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: jFG0`n}I
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CountBean.java S[:xqzyDg
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/* v Y|!
* CountData.java 72db[
* m>&HuHf
* Created on 2007年1月1日, 下午4:44 &lc8G
* 4/>Our 5
* To change this template, choose Tools | Options and locate the template under xl4=++pu)
* the Source Creation and Management node. Right-click the template and choose J]/}ojW3
* Open. You can then make changes to the template in the Source Editor. ?>uew^$d[w
*/ E">T*ao
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package com.tot.count; uV6g[J
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/** $A\m>*@
* vlWw3>4
* @author wVK*P
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*/ vFmJ;J
public class CountBean { 'md0] R|
private String countType; -C7 FuD[Xw
int countId; uYO|5a<f~
/** Creates a new instance of CountData */ Mio>{%/
public CountBean() {} @)YY\l#
public void setCountType(String countTypes){ XFZ~ #DT&
this.countType=countTypes; B33$ u3d
} <|6%9@
public void setCountId(int countIds){ &Y>zT9]$K
this.countId=countIds; WV<tyx9Z
} j#A%q"]8
public String getCountType(){ f?fKhu2
return countType; 43:t
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} B~WtZ-%%E
public int getCountId(){ j}HFs0<L
return countId; pNaiXu3
} H:&?ha,9
} h=VqxGC&
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CountCache.java nY-* i!H
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/* Q%ad q-B
* CountCache.java 8Cf|*C+_'
* \|=mD}N
* Created on 2007年1月1日, 下午5:01 3 pWM~(#>-
* )6oGF>o>
* To change this template, choose Tools | Options and locate the template under pgc3jP!
* the Source Creation and Management node. Right-click the template and choose oY9FK{
* Open. You can then make changes to the template in the Source Editor. h^|5|l
*/ L^Wz vv]
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package com.tot.count; Nud,\mXrY[
import java.util.*; eb:A1f4L
/** ?r_kyuU
* L&2u[ml
* @author Pi6C/$
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*/ %IZ)3x3l
public class CountCache { i2,U,>.
public static LinkedList list=new LinkedList(); Q
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/** Creates a new instance of CountCache */ Z|6{T
public CountCache() {}
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public static void add(CountBean cb){ &_-](w`
if(cb!=null){ ]?l{j
list.add(cb); HxwlYx,4
} *YV
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} >l1r,/\\
} X)Gp7k1w
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CountControl.java %e%7oqR?
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/* [=M%
* CountThread.java +++pI.>(*Q
* =
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* Created on 2007年1月1日, 下午4:57 Di(9]:+
* RVM&4#E
* To change this template, choose Tools | Options and locate the template under 7nE"F!d+0
* the Source Creation and Management node. Right-click the template and choose Epjff@7A
* Open. You can then make changes to the template in the Source Editor. /XpSe<3
*/ Lk,+Tfk"
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package com.tot.count; [/9(NUf
import tot.db.DBUtils;
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import java.sql.*; [1Dm<G
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/** .Ao0;:;(2-
* )iE"Tl
* @author <4X?EYaTq
*/ !C&%T]
public class CountControl{ 'CV^M(o'9
private static long lastExecuteTime=0;//上次更新时间 .[pUuVq]
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 J\`^:tcG
/** Creates a new instance of CountThread */ I0w%8bs
public CountControl() {} KCqqJ}G
public synchronized void executeUpdate(){ &d^=siL
Connection conn=null; S7sb7c'4 k
PreparedStatement ps=null; ^X?D#\
try{ O.\h'3C
conn = DBUtils.getConnection(); *8A6Q9YT
conn.setAutoCommit(false); 5w3Fqu>39?
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); F@SG((`
for(int i=0;i<CountCache.list.size();i++){ otriif@+Z
CountBean cb=(CountBean)CountCache.list.getFirst(); S!dHNA:iU
CountCache.list.removeFirst(); >;lKLGJrd>
ps.setInt(1, cb.getCountId()); B@cz
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ps.executeUpdate();⑴ \+B?}P8N*l
//ps.addBatch();⑵ WmVVR>0V|
} ejcwg*i
//int [] counts = ps.executeBatch();⑶ qo;)X0N
conn.commit(); IC~ljy]y_
}catch(Exception e){ lo:~aJ8
e.printStackTrace(); X>3^a'2,E
} finally{ d6b.zP
try{ /~hbOs/
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if(ps!=null) { /bcY6b=:
ps.clearParameters(); g [L
ps.close(); h}6_ybmZ
ps=null; eV;me>,
} j%xBo:
}catch(SQLException e){} P;GprJ`l
DBUtils.closeConnection(conn); &oN/_7y
} 'lQYJ0
} E+{5-[Zc*$
public long getLast(){ m5gI~1(9
return lastExecuteTime; wRbw
} ~3 @*7B5Q
public void run(){
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long now = System.currentTimeMillis(); 9ECS,r*B
if ((now - lastExecuteTime) > executeSep) { VkXn8J
//System.out.print("lastExecuteTime:"+lastExecuteTime); #s^s_8#&e
//System.out.print(" now:"+now+"\n"); K%2I
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); :~-i&KNk
lastExecuteTime=now; <!!nI%NC
executeUpdate(); AU`OESSI
} x5vzPh`
else{ B9W/bJ6%
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); G"Pj6QUva
} |[WL2<
} <Kp+&(l,l
} FO^24p
//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 P#bm uCOS
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类写好了,下面是在JSP中如下调用。 )52#:27F
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<% )0F^NU
CountBean cb=new CountBean(); /j
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cb.setCountId(Integer.parseInt(request.getParameter("cid"))); swt\Ru6,
CountCache.add(cb); f?m5pax|
out.print(CountCache.list.size()+"<br>"); E7LbSZ
CountControl c=new CountControl(); l#ygb|=x
c.run(); Ou!)1UFI
out.print(CountCache.list.size()+"<br>"); `skH-lk,
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