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: zWHq4@K
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CountBean.java k3~9;Z
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/* ;_<R +w3-
* CountData.java uO?+vYAN
* )!T~l(g
* Created on 2007年1月1日, 下午4:44 ex3Qbr
* 6TtB3;5
* To change this template, choose Tools | Options and locate the template under La4S/.
* the Source Creation and Management node. Right-click the template and choose v}B%:1P4
* Open. You can then make changes to the template in the Source Editor. } M#e\neii
*/ ,g*!NK_:5t
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package com.tot.count; +>$]leqa
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/** oMh$:jR $
* 0RUk^
* @author 6Rc=!_v^
*/ Knq9"k
public class CountBean { K1&
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private String countType; / f%mYL
int countId; yI0bSu<j-
/** Creates a new instance of CountData */ K/Q"Z*
public CountBean() {} _(W@FS
public void setCountType(String countTypes){ dG\wW@}J
this.countType=countTypes; jLVJ+mu
} 1W^hPY
public void setCountId(int countIds){ 6{Wo5O{!\
this.countId=countIds; f:c'j`
} 8|u4xf<
public String getCountType(){ 1+l 8%G=hB
return countType; rIyH/=;
} Hbm 4oYN
public int getCountId(){ _;lw,;ftA
return countId; $( hT{C,K
} $] 6u#5
} lj4Fg*/Yn
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CountCache.java Q&9yrx.
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/* S-Uod y
* CountCache.java NBikYxa
* .~z'm$s1o
* Created on 2007年1月1日, 下午5:01 96=<phcwN[
* gI+8J.AG=
* To change this template, choose Tools | Options and locate the template under FG? Mc'r&
* the Source Creation and Management node. Right-click the template and choose fi+}hGj(r
* Open. You can then make changes to the template in the Source Editor. . [|UNg
*/ SZyk G[
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package com.tot.count; IwYeKN6s
import java.util.*; rK3kg2H
/** 3jmo[<p*x
* .;#T<S"
* @author q=1 NRG
*/ uuzV,q
public class CountCache { N& _~y|
public static LinkedList list=new LinkedList(); Z6!Up1
/** Creates a new instance of CountCache */ B#sCB&(
public CountCache() {} f?3-C8hU
public static void add(CountBean cb){ N Ob`)qb
if(cb!=null){ N&9o 1_}
list.add(cb); T j$'B[cv
} eUPa5{P
} 9&mSF0q
} o%d
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CountControl.java eP{srP3 9
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/* ou,[0B3n0
* CountThread.java kZ]H[\Fs
* GP:<h@:798
* Created on 2007年1月1日, 下午4:57 xtV+Le%
* %sa?/pjK
* To change this template, choose Tools | Options and locate the template under j"W>fC/u
* the Source Creation and Management node. Right-click the template and choose b)wcGBS
* Open. You can then make changes to the template in the Source Editor. w)btv{*
*/ k"wQ9=HP7
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package com.tot.count; rd <m:r
import tot.db.DBUtils; w5FIHYl6B
import java.sql.*; 2TK \pfD
/** %?~'A59
* &@=Jm
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* @author |vI*S5kn6A
*/ QM$UxWo-
public class CountControl{ ,'L>:pF3
private static long lastExecuteTime=0;//上次更新时间 PyeNu3Il4
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 6[bopin
/** Creates a new instance of CountThread */ D9rQ%|}S
public CountControl() {} *TOd Iq&z
public synchronized void executeUpdate(){ .i0K-B
Connection conn=null; kpOdyn(
PreparedStatement ps=null; 5LeZ?'"c
try{ K_Y-N!h
conn = DBUtils.getConnection();
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conn.setAutoCommit(false); (;NJ<x
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ''17(%
for(int i=0;i<CountCache.list.size();i++){ woI5a ee|
CountBean cb=(CountBean)CountCache.list.getFirst(); =H95?\}T[
CountCache.list.removeFirst(); dQ:,pe7A
ps.setInt(1, cb.getCountId()); z]7 WC
ps.executeUpdate();⑴ A(Ct^/x-
//ps.addBatch();⑵ b?wrOS
}
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//int [] counts = ps.executeBatch();⑶ b,!C8rJ
conn.commit(); 1{uxpYAP=
}catch(Exception e){ kG^76dAQL
e.printStackTrace(); \!KE_7HRu
} finally{ B|`?hw@g+
try{ |x[I!I7.F
if(ps!=null) { X><C#G
ps.clearParameters(); iTxWXij
ps.close(); _"DC)
ps=null; IsXNAYj
} MT6p@b5
}catch(SQLException e){} \PX4>/d@y
DBUtils.closeConnection(conn); vu0Ql1
} zLJ>)v$81
}
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public long getLast(){ j
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return lastExecuteTime; j?T'N:Qd
} 7UTfafOGX
public void run(){ `IHP_IfR
long now = System.currentTimeMillis(); )Q2Ap&
if ((now - lastExecuteTime) > executeSep) { t~2oEwTm
//System.out.print("lastExecuteTime:"+lastExecuteTime); f \&X$g
//System.out.print(" now:"+now+"\n"); pyEQb#
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); >t+ ENYb
lastExecuteTime=now; &61U1"&$ R
executeUpdate(); lZzW-
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} Bc>j5^)8w
else{ m\teE]8x
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); S!K<kn`E3
} U1\EwBK8*T
} 3Tr,waV
} ammi4k/
//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 fe .=Z&
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类写好了,下面是在JSP中如下调用。 '1u?-2
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<% ,%!m%+K9a
CountBean cb=new CountBean(); ?;~!C2Zs
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); N2:Hdu:
CountCache.add(cb); XJul~"
out.print(CountCache.list.size()+"<br>"); T!/o^0w
CountControl c=new CountControl(); xd?=#d
c.run(); NKY|Z\
out.print(CountCache.list.size()+"<br>"); i0M6;W1T
%>