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: mJ L=H
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CountBean.java \RDS~u\d
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/* 6#DDMP8;I
* CountData.java 8rY[Q(]
* {<1 ]cP
* Created on 2007年1月1日, 下午4:44 y$C\b\hM
* ErXzKf
* To change this template, choose Tools | Options and locate the template under u</LgOP`-
* the Source Creation and Management node. Right-click the template and choose -oR P ZtW
* Open. You can then make changes to the template in the Source Editor. R /0zB
*/ ZF~@a+o
*'jI>^o
package com.tot.count; 5VR=D\j
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/** GPs//
* pDV8B/{
* @author A{Dy3tm=
*/ /@QPJ~%8Ud
public class CountBean { @pkQ2OM
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private String countType; N(=Z4Nk5
int countId; ap|$8G
/** Creates a new instance of CountData */ %UokR"
public CountBean() {} 1E]TH/JK
public void setCountType(String countTypes){ * faG0le
this.countType=countTypes; S5>?jn1
} ft><Ql3
public void setCountId(int countIds){ )LDBvpJyQ
this.countId=countIds; 5Sv;a(}
} JsD|igqF-
public String getCountType(){ !}PZCbDhL
return countType; BMs?+
} iininITOS{
public int getCountId(){ ;Qq<5I"y
return countId; m;@8z[
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} YgL{*XYAt
} eNc>^:&y*
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CountCache.java &f($= 68
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/* c%@<
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* CountCache.java Ssg1p#0J
* S-%itrB*
* Created on 2007年1月1日, 下午5:01 [2\jQv\Y
* v1}9i3Or#
* To change this template, choose Tools | Options and locate the template under ~6Pv5DKq
* the Source Creation and Management node. Right-click the template and choose 8$`$24Wx
* Open. You can then make changes to the template in the Source Editor. ^n~bx*f
*/ 1'4?}0Dok
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package com.tot.count; [D_s`'tg
import java.util.*; =}UcYC6l
/** (bp4ly^
* |e{ ^Yf4
* @author ^aR^M\38
*/ []b=
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public class CountCache { SQs+4YJ
public static LinkedList list=new LinkedList(); r%\%tz'`j
/** Creates a new instance of CountCache */ %i5tf;x6i
public CountCache() {} $q*hE&x
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public static void add(CountBean cb){ C8t;E`
if(cb!=null){ I_\?w SNGM
list.add(cb); =M9;`EmC
} yIYQ.-DkS+
} MnTJFo"
} !q!5D`
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CountControl.java 7A"v:e
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/* 4@r76v}{
* CountThread.java G3dA`3
* w8}jmpnI
* Created on 2007年1月1日, 下午4:57 )m_q2xV
* l/-qVAd!q
* To change this template, choose Tools | Options and locate the template under wQX18aF/#d
* the Source Creation and Management node. Right-click the template and choose ~CuJ$(9Y
* Open. You can then make changes to the template in the Source Editor. pS+hE4D
*/ Te2C<c
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package com.tot.count; ~$d(@T&
import tot.db.DBUtils; D6,Ol4d
import java.sql.*; kX%vTl7F
/** /tj_WO_
* bXi(]5
* @author 8_/,`}9
*/ @Nn'G{8OG
public class CountControl{ [*U.bRs
private static long lastExecuteTime=0;//上次更新时间 H5Bh?mw2
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 46U*70
/** Creates a new instance of CountThread */ RQYD#4|
public CountControl() {} V 5D8z
public synchronized void executeUpdate(){ QjOY1Xze
Connection conn=null; . ZP$,
PreparedStatement ps=null; lk.Mc6)
try{ bT15jNa
conn = DBUtils.getConnection(); r;_*.|AH
conn.setAutoCommit(false); GBY{O2!3u
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); _$_,r H
for(int i=0;i<CountCache.list.size();i++){ ,H>'1~q
CountBean cb=(CountBean)CountCache.list.getFirst(); *$Y_ %}
CountCache.list.removeFirst(); #'dNSez5
ps.setInt(1, cb.getCountId()); '*D>/hn|:]
ps.executeUpdate();⑴ |j=Pj)5J
//ps.addBatch();⑵ S!66t?vHB
} ?=G{2E.
//int [] counts = ps.executeBatch();⑶ 'x6rU"e $J
conn.commit(); GT,1t=|&V
}catch(Exception e){ Y<h6m]H
e.printStackTrace(); xnxNc5$oE
} finally{ Rxlz`&
try{ |3 mcL'
if(ps!=null) { {Z1KU8tp
ps.clearParameters(); {q! :t0X.Y
ps.close(); dU-nE5
ps=null; 3
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} DE+k'8\T
}catch(SQLException e){} ?[;>1+D
DBUtils.closeConnection(conn); De2$:?
} w=FU:q/
} ^l<!:SS
public long getLast(){ k}C4:?AT
return lastExecuteTime; WO6R04+WV
} <99/7>#
public void run(){ k$GtzjN
long now = System.currentTimeMillis(); 2~R%_r+<
if ((now - lastExecuteTime) > executeSep) { 5Q\ hd*+g
//System.out.print("lastExecuteTime:"+lastExecuteTime); wjXv{EsMq
//System.out.print(" now:"+now+"\n"); !v8](UI8-
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); qu&p)*M5
lastExecuteTime=now; =b, m31
executeUpdate(); 0g9y4z{H
} zkquXzlgB
else{ >qBJK)LHOv
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ~n$\[rQ
} Ehxu`>@N
} tUt_Q;%yC
} p3>Md?e
//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 Tp|>(~;ai
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类写好了,下面是在JSP中如下调用。 9N<=,!;5~s
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<% Lp(i&A
CountBean cb=new CountBean(); >pp#>{}
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); @,9YF}
CountCache.add(cb); Z/T(4
out.print(CountCache.list.size()+"<br>"); tSe[*V4{'
CountControl c=new CountControl(); |h&Z.
c.run(); yb,X
}"Et
out.print(CountCache.list.size()+"<br>"); #lO ^PK
%>