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: O^v^GG=e;C
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CountBean.java !uLW-[F,
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/* bE
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* CountData.java R9Wh/@J]
* e0%?;w-TL
* Created on 2007年1月1日, 下午4:44 "h'0&ZP~_
* $F-qqkR$
* To change this template, choose Tools | Options and locate the template under _IJPZ'Hr
* the Source Creation and Management node. Right-click the template and choose Q6Z%T.1
* Open. You can then make changes to the template in the Source Editor. Q#8}pBw
*/ w}VS mt$F
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package com.tot.count; 'NF_!D
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/** u1a5Vtel
* rMIr&T
* @author ,@ A1eX}
*/ sXp>4MomV
public class CountBean { #9 5.KkF
private String countType; h(!x&kZq.
int countId; L@Fw;G|%'
/** Creates a new instance of CountData */ ALS\}_8
public CountBean() {} EzOO6
public void setCountType(String countTypes){ 2@ vSe
this.countType=countTypes; -M}#-qwf
} ;u!qu$O
public void setCountId(int countIds){ 0Qvbc}KP8
this.countId=countIds; ]YQ[ )
} >=-w2&
public String getCountType(){ vwDnz/-
return countType; k`Nc<nN8
} l`8S1~j
public int getCountId(){ 1a4HThDXP
return countId; ?ihkV?;)
} 'L)@tkklp
} %E Jv!u*-
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CountCache.java Qi`Lj5;\F
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/* $6w[h7
* CountCache.java !qPVC\l
* YlDui8.N
* Created on 2007年1月1日, 下午5:01 /gT$ d2{
* hXdc5 ?i?
* To change this template, choose Tools | Options and locate the template under mw)KyU#l,:
* the Source Creation and Management node. Right-click the template and choose F2!C^r,~L
* Open. You can then make changes to the template in the Source Editor. !K^.r_0H.
*/ IBWUXG;
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package com.tot.count; ^Ts|/+}'i
import java.util.*; MjCD;I:C.
/** $A\fm`
* /,dcr*
* @author @G< J+pm
*/ BYt#aqf
public class CountCache { :iJ+ImBpK
public static LinkedList list=new LinkedList(); nPh5(&E
/** Creates a new instance of CountCache */ w1B!z
public CountCache() {} [YG\a5QK
public static void add(CountBean cb){ @ SaU2
if(cb!=null){ s7=CH
list.add(cb); V8ka*VJ(B
} 'EoJo9p6}
} :4s{?IY)l
} :GXiA
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CountControl.java ^6s<
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/* @Z> {/
* CountThread.java ]TQ2PVN2
* v'uWmL7C
* Created on 2007年1月1日, 下午4:57 ve[` 0
* xrDHXqH
* To change this template, choose Tools | Options and locate the template under S4uX utd
* the Source Creation and Management node. Right-click the template and choose =#]^H c
* Open. You can then make changes to the template in the Source Editor. <EFA^,3t%
*/ ,K=\Y9l3
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package com.tot.count; ,> lOmyh
import tot.db.DBUtils; j\&
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import java.sql.*; *4#)or
/** ,.[T]37
* $Kgw6
* @author S~L$sqt
*/ rC.z772y%
public class CountControl{ {/`iZzPg
private static long lastExecuteTime=0;//上次更新时间 I$!rNfrs
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 zhtNL_
/** Creates a new instance of CountThread */ +-YMW;5
public CountControl() {} 7/QQ&7+NkS
public synchronized void executeUpdate(){ 9I>qD
Connection conn=null; 9qS~-'&q#
PreparedStatement ps=null; }&A!h
try{ $5kb3x<W
conn = DBUtils.getConnection(); DXu915
conn.setAutoCommit(false); FrBoE#
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?");
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for(int i=0;i<CountCache.list.size();i++){ Q qGf*
CountBean cb=(CountBean)CountCache.list.getFirst(); .%;`:dtj
CountCache.list.removeFirst(); -;1'{v
ps.setInt(1, cb.getCountId()); ?145^ w
ps.executeUpdate();⑴ ;sd[Q01
//ps.addBatch();⑵ Z .6M~
} !$N^Ak5#
//int [] counts = ps.executeBatch();⑶ {`,dWjy{%
conn.commit(); _/Ky;p.
}catch(Exception e){ Xkcy~e
e.printStackTrace(); +bpUb0.W
} finally{ C3q}Dh+]
try{ .vsrZ_y?
if(ps!=null) { 6'CZfs\
ps.clearParameters(); |#9Nu9ak
ps.close(); *R1m=
ps=null; IcmTF #{D
} )D'SfNx#{
}catch(SQLException e){} ^o&3 +s}M
DBUtils.closeConnection(conn); GJ"S*30
} q6DuLFatc*
} &Omo\Oq&W>
public long getLast(){ lz2B,#
return lastExecuteTime; 3z7SK Gy
} nvY3$ Ty
public void run(){ Tbf't^Ot$
long now = System.currentTimeMillis(); MLwh&I9)
if ((now - lastExecuteTime) > executeSep) { i) v
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//System.out.print("lastExecuteTime:"+lastExecuteTime); <q@/Yy32
//System.out.print(" now:"+now+"\n"); @@~OA>^
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); j}9][Fm1*
lastExecuteTime=now; {l$DNnS
executeUpdate(); /)RyRS8c
} ILi{5L
else{ ]}7FTMGbY
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ipzv]c&
} N{oi }i6
} ~[n]la
} kaM=Fk=t
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 zq]I"0Bi.
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类写好了,下面是在JSP中如下调用。 S -$ L2N
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<% %oPW`r
CountBean cb=new CountBean(); m? 3!
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 0u[Vd:()v(
CountCache.add(cb); c;siMWw;
out.print(CountCache.list.size()+"<br>"); &b :u~puM
CountControl c=new CountControl(); JX4uH>6
c.run(); <ZmC8&Uo
out.print(CountCache.list.size()+"<br>"); dy/\>hu
%>