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: _zG[b/:p
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CountBean.java w)<h$<tU
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/* AiUK#I
* CountData.java xlm:erP
* ^K?Mq1"Db
* Created on 2007年1月1日, 下午4:44 AcIw;
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* +nKf ^rG
* To change this template, choose Tools | Options and locate the template under JQ<9~J
* the Source Creation and Management node. Right-click the template and choose 4mci@1K#^
* Open. You can then make changes to the template in the Source Editor. U&OE*dq
*/ `{+aJ0<S
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package com.tot.count; qlg?'l$03)
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/** oLc
* FQBAt0
* @author ~+&Z4CYb
*/ n_S)9C'=
public class CountBean { 9t"/@CH{
private String countType; NaC}KI`
int countId; %-O[%Dy
/** Creates a new instance of CountData */ ~+anI
public CountBean() {} gPY Cw?zQ
public void setCountType(String countTypes){ \heQVWRl
this.countType=countTypes; a+e8<fM yT
} =`f"8,5
public void setCountId(int countIds){ qVr?st
this.countId=countIds; KFf6um
} v0W/7?D
public String getCountType(){ ^cI 0d,3=
return countType; F(;95TB
} 8]A`WDO3
public int getCountId(){ Qg5-I$0
return countId; ^T_2s
} ;oJCV"y6$
} xf4`+[
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CountCache.java mAuN* (
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/* 0ChdFf7
* CountCache.java Ir$:e*E>
* . *c%A^>
* Created on 2007年1月1日, 下午5:01 [8rl{~9E
* }Oe9Zq
* To change this template, choose Tools | Options and locate the template under ^<v]x;
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* the Source Creation and Management node. Right-click the template and choose S1E=EVG
* Open. You can then make changes to the template in the Source Editor. }NF7"tOL
*/ #RVN7-x
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package com.tot.count;
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import java.util.*; #]e](j>]
/** ;`}b
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* 0|OmQ\SQ
* @author _?~)B\@~0
*/ >o8N@`@VK-
public class CountCache { 8\9s,W:5
public static LinkedList list=new LinkedList(); c@)}zcw*
/** Creates a new instance of CountCache */ l ArDOFl]x
public CountCache() {} YY9Ub
public static void add(CountBean cb){ ;eiqzdP
if(cb!=null){ I;3Uzv
list.add(cb); [LrA_N
} L7 g4'
} U=>4=gsG
} Z*M-PaU}
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CountControl.java 8~eYN-#W&
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/* <:Z-zQp)?
* CountThread.java 93fClF|@
* V8IEfU
* Created on 2007年1月1日, 下午4:57 Q0-}!5`E1$
* $+Zj)V(
* To change this template, choose Tools | Options and locate the template under Bw8&Amxx:
* the Source Creation and Management node. Right-click the template and choose '(&,i/O
* Open. You can then make changes to the template in the Source Editor. OE_>Kw7q
*/ }q<%![%
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package com.tot.count; V;>u()
import tot.db.DBUtils; E@D}Sqt
import java.sql.*; M,/{ 53
/** q? 2kD"%$
* N[8y+2SZ
* @author P4.snRQ
*/ O/bpm-h`8c
public class CountControl{ K!onV3mR
private static long lastExecuteTime=0;//上次更新时间 h;`]rK;g
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 dRPX`%J
/** Creates a new instance of CountThread */ &~a/Upz0]_
public CountControl() {} &s<'fSI
public synchronized void executeUpdate(){ /6d:l>4
Connection conn=null; Ialbz\;F2%
PreparedStatement ps=null; )R]gJ_,c
try{ _.G p}0a
conn = DBUtils.getConnection(); 1)N{!w`
conn.setAutoCommit(false); BHEZ<K[U
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); o7WK"E!pF'
for(int i=0;i<CountCache.list.size();i++){ bsgr g
CountBean cb=(CountBean)CountCache.list.getFirst(); p@bcf5'
CountCache.list.removeFirst(); T!pjv8y@R
ps.setInt(1, cb.getCountId()); { 0vHgi
ps.executeUpdate();⑴ eE-c40Bae
//ps.addBatch();⑵ (v$$`zh
} 1pHt3Vc(G
//int [] counts = ps.executeBatch();⑶ {rWFgn4Li
conn.commit(); &0QtHcXpR
}catch(Exception e){ ^VAvQ(b!:i
e.printStackTrace(); Q^z&;%q1
} finally{ "8YXFg
try{ +\@WOs
if(ps!=null) { ;yVT:qd
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ps.clearParameters(); O]N
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ps.close(); ~Y /55uC
ps=null; Vs~!\<?
} rP7~R
}catch(SQLException e){} t_Rpeav
DBUtils.closeConnection(conn); Bq) aA)gF
} d:1TSJff%/
} OJ Y_u[
public long getLast(){ 2Ed
return lastExecuteTime; xBW{Wyh
} 6pi^ rpo
public void run(){ ZJeTx.Gi6
long now = System.currentTimeMillis(); v9K{oB
if ((now - lastExecuteTime) > executeSep) { ~[d |:]
//System.out.print("lastExecuteTime:"+lastExecuteTime); K%/:V
//System.out.print(" now:"+now+"\n"); 6fr@y=s2:
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 'AjDB:Mt$
lastExecuteTime=now; Bm&% N?9
executeUpdate(); S|HnmkV66
} N&'05uWY}
else{ H^\2,x Z
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); sHi *\
} K
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} m6D]
} HLml:B[F(
//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 69>N xr~k
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类写好了,下面是在JSP中如下调用。 84uHK)h<%
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<% 39zwPoN>
CountBean cb=new CountBean(); Hjtn*^fo^
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); !YCus;B~
CountCache.add(cb); @3@oaa/v
out.print(CountCache.list.size()+"<br>"); [J71aH
CountControl c=new CountControl(); |rg4j
c.run(); }3&~YBx;:
out.print(CountCache.list.size()+"<br>"); #0wH.\79
%>