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: {LTb-CB
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CountBean.java =Xzqp,
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/* Malt7M
* CountData.java 9x.vz
* uHBX}WH
* Created on 2007年1月1日, 下午4:44 t+Mr1e
* XP5q4BM
* To change this template, choose Tools | Options and locate the template under =:`1!W0I
* the Source Creation and Management node. Right-click the template and choose T_ Q/KhLU
* Open. You can then make changes to the template in the Source Editor. (u85$_C
*/ [YP8z~
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package com.tot.count; w_G/[R3
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/** nS[0g^}
* b_ Sh#d&
* @author 0TU~Q
*/ udB:ys
public class CountBean { u,[Yaw"L
private String countType; o*97Nbjn
int countId; VuFMjY
/** Creates a new instance of CountData */ Mo
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public CountBean() {} !.iu_xJ
public void setCountType(String countTypes){ =%Gecj
this.countType=countTypes; wRf_IBhCd
} $=iz&{9
public void setCountId(int countIds){ UV)[a%/SB&
this.countId=countIds; ^te9f%>$l
} 2N)=fBF%-
public String getCountType(){ lW'6rat
return countType; _Pa(5-S'KR
} a}`4BMi3
public int getCountId(){ X;sl?8HG!<
return countId; .{HU1/!
} KJ,{w?p~
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} 8kAG EiC
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CountCache.java BMU~1[r
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/* @z$V(}(O^
* CountCache.java Zp@p9][C
* fS-#dJC";`
* Created on 2007年1月1日, 下午5:01 Zi$a6
* {#uX
* To change this template, choose Tools | Options and locate the template under JoKD6Q1D
* the Source Creation and Management node. Right-click the template and choose M]jzbJ3Q
* Open. You can then make changes to the template in the Source Editor. ko
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*/ 1 dz&J\|E#
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package com.tot.count; u%5B_<90V
import java.util.*; ho#]?Z#
/** [:a;|t
* c G?RisSZ
* @author f|?i6.N>f
*/ vkE6e6,Qc
public class CountCache { 8_U*_I7(
public static LinkedList list=new LinkedList(); J\_tigd
/** Creates a new instance of CountCache */ "FcA:7 +
public CountCache() {} +F&w~UT
public static void add(CountBean cb){ -:pLlN-f
if(cb!=null){ 0Z2![n
list.add(cb); V5K`TC^
} Hh$D:ZO
} /4w&! $M-
} ],>Z'W
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CountControl.java )Y
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/* Wh(V?!^@5
* CountThread.java ?b2"~A
* B Gh%3"q
* Created on 2007年1月1日, 下午4:57 ocAoqjlT[
* ?*tpW75hR[
* To change this template, choose Tools | Options and locate the template under z]=A3!H/Y
* the Source Creation and Management node. Right-click the template and choose _tb)F"4V
* Open. You can then make changes to the template in the Source Editor. 3@KX|-
*/ )]n:y M
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package com.tot.count; +x-n,!(
import tot.db.DBUtils; 8>T
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import java.sql.*; 9FX'Uw s
/** 5=.,a5
* fJd!;ur)0
* @author JdfjOlEb
*/ 72&xEx
public class CountControl{ mj%Iow.
private static long lastExecuteTime=0;//上次更新时间 1}QU\N(t
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 r_-iOxt~5
/** Creates a new instance of CountThread */ W _yVVr
public CountControl() {} d;
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public synchronized void executeUpdate(){ "DjD"?/b
Connection conn=null; S3P;@Rm
PreparedStatement ps=null; v /G,
try{ 06]J]
conn = DBUtils.getConnection(); 0KHA5dt
conn.setAutoCommit(false); (Y)$+9
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); )4D |sN
for(int i=0;i<CountCache.list.size();i++){ )<UNiC
CountBean cb=(CountBean)CountCache.list.getFirst(); QApil
CountCache.list.removeFirst(); =sG C
ps.setInt(1, cb.getCountId()); ]}w~fjq
ps.executeUpdate();⑴ 3EI$tP @4
//ps.addBatch();⑵ |jU/R
} V'mQ{[{R
//int [] counts = ps.executeBatch();⑶ :&/'rMi<T
conn.commit(); # yAt `
}catch(Exception e){ u1~H1
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e.printStackTrace(); f]qPxRw
} finally{ (c axl^=
try{ ?N~rms
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if(ps!=null) { y['$^T?oP
ps.clearParameters(); jri=UGf
ps.close(); \uc]+nV!o
ps=null; JpcG5gX^B
} mcP]k8?C
}catch(SQLException e){} ^{T]sv
DBUtils.closeConnection(conn);
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} S4n\<+dR<
} F
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public long getLast(){ +4Aj/$%[q
return lastExecuteTime; [d`J2^z}
} ",k"c}3G
public void run(){ p`fUpARA!
long now = System.currentTimeMillis(); }Y[xj{2$O
if ((now - lastExecuteTime) > executeSep) { ^RAst1q7
//System.out.print("lastExecuteTime:"+lastExecuteTime); xA& tVQ2!
//System.out.print(" now:"+now+"\n"); 8d?r )/~
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); *P7 H=Yf&
lastExecuteTime=now; SP?~i@H
executeUpdate(); g`i?]6c}jt
} tg_xk+x
else{ M+j V`J!
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); sG7G$G*ta!
} y-6k<RN
} R}_B\# Q
} w<#/ngI2
//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 :[xFp}w{
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类写好了,下面是在JSP中如下调用。 "m,)3zND3
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<%
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CountBean cb=new CountBean(); _JNSl2
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); s;e%*4
CountCache.add(cb); w%~UuJ#i
out.print(CountCache.list.size()+"<br>"); JN)@bP
CountControl c=new CountControl(); `yJ3"{uO
c.run(); h]T
out.print(CountCache.list.size()+"<br>"); 0`UI^Y~Q
%>