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: gu|cQ2xV
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CountBean.java [[A}MF*@
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/* Sft+Gb6
* CountData.java +/|t8z FWs
* V'm4DR#M
* Created on 2007年1月1日, 下午4:44
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* svj0;x5
* To change this template, choose Tools | Options and locate the template under u~7
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* the Source Creation and Management node. Right-click the template and choose ~Kll.
* Open. You can then make changes to the template in the Source Editor. l0@+&Xj
*/ d>k"#|
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package com.tot.count; cms9]
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/** VqBb=1r%o7
* KOYcT'J@vR
* @author Nt/#Qu2#br
*/ mZ!1Vh
public class CountBean {
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private String countType; ;'7gg]
int countId; ? 1
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/** Creates a new instance of CountData */ 72akOx
public CountBean() {} ])D39
public void setCountType(String countTypes){ 79G& 0 P\
this.countType=countTypes; [~UCYYl
} 3 6-Sw
public void setCountId(int countIds){ M.h8Kr!.
this.countId=countIds; w^N3Ma
} Pp~:e}
public String getCountType(){ p)y'a+|7
return countType; *-lw2M9V
} "&{sE RYY
public int getCountId(){ x17K8De
return countId; Kq4b`cn{_
} 5* 3T+OK
} 5rPK7Jh`B
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CountCache.java {wy#HYhv
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/*
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* CountCache.java XmI63W*
* Y2 QX9RN
* Created on 2007年1月1日, 下午5:01 04}" n
* )D>= \Me
* To change this template, choose Tools | Options and locate the template under *wNO3tP't
* the Source Creation and Management node. Right-click the template and choose Di>B:=
* Open. You can then make changes to the template in the Source Editor. /+g)J0u
*/ Lcow2 SbH
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package com.tot.count; hJkF-yW
import java.util.*;
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/** h&O8e;S#
* *r|)@K|
* @author C)v*L#{%
*/ f>kW\uC
public class CountCache { i?D
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public static LinkedList list=new LinkedList(); f.Feo
/** Creates a new instance of CountCache */ 8-uRn38
public CountCache() {} Y>i5ubR~
public static void add(CountBean cb){ 6>R|B?I%
if(cb!=null){ 9aKt (g6
list.add(cb); c2fqueK|:W
} ml\2%07
} f'Cx%
} zilM+BZ8
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CountControl.java K! e51P
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/* -ttH{SslM
* CountThread.java Y}UVC|Ef
* T2p;#)dP
* Created on 2007年1月1日, 下午4:57 *!-J"h
* KE*8Y4#9
* To change this template, choose Tools | Options and locate the template under @b5zHXF83E
* the Source Creation and Management node. Right-click the template and choose AttS?TZr
* Open. You can then make changes to the template in the Source Editor. O=2SDuBZ
*/ sBV})8]KM
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package com.tot.count; B>XfsZS
import tot.db.DBUtils; Ir\f_>7
import java.sql.*; RhQ[hI
/** P{ HYZg
* [zMnlO
* @author 1SO!a R#g
*/ K]s*rPT/,
public class CountControl{ ,"U_oa3
private static long lastExecuteTime=0;//上次更新时间 ?D8+wj
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 Eu)(@,]we
/** Creates a new instance of CountThread */ 3rh@|fg)E
public CountControl() {} }=T=Z#OgH
public synchronized void executeUpdate(){ `iT{H]po
Connection conn=null; IyJHKDFk
PreparedStatement ps=null; nlsif
try{ ~]LkQQ'
conn = DBUtils.getConnection(); V_p[mSKJv
conn.setAutoCommit(false); TOC2[mc'
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 6Qh@lro;y
for(int i=0;i<CountCache.list.size();i++){ U2TR>0l
CountBean cb=(CountBean)CountCache.list.getFirst(); G>>TB{}
CountCache.list.removeFirst(); _&xi})E^O]
ps.setInt(1, cb.getCountId()); lU&[){
ps.executeUpdate();⑴ 66 @#V
//ps.addBatch();⑵ I`-N]sf^
} v"3($?au0
//int [] counts = ps.executeBatch();⑶ Rt=zqfJ
conn.commit(); &K@ RTgb
}catch(Exception e){ mNDz|Ln
e.printStackTrace(); b`yb{&
,?
} finally{ T2/lvvG
try{ &U7INUL
if(ps!=null) { PbpnjvVrM
ps.clearParameters(); A$Tp0v`t
ps.close(); H68~5lJY^]
ps=null; wcW8"J'AH
} (eEs0
}catch(SQLException e){} T\3aT
DBUtils.closeConnection(conn); 5N.-m;s
} BK;Gh0mp
} {.mPe|
public long getLast(){ Oll,;{<O
return lastExecuteTime; TP R$oO2
} _G0_<WH6
public void run(){ !${7 )=|=1
long now = System.currentTimeMillis(); !]*Cwbh.
u
if ((now - lastExecuteTime) > executeSep) { u zgQ_
//System.out.print("lastExecuteTime:"+lastExecuteTime); n4%ZR~9WH
//System.out.print(" now:"+now+"\n"); 4SDUTRoa
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); S;L=W9=wby
lastExecuteTime=now; 9?J
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executeUpdate(); _`- trE.
} ckhU@C|=*
else{ Md[M}d8
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); jqv"8S5
} CaE1h9
} b;k3B7<
} R.'-jvO
//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 h}$g}f%$+
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类写好了,下面是在JSP中如下调用。 RM|2PG1m
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<% R q
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CountBean cb=new CountBean(); {Uj-x
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cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ta+MH,
CountCache.add(cb); L5j%4BlK/
out.print(CountCache.list.size()+"<br>"); p()#+Xy
CountControl c=new CountControl(); lC8Z@wkjO
c.run(); 'JK"3m}nT
out.print(CountCache.list.size()+"<br>"); X"Ca
%>