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: m@.4Wrv
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CountBean.java Y<:%_]]
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/* Sq/M
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* CountData.java ml.l( 6A
* iBwl(,)?m2
* Created on 2007年1月1日, 下午4:44 s#&jE
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* kR7IZo"q
* To change this template, choose Tools | Options and locate the template under x%k4Lm
* the Source Creation and Management node. Right-click the template and choose Ig"Krz
* Open. You can then make changes to the template in the Source Editor. RR{]^g51
*/ 63UAN0K%
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package com.tot.count; ^TVy:5Ag
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/** ^USj9HTK
* Au#(guvm
* @author 0?BT*
*/ Ooc,R(
public class CountBean { Zla5$GM
private String countType; Ag }hyIl
int countId; lEQ63)Z
/** Creates a new instance of CountData */ zu(/c
public CountBean() {} '1~mnmiP
public void setCountType(String countTypes){ P-K\)65{Y
this.countType=countTypes; a^iefwsNc
} _jy*`$"q(
public void setCountId(int countIds){ ,@R~y
this.countId=countIds; m0paGG
}
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public String getCountType(){ ^TVica
return countType; L q'*B9
} x@m"[u
public int getCountId(){ ZL #4X*zT
return countId; \ s`'3y
} G2ZF`WQ
} yf*MG&}
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CountCache.java v#IW;Rj8
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/* E+dr\Xhv
* CountCache.java @,CCwiF'q
* Z?oFee!4
* Created on 2007年1月1日, 下午5:01 K*'(;1AiW
* 2[[pd&MJZ
* To change this template, choose Tools | Options and locate the template under }KCXo/y
* the Source Creation and Management node. Right-click the template and choose mc?5,oz;pz
* Open. You can then make changes to the template in the Source Editor. A~\:}PN
*/ q!7z4Cn
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package com.tot.count; P}~6yX
import java.util.*; ZWG$MFEjl
/** ]d9;YVAU
* lD6hL8[
* @author &w*.S@ ;
*/ 6f?5/hq
public class CountCache { |08 tQ
public static LinkedList list=new LinkedList(); QV L92"
/** Creates a new instance of CountCache */ <#7}'@
public CountCache() {} ~YlbS-
public static void add(CountBean cb){ AVOqW0Z+y
if(cb!=null){ 9TO
list.add(cb); 2Q|Vg*x\U
} !Lb9KDk
} t.j q]L
}
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CountControl.java ``1#^ `
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/* pHsp]a
* CountThread.java }z,4IHNn
* B:n9*<v(
* Created on 2007年1月1日, 下午4:57 $A7[?Ai ?
* "}\z7^.W>
* To change this template, choose Tools | Options and locate the template under -[~{c]/ c
* the Source Creation and Management node. Right-click the template and choose pA!+;Y!ZB<
* Open. You can then make changes to the template in the Source Editor. |5F]y"Nb
*/ [m|\N
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package com.tot.count; uCNQ.Nbf C
import tot.db.DBUtils; !z{bqPlFGG
import java.sql.*; KB&t31aq
/** @>qzRo
* LdU, 32
* @author wQ2'%T|t
*/ _Eq:Qbw#
public class CountControl{ yh]#V"W3
private static long lastExecuteTime=0;//上次更新时间 X3!btxa%t
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 4L^KR_h/
/** Creates a new instance of CountThread */ "h_n/}r=
public CountControl() {} s+yBxgQ/
public synchronized void executeUpdate(){ '@AK0No\W
Connection conn=null; 3iV/7~
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PreparedStatement ps=null; W7l/{a
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try{ {tu* ="d=
conn = DBUtils.getConnection(); %ia/i :
conn.setAutoCommit(false); Mn7 y@/1
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); wI
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for(int i=0;i<CountCache.list.size();i++){ z/F(z*'v
CountBean cb=(CountBean)CountCache.list.getFirst(); QD+dP nZu
CountCache.list.removeFirst(); (+@3Dr5o0}
ps.setInt(1, cb.getCountId()); Vhz?9i6|g^
ps.executeUpdate();⑴ '|J-8"
//ps.addBatch();⑵ &%fy
} g5V9fnb!d
//int [] counts = ps.executeBatch();⑶ WyA>OB<Zeq
conn.commit(); mf,mKgfG
}catch(Exception e){ X~ P0Q
e.printStackTrace(); 2~2
} finally{ @gE
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try{ lh7{2WQ
if(ps!=null) { T_[W=9
ps.clearParameters(); +;Q&
ps.close(); +m:U9K(\h
ps=null; !b rN)b)f
} =XQ3sk6U
}catch(SQLException e){} n6O1\}YB
DBUtils.closeConnection(conn); !g=,O6
} UmiW_JB
} ^^jF*)DT@
public long getLast(){ ~b3xn T
return lastExecuteTime; G/Kz_Y,
} VXn]*Mo
public void run(){ MZn7gT0
long now = System.currentTimeMillis(); ?lR)Hi
if ((now - lastExecuteTime) > executeSep) { %ghQ#dZ]&
//System.out.print("lastExecuteTime:"+lastExecuteTime); ^5 F-7R8Q
//System.out.print(" now:"+now+"\n"); {KeHqM}e
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); nl*{@R.q @
lastExecuteTime=now; #n{wK+lz
executeUpdate(); _AI2\e
} <C+:hsS=
else{ {8@?9Z9R{
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); e~'y %| D
} 2i |wQU5w
} 9{70l539
} /-^gK^
//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 WE|L{
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类写好了,下面是在JSP中如下调用。 ~<Gs<c}z
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<% 6M"J3\
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CountBean cb=new CountBean(); dvyE._/v
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); L(`^T`
CountCache.add(cb); TkWS-=lNH0
out.print(CountCache.list.size()+"<br>"); m?;)C~[
CountControl c=new CountControl(); c*~/[:}
c.run(); %+gze|J
out.print(CountCache.list.size()+"<br>"); "Z&qOQg%3
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