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: _;W.q7b]
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CountBean.java W4t;{b
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/* {WJ m
* CountData.java G5{T5#
* W= ig.-
* Created on 2007年1月1日, 下午4:44 <'}YyU=
* *HU &4E\a
* To change this template, choose Tools | Options and locate the template under l(yZO$
* the Source Creation and Management node. Right-click the template and choose +<'Ev~
* Open. You can then make changes to the template in the Source Editor. -TLlwxc^%
*/ I"xo*}
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package com.tot.count; )Fc%+TpKi
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/** .7^c@i[
* '"`IC\N^
* @author R1PkTZP&
*/ dLH(D: `
public class CountBean { Upx G@b
private String countType; .Q<>-3\K
int countId; "x%Htq@
/** Creates a new instance of CountData */ _qU4Fadgm
public CountBean() {} C=-=_>Q,L<
public void setCountType(String countTypes){ 3W V"U
this.countType=countTypes; 3\AU 72-
} '-wj9OU
public void setCountId(int countIds){ bkRLC_/d
this.countId=countIds; -<6\1J
} } j<)L,
public String getCountType(){ __uA}fZp
return countType; j*d
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} :{{F *FM;
public int getCountId(){ GeI-\F7b
return countId; Cwr~HY
} _ "E$v&_
} {M3qLf~z#C
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CountCache.java I) rCd/
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/* 9X[kEl
* CountCache.java u\a#{G;Z
* GXcJ< v
* Created on 2007年1月1日, 下午5:01 eJ,/:=QQ{
* @efh{
* To change this template, choose Tools | Options and locate the template under "_P;2N6
* the Source Creation and Management node. Right-click the template and choose 8<5]\X
* Open. You can then make changes to the template in the Source Editor. rW<KKGsRWQ
*/ +\x,HsUc"
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package com.tot.count; Y2|#V#
import java.util.*; ^9m\=5d
/** $': E\*ICb
* ;
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* @author %) /s; Q,
*/ phQUD
public class CountCache { EJj.1/]|r
public static LinkedList list=new LinkedList(); dMPc:tJT
/** Creates a new instance of CountCache */ c>,KZ!
public CountCache() {} {SOr#{1z*
public static void add(CountBean cb){ X1,I
if(cb!=null){ FO+Zue.RS
list.add(cb); `-.%^eIp
} svsq g{9z
} -#7'r<I9@
} ,NOsFO-`<
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CountControl.java D!@Ciw
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/* Wfu(*
* CountThread.java '>NCMB{*
* 7X`l&7IXP
* Created on 2007年1月1日, 下午4:57 ,%6P0#-
* C7XxFh
* To change this template, choose Tools | Options and locate the template under kh!FR u h
* the Source Creation and Management node. Right-click the template and choose Z|%_&M
* Open. You can then make changes to the template in the Source Editor. r~E=4oB7
*/ Az9?Ra;U
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package com.tot.count; 1!ii;s^e
import tot.db.DBUtils; R"4Vtww
import java.sql.*; 1=r#d-\tR
/** j@=%_^:i
* R}'bP
* @author R(!s
*/ @V(*65b2
public class CountControl{ B+Rm>^CBm
private static long lastExecuteTime=0;//上次更新时间 y.anl
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 I+BHstF5um
/** Creates a new instance of CountThread */ Bu#E9hJFvA
public CountControl() {} ^({})T0wu
public synchronized void executeUpdate(){ %u? >#
Connection conn=null; 3e
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PreparedStatement ps=null; +:8fC$vVfC
try{ E08klC0
conn = DBUtils.getConnection(); >x/z7v?^I
conn.setAutoCommit(false); Bs13^^hu
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); wZG\>9~
for(int i=0;i<CountCache.list.size();i++){ l-fi%Z7C
CountBean cb=(CountBean)CountCache.list.getFirst(); 3Q"<<pi!~
CountCache.list.removeFirst(); lun#^ J
ps.setInt(1, cb.getCountId()); 1uG"f<TsR
ps.executeUpdate();⑴ +GG9^:<yr
//ps.addBatch();⑵ ;>#wU'
} <
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//int [] counts = ps.executeBatch();⑶ 'ZT^PV\
conn.commit(); 1Y/s%L
}catch(Exception e){ ATJWO1CtB
e.printStackTrace(); XO`0>^g
} finally{ ]@dZ{H|
try{ ?b*s.
^
if(ps!=null) { }]e-{C}
ps.clearParameters(); ?Fi=P#
ps.close(); C.~,qmOP
ps=null; F{Z~ R
} #eQJEajv5
}catch(SQLException e){} rEv@YD
DBUtils.closeConnection(conn); N|1M1EBOu>
} )n+Lo&C<
} wy yWyf
public long getLast(){ QXL'^uO
return lastExecuteTime; ,eOB(?Ku
} C+'/>=>a.
public void run(){ vo`2\R.
long now = System.currentTimeMillis(); uH/J]zKR
if ((now - lastExecuteTime) > executeSep) { 34z"Pm
//System.out.print("lastExecuteTime:"+lastExecuteTime); R,gR;Aarw
//System.out.print(" now:"+now+"\n"); \Npxv
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); mIurA?&7!
lastExecuteTime=now; 3cFf#a #
executeUpdate(); AZ0;3<FfLp
} j\,EO+ZQCv
else{ L\Aq6q@c
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 9`wZz~hL"
} JX-'
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} R?68*}
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} | 1E|hh@k
//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 |s'Po^Sy
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类写好了,下面是在JSP中如下调用。 <d,b '<z
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<% lH-/L(h2
CountBean cb=new CountBean(); Z9:-rcr
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ?$vCW|f
CountCache.add(cb); [OM7g'?S0
out.print(CountCache.list.size()+"<br>"); u&`XB|~
CountControl c=new CountControl(); D6%J\C13`
c.run(); c0PIc^R(@
out.print(CountCache.list.size()+"<br>"); ?h.wK
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