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: ?9m@ S#@
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CountBean.java o<nkK+=Afm
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/* Z2hIoCT
* CountData.java S|v")6
* (b>B6W\&
* Created on 2007年1月1日, 下午4:44 x#,nR]C
* "qv J-Y
* To change this template, choose Tools | Options and locate the template under W<s5rM x
* the Source Creation and Management node. Right-click the template and choose <c$K3
* Open. You can then make changes to the template in the Source Editor. Q=Y1kcTOn
*/ UfAN)SE"
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package com.tot.count; ju {\7X5
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/** 3lD1G~
* |\_d^U&`
* @author fPu,@
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*/ 8^|lsB}x?
public class CountBean { OXCf
private String countType; _vgFcE~E@
int countId; W2G@-`,
/** Creates a new instance of CountData */ B gB]M3Il
public CountBean() {} z;d]=PT
public void setCountType(String countTypes){ h,%b>JFo
this.countType=countTypes; r&?i>.Kz8
} z9)I@P"
public void setCountId(int countIds){ L>Soj|WUy(
this.countId=countIds; U|}Bk/0.
} JVk"M=c
public String getCountType(){ -cW'g
return countType; dpWBY3(7a
} l/F'W}
public int getCountId(){ B2DWSp-8*
return countId; K\a=bA}DG
} 8KhE`C9z
} `oUuAL
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CountCache.java {Mx3G*hr
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/* -^+!:0';
* CountCache.java NT}r6V(Aju
* ~99DE78
* Created on 2007年1月1日, 下午5:01 :M'V**A(
* tV5Uz&:b
* To change this template, choose Tools | Options and locate the template under I? o)X!
* the Source Creation and Management node. Right-click the template and choose (#`1[n+b`x
* Open. You can then make changes to the template in the Source Editor. v?en-,{A
*/ r^,XpRe&M
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package com.tot.count; BqA
import java.util.*; 2AK]x`GY
/** Gcz@z1a=n
* /<WK2G
* @author w;Jby
*/ ;)nV
public class CountCache { ~xSAR;8
public static LinkedList list=new LinkedList(); ollk {N
/** Creates a new instance of CountCache */ sq~9
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public CountCache() {} A:-r2;xB
public static void add(CountBean cb){ quEP"
if(cb!=null){ G^Q8B^Lg
list.add(cb); C_~hX G
} X|iWnz+^
} V<%eWT)x7C
} 9;*-y$@
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CountControl.java ;5(ptXX1W
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/* /PuN+M
* CountThread.java ,m)k;co^
* !QTfQ69Y0
* Created on 2007年1月1日, 下午4:57 vm
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* 2GRdfX
* To change this template, choose Tools | Options and locate the template under qB0F9[U
* the Source Creation and Management node. Right-click the template and choose B<p -.tv
* Open. You can then make changes to the template in the Source Editor. ;&N=t64"
*/ vL,:Yn@b
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package com.tot.count; yaD_c;
import tot.db.DBUtils; X/l{E4Ex
import java.sql.*; 3r]:k)J
/** ~Os1ir.
* SL O~
* @author I}S~,4
*/ 9AgTrP
public class CountControl{ X>W2aDuEZ
private static long lastExecuteTime=0;//上次更新时间 h/a|-V}m&
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 -~'{WSJ
/** Creates a new instance of CountThread */ #rkz:ir4
public CountControl() {} 2Vn~o_ga
public synchronized void executeUpdate(){ +=Q/'g
Connection conn=null; #2~-I
PreparedStatement ps=null; th?w&;L
try{ {#,eD
conn = DBUtils.getConnection();
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conn.setAutoCommit(false); 7i$)iNW
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); sOY+X
for(int i=0;i<CountCache.list.size();i++){ f0lpwwe
CountBean cb=(CountBean)CountCache.list.getFirst(); |pA
CountCache.list.removeFirst(); g$N/pg2>cT
ps.setInt(1, cb.getCountId()); [10y 13
ps.executeUpdate();⑴ 6|Qg=4_FHt
//ps.addBatch();⑵ sG6ts,={
} t(RJc
//int [] counts = ps.executeBatch();⑶ \69h>h
conn.commit(); {Hu@|Q\~&
}catch(Exception e){ <V~B8C!)
e.printStackTrace(); oY K(=j
} finally{ ~Gz
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try{ 8NJxtT~0c~
if(ps!=null) { *@zh
ps.clearParameters(); +[R,wsG
ps.close(); ,@#))2<RK
ps=null; DN GXp5I
} m/T3Um
}catch(SQLException e){} P~H?[
;
DBUtils.closeConnection(conn); lI<Q=gd
} nbMxQODk
} ;
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public long getLast(){ ,Y\`n7Ww
return lastExecuteTime; +'lj\_n
} rEF0A&5
public void run(){ a^ __Z3g,
long now = System.currentTimeMillis(); :Q=tGj\G
if ((now - lastExecuteTime) > executeSep) { lzE{e6
//System.out.print("lastExecuteTime:"+lastExecuteTime); D\ ;(BB
//System.out.print(" now:"+now+"\n"); 5(+PIKCjC
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); U_8 Z&
lastExecuteTime=now; fVXZfq6
executeUpdate(); 6`
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} bl8EzO
else{ FkH HTO
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); `Pcbc\"*y
} 6VsgZ"Il
} x/B1\U
I
} UK7pQt}9
//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 4Ucs9w3[
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类写好了,下面是在JSP中如下调用。 e}u68|\EC
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<% EDA%qNd]j
CountBean cb=new CountBean(); 5p}ri,Y<
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); Y_gMoo
CountCache.add(cb); @BfJb[A#
out.print(CountCache.list.size()+"<br>"); :< d.
CountControl c=new CountControl(); I0qSx{K
c.run(); 0'QX*xfa>
out.print(CountCache.list.size()+"<br>"); d5z=fH9
%>