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: X5|/s::u
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CountBean.java >[fVl8G_0
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/* ~P#zhHw
* CountData.java <N=p:e,aN,
* `s>=Sn&UP
* Created on 2007年1月1日, 下午4:44 @IY?DO
* xhkWKB/7
* To change this template, choose Tools | Options and locate the template under %"[dGB$S
* the Source Creation and Management node. Right-click the template and choose #"8[8jyV
* Open. You can then make changes to the template in the Source Editor. Te@6N\g
*/ B4:l*P'
*/^2RZg|W
package com.tot.count; u1{ym_
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/** m?VRX.>
* m_"p$m;
* @author 9N
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*/
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public class CountBean { _|
private String countType; GP[r^Z
int countId; ,;iBeqr5
/** Creates a new instance of CountData */ RYZE*lWUh
public CountBean() {} ](=wlq)
public void setCountType(String countTypes){ qm}>J^hnB#
this.countType=countTypes; s>VEuLY*
} <VaMUm<2
public void setCountId(int countIds){ %|(?!w7
this.countId=countIds; C9F+e
} IbJ[Og^Qyu
public String getCountType(){ 5nx<,-N*BP
return countType; Az< 9hk
} yD"0=\
public int getCountId(){ K>cz63}S
return countId; ;\.JV '
} YZH#5]o8
} `<}V
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CountCache.java [+l
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/* k<Tez{<
* CountCache.java 3Q$'qZw p
* hygnC`|
* Created on 2007年1月1日, 下午5:01 !-5S8b
* 3K#mF7)a
* To change this template, choose Tools | Options and locate the template under _rMT{q3
* the Source Creation and Management node. Right-click the template and choose 5':Gu}Vq
* Open. You can then make changes to the template in the Source Editor. 8_IOJ]:w
*/ hyOm9WU
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package com.tot.count; ;sChxQ=.^
import java.util.*; SCurO9RN
/** WR
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* Itr7lv'5xx
* @author {x|kg;
*/ E./__Mz@
public class CountCache { '>e79f-O)
public static LinkedList list=new LinkedList(); P*SCHe'
/** Creates a new instance of CountCache */ zvGK6qCk
public CountCache() {} TsX+. i'
public static void add(CountBean cb){ Sn(l$wk=
if(cb!=null){ #A3v]'7B
list.add(cb); ~n/Aq*
} *vRI)>wU
} J`r,_)J"2
} {,Bb"0 \
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CountControl.java fQQsb 5=i
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/* 6)wy^a|pb
* CountThread.java i-k >U}[%
* |}M0,AS
* Created on 2007年1月1日, 下午4:57 x[vBK8
* z+k=|RMau
* To change this template, choose Tools | Options and locate the template under zkh hN"bX
* the Source Creation and Management node. Right-click the template and choose sOl>5:D6
* Open. You can then make changes to the template in the Source Editor. oSn! "<x
*/ g8I!E$
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package com.tot.count; M?Ndy*]
import tot.db.DBUtils; JY2/YDJ
import java.sql.*; }Kj Ju;
/** W-z90k4Z5
* lMC{SfdH
* @author cq,v1Y<
*/ _~;&)cn,0
public class CountControl{ b "
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private static long lastExecuteTime=0;//上次更新时间 hj&fQ}X
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 5iQmZ[
/** Creates a new instance of CountThread */ zLsb`)!
public CountControl() {} Ufdl|smt1
public synchronized void executeUpdate(){ 5{13V*<
Connection conn=null; <&5m N
PreparedStatement ps=null; yuHZ&e
try{ X(k{-|9]
conn = DBUtils.getConnection(); KdT[*-
conn.setAutoCommit(false); Q(510)
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); iuC7Y|
for(int i=0;i<CountCache.list.size();i++){ u^Nxvx3l0
CountBean cb=(CountBean)CountCache.list.getFirst(); <vB<`
CountCache.list.removeFirst(); }bf=Ntk
ps.setInt(1, cb.getCountId()); D<U
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ps.executeUpdate();⑴ b mOqeUgB
//ps.addBatch();⑵ OXHvT/L`
} +VCo$o
//int [] counts = ps.executeBatch();⑶ r{\BbUnf)
conn.commit(); 38c?^
}catch(Exception e){ y=AsgJ
e.printStackTrace(); e}42/>}#D
} finally{ %MJL5
try{ bLgL0}=n
if(ps!=null) { MA\m[h]
ps.clearParameters(); =)I"wR"v$
ps.close(); E6Q]A~
ps=null; A8pj~I/*-
} T[;;9z
}catch(SQLException e){} SY-ez91
DBUtils.closeConnection(conn); i;o}o*=
} I^~=,D
} {L@+(I
public long getLast(){ 0K<x=-cCB
return lastExecuteTime; ,~4H{{<j
} X^}A*4j
public void run(){ Rj[hhSx 2
long now = System.currentTimeMillis(); TUh&d5a9H
if ((now - lastExecuteTime) > executeSep) { ]^=|Zd-
//System.out.print("lastExecuteTime:"+lastExecuteTime); qib7Z]j
//System.out.print(" now:"+now+"\n"); 6HoqEku/Q
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); fb\DiKsW
lastExecuteTime=now; ugYw<
executeUpdate(); /+VIw`E
} (1 CJw:
else{ ?Z q_9T7
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 4%
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} AL$W +')
} bGv*-;*
} 'p%=<0vrr
//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 ZJ;LD*
*'D=1{WZ!
类写好了,下面是在JSP中如下调用。 gH %y
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<% \6sqyWI
%
CountBean cb=new CountBean(); xXX/]x>
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); A\K,_&x1Z
CountCache.add(cb); )^4hQ3BS
out.print(CountCache.list.size()+"<br>"); ^q
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CountControl c=new CountControl(); KOjluP
c.run(); gQ37>
out.print(CountCache.list.size()+"<br>"); 0rD#s{?
%>