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: BF(.^oh"n0
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CountBean.java Ju 0
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/* &KZr`"cT#
* CountData.java s.uV,E*wu
* |oI]
* Created on 2007年1月1日, 下午4:44 $bT<8:g
* P% ZCACzV
* To change this template, choose Tools | Options and locate the template under ~^pV>>LX|
* the Source Creation and Management node. Right-click the template and choose 1{7*0cv$iL
* Open. You can then make changes to the template in the Source Editor. (*\*7dIo
*/ v08Xe*gNU
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package com.tot.count; fu6Ir,
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/** b63 tjqk
* 5t&;>-A'?'
* @author Rr/sxR|0_
*/ MehMhHY
public class CountBean { wnoL<p
private String countType; V:vYS
int countId; UL
/** Creates a new instance of CountData */ :#=XT9
public CountBean() {} XAf,k&f3
public void setCountType(String countTypes){ uzpW0(_i3a
this.countType=countTypes; QCvz| )
} )cd5iE:FO
public void setCountId(int countIds){ tE]0
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this.countId=countIds; MTxe5ob`$Q
} y.'5*08S0
public String getCountType(){ %qf ?_2v
return countType; C:WXI;*cr
} +)eI8o0#
public int getCountId(){ ic_q<Y}
return countId; _9Zwg+oO[
} C0$KpUB
} D[ -Gzqh
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CountCache.java 7P$>T
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/* `78:TU~5S
* CountCache.java L]C|&KP
* HMymoh$Q
* Created on 2007年1月1日, 下午5:01 WG0Ne;Ho
* ev_4!+ko
* To change this template, choose Tools | Options and locate the template under /T_@rm
* the Source Creation and Management node. Right-click the template and choose (dh{Gk4=+
* Open. You can then make changes to the template in the Source Editor. {!`0i
*/ vdLBf+Zi
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package com.tot.count; %kRQ9I".
import java.util.*; )Kw
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/** #M5R>&?Jqz
* ^t{2k[@
* @author .0b$mSV[
*/ KDODUohC
public class CountCache { d?uN6JH9
public static LinkedList list=new LinkedList(); ogrh"
/** Creates a new instance of CountCache */ n%J{Tcn6
public CountCache() {} bm+
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public static void add(CountBean cb){ 8IX,q
if(cb!=null){ ^mA ^7jB
list.add(cb); gISG<!+X^
} V"T48~Ue
} <FfdOK_
} /Dl{I7W
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CountControl.java M'
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/* vl{G;[6
* CountThread.java ?!4xtOA
* V#Hg+\{d
* Created on 2007年1月1日, 下午4:57 cR0OJ'w
* ph;ds+b
* To change this template, choose Tools | Options and locate the template under b;X|[tB
* the Source Creation and Management node. Right-click the template and choose o'8`>rb
* Open. You can then make changes to the template in the Source Editor. TNHkHR[&
*/ #:yh2y7a%
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package com.tot.count; (rM-~h6g
import tot.db.DBUtils; ,a&&y0,
import java.sql.*; /kLG/ry8l:
/** PSM~10l,
* CSC
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* @author 2Bf]#l{z
*/ SGuLL+|W#8
public class CountControl{ Sas&P:#r
private static long lastExecuteTime=0;//上次更新时间 #@*;Y(9Ol
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 X
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/** Creates a new instance of CountThread */ EO<{Bj=2
public CountControl() {} NZ}DbA+g;|
public synchronized void executeUpdate(){
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Connection conn=null; sSM^net0
PreparedStatement ps=null; ^`96L
try{ :UMtknV
conn = DBUtils.getConnection(); oY#62&wk4
conn.setAutoCommit(false); |N{?LKR
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); d'4^c,d
for(int i=0;i<CountCache.list.size();i++){ eiNF?](3O
CountBean cb=(CountBean)CountCache.list.getFirst(); _wC4n }J
CountCache.list.removeFirst(); :j}]nS
ps.setInt(1, cb.getCountId()); )9.i'{{ 0
ps.executeUpdate();⑴ -jv%BJJlX
//ps.addBatch();⑵ +EtL+Y(U
} / p_mFA]@
//int [] counts = ps.executeBatch();⑶ u0)~Im,X
conn.commit(); zO)>(E?
}catch(Exception e){ [HV>4,,3"
e.printStackTrace(); 2Op\`Ht&
} finally{ wcdD i[E>i
try{ w
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if(ps!=null) { kFJ sB,2-
ps.clearParameters(); errT7&@,A
ps.close(); Zr&~gXmVS
ps=null; jP]I>Tq
} 3kl<~O|Fs
}catch(SQLException e){} f^tCD'Vmi
DBUtils.closeConnection(conn); IwE{Zvr
} <0Mc\wy
} 0nh;0Z
public long getLast(){ ((2 g
return lastExecuteTime; NaR/IsN8%
} 8op,;Z7Y
public void run(){ 3M;[.b
long now = System.currentTimeMillis(); FXHcy:)}G
if ((now - lastExecuteTime) > executeSep) { {Q&@vbw'
//System.out.print("lastExecuteTime:"+lastExecuteTime); ,r&:C48dI
//System.out.print(" now:"+now+"\n"); Eagl7'x
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); >O{[w'sWa
lastExecuteTime=now; 7lo`)3mB
executeUpdate(); k3-'!dW<
} ;oKN 8vI#7
else{ &I&:
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); Ac0^`
} 9rB,7%@EL
} 5BL4VGwJ
} Lq&;`)BJ
//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 `W3;LTPEb
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类写好了,下面是在JSP中如下调用。 "|2|Vju%
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<% 1YGj^7V)|Z
CountBean cb=new CountBean(); w
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cb.setCountId(Integer.parseInt(request.getParameter("cid"))); *K{-J*
CountCache.add(cb); R3HfE*;Z
out.print(CountCache.list.size()+"<br>"); 2WP73:'t
CountControl c=new CountControl(); rQ^X3J*`
c.run(); =Me94w>G3X
out.print(CountCache.list.size()+"<br>"); V/=NIeSE
%>