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: yi"V'Us
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CountBean.java o(]kI?`
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/* $ENA$
* CountData.java F&lWO!4
* q!7z4Cn
* Created on 2007年1月1日, 下午4:44 6?+bi\6
* P}~6yX
* To change this template, choose Tools | Options and locate the template under qdCa]n!d
* the Source Creation and Management node. Right-click the template and choose Rde#=>@V
* Open. You can then make changes to the template in the Source Editor. IxYuJpi
*/ 0+P_z(93?
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package com.tot.count; Za jQ B
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/** 1jh^-d5
* NVS U)#
* @author )$P!7$C-
*/ (jPN+yQ
public class CountBean { `dMOBYV
private String countType; g`y
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int countId; }LM^>M%
/** Creates a new instance of CountData */ 1zGEf&rv:
public CountBean() {} j{7_p$JM
public void setCountType(String countTypes){ W6K]jIQ
this.countType=countTypes; }bIEW ho
} @0A0\2
public void setCountId(int countIds){ O1JGv8Nr
this.countId=countIds; wS%I.
} ] \4-e2N`\
public String getCountType(){ "#rlL^9v
return countType; S!#7]wtbP
} ?%JH4I2
public int getCountId(){ HGC>jeWd_
return countId; Um9!<G=;
} 4_&$isq
} U2ecvq[T
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CountCache.java @=K> uyB
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/* O2:m)@
* CountCache.java #8R\J[9
* d}>Nl$
* Created on 2007年1月1日, 下午5:01 jXGr{n
* 5ii`!y
* To change this template, choose Tools | Options and locate the template under k^C;"awh
* the Source Creation and Management node. Right-click the template and choose d{9rEB?
* Open. You can then make changes to the template in the Source Editor. PP[{c
*/ "h_n/}r=
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package com.tot.count; TcpD*%wW
import java.util.*; >Hic
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/** gD _tBv
* lk}R#n$
* @author &%fy
*/ 3i?{E^
public class CountCache { &hB~Z(zS!
public static LinkedList list=new LinkedList(); Z!G;q}zZ!
/** Creates a new instance of CountCache */ S%Pk@n`z]
public CountCache() {} 6%U1%;
public static void add(CountBean cb){ Gw~^6( Qu
if(cb!=null){ J^
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list.add(cb); cP$b>3O
} >`5iq.v
} n2Dnpe:
} +_Fsiu_b
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CountControl.java n6O1\}YB
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/* UmiW_JB
* CountThread.java ^^jF*)DT@
* @2CYv>
* Created on 2007年1月1日, 下午4:57 G/Kz_Y,
* | (v/>t
* To change this template, choose Tools | Options and locate the template under MZn7gT0
* the Source Creation and Management node. Right-click the template and choose ?lR)Hi
* Open. You can then make changes to the template in the Source Editor. +SrE
*/ ^5 F-7R8Q
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package com.tot.count; nl*{@R.q @
import tot.db.DBUtils; #n{wK+lz
import java.sql.*; _AI2\e
/** <C+:hsS=
* {8@?9Z9R{
* @author e~'y %| D
*/ 2i |wQU5w
public class CountControl{ 9{70l539
private static long lastExecuteTime=0;//上次更新时间 /-^gK^
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 <=19KSGFt
/** Creates a new instance of CountThread */ oleRQ=
public CountControl() {} 3R4-MK
public synchronized void executeUpdate(){ M%9PVePOe
Connection conn=null; I?F^c6M=
PreparedStatement ps=null; '%K,A-7W
try{ L & PhABZ
conn = DBUtils.getConnection(); LuQ=i`eXx
conn.setAutoCommit(false); /!7m@P|&D
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); B;7L:
for(int i=0;i<CountCache.list.size();i++){ 299; N
CountBean cb=(CountBean)CountCache.list.getFirst(); 7NJ1cQ-}t
CountCache.list.removeFirst(); j g$%WAEb
ps.setInt(1, cb.getCountId()); NSM-p.I9
ps.executeUpdate();⑴ V=E9*$b]
//ps.addBatch();⑵ #a}fI
} o{zo-:>Jp
//int [] counts = ps.executeBatch();⑶ {I(Euk>lR
conn.commit(); K6|*-Wo.
}catch(Exception e){ 'lIT7MK
e.printStackTrace(); :/Sx\Nz78
} finally{ )(75dUl
try{ 7b'XQ/rs
if(ps!=null) { }tj@*n_
ps.clearParameters(); a*%>H(x
ps.close(); Ce`{M&NSWX
ps=null; jsi\*5=9p<
} Z;??j+`Eo
}catch(SQLException e){} :LcR<>LZ
DBUtils.closeConnection(conn); i~l0XjQbs
} $?;aW^E
} OZk(VMuI
public long getLast(){ 8$3 Tu"+;
return lastExecuteTime; ^pZ(^
} C/
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public void run(){ wl5!f|
long now = System.currentTimeMillis(); t^u X9yvx
if ((now - lastExecuteTime) > executeSep) { 7,Z%rqf\)
//System.out.print("lastExecuteTime:"+lastExecuteTime); =I7#Vtd^K<
//System.out.print(" now:"+now+"\n"); M;3uG/E\
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); y4M<L. RO
lastExecuteTime=now; H>_%ZXL
executeUpdate(); YSv\T '3
} bU_9GGG|
else{ HjV83S;
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); :K2N7?shA
} Q1s`d?P/`
} &t%ICz&3
} |\N[EM%.@
//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 .c~;/@{
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类写好了,下面是在JSP中如下调用。 BnAia3z
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<% fqvA0"tv
CountBean cb=new CountBean(); N}\$i&Vi
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 3go!P])
CountCache.add(cb); rq2XFSXn
out.print(CountCache.list.size()+"<br>"); o.Q|%&1
CountControl c=new CountControl(); E: XzX Fxx
c.run(); #7gOtP#{
out.print(CountCache.list.size()+"<br>"); &\c$s
%>