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: bD35JG^&i
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CountBean.java Q,.By&
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/*
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* CountData.java 6b?`:$Cw3)
* <EMkD1e
* Created on 2007年1月1日, 下午4:44 =m}TU)4.
* ^m*3&x8
* To change this template, choose Tools | Options and locate the template under ]gu1#
* the Source Creation and Management node. Right-click the template and choose 6Rcua<;2P
* Open. You can then make changes to the template in the Source Editor. ~TDzq -U)
*/ 4`nqAX~'f
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package com.tot.count; L=,OZ9aA
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/** qZaO&"q
* mD7}t
* @author *z0K%@M
*/ +W9]ED
public class CountBean { %3M95UZ2
private String countType; TPHYz>D]
int countId; -!cIesK;<
/** Creates a new instance of CountData */ !!FR[NK
public CountBean() {} 9\v.qo.
public void setCountType(String countTypes){ ~m=$VDWm
this.countType=countTypes; S'o ]=&
} .Y1bY :=
public void setCountId(int countIds){ bM"fk&
this.countId=countIds; 2MuO*.9D
} ga-{!$b*
public String getCountType(){ HsnG4OE
return countType; \c{R <Hh
} uPkb, :6~Z
public int getCountId(){ Gn59yG!4
return countId; u_.HPA
} ]:&n-&@L
} iJ)0Y~
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CountCache.java #{x5L^v>]
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/* %M9;I
* CountCache.java zPVd(V~(T
* KmQ^?Ad-C
* Created on 2007年1月1日, 下午5:01 LeSHRoD
* 1Bg_FPu
* To change this template, choose Tools | Options and locate the template under 1}!L][(
* the Source Creation and Management node. Right-click the template and choose P-'_}*wxi
* Open. You can then make changes to the template in the Source Editor. "cMNdR1^,y
*/ xuUx4,Z
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package com.tot.count; T~X41d\
import java.util.*; q#NR32byF
/** aG!
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* mc
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* @author D{p5/#|r
*/ e1unzpWN
public class CountCache { \ZSTKi?
public static LinkedList list=new LinkedList(); R\5Vq$Q
/** Creates a new instance of CountCache */ "Sjr_!u
public CountCache() {} !
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public static void add(CountBean cb){ .x}gg\
if(cb!=null){ ;,XyN+2H
list.add(cb); ;/'|WLI9
} tz4
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} ,
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} ~c*
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CountControl.java 6tn+m54_
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/* vXdZmYrC
* CountThread.java X|b2c+I
* 9t K>gwb
* Created on 2007年1月1日, 下午4:57 KE.Dt
* A
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* To change this template, choose Tools | Options and locate the template under ?x3Jv<G0*
* the Source Creation and Management node. Right-click the template and choose :.uk$jx
* Open. You can then make changes to the template in the Source Editor. 8o|P&q(v*
*/ ,Ff n)+
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package com.tot.count; {.CMD9F[
import tot.db.DBUtils; 40#9]=;}
import java.sql.*; SEM8`lnu
/** 5HKW"=5Cf
* .Evy_o\^
* @author Izo! rC
*/ %NajFjBI
public class CountControl{ nt ,7u(
private static long lastExecuteTime=0;//上次更新时间 >(3\kiYS
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 cp6WMHLj
/** Creates a new instance of CountThread */ U
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public CountControl() {} g97]Y1g
public synchronized void executeUpdate(){ r:&|vP
Connection conn=null; i sW\MB]
PreparedStatement ps=null; sJZ!sznn
try{ 8TWTbQ
conn = DBUtils.getConnection(); WVX`<
conn.setAutoCommit(false); Qi9-z'
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); E0 l_--
for(int i=0;i<CountCache.list.size();i++){ Y3',"
CountBean cb=(CountBean)CountCache.list.getFirst(); qZk:mlYd
CountCache.list.removeFirst(); A\$
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ps.setInt(1, cb.getCountId()); P)6lu8zQ
ps.executeUpdate();⑴ t6lE#<xZV;
//ps.addBatch();⑵ n~g LPHY
} Vz%OV}\
//int [] counts = ps.executeBatch();⑶ \9:wfLF8!
conn.commit(); 4=[7Em?oLb
}catch(Exception e){ x /mp=
e.printStackTrace(); {0v*xL_O^
} finally{
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try{ O1P=#l iYX
if(ps!=null) { qOy=O
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ps.clearParameters(); j9R6ta3\l
ps.close(); `tEo]p
ps=null; ^G|98yc!'
} +?m0Q;%b
}catch(SQLException e){} ]lBGyUJn
DBUtils.closeConnection(conn); 6bO~/mpWT~
} a~]bD
} >v+jh(^
public long getLast(){ Y`GOER
return lastExecuteTime; d=3'?l`
} 6GL=)0Ah
public void run(){ T!2=*~A
long now = System.currentTimeMillis(); jqnCA<G~B-
if ((now - lastExecuteTime) > executeSep) { 3
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//System.out.print("lastExecuteTime:"+lastExecuteTime); }< 5F
//System.out.print(" now:"+now+"\n"); C~4PE>YtTv
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); %.HJK
lastExecuteTime=now; pz|'l:v^
executeUpdate(); _\8qwDg"#e
} aP-<4uGx
else{ S*
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//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); kH948<fk3
} 9X}I>
} G"dS+,Q
} J
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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 SOf{Hx0C6
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类写好了,下面是在JSP中如下调用。 ZcE_f>KV
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<% rN/|(@
CountBean cb=new CountBean(); :aAEJ
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); n,'OiVl[
CountCache.add(cb); h9s >LY
out.print(CountCache.list.size()+"<br>"); &1|?BZv
CountControl c=new CountControl(); K>/%X!RW
c.run(); \2C`<h$fN
out.print(CountCache.list.size()+"<br>"); (bp9Pj w
%>