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: "xI70c{
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CountBean.java tZXq<k9
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/* ;W 3#q:
* CountData.java H\%^n<]#
* "g5<j p
* Created on 2007年1月1日, 下午4:44 ge#0Q L0K
* 5)c B\N1u
* To change this template, choose Tools | Options and locate the template under Lo<WK
* the Source Creation and Management node. Right-click the template and choose ?]%ZJd
* Open. You can then make changes to the template in the Source Editor. >b7Yk)[%
*/ xe4`D>LUo
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package com.tot.count; ZGw6Bd_I
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/** X :#}E7]j
* {^@vCBE+
* @author 6:Hd `
*/ %zKTrsMZ
public class CountBean { `_iK`^(-
private String countType; " k0gZb
int countId; Y=?Tm,z4
/** Creates a new instance of CountData */ ]\1H=g%Ou
public CountBean() {} l NLa:j
public void setCountType(String countTypes){ Qef5eih
this.countType=countTypes; M7fPaJKL
} IKrojK8-?
public void setCountId(int countIds){ {1"kZL
this.countId=countIds; u0Bz]Ux/Q
} `t7z
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public String getCountType(){ K_Pbzj4(P
return countType; csFLBP
} h1~/zM/`
public int getCountId(){ 7](aPm8
return countId; \zJb}NbnT
} ms&6N']
} XI'.L ~
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CountCache.java %oOSmt
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/* P6 7*-Ki
* CountCache.java ,7I
* hg7_ZjO
* Created on 2007年1月1日, 下午5:01 oe*fgk/o9
* 3:aj8F2
* To change this template, choose Tools | Options and locate the template under QQ/9ZI5
* the Source Creation and Management node. Right-click the template and choose "sSY[6Kp!
* Open. You can then make changes to the template in the Source Editor. .wO-2h{Q
*/ !GJT-[
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package com.tot.count; vX?C9Fr 2
import java.util.*; d"=)=hm!
/** )GfL?'Z
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* @author `i
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*/ 7/HX!y{WP
public class CountCache { v]'\]U^
public static LinkedList list=new LinkedList(); uovSe4q5q
/** Creates a new instance of CountCache */ RGLJaEl !
public CountCache() {} s$kvLy<
public static void add(CountBean cb){ SN 4JX
if(cb!=null){ FMtg7+Q|>
list.add(cb); sk5B} -
} t=\
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} Mn 8|
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} G '%ZPh89
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CountControl.java x9o(q`N
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/* ?@^gpVK{
* CountThread.java BS2'BS8
* 6"9(ce
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* Created on 2007年1月1日, 下午4:57 gSHN,8.
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* ,:{+-v(
* To change this template, choose Tools | Options and locate the template under ',1[rWyc
* the Source Creation and Management node. Right-click the template and choose _4
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* Open. You can then make changes to the template in the Source Editor. Qoa&]]
*/ /&E]qc*-p
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package com.tot.count; 50dx[v8
import tot.db.DBUtils; R"{P#U,HNO
import java.sql.*; $T_>WUiK
/** ? r}2JHvN
* ( m7qc
* @author l15Z8hYhj
*/ 6H!l>@a7v
public class CountControl{ yb-4[C:i
private static long lastExecuteTime=0;//上次更新时间 @zJiR{Je-U
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 `Bb32L
/** Creates a new instance of CountThread */ xS; tmc
public CountControl() {} Z6nQW53-
public synchronized void executeUpdate(){ FP")$
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Connection conn=null; Ih[k{p
PreparedStatement ps=null; ltv~Kh
try{ ctPT=i60
conn = DBUtils.getConnection(); ~i]4~bkH2
conn.setAutoCommit(false); sw50lId
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); e35 ")z~
for(int i=0;i<CountCache.list.size();i++){ %NcBq3
CountBean cb=(CountBean)CountCache.list.getFirst(); 4WPco"xH!
CountCache.list.removeFirst(); j>5X^Jd
ps.setInt(1, cb.getCountId()); P=a&>i
ps.executeUpdate();⑴ wjTW{Bg~G
//ps.addBatch();⑵ ^[6#Kw&E
} (ylZ[M&B:
//int [] counts = ps.executeBatch();⑶ iM$iZ;Tp
conn.commit(); {5 3#Xd
}catch(Exception e){ vcZ"4%w
e.printStackTrace(); @W=:r/
} finally{ I5]58Ohx
try{ \0)2 u[7
if(ps!=null) { }+giQw4
ps.clearParameters(); @cQ
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ps.close(); BnG{)\s
ps=null; d>0 j!+s
} HP=5a.
}catch(SQLException e){} 4O4}C#6(4
DBUtils.closeConnection(conn); )"g @"LJ=
} 8mC$p6Okd
} (S_1C,
public long getLast(){ t1p[!53(
return lastExecuteTime; @vO~'Xxq!
} Hn]6re
public void run(){ 6ZQ$5PY
long now = System.currentTimeMillis(); D 77$aCt
if ((now - lastExecuteTime) > executeSep) { P)[QC
//System.out.print("lastExecuteTime:"+lastExecuteTime); ^vZu[m
//System.out.print(" now:"+now+"\n"); (hIe!"s*
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); aN';_tGvK
lastExecuteTime=now; lr[&*v?h
executeUpdate(); gu1n0N`b
} !N/?b^y
else{ \*#E4`Y
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ]{AHKyA{:
} ~7H?tp.Dw
} X=VaBy4#
} 4rypT-%^ ;
//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 i x_a
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类写好了,下面是在JSP中如下调用。 _@Y17L.
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<% fK{Z{)D
CountBean cb=new CountBean(); @9g!5dcT
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); R+Rb[,m
CountCache.add(cb); f|,2u5
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out.print(CountCache.list.size()+"<br>"); ):V)Hrq?x
CountControl c=new CountControl(); P9]95.j
c.run(); ^mZTki4
out.print(CountCache.list.size()+"<br>"); !/Wv\qm
%>