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: )V1xL_hx/
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CountBean.java
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/* !/p|~K
* CountData.java )J 'F]s
* lq9|tt6Z
* Created on 2007年1月1日, 下午4:44 nq!=9r
* IH`Q=Pj
* To change this template, choose Tools | Options and locate the template under FDl/7P`b(
* the Source Creation and Management node. Right-click the template and choose C'I&<
* Open. You can then make changes to the template in the Source Editor. sx#O3*'>1
*/ 76w[X=Fv
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package com.tot.count; (9u`(|x
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/** q9vND[BQ
* 4FaO+Eo,8
* @author Z|_V ;*
*/ 4V:W 8k 9D
public class CountBean { x:)H Ii q/
private String countType; 6u"wgX]H
int countId; 6(QfD](2}
/** Creates a new instance of CountData */ dUv@u!}B
public CountBean() {} wH|%3@eJ
public void setCountType(String countTypes){ $+WXM$N
this.countType=countTypes; X;!*D
} s&E,$|80
public void setCountId(int countIds){ Iy_5k8]
this.countId=countIds; ={BC0,
} i*|HN"!
public String getCountType(){ @|:fm()
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return countType; ya2sS9^T[
} `/WxEu3
public int getCountId(){ zLl-{Kk
return countId; }5fd:B m;
} f6I)c$]Q
} 5X^\AW
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CountCache.java NV./p`k
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/* Hdyl]q-(P
* CountCache.java ;>7~@
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* gxO~44"
* Created on 2007年1月1日, 下午5:01 h!wq&Vi4
* zYaFbNi
* To change this template, choose Tools | Options and locate the template under Qb^{`
* the Source Creation and Management node. Right-click the template and choose uRy}HLZ"
* Open. You can then make changes to the template in the Source Editor. f hK<P_}
*/ ;SXkPs3q
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package com.tot.count; BQfnoF
import java.util.*; QI[WXxp
/** uT]$R
* _EMXx4J
* @author ?Q_ @@)
*/ 6?,qysm06
public class CountCache { xtGit}
public static LinkedList list=new LinkedList(); J;>;K6pW
/** Creates a new instance of CountCache */ B}04E^
public CountCache() {} ILCh1=?{9r
public static void add(CountBean cb){ al#(<4sJ
if(cb!=null){ ;\th.!'rn
list.add(cb); .J -k^+-
} 46vC/
} ">7xSWR*4
} p@78Xmu?q
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CountControl.java vs8[352
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/* oJM;CN
* CountThread.java =RUy4+0>F
* 6`2i'flv
* Created on 2007年1月1日, 下午4:57 HxK'u4I
* ;8#6da,
* To change this template, choose Tools | Options and locate the template under 3z0Bg
* the Source Creation and Management node. Right-click the template and choose \2u7>fU!
* Open. You can then make changes to the template in the Source Editor. KF&8l/f
*/ 9(fh+
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package com.tot.count; qdQ4%,E[
import tot.db.DBUtils; kt
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import java.sql.*; {#+K+!SvDX
/** G9xl-ag+z
* MY{Kq;FvRP
* @author ->qRGUW
*/ JRBz/ j
public class CountControl{ Hva!6vwO%O
private static long lastExecuteTime=0;//上次更新时间 JAHmmNlW
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 k|x mZA*
/** Creates a new instance of CountThread */ y:\<FLR}j
public CountControl() {} T}\>8EEG
public synchronized void executeUpdate(){ !l dE9 .
Connection conn=null; ~98q1HgS]D
PreparedStatement ps=null; #U0| j?!D
try{ BUZ74
conn = DBUtils.getConnection(); [e,xC!2
conn.setAutoCommit(false); YQ+8lANC
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); X%-"b`
for(int i=0;i<CountCache.list.size();i++){ jA8Bmwt;w
CountBean cb=(CountBean)CountCache.list.getFirst(); H`<u2fo|p
CountCache.list.removeFirst(); 1<h@^s ;
ps.setInt(1, cb.getCountId()); ~~Cd9Hzi
ps.executeUpdate();⑴ +Q"s!\5
//ps.addBatch();⑵ fV9+FOZn
} )2"WC\%
//int [] counts = ps.executeBatch();⑶ &2:WezDF
conn.commit(); !rgXB(
}catch(Exception e){ zx)}XOYf
e.printStackTrace(); .z
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} finally{ 3q'nO-KJ
try{ N]8/l:@
if(ps!=null) { qKXg'1#E)
ps.clearParameters(); 1grcCL
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ps.close(); Y".?j5f?
ps=null; F+c8
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} %Lx#7bR U
}catch(SQLException e){} 1$))@K-I
DBUtils.closeConnection(conn); Q~^v=ye
} DB"z93Mr<K
} ,P`:`XQ>_B
public long getLast(){ [)}`w;#
return lastExecuteTime; =WF@S1
} Fu?_<G%Ynp
public void run(){ eOVln1a
long now = System.currentTimeMillis(); c&#Q`m
if ((now - lastExecuteTime) > executeSep) { s'/_0
//System.out.print("lastExecuteTime:"+lastExecuteTime); /hg^hF
//System.out.print(" now:"+now+"\n"); J}Z\I Y,
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); u YFy4E3
lastExecuteTime=now; %b
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executeUpdate(); 0(5qVJ12
} 3#fg
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else{ 5a6d3u/
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); {2xc/
} ='I2&I,)
} (CDh,ZN;|
} =sAOWI,8!
//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 Aa-OMo;~
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类写好了,下面是在JSP中如下调用。 3-y2i/4}$
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<% |p/[sD+M
CountBean cb=new CountBean(); 9-#=xE9'U
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); %7[d5[U~ZA
CountCache.add(cb); !K.)Qr9 V
out.print(CountCache.list.size()+"<br>"); @B)5Ho
CountControl c=new CountControl(); m{*_%tjN0
c.run(); O~J f"Ht
out.print(CountCache.list.size()+"<br>"); UM1h[#?&V)
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