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: f_[<L
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CountBean.java (]b!{kS
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/* )u3 Zm
* CountData.java W;_nK4$%'
* 3l)h yVf&
* Created on 2007年1月1日, 下午4:44 Tg!i%v(-t
* 'I_Qb$
* To change this template, choose Tools | Options and locate the template under %R@X>2l/_
* the Source Creation and Management node. Right-click the template and choose N U|d
* Open. You can then make changes to the template in the Source Editor. pF&(7u
*/ D|@/yDQ
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package com.tot.count; MG[o%I96
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/** >"gf3rioW
* *4_jA](
* @author sW)Zi
*/ TftHwe):V
public class CountBean { HU%o6c w
private String countType; )_{dWf1
int countId; "5;;)\o~
/** Creates a new instance of CountData */ +u!0rLb
public CountBean() {} mu?Eco`~
public void setCountType(String countTypes){ P/xKnm~
this.countType=countTypes; '6Ay&A3N]
} R>,:A%?^b5
public void setCountId(int countIds){ ) _mr! z(S
this.countId=countIds; KC(xb5x
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} 3= xhoRX
public String getCountType(){ /GIxR6i
return countType; CLeG<Hi
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} hQ]H
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public int getCountId(){ _u{c4U0,
return countId; XEn*?.e
} ,oaw0Vw
} +|bmT
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CountCache.java gN24M3{C
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/* xZ|Y?R5m
* CountCache.java NG
* YhOlxON
* Created on 2007年1月1日, 下午5:01 rA2g&
* GDu~d<R H
* To change this template, choose Tools | Options and locate the template under nA
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* the Source Creation and Management node. Right-click the template and choose <@}I0
* Open. You can then make changes to the template in the Source Editor. @fs`=lL/
*/ [[>wB[w
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package com.tot.count; Y2d;E.DH8
import java.util.*; w;k):;$
/** si&S%4(
* tjGd )
* @author }-~X4u#
*/ F;gx%[$GX
public class CountCache { e&>;*$)
public static LinkedList list=new LinkedList(); Jrg2/ee,*
/** Creates a new instance of CountCache */ qHNE8\9
public CountCache() {} %=?cZfFqO
public static void add(CountBean cb){ AZa6Cw
if(cb!=null){ k]5Bykf`Ky
list.add(cb); A|L 8P
} h~(G$':^
} A,%C,*)Cg
} ~_Lr=C D;4
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CountControl.java Gm9hYhC8
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/* {"&SJt[%X
* CountThread.java ]8icBneA~'
* ZO4*sIw%
* Created on 2007年1月1日, 下午4:57 6oLwfTy
* _~q?_'kx
* To change this template, choose Tools | Options and locate the template under ow0!%|fO
* the Source Creation and Management node. Right-click the template and choose -O&CI)`;B
* Open. You can then make changes to the template in the Source Editor. AC;V
m: @{
*/ \3'9Uz,OC
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package com.tot.count; abJ"
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import tot.db.DBUtils; mt5KbA>nU
import java.sql.*; ]da^xWK
/** x_c7R;C
* )(tM/r4`c&
* @author [5uRS}!
*/ 'v\L @"
public class CountControl{ }|5VRJA
private static long lastExecuteTime=0;//上次更新时间 /[ 6j)HIS
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 8me ]JRw
/** Creates a new instance of CountThread */ 9*E7}b,
public CountControl() {} e|&6$A>4]
public synchronized void executeUpdate(){ )ZBY* lk9
Connection conn=null; [74F6Qp
PreparedStatement ps=null; 3/b;7\M
try{ UN%Vg:=
conn = DBUtils.getConnection(); m}8[#:
conn.setAutoCommit(false); ?gPKcjgoH!
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ,_X/Gb6)
for(int i=0;i<CountCache.list.size();i++){ 5*E#*H
CountBean cb=(CountBean)CountCache.list.getFirst(); N.4q.
CountCache.list.removeFirst(); hSK;V<$[Z
ps.setInt(1, cb.getCountId()); Hewd4k
ps.executeUpdate();⑴ NM0tp )h
//ps.addBatch();⑵ !A>z(eIsv`
} $b<6y/"
//int [] counts = ps.executeBatch();⑶ 2-"0 ^n{
conn.commit(); QT9n,lX
}catch(Exception e){ lip[n;Ir>
e.printStackTrace(); xS7$%w['
} finally{ N<QjdD&
try{ HLBkR>e
if(ps!=null) { *loOiM\5a
ps.clearParameters(); 70lfb`
ps.close(); e#,~,W.H
ps=null; UG'bOF4
} `60gFVu
}catch(SQLException e){} /
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DBUtils.closeConnection(conn); avy"r$v_&
} .`7cBsXH
} r?CI)Y;
public long getLast(){ A].>.AI
return lastExecuteTime; 16L]=&@
} 4QIE8f
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public void run(){ ]r3Kg12Mi
long now = System.currentTimeMillis(); .i^7|o:
if ((now - lastExecuteTime) > executeSep) { CiR%Ujf
//System.out.print("lastExecuteTime:"+lastExecuteTime); p-%|P]&
//System.out.print(" now:"+now+"\n"); xr7+$:>a
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); bsd99-_(4
lastExecuteTime=now; * ,v|y6
executeUpdate(); .))v0
} n!6Z]\8~$
else{ |oub!fG4
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); goJ|oi
} j
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} SxK:]Aw
} A~Xq,BxCV
//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 vA)O{W\o
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类写好了,下面是在JSP中如下调用。 *jMk/9oa<N
# wc \T
<% dq IlD!
CountBean cb=new CountBean(); @\w,otT
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); W5/0`[4
CountCache.add(cb); +,v-=~5
out.print(CountCache.list.size()+"<br>"); YUQtMf9
CountControl c=new CountControl(); LkLN7|
c.run(); SEl#FWR
out.print(CountCache.list.size()+"<br>"); q>s-Y|
%>