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: '1kj:Np
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CountBean.java },n,P&M\`
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/* i)ES;b4
* CountData.java Vav+$l|j@
* @T,H.#bL
* Created on 2007年1月1日, 下午4:44 S}v{^vR
* o$H Jg
* To change this template, choose Tools | Options and locate the template under ~-`BSR
* the Source Creation and Management node. Right-click the template and choose H(%] Os
* Open. You can then make changes to the template in the Source Editor. {>UMw>T[
*/ Z68Wf5@to&
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package com.tot.count; LDi ezi
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/** Mc$v~|i6
* d_WnK{
* @author \@PUljU]
*/ }eDX8b8emA
public class CountBean { r"u(!~R
private String countType; xo)?XFM2
int countId; YCB 3
/** Creates a new instance of CountData */ UTK.tg
public CountBean() {} 53u.pc
public void setCountType(String countTypes){ xeP;"J}
this.countType=countTypes; M#lVPXS
} (g)lv)4P
public void setCountId(int countIds){ X!MfJ^)q
this.countId=countIds; \")YKN=W
} dV2b)p4J
public String getCountType(){ $ Pb[c%'
return countType; ^K77V$v
} Ng;b!S
public int getCountId(){ Am=PUQF$
return countId; YI),q.3X~
} sei!9+bZr
} zk 'e6
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CountCache.java 73sAZa|
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/* CQuvbAo
* CountCache.java ,YMdXYu`s
* \$HB~u%dr
* Created on 2007年1月1日, 下午5:01 U5ud?z()OA
* p2NB~t7Z
* To change this template, choose Tools | Options and locate the template under A_q3p\b
* the Source Creation and Management node. Right-click the template and choose "6NNId|Y
* Open. You can then make changes to the template in the Source Editor. (zLIv9$
*/ $5"-s]
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package com.tot.count; |xgCV@
import java.util.*; 36Z`.E>~L
/** fi4/@tV?$L
* ]zMBZs
* @author "$"mWF-
*/ <ZvPtW
public class CountCache { Z-p^3t'{
public static LinkedList list=new LinkedList(); zUgkY`]:BJ
/** Creates a new instance of CountCache */ z?_}+
public CountCache() {} nPIR1Z
public static void add(CountBean cb){ xo 'w+Av
if(cb!=null){ n]{}C.C=
list.add(cb); yExyx?j.
} /sC[5G%
} YIk6:W{
} ?
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CountControl.java 4aGpKvW
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/* Mc3h
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* CountThread.java {}C7VS1
* ?#c@Ag%
* Created on 2007年1月1日, 下午4:57 COL8YY
* fU~y481A
* To change this template, choose Tools | Options and locate the template under R]sjG<
* the Source Creation and Management node. Right-click the template and choose h=y(2xA
* Open. You can then make changes to the template in the Source Editor. v;qL?_:=c
*/ Oc+L^}elJ
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package com.tot.count; VQ;-
dCV
import tot.db.DBUtils; %t|2GIu
import java.sql.*; CKt~#$ I%
/** <4HuV.K
* >Ez}r(QQ^
* @author iw;Alav"x
*/ ^a 5~FI:
public class CountControl{ cW/~4.v$
private static long lastExecuteTime=0;//上次更新时间 ,ZW.P`
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 P3FpU<OBwp
/** Creates a new instance of CountThread */ ]b=A/*z
public CountControl() {} Cu<ojN- $
public synchronized void executeUpdate(){ ^n5QKHD
Connection conn=null; TEyPlSGG
PreparedStatement ps=null; J@{Bv%
try{ .%h_W\M<l
conn = DBUtils.getConnection(); -;.fU44O[#
conn.setAutoCommit(false); ]@]"bF!Dn
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); =n?@My?;
for(int i=0;i<CountCache.list.size();i++){ m{Xf_rQ
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CountBean cb=(CountBean)CountCache.list.getFirst(); a'fb0fz
CountCache.list.removeFirst(); EqwA8?M
ps.setInt(1, cb.getCountId()); )p](*Z^
ps.executeUpdate();⑴ OVK(:{PwS
//ps.addBatch();⑵ &1n0(qB
} ~%q e,
//int [] counts = ps.executeBatch();⑶ kQcQi}e
conn.commit(); 1fG@r%4
}catch(Exception e){ Gwk@X/q
e.printStackTrace(); qo![#s
} finally{ imuHSxcaV
try{ $>`8'I
if(ps!=null) { p`C5jfI
ps.clearParameters(); Q'LU?>N)/
ps.close(); PkO(Y!
ps=null; I*t}gvUt9
} sbb{VV`I
}catch(SQLException e){} <m\TZQBD
DBUtils.closeConnection(conn); 8;bOw
} \Bf{/r5x
} *V+fRN4 W
public long getLast(){ P|4a}SWU
return lastExecuteTime; v7RDoO]I
} /;J;,G`?
public void run(){ Xp@OIn
long now = System.currentTimeMillis(); OTm"Iwzu@
if ((now - lastExecuteTime) > executeSep) { B!lw>rUMQ
//System.out.print("lastExecuteTime:"+lastExecuteTime); @bE?WXY
//System.out.print(" now:"+now+"\n"); 34:=A0z
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ^Y!`wp2vn
lastExecuteTime=now;
D-/A>
executeUpdate(); 7hQl,v< 5
} &'j77tqOk
else{ n$K_KU v
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); nfR5W~%*:
} *0tNun 5=3
} Z7/lFS'~N
} P^r8JhDJ
//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 EJsb{$u
_t7A'`Dh]
类写好了,下面是在JSP中如下调用。 uW|y8 BP $
W*#/@/5
<% ?2agU
CountBean cb=new CountBean(); IbC)F> Dq
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); :JmNy<
CountCache.add(cb); )eV]M~K:
out.print(CountCache.list.size()+"<br>"); 1U!CD-%(
CountControl c=new CountControl(); a'r\e2/e?H
c.run(); -`JY] H
out.print(CountCache.list.size()+"<br>"); 16U@o>O
%>