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: e
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CountBean.java > H!sD\b
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/* Xz+%Ym
* CountData.java *o6}>;
* bx0.(Nv/X
* Created on 2007年1月1日, 下午4:44 u6qK4*eAD
* ]?eZDf~
* To change this template, choose Tools | Options and locate the template under q2qi~}l
* the Source Creation and Management node. Right-click the template and choose 6j<9Y
* Open. You can then make changes to the template in the Source Editor. M tN>5k c
*/ CVj^{||eF
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package com.tot.count; RJrz ~,}
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/** n
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* qpjY &3SI
* @author 1Ms[$$b$
*/ /k#-OXP~
public class CountBean { g 9_ zkGc7
private String countType; ~wvt:E,fC
int countId; d+9V% T
/** Creates a new instance of CountData */ .Ro/ioq
public CountBean() {} LD$5KaOW
public void setCountType(String countTypes){ 2;}leZ@U
this.countType=countTypes; 7=G2sOC
} S$6|KY u
public void setCountId(int countIds){ ewZ?+G+m
this.countId=countIds; 2w?q7N%
} 44]s`QyG
public String getCountType(){ o<`vh*U@,4
return countType; C"hN2Z!CD|
} @KN+)q P
public int getCountId(){ #lYyL`B+~
return countId; 6EqA Y`y
} q!Du
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} A~zn;
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CountCache.java U( YAI%O
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/* #NS|9jW
* CountCache.java ]z'&oz
* =~D? K9o
* Created on 2007年1月1日, 下午5:01 iSW2I~PD
* d
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* To change this template, choose Tools | Options and locate the template under 0YH5B5b
* the Source Creation and Management node. Right-click the template and choose =7Ln&tZ
* Open. You can then make changes to the template in the Source Editor. }0'=}BE
*/ xQoZ[
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package com.tot.count; L\:|95Yq
import java.util.*; VUb>{&F[
/** q6zVu(
* 7CIN!vrC|1
* @author /x VHd
*/ w^yb`\$
public class CountCache { X Xque-
public static LinkedList list=new LinkedList(); dkQ4D2W*\
/** Creates a new instance of CountCache */ (jc@8@Wo.
public CountCache() {} <2$vo
public static void add(CountBean cb){ y Zafq"o
if(cb!=null){ &Mh.PzO=b
list.add(cb); L^J4wYFTO
} ]e>qvSuYh
} 6g(;2gY
} bLqy7S9x
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CountControl.java inh0p^
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/* HJL! ;i
* CountThread.java ,OE&e*1
* tKbxC>w
* Created on 2007年1月1日, 下午4:57 /cjz=r1U>
* z.vQ1~s
* To change this template, choose Tools | Options and locate the template under C @(@n!o:!
* the Source Creation and Management node. Right-click the template and choose ZU4=&K
* Open. You can then make changes to the template in the Source Editor. @rl5k(
*/ r- 8Awa
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package com.tot.count; mdi!Q1pS
import tot.db.DBUtils; {u'szO}k
import java.sql.*; o`T.Zaik,
/** X+X:nL.t
* yD\q4G
* @author 1w,_D.1'
*/ c<lp<{;
public class CountControl{ uD\R3cY
private static long lastExecuteTime=0;//上次更新时间 crmQn ^4\
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 W .a>K$
/** Creates a new instance of CountThread */ byHc0ktI\
public CountControl() {} i3-5~@M
public synchronized void executeUpdate(){ 2)}n"ibbT
Connection conn=null; Q*DT" W/0
PreparedStatement ps=null; m\:^9A4HCg
try{ o9kJ90{D=
conn = DBUtils.getConnection(); Cbbdq%ySI
conn.setAutoCommit(false); $BqiC!~
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); {K^5q{u
for(int i=0;i<CountCache.list.size();i++){ w$]G$e
CountBean cb=(CountBean)CountCache.list.getFirst(); .N(R~_
CountCache.list.removeFirst(); [2:d@=%.
ps.setInt(1, cb.getCountId()); ysaRH3M
ps.executeUpdate();⑴ )gpN
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//ps.addBatch();⑵
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} vNO&0~
//int [] counts = ps.executeBatch();⑶ U[]yN.J
conn.commit(); RdCGK?s
}catch(Exception e){ wL;OQhI
e.printStackTrace(); /b+~BvTh
} finally{ YPK@BmAdE
try{ #MC#K{Xd
if(ps!=null) { &;Ncc,jb
ps.clearParameters(); O,$*`RZpx
ps.close(); fB2ILRc
ps=null; ak 7%
} 2&hv6Y1
}catch(SQLException e){} kZ9Gl!g
DBUtils.closeConnection(conn); x{H+fq,M
} n:AZ(f
} Yy~x`P'g!
public long getLast(){ e$LC
return lastExecuteTime; 9Po>laT
5
} 8mX!mYO3c
public void run(){ +3,7 Apj
long now = System.currentTimeMillis(); Th_@'UDa
if ((now - lastExecuteTime) > executeSep) { Agd"m4!
//System.out.print("lastExecuteTime:"+lastExecuteTime); <bcf"0A
//System.out.print(" now:"+now+"\n"); 0\mf1{$"!7
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); _Sjj|j
lastExecuteTime=now; vfSPgUB)
executeUpdate(); ,='Ihi
} z~{08M7
else{ _L,~WYRo
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); MN: {,#d0
} #}Qe{4L
} /_{-~0Z=@B
} T;u;r@R/
//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 P@y)K!{Nk
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类写好了,下面是在JSP中如下调用。 *`a$6F7m4
tP_.-//
<% r] /Ej!|
CountBean cb=new CountBean(); f2.=1)u.
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 2Z; !N37U
CountCache.add(cb); XX=OyDLqP
out.print(CountCache.list.size()+"<br>"); 2)EqqX[D
CountControl c=new CountControl(); 73qE!(
c.run(); QL0q/S1*
out.print(CountCache.list.size()+"<br>"); 'a(y]QG
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