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: xL" |)A =
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CountBean.java &
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/* $r3i2N-I
* CountData.java Zcc9e03
* `Ry]y"K
* Created on 2007年1月1日, 下午4:44 YtWJXkB
* ~#/hzS
* To change this template, choose Tools | Options and locate the template under C7O6qpO
* the Source Creation and Management node. Right-click the template and choose 1w&!H]%{
* Open. You can then make changes to the template in the Source Editor. *2X0^H|dS
*/ 3=L.uXVb
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package com.tot.count; RZCq {|L
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/** J^g!++|2P
* T|TO }_x
* @author S)/_muP
*/ to$h2#i_
public class CountBean { a.zpp'cEb
private String countType; \~_9G{2?
int countId; ,#kIr
/** Creates a new instance of CountData */ pt}X>ph{
public CountBean() {} wLH] <k
public void setCountType(String countTypes){ nxl[d\ap+n
this.countType=countTypes; 10U9ZC
} Qg<(u?7N
public void setCountId(int countIds){ .?hP7;hhI
this.countId=countIds; d09k5$=gJ
} cx0*X*
public String getCountType(){ BGu?<bET
return countType; Y"wUt &
} j ku}QM^
public int getCountId(){ g"> {9YE
return countId; # m *J&
} Kc^;vT>3
} LoGVwRmoC
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CountCache.java #&7}-"Nd
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/* TG5XSy
* CountCache.java P->y_4O
* ]: ~OG@(
* Created on 2007年1月1日, 下午5:01 o+$7'+y1n-
* ,kn">k9
* To change this template, choose Tools | Options and locate the template under 'u1?tQ=gmk
* the Source Creation and Management node. Right-click the template and choose Ez-[
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* Open. You can then make changes to the template in the Source Editor. X7g1:L1Ys
*/ G"XVn~]
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package com.tot.count; =>! Y{:
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import java.util.*;
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/** }B.H|*uO
* |a!fhl+
* @author v*[.a#1^
*/ AD<q%pu&H?
public class CountCache { M )2`+/4
public static LinkedList list=new LinkedList(); x HhN
/** Creates a new instance of CountCache */ ;{%\9nS
public CountCache() {} {b
public static void add(CountBean cb){ _\GC(
if(cb!=null){ =Fr(9(
list.add(cb); )6J9J+%bi
} ])!o5`ltZ
} a0ObBe'
} Aj4T"^fv
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CountControl.java Sh8"F@P8
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/* }-6)gWe
* CountThread.java }-sdov<<
* +qwjbA+
* Created on 2007年1月1日, 下午4:57 L-k@-)98
* ynhmMy%
* To change this template, choose Tools | Options and locate the template under ?CA,
* the Source Creation and Management node. Right-click the template and choose 8Bjib&im
* Open. You can then make changes to the template in the Source Editor. c. 2).Jt,
*/ &@yo;kB
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package com.tot.count; k|H:
import tot.db.DBUtils; |]X
import java.sql.*; k<\$OoOZ
/** &E=>Hj(dTG
* UaB @
* @author 0ok-IHE<
*/ 9B7^lR
public class CountControl{ 9^G/8<^^>
private static long lastExecuteTime=0;//上次更新时间 Aw5HF34J
private static long executeSep=60000;//定义更新间隔时间,单位毫秒
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/** Creates a new instance of CountThread */ Gnq?"</
public CountControl() {} }=]M2}
public synchronized void executeUpdate(){ {R?U.eJW
Connection conn=null; tyqT
PreparedStatement ps=null; e!=kWc
try{ 4Q6mo/=H
conn = DBUtils.getConnection(); d*%`!G
conn.setAutoCommit(false); &?yZv{
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); VQS~\:1
for(int i=0;i<CountCache.list.size();i++){ I\$X/t +dH
CountBean cb=(CountBean)CountCache.list.getFirst(); cbT7CG
CountCache.list.removeFirst(); K%RxwM
ps.setInt(1, cb.getCountId()); #a8B/-
ps.executeUpdate();⑴
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//ps.addBatch();⑵ aD$v2)RR
} l.NEkAYPmH
//int [] counts = ps.executeBatch();⑶ ry` z(f
conn.commit(); ZU%[guf
}catch(Exception e){ >)M`IU[d^.
e.printStackTrace();
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} finally{ 428>BQA
try{ io{@^1ab
if(ps!=null) { Qh'ATo
ps.clearParameters(); 1NgCw\
ps.close(); 9vvx*rD
ps=null; W)f/0QX}W
} Pf\D-1gi
}catch(SQLException e){} =t H:,SH
DBUtils.closeConnection(conn); 5?F__Hx*2
} jGpN,/VQa
} Tw;3_Lj
public long getLast(){ ([m
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return lastExecuteTime; Lja>8m
} xY^%&n
public void run(){ 75/(??2
long now = System.currentTimeMillis(); 2bkX}FWd;
if ((now - lastExecuteTime) > executeSep) { 'g
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//System.out.print("lastExecuteTime:"+lastExecuteTime); A"G
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//System.out.print(" now:"+now+"\n"); ^Uf]Q$uCjE
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); sEGO2xeI
lastExecuteTime=now; .@@?Pj?)
executeUpdate(); K)DDk9*
} j;-1J_e5
else{ ^5h]Y;tx
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ;E3>ay6m8
} <?riU\-]y
} ='s(|
} [nrYpb4
//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 G?;e-OhV
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类写好了,下面是在JSP中如下调用。 6MT1$7|P&x
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<% #0P$M!%
CountBean cb=new CountBean(); :?g:~+hfO
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); $',K7%y
CountCache.add(cb); x"gd8j]s
out.print(CountCache.list.size()+"<br>"); %B5wH_p
CountControl c=new CountControl(); }:KEj_~.
c.run(); zGAq-<
out.print(CountCache.list.size()+"<br>"); =IQ5<;U3
%>