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($a$
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CountBean.java #TeAw<2U
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/* ``rYzj_
* CountData.java <0jM07\<
* '68#7Hs.
* Created on 2007年1月1日, 下午4:44 ;^)4u
* ;L%\[H>G
* To change this template, choose Tools | Options and locate the template under ;9Wimf]G,E
* the Source Creation and Management node. Right-click the template and choose |]Y6*uEX<
* Open. You can then make changes to the template in the Source Editor. RE]*fRe7#
*/ GW.Y=S
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package com.tot.count; H87k1^}HV
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/** v|3mbApv
* C9>^!?>
* @author !!~r1)zN
*/ G=kW4rAk
public class CountBean { NZwi3
private String countType; Ov.oyke4
int countId; J*^ i=y
/** Creates a new instance of CountData */ D8$4P T0u
public CountBean() {} $?pfst~;O
public void setCountType(String countTypes){ ykGA.wo7/P
this.countType=countTypes; dzV2;
} @%^h|g8>Fu
public void setCountId(int countIds){ "|PX5
this.countId=countIds; ~C?)-
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} KHeeB `V>J
public String getCountType(){ 7!6v4ZA
return countType; 7--E$!9O,
} +.*=Fn22
public int getCountId(){ "!D,9AkZS
return countId; =:H EF;!
} tS,AS,vy]
} 8N`Rf;BM
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CountCache.java $bZ5@)E
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/* 3i9~'j;F3
* CountCache.java jgfr_"@A
* e&Z ?I2J
* Created on 2007年1月1日, 下午5:01 =^)$my\C:
* `t
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* To change this template, choose Tools | Options and locate the template under aZo>3z;
* the Source Creation and Management node. Right-click the template and choose %V#? 1{
* Open. You can then make changes to the template in the Source Editor. 0P;LH3sx
*/ DMKtTt[}
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package com.tot.count; Z)}2bJwA
import java.util.*; "`*
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/** %e+*&Z',
* 58o&Dv6?
* @author U.N&~S
*/ 7De BeY
public class CountCache { # `@jVX0
public static LinkedList list=new LinkedList(); +.xK`_[M
/** Creates a new instance of CountCache */ !0v3Lu~j
public CountCache() {} 2=naPTP(
public static void add(CountBean cb){ uaha)W;'9
if(cb!=null){ nM99AW
list.add(cb); ]qEg5:yY
} Xpfw2;`U'
} Z[1|('
} r(zn1;zl
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CountControl.java &(|x-OT
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/* Ejyo
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* CountThread.java n6C!5zq7U
* e&NJj:Ph*
* Created on 2007年1月1日, 下午4:57 GX*9R>
* j%81q
* To change this template, choose Tools | Options and locate the template under l}D /1~d
* the Source Creation and Management node. Right-click the template and choose S&c5Q*->[
* Open. You can then make changes to the template in the Source Editor. '7.4!I0'
*/ ( F4c0
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package com.tot.count; g)IW9q2
import tot.db.DBUtils; UM^~a$t
import java.sql.*; #E_<}o
/** #+|0 o-
* U/h@Q\~U
* @author STPRC&7;
*/ D|'[ [=
public class CountControl{ ,z>w^_
private static long lastExecuteTime=0;//上次更新时间 1L=)93,M
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 mR8tW"Z2
/** Creates a new instance of CountThread */ yI%q3lB}^
public CountControl() {} 3XNk*Y[5
public synchronized void executeUpdate(){ &{ZUY3
Connection conn=null; 4Wa*Pcj
PreparedStatement ps=null; zqp>Xw
try{ EWOa2^%}Z\
conn = DBUtils.getConnection(); dKa2_|k'
conn.setAutoCommit(false); 0(o.[%Ye
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); }$(\,SzW
for(int i=0;i<CountCache.list.size();i++){ !mUO/6Q hq
CountBean cb=(CountBean)CountCache.list.getFirst(); A!R'/m'VG
CountCache.list.removeFirst(); zA/Fh(uX
ps.setInt(1, cb.getCountId()); D?4bp'0 3
ps.executeUpdate();⑴ 4EaxU !BT
//ps.addBatch();⑵ ieXi6^M$
} 8uA!Vrp3
//int [] counts = ps.executeBatch();⑶ Jw{duM;]
conn.commit(); #RHt;SFx
}catch(Exception e){ 6r`Xi&
e.printStackTrace(); 4I*'(6
,!
} finally{ 1had8K-
try{ 6.6?Rp".
if(ps!=null) { eK}GBBdO
ps.clearParameters(); ?MS!t6
ps.close(); 2W#^^4^+
ps=null; 1Afy$It/{
} x1Z*R+|>2
}catch(SQLException e){} amWKykVS5
DBUtils.closeConnection(conn); > iYdr/^a
} {$v^2K'C
} }^^c/w_
public long getLast(){ aP
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return lastExecuteTime; {xh5s<uOj
} )mjGHq2
public void run(){ h67{qY[J[
long now = System.currentTimeMillis(); t=fP^bJ
if ((now - lastExecuteTime) > executeSep) { :@-.whj
//System.out.print("lastExecuteTime:"+lastExecuteTime); %.HLO.A
//System.out.print(" now:"+now+"\n"); 5Sb-Bn
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ]ZNFrpq
lastExecuteTime=now; z:1t
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executeUpdate(); zV(aw~CbZ
} F_4Et
else{ E0+~c1P-
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); U\M9sTqo
} ES8(:5
} \r [@A3O
} 7OS i2
//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 08! _B\
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类写好了,下面是在JSP中如下调用。 f>3)}9?xc}
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<% N7YCg
CountBean cb=new CountBean(); B![:fiR`
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); {SD%{
CountCache.add(cb); ekqS=KfWl;
out.print(CountCache.list.size()+"<br>"); .K`n;lVs
CountControl c=new CountControl(); -<M+ $hK\
c.run(); "bQi+@
out.print(CountCache.list.size()+"<br>"); k;)mc+ ~+
%>