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: S$1dXXT
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CountBean.java Nk&$b
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/* ew\ZF qA;
* CountData.java +oR wXO3W
* LM?UV)
* Created on 2007年1月1日, 下午4:44 8ZvozQE
* wEMg~Hh
* To change this template, choose Tools | Options and locate the template under 7~7_T#dTh
* the Source Creation and Management node. Right-click the template and choose mybvD
* Open. You can then make changes to the template in the Source Editor. ^V;2v? O
*/ A"R5Fd%6pc
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package com.tot.count; 6qkMB|@Ix
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/** R,KoymXP
* LGF5yRk
* @author qo62!q
*/ M_EXA _
public class CountBean { E6mwvrm8
private String countType; @G:aW\Z
int countId; d6;"zW|Ec
/** Creates a new instance of CountData */ = ,^eQZR:
public CountBean() {} T{Y;-m
public void setCountType(String countTypes){ 3( `NHS~h
this.countType=countTypes; O'~;|-Z<
} ;&MI
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public void setCountId(int countIds){ MNZD-[
this.countId=countIds; ~x 0x.-^A
} 6[l{@*r"
public String getCountType(){ ELqpIXq#
return countType; `dK%I
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} NY9\a[[^[8
public int getCountId(){ ?Z[`sm
return countId; >{huaN B
} QocR)aN=+
} Qg' {RAV8
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CountCache.java Rw#4 |&
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/* Hj^_Cp]@*
* CountCache.java y7WO:X&
* Aq:1
* Created on 2007年1月1日, 下午5:01 `UDB9Ca
* hRKA,u/G
* To change this template, choose Tools | Options and locate the template under <u%&@G$F>
* the Source Creation and Management node. Right-click the template and choose f=/IwMpn
* Open. You can then make changes to the template in the Source Editor. _"R /k`8
*/ A6#5 z
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package com.tot.count; t?<pyw $
import java.util.*; 7"0l>0 \
/** wYIlp
* {e'V^l.v
* @author MeXGE
*/ 380M&Guh
public class CountCache { ;u
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public static LinkedList list=new LinkedList(); T0=%RID%=
/** Creates a new instance of CountCache */ :Lze8oY(D}
public CountCache() {} zxffjz,Fe:
public static void add(CountBean cb){ c-gpO|4>
if(cb!=null){ "[t (u/e
list.add(cb); (c=.?{U
} E+xC1U
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} HbXYinG%
} smTPca)7s
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CountControl.java EvQMt0[?EW
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/* <W<>=vDzyE
* CountThread.java 9C2DW,?
* N);2 2-
* Created on 2007年1月1日, 下午4:57 N|53|H
* [c_o.`S_\
* To change this template, choose Tools | Options and locate the template under d"Aer
* the Source Creation and Management node. Right-click the template and choose 27q=~R}
* Open. You can then make changes to the template in the Source Editor. "Gh5
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*/ ql_GN[c/
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package com.tot.count; (h3f$
import tot.db.DBUtils; Oj ?
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import java.sql.*; *8?0vkZZ2
/** O${B)C,
* N,M[Opm
* @author ~M!s0jT
*/ ]= nM|e
public class CountControl{ Sdn4y(&TP
private static long lastExecuteTime=0;//上次更新时间 Td"_To@jd
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 7 _*k<W7|
/** Creates a new instance of CountThread */ ]> dCt<
public CountControl() {} "ke>O'
public synchronized void executeUpdate(){ py8)e7gX=
Connection conn=null; ZN `D!e6
PreparedStatement ps=null; 9C_Vb39::$
try{ +M^+qt;]V
conn = DBUtils.getConnection(); 3+>;$
conn.setAutoCommit(false); +J<igb!S
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); %SHgXd#X
for(int i=0;i<CountCache.list.size();i++){ v62M8r,Y
CountBean cb=(CountBean)CountCache.list.getFirst(); {InD/l'v6n
CountCache.list.removeFirst(); ?@uyqi~:U
ps.setInt(1, cb.getCountId()); C0> Z<z
ps.executeUpdate();⑴ zm7IkYF
//ps.addBatch();⑵ zF-R$_]av
} f;7I{Z\<
//int [] counts = ps.executeBatch();⑶ NplWF\5y
conn.commit(); .lt|$["
}catch(Exception e){ 2LqJ.HH
e.printStackTrace(); B
!}/4"
} finally{ oFC]L1HN&
try{ :,'yHVG\
if(ps!=null) { ]W9 {<+&
ps.clearParameters(); aIXN wnq
ps.close(); > q!:*
ps=null; U6/$CH<pe
} #o/
}catch(SQLException e){} #D2.RN
DBUtils.closeConnection(conn); Y"dUxv1Ap
} z +NwGVk3
} jf
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public long getLast(){ ;[,r./XmH
return lastExecuteTime; f+xhS,iDR
} T4lE-g2%M
public void run(){ <T|?`;K
long now = System.currentTimeMillis(); a\@k5?
if ((now - lastExecuteTime) > executeSep) { J+o6*t2|
//System.out.print("lastExecuteTime:"+lastExecuteTime);
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//System.out.print(" now:"+now+"\n"); jMV9r-{*+
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); -Y=o
lastExecuteTime=now; Qf:#{~/
executeUpdate(); |Y")$pjz
} "gCqb;^
else{ CL)*cu6zG
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); N" =$S|Gs
} &4R-5i2a
} ]QJWqY
} ![l`@NH[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 1@"os[9
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类写好了,下面是在JSP中如下调用。 WnkI i,<
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<% =)Z~w`
CountBean cb=new CountBean(); L63B# H"
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); M?QK4Zxb6U
CountCache.add(cb); |q+dTy_n
out.print(CountCache.list.size()+"<br>"); 1X,\:F.-+
CountControl c=new CountControl(); 6Ex16
c.run(); ,}jey72/k
out.print(CountCache.list.size()+"<br>"); IB%Hv]
%>