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: H?$gHZPI
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CountBean.java h-6zQs
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/* 2x<4&^
* CountData.java j5~nLo2
* NjP7?nXSx
* Created on 2007年1月1日, 下午4:44 MGfIA?u
* _}3NLAqg
* To change this template, choose Tools | Options and locate the template under 29kR7[k
* the Source Creation and Management node. Right-click the template and choose }&Kl)2:O
* Open. You can then make changes to the template in the Source Editor. AroYDR,3+
*/ m'YYkq(5%Z
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package com.tot.count; N)Qz:o0W
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/** 09sdt;V Q
* $ i;_yTht
* @author !lk9U^wnd
*/ !7y:|k,ac
public class CountBean { X].Igb)2
private String countType; i8i~b8r]
int countId; q^^&nz<A
/** Creates a new instance of CountData */ E=L1q)
public CountBean() {} YT\.${N
public void setCountType(String countTypes){ ?
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this.countType=countTypes; sQgJ`+Y8_
} LypBS]ru
public void setCountId(int countIds){ 6'6,ySo]
this.countId=countIds; t# <(Q
} .qg 2zE$0
public String getCountType(){ ?i5=sK\
return countType; h[}e5A]}
} 8s)(e9Sr
public int getCountId(){ t>%+[7?6
return countId; xay~fD
} Hwiftx
} #!R =h|
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CountCache.java ;noZmPa
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/* zIy&gOX
* CountCache.java Rs;Y|W4'
* I.hy"y2&
* Created on 2007年1月1日, 下午5:01 B
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* S7f"\[Aw
* To change this template, choose Tools | Options and locate the template under ve@E.`
* the Source Creation and Management node. Right-click the template and choose Pe)SugCs
* Open. You can then make changes to the template in the Source Editor. t)^18 z
*/ ]D&\|,,(
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package com.tot.count; Ys+NIV#Q
import java.util.*; gN5;Uk
/** /\d@A B^5I
* RAAu3QKu
* @author NNn sq@?6
*/ 5[|ZceY
public class CountCache { 'NSfGC%7R
public static LinkedList list=new LinkedList(); &9Xn:<"`)
/** Creates a new instance of CountCache */ t2RL|$>F1
public CountCache() {} #kRt\Fzq
public static void add(CountBean cb){ 7O\ Qxc\
if(cb!=null){ f/UIpswrZ'
list.add(cb); F@rx/3
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} $J!WuOz4^i
} lOu&4Kq{g
} [VY265)g
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CountControl.java U}^`R,C
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/* `*w!S8} m;
* CountThread.java *r].EBJ\
*
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* Created on 2007年1月1日, 下午4:57 {I]>!V0j!
* Gc2:^FVlh
* To change this template, choose Tools | Options and locate the template under uow{a*qd6
* the Source Creation and Management node. Right-click the template and choose |ohCA&k%;
* Open. You can then make changes to the template in the Source Editor. v9XevLs
*/ =}
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package com.tot.count; Bz4;R9_%I
import tot.db.DBUtils; ;(Kj-,>
import java.sql.*; DQ9}('^
/** z(Q 5?+P
* IA^*?,AZy
* @author ]@
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*/ $n_ax\15
public class CountControl{ AGK{t+`
private static long lastExecuteTime=0;//上次更新时间 Z:.*fs5
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 Bnh*;J0
/** Creates a new instance of CountThread */ RKD$'UWX
public CountControl() {} m t}3/d
public synchronized void executeUpdate(){ <Xb$YB-c
Connection conn=null; `[F[0fY-
PreparedStatement ps=null; Wh^wKF~%
try{ A1F!I4p5
conn = DBUtils.getConnection(); rHJtNN8$k
conn.setAutoCommit(false); O1Nya\^g<I
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 3h**y
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for(int i=0;i<CountCache.list.size();i++){ ,QPo%{:p
CountBean cb=(CountBean)CountCache.list.getFirst(); `P?!2\/
CountCache.list.removeFirst(); 2c%b
ps.setInt(1, cb.getCountId()); m*'87a9q0
ps.executeUpdate();⑴ &FY7
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//ps.addBatch();⑵ u$ff %`E
} 8DcIM(;Z
//int [] counts = ps.executeBatch();⑶
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conn.commit(); ie}?}s
}catch(Exception e){ OpLUmn
e.printStackTrace(); `Tc"a_p9t
} finally{ } bm ^`QY
try{ 8]&\FA 8
if(ps!=null) { y)mtSA8
ps.clearParameters(); /TY=ig1z
ps.close(); M s Q=1
ps=null; 1)J'
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} y;=/S?L.:
}catch(SQLException e){} %6E:SI4
DBUtils.closeConnection(conn); )M_|r2dDq3
} Esdw^MGL2
} <8BNqbX
public long getLast(){ <F?UdMT4y
return lastExecuteTime; Jp-6]uW
} gfQ1p ?
public void run(){ X{8g2](z.
long now = System.currentTimeMillis(); >;+q,U}
if ((now - lastExecuteTime) > executeSep) { ]
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//System.out.print("lastExecuteTime:"+lastExecuteTime); `ZGKM>q`
//System.out.print(" now:"+now+"\n"); T[%@B"
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); E^? 3P'%^
lastExecuteTime=now; L16">,5
executeUpdate(); vQmqYyOc2
} }xpo@(e
else{ Ti$_V_
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); XvI Y=~
} <`d;>r=4z
} ?JMy
} %a|m[6+O
//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 Ie{L-Na
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类写好了,下面是在JSP中如下调用。 'wVi>{?
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<% wVkRrFJ
CountBean cb=new CountBean(); +Sak_*fq
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); &;[e
CountCache.add(cb); PGhYkj2
out.print(CountCache.list.size()+"<br>"); lS/l
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CountControl c=new CountControl(); f{)n xd
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c.run(); YcN &\(
out.print(CountCache.list.size()+"<br>"); _:HQ4s@
%>