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: `fTH"l1zn
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CountBean.java oT76)O
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/* HQtR;[1
* CountData.java 52X[{
*
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* Created on 2007年1月1日, 下午4:44 &B1j,$NRc
* Qt-7jmZw1
* To change this template, choose Tools | Options and locate the template under 5&59IA%S
* the Source Creation and Management node. Right-click the template and choose 4eFqD;
* Open. You can then make changes to the template in the Source Editor. *Ubsa9'fS
*/ Y~E
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package com.tot.count; <{ZDD]UGs0
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/** i}u,_
}
* bwrM%BL
* @author #)}K,FDd
*/ m*bTELb
public class CountBean { /thFs4
private String countType; 1SAO6Wh
int countId; rra|}l4Y
/** Creates a new instance of CountData */ EM2=g9y
public CountBean() {} hn`yc7<}(u
public void setCountType(String countTypes){ %mqep5n(
this.countType=countTypes; ]>vC.iYp
} `!,"">5
public void setCountId(int countIds){ %#go9H(K
this.countId=countIds; _HMQx_e0YM
} k)j6rU
public String getCountType(){ +56N}MAs
return countType; -!@]z2uU
} v2Ft=_*G|
public int getCountId(){ s9# WkDR
return countId; PHAM(iC&D
} 7%j1=V/
} 1U)U {i7j
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CountCache.java Lm-f0\(
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/* > J.q3
* CountCache.java v(0IQ
* 'zJBp 9a%
* Created on 2007年1月1日, 下午5:01 e
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* !n`9V^`
* To change this template, choose Tools | Options and locate the template under 7MbV|gM}
* the Source Creation and Management node. Right-click the template and choose i C)+5L#'
* Open. You can then make changes to the template in the Source Editor. "]SA4Ud^
*/ dI(1L~
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package com.tot.count; C.|.0^5
import java.util.*; q1^bH6*fl
/** ,kQCCn]
* ]D.}
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* @author m~I@q
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*/ p=XEMVqm
public class CountCache { (X?HuWTm
public static LinkedList list=new LinkedList(); !We9T )e
/** Creates a new instance of CountCache */ uVth&4dh9
public CountCache() {} QbJE+m5
public static void add(CountBean cb){ }j)][{i*x
if(cb!=null){ R+*-i+]Q#7
list.add(cb); R@df~
} uv|RpIv e:
} 8l>7=~Egp
} q _INGCJ
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CountControl.java C6JwJYa
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/* m@i](1*T|
* CountThread.java +xL' LCx
* u<U8LR=)V5
* Created on 2007年1月1日, 下午4:57 Y=?Tm,z4
* Cl8S_Bz
* To change this template, choose Tools | Options and locate the template under o$p]
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* the Source Creation and Management node. Right-click the template and choose og?L 9
* Open. You can then make changes to the template in the Source Editor. K3*-lO:A9
*/ h.pVIO`
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package com.tot.count; jX7;hQ+P
import tot.db.DBUtils; swz)gh-*
import java.sql.*; 5E#8F
/** D nl|B\
* 5yL\@7u`
* @author N0pA ,&
*/ ;S9
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public class CountControl{ *L&|4|BF2
private static long lastExecuteTime=0;//上次更新时间 lqcPV) n
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 <lZVEg
/** Creates a new instance of CountThread */ s7(1|}jh
public CountControl() {} v=_Ds<6n
public synchronized void executeUpdate(){ en"\2+{Cg
Connection conn=null; cK- jN9U
PreparedStatement ps=null; `.g'bZ<v/
try{ V
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conn = DBUtils.getConnection(); jA? 7>"|
conn.setAutoCommit(false); vX?C9Fr 2
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); d"=)=hm!
for(int i=0;i<CountCache.list.size();i++){ )GfL?'Z
CountBean cb=(CountBean)CountCache.list.getFirst(); sB*!Nf^y
CountCache.list.removeFirst(); v'Pbx
ps.setInt(1, cb.getCountId()); Nh01NY;
ps.executeUpdate();⑴ rMoz+{1A
//ps.addBatch();⑵ 58t_j54
} ,`8:@<e
//int [] counts = ps.executeBatch();⑶ E#E&z (G2
conn.commit(); ^KJi|'B
}catch(Exception e){ A6I^`0/
e.printStackTrace(); @8Cja.H
} finally{ 4nXemU=
try{ 'Yaq; mDY
if(ps!=null) { V$_.&S?(Y
ps.clearParameters(); X"V)oC
ps.close(); Gs>4/
ps=null; !<<wI'8
} C{G;G@/7
}catch(SQLException e){} :(K JLa]
DBUtils.closeConnection(conn); 5`6U:MDq
} gL&)l!2Y
}
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public long getLast(){ B2:GGZ|jS
return lastExecuteTime; q26qY5D
} u"F{cA!B
public void run(){ 9aYVbq""
long now = System.currentTimeMillis(); k/M{2Po+
if ((now - lastExecuteTime) > executeSep) { !TN)6e7`
//System.out.print("lastExecuteTime:"+lastExecuteTime); H~?7:K
//System.out.print(" now:"+now+"\n"); BxiR0snf0q
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); DFbhy
lastExecuteTime=now; sVH
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executeUpdate(); Ri3*au/Q
} h^YUu`P
else{ yJ>Bc
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); F9>"1
} 4,&f#=Y
} 1*f/Y9 Z
} 09=w
//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 _U
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类写好了,下面是在JSP中如下调用。 /vPr^Wv
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<% [[O4_)?el
CountBean cb=new CountBean(); ;3iWV"&_A
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); Q$5%9
CountCache.add(cb); ^}UFtL i
out.print(CountCache.list.size()+"<br>"); ny0]Q@
CountControl c=new CountControl(); P=a&>i
c.run(); wjTW{Bg~G
out.print(CountCache.list.size()+"<br>"); ^[6#Kw&E
%>