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: W.OcmA>x
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CountBean.java :;[pl|}tM
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/* y]|Hrx
* CountData.java r[xj,eIb
* \_?A8F
* Created on 2007年1月1日, 下午4:44 VwfeaDJw
* ^):m^w.
* To change this template, choose Tools | Options and locate the template under $hexJzX
* the Source Creation and Management node. Right-click the template and choose ~B!O
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* Open. You can then make changes to the template in the Source Editor. 9kmEg$WM
*/ 0zrgK;9
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package com.tot.count; (XtN3FTY
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/** IS *-MLi
* v ~|~&Dwq
* @author |l\&4/SJ
*/ -#0(Jm'
public class CountBean { @c&}\#;
private String countType; E6"+\-e
int countId; hLYy
/** Creates a new instance of CountData */ [?rK9I&
public CountBean() {} GT$.#};u
public void setCountType(String countTypes){ #CKPNk
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this.countType=countTypes; s Xyc _3N
} V+#Sb
public void setCountId(int countIds){ RTN?[`
this.countId=countIds; (,Zy2wr=
} 0vN <0
public String getCountType(){ zrt \]h+
return countType; o+UCu`7e
} +O`3eP`u
public int getCountId(){ Ore>j+
return countId; +ZH-'l
} A*d Pw.
} }j=UO*|
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CountCache.java |C:^BWrU*
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/* #-76E
* CountCache.java vW`Dy8`06
* USF9sF0l
* Created on 2007年1月1日, 下午5:01 3r{3HaN(^'
* ckR>ps[ u
* To change this template, choose Tools | Options and locate the template under L $R"?O7
* the Source Creation and Management node. Right-click the template and choose { +d](+$
* Open. You can then make changes to the template in the Source Editor. +NML>g#F~z
*/ ra87~kj<
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package com.tot.count; l&rS\TCkp
import java.util.*; ITcgpK6k
/** t8vR9]n
* L=`QF'Im
* @author l%vX$Kw
*/ Ir%L%MuR]
public class CountCache { |'mwr!
public static LinkedList list=new LinkedList(); UC3&:aQ!
/** Creates a new instance of CountCache */ ,4kly_$BH
public CountCache() {} Q-A:0F&{t
public static void add(CountBean cb){ &(M][Uo{|'
if(cb!=null){ -D=J/5L#5
list.add(cb); "*08?KA
} %6A."sePO
} <( "M;C3y
} NifD
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CountControl.java E?\&OeAkO
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/* GnAG'.t-Z
* CountThread.java D~~"wos
* I,[njlO:
* Created on 2007年1月1日, 下午4:57 ;/ wl.'GA
* X<:B"rPuK
* To change this template, choose Tools | Options and locate the template under N, `q1B
* the Source Creation and Management node. Right-click the template and choose
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* Open. You can then make changes to the template in the Source Editor. 54[#&T$S
*/ Sq#AnD6To
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package com.tot.count; VU8EjuOetb
import tot.db.DBUtils; c@SNbY4}%
import java.sql.*; }sy^ed
/** VO"/cG;]*
* 6JrwPZB
* @author ^?+qNbK
*/ |3LD"!rEx
public class CountControl{ /-J
private static long lastExecuteTime=0;//上次更新时间 .>QzM>zO
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 jl-2)<
/** Creates a new instance of CountThread */ Whoqs_Mm{
public CountControl() {} qV;E%XkkS
public synchronized void executeUpdate(){ =sm<B^yj
Connection conn=null; EC9bCd-z
PreparedStatement ps=null; #@pgB:~lB
try{ &Hz{
conn = DBUtils.getConnection(); dh9Qo4-{
conn.setAutoCommit(false); VtP^fM^{
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ^pB}eh.@U
for(int i=0;i<CountCache.list.size();i++){ fL xGaOT
CountBean cb=(CountBean)CountCache.list.getFirst(); W4OL{p-\/
CountCache.list.removeFirst(); e0s*
ps.setInt(1, cb.getCountId()); !
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ps.executeUpdate();⑴ J&P{7a
//ps.addBatch();⑵ BE0Ov{'
} t`M4@1S"'
//int [] counts = ps.executeBatch();⑶ {^J/S}L]
conn.commit(); V /.Na(C~
}catch(Exception e){ `!Z0;qk
e.printStackTrace(); Fb2,2Px
} finally{ x3>ZO.Q
try{ lw\+!}8(
if(ps!=null) { /Dd.C<F
ps.clearParameters(); W8blHw"
ps.close(); bk(q8xR`
ps=null; L/J1;
} 5taR[ukM
}catch(SQLException e){} MQc<AfW3/
DBUtils.closeConnection(conn); G_m $?0\
} f-.dL
} J#>)+
public long getLast(){ a/\SPXQ/9
return lastExecuteTime; ]iU8n (5f
} )])nd"E
public void run(){ }}Zwdpo
long now = System.currentTimeMillis(); V),wDyi
if ((now - lastExecuteTime) > executeSep) { ~mF^t7n]
//System.out.print("lastExecuteTime:"+lastExecuteTime); 3# g"Z7/
//System.out.print(" now:"+now+"\n"); D%`O.2T Y|
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); !1b}M/Wx
lastExecuteTime=now; Ir\P[A
executeUpdate(); DX2_}|$!
} SD/=e3
else{ |D% O`[k+
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 40e(p/Qka
} bmOK8
} f};RtRo2
} _2-fH
//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 *5QN:
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类写好了,下面是在JSP中如下调用。 adcH3rV
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<% UF&B7r
CountBean cb=new CountBean(); /~(T[\E<
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); J9%I&lu/
CountCache.add(cb); {xD\w^
out.print(CountCache.list.size()+"<br>"); H9\,;kM)
CountControl c=new CountControl(); "u.'JE;j
c.run(); SeV`RUO
out.print(CountCache.list.size()+"<br>"); 8aqH;|fG}
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