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: g&X$)V4C
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CountBean.java jsjH.O
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/* :<!a.%=
* CountData.java +H8]5~',L%
* e'p'{]r<w
* Created on 2007年1月1日, 下午4:44 l7n c8K
* 6gNsh
* To change this template, choose Tools | Options and locate the template under 3N[t2Y1r
* the Source Creation and Management node. Right-click the template and choose FG:(H0
* Open. You can then make changes to the template in the Source Editor. G-~+F nUC
*/ 8-+Ce;h
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package com.tot.count; %?^IS&]Z
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/** Jzo|$W
* (~#{{Ja
* @author t[Qf|#g
*/ B!4chxzUZ
public class CountBean { ( hp 52Vse
private String countType; UBLr|e>dQE
int countId; FxW~Co
/** Creates a new instance of CountData */ 3)3?/y)_
public CountBean() {} jEo)#j];`<
public void setCountType(String countTypes){ >;LXy
this.countType=countTypes; M2l0x @|
} iP)`yB5 `
public void setCountId(int countIds){ il|e5TD^
this.countId=countIds; )w4i0Xw^C:
} ~+
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public String getCountType(){ -XRn%4EX?
return countType; j
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} Op0n.\>
public int getCountId(){ yb\T<*
return countId; .nl!KzO6g
} [3"k :
} F0(P2j
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CountCache.java zmB6Y
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/* D=Jj !;
* CountCache.java _)XQb1]
*
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* Created on 2007年1月1日, 下午5:01 ,1&Pb %}
* g(& hu S
* To change this template, choose Tools | Options and locate the template under '"qTmo!
* the Source Creation and Management node. Right-click the template and choose mSdByT+dG
* Open. You can then make changes to the template in the Source Editor. :#7"SEud}
*/ 6?i]oy^X]p
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package com.tot.count; '{*{
import java.util.*; _UI*W&*
/** xq$(=WPI
* `ECY:3"$KA
* @author {%Cb0Zh
*/ Vq-W|<7C=
public class CountCache { <hkSbJF
public static LinkedList list=new LinkedList(); ]ie38tX$
/** Creates a new instance of CountCache */ F#-mseKhc
public CountCache() {} ",O |uL
public static void add(CountBean cb){ >8M=REn4
if(cb!=null){ Bie#GKc
list.add(cb); =>3wI'I
} #0kVhx7%
} Is&0h|
} >-oB%T
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CountControl.java 8L1vtYz
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/* X(_xOU)V
* CountThread.java RRRF/Z;))
* !B|Aq-
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* Created on 2007年1月1日, 下午4:57 v'RpsCov
* w2X0.2)P2
* To change this template, choose Tools | Options and locate the template under /{Mo'.=Z
* the Source Creation and Management node. Right-click the template and choose 03pD<
* Open. You can then make changes to the template in the Source Editor. <fSWX>pR
*/ aW=c.Q.
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package com.tot.count; 0{Uc/
import tot.db.DBUtils; Eqizx~e qq
import java.sql.*; pKZRgA#kN
/** RW-)({
* 05>mR qVL
* @author YN]xI
*/ $;iMo/
public class CountControl{ e'I/}J
private static long lastExecuteTime=0;//上次更新时间 (/gv
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private static long executeSep=60000;//定义更新间隔时间,单位毫秒 cV$an
/** Creates a new instance of CountThread */ $Z|HFV{
public CountControl() {} b!p]\B!
public synchronized void executeUpdate(){ NMs8^O|0
Connection conn=null; r{cmw`WA/P
PreparedStatement ps=null; DplS\}='s
try{ )fy-]Ky
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conn = DBUtils.getConnection(); r{ >`"
conn.setAutoCommit(false); `uP:UQ9S
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); =Gv*yR*]t
for(int i=0;i<CountCache.list.size();i++){ ~%chF/H
CountBean cb=(CountBean)CountCache.list.getFirst(); _"%hcCMw
CountCache.list.removeFirst(); d4~;!#<
ps.setInt(1, cb.getCountId()); - f?8O6e
ps.executeUpdate();⑴ XQ3"+M_KG
//ps.addBatch();⑵ ]J1oY]2~
} yopC
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//int [] counts = ps.executeBatch();⑶ =cR"_ Z[8X
conn.commit(); e j,)<*
}catch(Exception e){ &2,3R}B/
e.printStackTrace(); .}9Lj
} finally{ ^r=Wj@`
try{ `.z"Q%uz
if(ps!=null) { X;bHlA-g
ps.clearParameters(); hv0bs8h
ps.close();
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ps=null; CM%Rz-c
} !F:ANoaS
}catch(SQLException e){} vX@TZet0
DBUtils.closeConnection(conn); /S{U|GBB%r
} 6&
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} dAWB.#
public long getLast(){ KS'n$
return lastExecuteTime; ;FGS(.mjlC
} c>Tf@Aog>
public void run(){ UY6aD~tD0
long now = System.currentTimeMillis(); 2U|"]tpM&
if ((now - lastExecuteTime) > executeSep) { 3qW](
//System.out.print("lastExecuteTime:"+lastExecuteTime); B[.$<$}G
//System.out.print(" now:"+now+"\n"); skm~~JM^
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 38 ]}+Bb
lastExecuteTime=now; ;Rlf[](iL
executeUpdate(); Z;O!KsJ
} t[r6 jo7
else{ Sa[?B
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); =X1oB,W{
} !,+<?o y
} `w&?SXFO8
} z:a7)z
//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 =2t=Zyp0Y
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类写好了,下面是在JSP中如下调用。 %4wEAi$I
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<% eQz.N<f"
CountBean cb=new CountBean(); c/7}5#Rs
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); h`dHk]O
CountCache.add(cb); ^g|j4N
out.print(CountCache.list.size()+"<br>"); ;hPVe_/
CountControl c=new CountControl(); %iB,hGatE
c.run(); NCdDG
out.print(CountCache.list.size()+"<br>"); -%Rw2@vU
%>