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:
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CountBean.java XZ%[;[
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/* `}ak]Z_
* CountData.java ;a?<7LIx
* uB)q1QQsqp
* Created on 2007年1月1日, 下午4:44 `t/j6e]
* _*H Hdd5I
* To change this template, choose Tools | Options and locate the template under CR$wzjP j
* the Source Creation and Management node. Right-click the template and choose (?l ]}p^[
* Open. You can then make changes to the template in the Source Editor. X$@`4
*/ LcGKYl(\K
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package com.tot.count; 4$iS@o|
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/** g>t1rZ
* bll[E}E|3
* @author *)RKU),3nL
*/ 6>]
public class CountBean { g**!'T4&o
private String countType; MFROAVPZ5
int countId; #e@NV4q
/** Creates a new instance of CountData */ #QFz /6
public CountBean() {} 9\EW~OgTu
public void setCountType(String countTypes){ }.o.*N
this.countType=countTypes; AE:(:U\
} iZG-ca
public void setCountId(int countIds){ Dn)yBA%
this.countId=countIds; _.9 5>`
} dU3A:uS^
public String getCountType(){ T^4 dHG-(
return countType; ;B@#,6t/
} 4~Qnhv7
public int getCountId(){ y#a,d||N1
return countId; n#6{K6}k~
} PE5*]+lW.
} .F,l>wUNe
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CountCache.java &.E/%pQ`
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/* c>$d!IKCL
* CountCache.java ?1L<VL=b
* _GkLspSaU
* Created on 2007年1月1日, 下午5:01 f+9eB
* wn@~80)$
* To change this template, choose Tools | Options and locate the template under 8=$X hC
* the Source Creation and Management node. Right-click the template and choose (l%?YME
* Open. You can then make changes to the template in the Source Editor. 68j1svz9
*/ ,<
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package com.tot.count; /k/X[/WO
import java.util.*; m}z6Bbis 0
/** -F?97&G$
* q;[HUyY,
* @author $9?:P}$v
*/ CF>&mXg\
public class CountCache { *sldv
public static LinkedList list=new LinkedList(); ,Vq$>T@z
/** Creates a new instance of CountCache */ vu)EB!%[
public CountCache() {} '!A}.wF0
public static void add(CountBean cb){ {Fwvuk
if(cb!=null){ F^/KD<cgK
list.add(cb); ^B1Ft5F`b
} i!%WEHPe
} w)ki<Dudg
} ulzX$
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CountControl.java Dh4Lffy
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/* B9|s`o)!
* CountThread.java dDA8IW![S
* @&G}'6vF!
* Created on 2007年1月1日, 下午4:57 Vz0(D
* D]_6OlIE#'
* To change this template, choose Tools | Options and locate the template under <cOjtq,0
* the Source Creation and Management node. Right-click the template and choose VHPqEaR
* Open. You can then make changes to the template in the Source Editor. eGT&&Y
*/ kBqgz|jE%
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package com.tot.count; lD0a<L3
import tot.db.DBUtils; !D F~]&
import java.sql.*; 6fw7\u
/** Y:/p0o
* =COQv= GT
* @author qv(3qY
*/ d-b<_k{p
public class CountControl{ M@KQOAzt
private static long lastExecuteTime=0;//上次更新时间 ]2l}[
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private static long executeSep=60000;//定义更新间隔时间,单位毫秒 c3GBY@m
/** Creates a new instance of CountThread */
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public CountControl() {} r-YJ$/J
public synchronized void executeUpdate(){ ' Z#_"s#L
Connection conn=null; ~~|Iw=:
PreparedStatement ps=null; O[= L#wi
try{ 8Tg1 >q<
conn = DBUtils.getConnection(); K !ILO
conn.setAutoCommit(false); 3Qd/X&P
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); TO]7cC
for(int i=0;i<CountCache.list.size();i++){ }J6:D]Q
CountBean cb=(CountBean)CountCache.list.getFirst(); ^;ZpK@Luk
CountCache.list.removeFirst(); -HGRrWS
ps.setInt(1, cb.getCountId()); 4
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ps.executeUpdate();⑴ QOK,-
//ps.addBatch();⑵ >yKz8SV#
} QGI@5
//int [] counts = ps.executeBatch();⑶ %0 {_b68x
conn.commit(); x*:VE57,z
}catch(Exception e){ U]}F A2
e.printStackTrace(); eH7x>[lH.
} finally{ KDb j
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try{ g%Tokl
if(ps!=null) { @]IRB1X
ps.clearParameters(); Csy$1;"A
ps.close(); HI{q#
ps=null; F?tWx+N<{
} q#AIN`H
}catch(SQLException e){} 9]Ue%%vM
DBUtils.closeConnection(conn); S'^ q
} ;o'r@4^&$R
} CyLwCS{V\
public long getLast(){ d+G%\qpzQ
return lastExecuteTime; @:RoY vk$
} Dqo#+_v
public void run(){ X+sKG5nS
long now = System.currentTimeMillis(); m5
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if ((now - lastExecuteTime) > executeSep) { ?;v\wx
//System.out.print("lastExecuteTime:"+lastExecuteTime); ?o.d FKUe
//System.out.print(" now:"+now+"\n"); N$e
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// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); mWYrUI
lastExecuteTime=now; ]QHp?Ii1
executeUpdate(); 5,p;b
} EPn!6W5^
else{ 5-GS@fY
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); "`cN k26JZ
} f8[O]MrO;
} vu@.;-2E%
} 'fl.&"/r
//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 {H(l"KuL
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类写好了,下面是在JSP中如下调用。 pTi7Xy!Cw
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<% bwhH2 ^ !
CountBean cb=new CountBean(); "[P3b"=gW
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); MG=8`J-`
CountCache.add(cb); O'IU1sU
out.print(CountCache.list.size()+"<br>"); Q<u?BA/
CountControl c=new CountControl(); :8eI_X
c.run(); ?R)dxuj
out.print(CountCache.list.size()+"<br>"); vE^tdzAG
%>