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: >p,FAz>
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CountBean.java OZed+t=
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/* 9m:G8j'
* CountData.java t!JD]j>q
* >wJt# ZB
* Created on 2007年1月1日, 下午4:44 (HD=m,}
* pR*)\@ma
* To change this template, choose Tools | Options and locate the template under "? t@Y
* the Source Creation and Management node. Right-click the template and choose <oP"kh<D4
* Open. You can then make changes to the template in the Source Editor. "2a&G3}t"
*/ 2,.;Mdl
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package com.tot.count; Rd^X.
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/** ZclZD{%8J
* 6y
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* @author XEvDtDR
*/ 0 CFON2I
public class CountBean { @/yJTMcf
private String countType; Zwxu3R_
int countId; q;0QI{:5v
/** Creates a new instance of CountData */ dB%q`7O
public CountBean() {} "Nlw&+
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public void setCountType(String countTypes){ x;L.j7lzA;
this.countType=countTypes; >ho$mvT
} yYri.n
public void setCountId(int countIds){ \~bx%VWW4
this.countId=countIds; z=/xv},
} '<eeCe-
public String getCountType(){ $Z!7@_Ys
return countType; sn6:\X<[
} A(dWAe,
public int getCountId(){ lX*IEAc
return countId; &hri4p/
} uBXl ltU
} *4oj '}
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CountCache.java U6M3,"?
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/* }W)c-91
* CountCache.java k,UezuV
* '4J];Nj0
* Created on 2007年1月1日, 下午5:01 3duWk sERC
* Z+ ?V10$
* To change this template, choose Tools | Options and locate the template under +#IsRiH%>
* the Source Creation and Management node. Right-click the template and choose 13v#
* Open. You can then make changes to the template in the Source Editor. @+(TM5Ub
*/ dD{{G:V
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package com.tot.count; P.Uz[_&l6
import java.util.*; gk.c"$2
/** `+>'18F
* aHzS>
* @author @ a?^2X^
*/ ; M%n=+[O
public class CountCache { EX.`6,:+2
public static LinkedList list=new LinkedList(); fZ)M
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/** Creates a new instance of CountCache */ alB[/.1
public CountCache() {} vn0}l6n3s
public static void add(CountBean cb){ *#n?6KqZ
if(cb!=null){
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list.add(cb); RO10$1IW.2
} sVjM^y24
} !0+!%Nr>J
} paG^W&`;
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CountControl.java zld[uhc>
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/* 2G9sKg,kL
* CountThread.java ?h*Ngbj>
* O%KP,q&}Y
* Created on 2007年1月1日, 下午4:57 &&\HE7*
* O=Cz*j
* To change this template, choose Tools | Options and locate the template under |re>YQ!zd
* the Source Creation and Management node. Right-click the template and choose E"|LA[o
* Open. You can then make changes to the template in the Source Editor. k Up[b~
*/ | ]DJz
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package com.tot.count; <,S5(pZ
import tot.db.DBUtils; ~VqDh*0
import java.sql.*; wgeR%#DW
/** qek[p_7
* 4Sq[I
* @author D$wl.r
*/ $&!i3#FF
public class CountControl{ :XP/ `%:
private static long lastExecuteTime=0;//上次更新时间 5[py{Gq
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 Qq. ht
/** Creates a new instance of CountThread */ xpb,Nzwt^
public CountControl() {} v[O }~E7'
public synchronized void executeUpdate(){ k{ru<cf
Connection conn=null; F/ODV=J-
PreparedStatement ps=null; XYM 5'
try{ YgN:$+g5
conn = DBUtils.getConnection(); w>]?gN?8Fe
conn.setAutoCommit(false); e/p 2| 4;
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 0F495'*A
for(int i=0;i<CountCache.list.size();i++){ +mgmC_Q(0
CountBean cb=(CountBean)CountCache.list.getFirst(); yX'f"*
CountCache.list.removeFirst(); uV@#;c4
ps.setInt(1, cb.getCountId()); `~hB-Z5dI
ps.executeUpdate();⑴ /7)l 22<
//ps.addBatch();⑵ L/U^1=Wi*O
} \:To>A32
//int [] counts = ps.executeBatch();⑶ s?irT;=
conn.commit(); ?C[W~m P
}catch(Exception e){ g{_wMf
e.printStackTrace(); ]&dU%9S
} finally{ (zO)J`z>
try{ ~KW|<n4m
if(ps!=null) { v%=@_`Ht
ps.clearParameters(); 0^L>J"o
ps.close(); 007(k"=oV
ps=null; 5a PPq~%
} LL}|#%4d
}catch(SQLException e){} fXV+aZ
DBUtils.closeConnection(conn); w4m)lQM
} <h*r
} xDU{I0M
public long getLast(){ 4NY}=e5
return lastExecuteTime; >+P5Zm(_
} jOYa}jm?
public void run(){ ^Pq4 n%x
long now = System.currentTimeMillis(); *" ("^_x\
if ((now - lastExecuteTime) > executeSep) { *K<|E15 ,
//System.out.print("lastExecuteTime:"+lastExecuteTime); /5l"rni
//System.out.print(" now:"+now+"\n"); GbLuXU
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); |A'y|/)#Z
lastExecuteTime=now; "
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executeUpdate(); G=.vo3
} /s'7[bSv
else{ )H'SU_YU
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); %]2hxTV
} 0I`)<o-
} q$|Wxnz
} vSOO[.=
//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 NM`5hd{
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类写好了,下面是在JSP中如下调用。 -/y]'_a
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<% [%);N\o2Y
CountBean cb=new CountBean(); P0B`H7D
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); v/fo`]zP
CountCache.add(cb); $y0[AB|V
out.print(CountCache.list.size()+"<br>"); k"kGQk4
CountControl c=new CountControl(); x?aNK$A~X
c.run(); eVXlQO
out.print(CountCache.list.size()+"<br>"); g?e$B}%
%>