!|V
//System.out.print(" now:"+now+"\n"); [2FXs52
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 5S7Z]DXiT8
lastExecuteTime=now; sV*Q8b*
executeUpdate(); Tl1?5
} ##n\9ipD
else{ /z'j:~`E
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); -~-2 g
} Kp&d9e{
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} X:e'@]Z)?
} !PQRlgcG
//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 UG!&n@R
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类写好了,下面是在JSP中如下调用。 MD
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<% u(o @_6
CountBean cb=new CountBean(); eU12*(
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); j=gbUXv/
CountCache.add(cb); {otvJ|'N
out.print(CountCache.list.size()+"<br>"); gTq-\k(
CountControl c=new CountControl(); m2}&5vD8-
c.run(); \vT8
)\
out.print(CountCache.list.size()+"<br>"); [Ytia#Vv
%>