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: $wn"+wX
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CountBean.java }`9}Q
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/* 2O5yS
* CountData.java {9Op{bZ
* :I }_
* Created on 2007年1月1日, 下午4:44 f6P5J|'
* -h8!O+7 .
* To change this template, choose Tools | Options and locate the template under }?Y+GT"E
* the Source Creation and Management node. Right-click the template and choose VmB/X))
* Open. You can then make changes to the template in the Source Editor. lA<IcW
*/ W$Bx?}x($
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package com.tot.count; K9*#H(
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/** y|X\f!
* E
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* @author #+eV5%Si
*/ wWflZ"%
public class CountBean { ud-.R~f{e
private String countType; Om0S^4y]x
int countId; {hM*h(W~3
/** Creates a new instance of CountData */ 7c6-S@L
public CountBean() {} R@0ELxzA
public void setCountType(String countTypes){ QE5
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this.countType=countTypes; E}qeh"sJt
} pz^"~0o5
public void setCountId(int countIds){ viBf".
this.countId=countIds; 2Xgw7`
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} >}/"gx
public String getCountType(){ +*
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return countType; 8X]j;Rb
} z@ A5t4+3
public int getCountId(){ 1W
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return countId; )x"Z$ jIs
} H2RNekck
} /kVy#sT|
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CountCache.java }~-)31e'`
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/* '
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* CountCache.java h3xX26l
* 6SsZK)X
* Created on 2007年1月1日, 下午5:01 t Q_}o[
* W.n@
* To change this template, choose Tools | Options and locate the template under R< xxwjt
* the Source Creation and Management node. Right-click the template and choose a(8]y.`Tv
* Open. You can then make changes to the template in the Source Editor. G$4lH>A&
*/ 'eqvK|Uj:
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package com.tot.count; Y@u{73H
import java.util.*; Li=l/
/** !HDk]
* qTyU1RU$9^
* @author ^m8\fCA*
*/ qr=U=oK
public class CountCache { 4[.-
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public static LinkedList list=new LinkedList(); Z/uRz]Hi
/** Creates a new instance of CountCache */ S,S_BB<Y[b
public CountCache() {} 7!JoP?!
public static void add(CountBean cb){ 6aQ{EO-]'=
if(cb!=null){ jO:<"l^+u
list.add(cb); =$Q3!bJ
} ,-DE;l^Q=
} N M~e
} *vsOL4I%
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CountControl.java o(~JZik
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/* w6Tb<ja
* CountThread.java ieS5*@^k
* eB$v'9S8/
* Created on 2007年1月1日, 下午4:57 .FHOOw1r=
* [AX).b
* To change this template, choose Tools | Options and locate the template under #0Oqw=F
* the Source Creation and Management node. Right-click the template and choose pdnL~sv
* Open. You can then make changes to the template in the Source Editor. N'm:V
*/ web&M!-
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package com.tot.count; `(B1 "qRi
import tot.db.DBUtils; !8=uBS%
import java.sql.*; x|<|eRYK
/** "v*RY "5#
* EUna_ 4=
* @author &<^@/osi
*/ !>S'eXt
public class CountControl{ `&9#!T.
private static long lastExecuteTime=0;//上次更新时间 V`fh,(:
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 J;_JHlK
/** Creates a new instance of CountThread */ Rb#Z\e}e-
public CountControl() {} ]r"{G*1Q
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public synchronized void executeUpdate(){ s^KxAw_IV
Connection conn=null; |+`hSA
PreparedStatement ps=null; W+K=M*^D;c
try{ P<4jY?.
conn = DBUtils.getConnection(); R?&S]?H
conn.setAutoCommit(false); #{
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); Q}fAAZ&7h
for(int i=0;i<CountCache.list.size();i++){ rX{|]M":T
CountBean cb=(CountBean)CountCache.list.getFirst(); =h_4TpDQ
CountCache.list.removeFirst(); \v-> '
ps.setInt(1, cb.getCountId()); @#Xzk?+
ps.executeUpdate();⑴ Ha+FH8rZ
//ps.addBatch();⑵ !&'xkw `
} &aF_y_f\
//int [] counts = ps.executeBatch();⑶ %W&=]&L
conn.commit(); A&t'uY6
}catch(Exception e){ ?ST}0F00}
e.printStackTrace(); Yaa
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} finally{ q75F^AvH
try{ 1@nR.v"$
if(ps!=null) { p6HZ2Q:a
ps.clearParameters(); RXWjFv~/
ps.close(); +.lO8
ps=null; `chf8
} y6PAXvv'{
}catch(SQLException e){} o$-8V:)6d
DBUtils.closeConnection(conn); dU&.gFw1
} >$Fc=~;Ba
} H`Z4a
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public long getLast(){ #!`zU4&2
return lastExecuteTime; l5h9Eq
} s)M2Z3>+
public void run(){ J<`RlDI
long now = System.currentTimeMillis(); 5W{>5.Arx)
if ((now - lastExecuteTime) > executeSep) { ~y|%D;
//System.out.print("lastExecuteTime:"+lastExecuteTime); wyc,Ir
//System.out.print(" now:"+now+"\n"); ~AE034_N
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); EhD|\WLx!
lastExecuteTime=now; yh0|f94m
executeUpdate(); 4
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} +p cj8K%
else{ vSnb>z1
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); %cm5Z^B1"
} X
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} .y\HQ^j
} _E30t( _.
//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 k]>k1Mi=
x#YOz7.
类写好了,下面是在JSP中如下调用。 Czci6Lz
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<% f<}!A$wd
CountBean cb=new CountBean(); zEhy0LLm
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); #VO2O0GR
CountCache.add(cb); <m6Xh^Ko;
out.print(CountCache.list.size()+"<br>"); ~<Lf@yu-{
CountControl c=new CountControl(); ?\O+#U%W
c.run(); RV$+g.4
out.print(CountCache.list.size()+"<br>"); "FXS;Jf
%>