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: P={8qln,X
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CountBean.java [5i}C
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/* xua
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* CountData.java ioJ|-@!#o
* " 3tk"#.#
* Created on 2007年1月1日, 下午4:44 Ng|c13A=
* d*R('0z{
* To change this template, choose Tools | Options and locate the template under
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* the Source Creation and Management node. Right-click the template and choose * _@t$W
* Open. You can then make changes to the template in the Source Editor. ~%?LFR'
*/ D]'/5]~z<
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package com.tot.count; ZVni'ym
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/** 7Cx-yv
* 0?*":o30
* @author .o)
*/ Sz-TarTF
public class CountBean { D-Q54 "^3
private String countType; q.ZkQN+
int countId; G2w0r,[
/** Creates a new instance of CountData */ -u~AY#*
public CountBean() {} n!h952"
public void setCountType(String countTypes){ d,E2l~s
this.countType=countTypes; #D^(dz*
} VJS1{n=;k
public void setCountId(int countIds){ "0m\y+%8
this.countId=countIds; $GQ{Ai:VwF
} />O.U?
public String getCountType(){ o3Z<tI8-V
return countType; M3s:B& /
} ,U.|+i{
public int getCountId(){ <~
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return countId; 4F,RlKHBl
} c/}-pZn<
} [<.dOe7|
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CountCache.java z-m:l;
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/* ;CDa*(e
* CountCache.java ~ep^S^V+
* t: 03
* Created on 2007年1月1日, 下午5:01 vz^=o'
* zKFiCP
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* To change this template, choose Tools | Options and locate the template under ntn ~=oL
* the Source Creation and Management node. Right-click the template and choose nG7E j#1
* Open. You can then make changes to the template in the Source Editor. <x1,4a~
*/ #YK=e&da
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package com.tot.count; p~z\&&0U0
import java.util.*; -#
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/** : 2A\X' @
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* @author ;-VXp80J
*/ o"g<Vz
public class CountCache { _uZVlu@
public static LinkedList list=new LinkedList(); /J!~0~F
/** Creates a new instance of CountCache */ {4r } jH
public CountCache() {} OQ+kOE&
public static void add(CountBean cb){ lh-zE5;
if(cb!=null){ nQ;M@k&9eV
list.add(cb); ZmS
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} bq z*90
} K
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} -;o0)DwZ
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CountControl.java ; g\rY
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/* ^t P|8k
* CountThread.java })C}'!+]
* =~'y' K]
* Created on 2007年1月1日, 下午4:57 }8Nr.gY
* @+Anp4%;Y
* To change this template, choose Tools | Options and locate the template under HjT -5>I7f
* the Source Creation and Management node. Right-click the template and choose iz2;xa*
* Open. You can then make changes to the template in the Source Editor. 9n;6;K#
*/ v
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package com.tot.count; K}tC8D
import tot.db.DBUtils; a.up&g_$
import java.sql.*; &,'CHBM
/** y|(?>\jBl
* z`!f'I--!
* @author )OZ
*/ w%~Mg3|
public class CountControl{ -NUA
private static long lastExecuteTime=0;//上次更新时间 wcL|{rUXba
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 n8o(>?Kw
/** Creates a new instance of CountThread */ e84O
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public CountControl() {} y)T|1)
public synchronized void executeUpdate(){ G`z=qa j
Connection conn=null; ' [%?j?2r
PreparedStatement ps=null; (
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try{ F+/#ugI
conn = DBUtils.getConnection(); 4]no#lVRJ
conn.setAutoCommit(false); *C,1x5
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); <h*$bx]9 +
for(int i=0;i<CountCache.list.size();i++){ ~X,ZZ 9H
CountBean cb=(CountBean)CountCache.list.getFirst(); Ki\J)l
CountCache.list.removeFirst(); p*~b5'+ C+
ps.setInt(1, cb.getCountId()); N2&h yM
ps.executeUpdate();⑴ K5 Z'kkOk
//ps.addBatch();⑵ oEsqLh9a|
} GE}>{x=^x
//int [] counts = ps.executeBatch();⑶ Z;cA_}5
conn.commit(); RH"EO4
}catch(Exception e){ /;`-[
e.printStackTrace(); QVe<Z A8N;
} finally{ d>Ky(wS
try{ B+[L/C}=;
if(ps!=null) { v8\pOI}c
ps.clearParameters(); 9%DLdc\z;
ps.close(); *u!l"0'\
ps=null; =/bC0bb{i
} gCM(h[7A
}catch(SQLException e){} YRU#/TP
DBUtils.closeConnection(conn); }M &hcw<
} 1
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} b#Vm;6BHD1
public long getLast(){ $Fv|w9
return lastExecuteTime; 2 P9{?Y
} 9.Yn]O
public void run(){ .> ^U
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long now = System.currentTimeMillis(); 9Qn*frdY,
if ((now - lastExecuteTime) > executeSep) { vn ^*
//System.out.print("lastExecuteTime:"+lastExecuteTime); qwYq9A$+
//System.out.print(" now:"+now+"\n"); I~25}(IDZ"
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ]_2<uK}fg
lastExecuteTime=now; r-5xo.J'
executeUpdate(); +g%Ah
} #fxdZm,
else{ i"#zb&~nF
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); k];fQ7}m<0
} (ljoD[kZ
} e4-7&8N+
} @"0n8y
//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 A&:~dZ:%w
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类写好了,下面是在JSP中如下调用。 qnnP*15`
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<% z}2
CountBean cb=new CountBean(); CwsC)]{/o
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); L%I8no-Q
CountCache.add(cb); p0C|ECH
out.print(CountCache.list.size()+"<br>"); @<B$LJ|jdG
CountControl c=new CountControl(); &\<?7Qj3U|
c.run(); X,`e1nsR
out.print(CountCache.list.size()+"<br>"); O:+?:aI@
%>