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: @kRe0:t
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CountBean.java w\8grEj
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/* L:%;
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* CountData.java L]9uY
* q2Ax-#
* Created on 2007年1月1日, 下午4:44 OGrp{s
* D8C@x`
* To change this template, choose Tools | Options and locate the template under K zKHC
* the Source Creation and Management node. Right-click the template and choose f-tjMa /_
* Open. You can then make changes to the template in the Source Editor. 0:Yz'k5
*/ |:L<Ko
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package com.tot.count; v/}M_E
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/** ?_(0cVi
* 2BsMFMIw1
* @author #/MUiV
*/ w<.{(1:v
public class CountBean { bJmVq%>;
private String countType; 7Ha
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int countId; t8E'd:pE
/** Creates a new instance of CountData */ VfAIx]Fa
public CountBean() {} AhiZ0W"
public void setCountType(String countTypes){ IM7k\
this.countType=countTypes; $DJp|(8
} BO5F6lyQ0P
public void setCountId(int countIds){ ? D2:'gg
this.countId=countIds; :S{[^-"
} 593D/^}D
public String getCountType(){ .3Jggp
return countType; r8pTtf#Q
} 0jro0f'
public int getCountId(){ ~^UQw?;
return countId; gmJiKuAL5
} ac p-4g+j
} Azxy!gDT"
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CountCache.java .zAB)rNc
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/* &D\~-fOGb
* CountCache.java MR:Co4(
* =mxmJFA
* Created on 2007年1月1日, 下午5:01 g|a2z_R
* ~^2Y*|{)
* To change this template, choose Tools | Options and locate the template under -4mUGh1dy
* the Source Creation and Management node. Right-click the template and choose \/p\QT@mm
* Open. You can then make changes to the template in the Source Editor. 4(B{-cK
*/ N1jj\.nB
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package com.tot.count; ]d&6 ?7 !>
import java.util.*; 4Cr|]o'
/** ~M6Q8Y9
* *`>(K&
* @author [R iCa
*/ '=EaZ>=
public class CountCache { (y7U}Sb'
public static LinkedList list=new LinkedList(); \::<]
/** Creates a new instance of CountCache */ 0%7c?3#
public CountCache() {} 8QV+DDZx
public static void add(CountBean cb){ lwIU|T<4
if(cb!=null){ /m%i"kki
list.add(cb); -)(HG)3
} |XzqP +t
} hhLEU_U
} ,kfUlv=
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CountControl.java a*o#,T5A
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/* /PN[g~3
* CountThread.java /!rH DcR
* j
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* Created on 2007年1月1日, 下午4:57 yeqZPzn
* "yxIaTZu
* To change this template, choose Tools | Options and locate the template under /KFCq|;7s,
* the Source Creation and Management node. Right-click the template and choose _[zO?Div[
* Open. You can then make changes to the template in the Source Editor. LRW7_XYz
*/ >_XRh
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package com.tot.count; .e%PK[o
import tot.db.DBUtils; r%A-
import java.sql.*; # kl?ww U
/** fFudoIC
* ^\Gaf5{
* @author \2~Cn c*O
*/ M^DYzJ
public class CountControl{ a^t#kdT
private static long lastExecuteTime=0;//上次更新时间 w0(A7L:L
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 NitWIj[U;
/** Creates a new instance of CountThread */ N
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public CountControl() {} A I}29L3C
public synchronized void executeUpdate(){ #)QR^ss)iw
Connection conn=null; 3Z;`n,g
PreparedStatement ps=null; _PZGns,u
try{ ,rx?Ig}kz
conn = DBUtils.getConnection(); ;2y3i5^k
conn.setAutoCommit(false); Hz&a~
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); m?VA 1
for(int i=0;i<CountCache.list.size();i++){ &[ejxK"
CountBean cb=(CountBean)CountCache.list.getFirst(); }w^Hm3Y^&
CountCache.list.removeFirst(); 8%q:lI
ps.setInt(1, cb.getCountId()); Ugzq;}V#
ps.executeUpdate();⑴ `Nmw
//ps.addBatch();⑵ (+lwt
} bII pJQ1.[
//int [] counts = ps.executeBatch();⑶ b7 %Z~
conn.commit(); ' ^L|}e
}catch(Exception e){ U[1Rw6
e.printStackTrace(); D#R5G
} finally{ Gv?3T Am8
try{ Y@N-q
if(ps!=null) { 3.>M=K~09
ps.clearParameters(); HE#IJB6BS?
ps.close(); }xXUCU<
ps=null; Dz4e.tvN
} >qkZn7C
}catch(SQLException e){} .&fG_(6|
DBUtils.closeConnection(conn); I~ Q2jg2
} y}Ji( q~
} \2F{r<A\@
public long getLast(){ nKpXRuFn\
return lastExecuteTime; X}x"+#\<@
} sI>I
public void run(){ .)J7 \z8m
long now = System.currentTimeMillis(); :98<dQIG
if ((now - lastExecuteTime) > executeSep) { b?S,%
//System.out.print("lastExecuteTime:"+lastExecuteTime); =Ts2a"n
//System.out.print(" now:"+now+"\n"); ypyqf55gK
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); g{0a]'ph
lastExecuteTime=now; mN+
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executeUpdate(); 2:b3+{\f
} !C ]5_
else{ eQK}J]S<
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); pK/r{/>r
} nX
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} NL`}rj
} vl1`s
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//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 t@=*k9
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类写好了,下面是在JSP中如下调用。 [\|`C4@3a
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<% YO&=fd*
CountBean cb=new CountBean(); |AD"}8
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 3(?V!y{@
CountCache.add(cb); ",&^ f
out.print(CountCache.list.size()+"<br>"); P D,s,A
CountControl c=new CountControl(); e'"2yA8dh"
c.run(); 7I\qEr57
out.print(CountCache.list.size()+"<br>"); wg-qq4Q\
%>