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: /B}lO0]:
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CountBean.java %AQIGBcgL
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/* L5,NP5RC
* CountData.java Qf@
* 4^URX>nx8
* Created on 2007年1月1日, 下午4:44 F8apH{&t
* %HJK;
* To change this template, choose Tools | Options and locate the template under p/h
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* the Source Creation and Management node. Right-click the template and choose *BR ^U$,e
* Open. You can then make changes to the template in the Source Editor. ,TFIG^Dvq
*/ h*v8#\b$J_
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package com.tot.count; N ,z6y5Lu
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/** mrw=T.
* s;A@*Y;v
* @author z[;z>8|c
*/ yeMB0Z*r
public class CountBean { Bi{$@n&?f
private String countType; Sm5H_m!
int countId; 87YyDWTn
/** Creates a new instance of CountData */ ^U!0-y
public CountBean() {} 6AhM=C
public void setCountType(String countTypes){ 8e(\%bX
this.countType=countTypes; GN2Sn`;
} >qF CB\(
public void setCountId(int countIds){ VzVc37Z>6
this.countId=countIds; J Px~VnE%%
} ,l)^Ft`5
public String getCountType(){ j?+X\PtQ
return countType; :*KHx|Q
} q*>&^V $M
public int getCountId(){ ;&)-;l7M
return countId; (}2~<
} pS7w' H
} - RU=z!{
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CountCache.java ;4pYK@9w_
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/* y9Us n8
* CountCache.java sdo[D
* AQwdw>I-FX
* Created on 2007年1月1日, 下午5:01 rQ qW_t%
* ,JQp'e
* To change this template, choose Tools | Options and locate the template under !/]WrGqbS
* the Source Creation and Management node. Right-click the template and choose &eX!#nQ_.
* Open. You can then make changes to the template in the Source Editor. XSyHk"g`
*/ io8'g3<
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package com.tot.count; TJR:vr
import java.util.*; @W"KVPd
/** I<6P;
* aq@8"b(.
* @author g0["^P1tV
*/ 9eQxit7
public class CountCache { rr02pM0
public static LinkedList list=new LinkedList(); 7V!*NBsl
/** Creates a new instance of CountCache */ MjC_ ( cs
public CountCache() {} HK0!P*
public static void add(CountBean cb){ '$ t
if(cb!=null){ KJaXg;,H
list.add(cb); _v> }_S
} f@|A[>"V
} P 'od`
} t^G"f;Ra+
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CountControl.java `ux{;4q
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/* EWkLXU6t
* CountThread.java n|R J;d30Q
* CU@Rob} s
* Created on 2007年1月1日, 下午4:57 !u[eaLxV
* (jRm[7H
* To change this template, choose Tools | Options and locate the template under ,NyY>~+
* the Source Creation and Management node. Right-click the template and choose QLiu2U o
* Open. You can then make changes to the template in the Source Editor. tnN.:%mZ
*/ |es?;s'
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package com.tot.count; BMG3|N^
import tot.db.DBUtils; Vy Xhl;
import java.sql.*; lJ}_G>GJ
/** KyYM fC
* ;Q OBBF3HG
* @author CUBEW~X}M
*/ i]YV {
public class CountControl{ e478U$
private static long lastExecuteTime=0;//上次更新时间 C'.L20qW
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ~obqG!2m
/** Creates a new instance of CountThread */ Oj3.q#)`Z
public CountControl() {} |Mup8(gCk
public synchronized void executeUpdate(){ aW)-?(6>
Connection conn=null; 4ew"
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PreparedStatement ps=null; H8Bs<2
try{ bnq;)>&
conn = DBUtils.getConnection(); j,lT>/
conn.setAutoCommit(false); pN:Kdi
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); :8=i kwQ
for(int i=0;i<CountCache.list.size();i++){ Ln')QN
CountBean cb=(CountBean)CountCache.list.getFirst(); aeFe!`F
CountCache.list.removeFirst(); cl=EA6P\X
ps.setInt(1, cb.getCountId()); )wam8k5
ps.executeUpdate();⑴ XHK<AO^
//ps.addBatch();⑵ O`x;,6Vr
} V@e?#iz
//int [] counts = ps.executeBatch();⑶ v7BA[j Qr
conn.commit(); 9kN}c<o
}catch(Exception e){ )t0$qd ]
e.printStackTrace(); n'wU;!W9
} finally{ EUD~CZhS"k
try{ );
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if(ps!=null) { 0%&1\rm+j
ps.clearParameters(); v5!d$Vctu
ps.close(); ]HKQDc'
ps=null; Z&Pg"a?\
} E4`N-3
}catch(SQLException e){} ]qethaNy
DBUtils.closeConnection(conn); jaTh^L
} .zA^)qgL
} 7E r23Q
public long getLast(){ j"ThEx0
return lastExecuteTime; PWaw]*dFmy
} nt 81Bk=
public void run(){ q@QksAq
long now = System.currentTimeMillis(); B8.Pn
if ((now - lastExecuteTime) > executeSep) { 9_L[w\P|4
//System.out.print("lastExecuteTime:"+lastExecuteTime); {@H6HqD
//System.out.print(" now:"+now+"\n"); *g:4e3Iy
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); +X#vVD3"
lastExecuteTime=now; /[a~3^Gs^
executeUpdate(); 3c#BKHNC
} 63q^ $I
else{ M>wYD\oeg
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 5A)2} D]
} $?
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} 5gb|w\N>
} 7,U=Qe;
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 iZ#!O*>
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类写好了,下面是在JSP中如下调用。 _(_a*ml
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<% s`M9
CountBean cb=new CountBean(); e}D3d=6`
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 6*PYFf`
CountCache.add(cb); hEA<o67
out.print(CountCache.list.size()+"<br>"); bx#>BK!
CountControl c=new CountControl(); L6t+zIUc-~
c.run(); j-4VB_N@
out.print(CountCache.list.size()+"<br>"); %}SGl${-
%>