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: <j+DY@*
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CountBean.java %4*-BCP
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/* |Ah'KpL8W
* CountData.java `A_CLVE
* GWsvN&nr
* Created on 2007年1月1日, 下午4:44 W1dpKv
* ycz6-kEp
* To change this template, choose Tools | Options and locate the template under )"`(+Ku&c
* the Source Creation and Management node. Right-click the template and choose Dp3&@M"^yY
* Open. You can then make changes to the template in the Source Editor. <l opk('7
*/ P-o/ax
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package com.tot.count; o$)pJ#";F
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/** j^-E,YMC
* mnh>gl!l
* @author >4
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*/ N_Q)AXr)
public class CountBean { P:,'
private String countType; ^K.
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int countId; XHKiz2Pc1
/** Creates a new instance of CountData */ ND $m|V-C
public CountBean() {} I|8'#QX
public void setCountType(String countTypes){ 0}tf*M+a
this.countType=countTypes; 2.)xWCG
} 3M\~#>
public void setCountId(int countIds){ @TBcVHy
this.countId=countIds; 'Z5l'Ac
} b&BkT%aA(G
public String getCountType(){ ?y_W%ogW
return countType; \]uD"Jqv#
} #}Y$+FtO
public int getCountId(){ HqC
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return countId; BPs|qb-
} jGy%O3/
} R-QSv$
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CountCache.java <cS"oBh&u0
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/* E}6q;"[
* CountCache.java {| ~
* @D1}).
* Created on 2007年1月1日, 下午5:01 @{/GdB,}
* `s1>7XWf
* To change this template, choose Tools | Options and locate the template under r{2V`h1/|
* the Source Creation and Management node. Right-click the template and choose cBcfGNTJ~
* Open. You can then make changes to the template in the Source Editor. 9n9Z
*/ l ld,&N8
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package com.tot.count; J,q6
import java.util.*; Uao8#<CkvJ
/** 0i/!by{@
* ),cozN=NM
* @author @ByD=
*/ E&>3 {uZI
public class CountCache { ]rC2jB\,M
public static LinkedList list=new LinkedList(); =c/jS
/** Creates a new instance of CountCache */ ZW+M<G
public CountCache() {} {o>51fXc)
public static void add(CountBean cb){ w8veh[%3n
if(cb!=null){ H#/ #yVw
list.add(cb); q~:H>;:G-
} zP554Gr ?
} oW
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} n$Nb,/o
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CountControl.java <e&88{jJ
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/* vtx3a^
* CountThread.java AUk-[i
* ~V34j:
* Created on 2007年1月1日, 下午4:57 py|ORVN(Z
* z3Id8G&>
* To change this template, choose Tools | Options and locate the template under =#=<%HPT
* the Source Creation and Management node. Right-click the template and choose @kh:o\
* Open. You can then make changes to the template in the Source Editor. &<dC3o!
*/ WzinEo{f
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package com.tot.count; LK>AC9ak<
import tot.db.DBUtils; ?58,Ja
import java.sql.*; |; [XZ ZZ
/** mM#[XKOC<
* 6&9}M Oc
* @author [d dKC)tA
*/ uy'I#^Bt
public class CountControl{ ;r8<
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private static long lastExecuteTime=0;//上次更新时间 OKo)p`BX
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 QH>e_
/** Creates a new instance of CountThread */ S[zETRSG
public CountControl() {} 2.p?gRO
public synchronized void executeUpdate(){ n3z]&J5fr
Connection conn=null; Z-U-n/6I
PreparedStatement ps=null; WMi$ATq
try{ >PbB /->
conn = DBUtils.getConnection(); ~SzHIVj:6
conn.setAutoCommit(false); Nh^
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); iVaCX Xf '
for(int i=0;i<CountCache.list.size();i++){ {u}d`%_.M
CountBean cb=(CountBean)CountCache.list.getFirst(); =# /BCL7
CountCache.list.removeFirst(); u=QG%O#B
ps.setInt(1, cb.getCountId()); tRtoA5
ps.executeUpdate();⑴ C}'Tmi
//ps.addBatch();⑵ {D{'
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} D`4>Wh/H
//int [] counts = ps.executeBatch();⑶ D`9 a"o
conn.commit(); WY& [%r
}catch(Exception e){ V|\dnVQ'-%
e.printStackTrace(); ZbAg^2
} finally{ pLiGky
try{ a>H8,a
if(ps!=null) { 5jNDr`pnu
ps.clearParameters(); $-w&<U$E
ps.close(); "7z1V{ ;Y
ps=null; XG!s+ShFV
} :aHLr[%Mz
}catch(SQLException e){} O3JBS^;V2
DBUtils.closeConnection(conn); >OxSrc@A
} ).$q9G
} ;h~v,h
public long getLast(){ EP'I
return lastExecuteTime; <$>Jsv
} Bj`ZH~T
public void run(){ x{_3/4
long now = System.currentTimeMillis(); q)f-z\
if ((now - lastExecuteTime) > executeSep) { w7E7r?)Wl|
//System.out.print("lastExecuteTime:"+lastExecuteTime); WU+OS(
//System.out.print(" now:"+now+"\n"); |& Pa`=sp
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); BcaX:C?f
lastExecuteTime=now; dCn'IM1
executeUpdate(); ix+sT|>
} 0ZAT;ea B
else{ <=Z`]8
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); U(6=;+q
} I xk+y?
} MszX9wl
} o+0x1Ct3P
//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 (#Ku`
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类写好了,下面是在JSP中如下调用。 y[A%EMd
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<% AuIg=-xR
CountBean cb=new CountBean(); )`,Y^`F2
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); =\FV_4)
CountCache.add(cb); *=b36M
out.print(CountCache.list.size()+"<br>"); |aX1PC)o_
CountControl c=new CountControl(); WNO!6*+
c.run(); zDohp 5,
out.print(CountCache.list.size()+"<br>"); D!WyT`T
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