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: n@//d.T
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CountBean.java dY.NQ1@"
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/* lQ?_1H~4=
* CountData.java \S)cVp)h
* (Cbm*VL
* Created on 2007年1月1日, 下午4:44 \m~Oaf;$
* <d$t*vnq
* To change this template, choose Tools | Options and locate the template under C&RZdh,$
* the Source Creation and Management node. Right-click the template and choose pw=o}-P{
* Open. You can then make changes to the template in the Source Editor. O`0\f8/.?
*/ OBnvY2)Ri
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package com.tot.count; XOPiwrg%p
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/** n<DZb`/uHZ
* @6{F4
* @author eZmwF@
*/ kwrM3nq
public class CountBean { *~8g:;u
private String countType; Kd7 Lpw1u]
int countId; >$;,1N $bd
/** Creates a new instance of CountData */ PS` F
public CountBean() {} D]+@pKb
public void setCountType(String countTypes){ w)"F=33}5
this.countType=countTypes; 9mB] \{^
} ~5n?=
public void setCountId(int countIds){ T&]IPOH9
this.countId=countIds; E&> 2=$~
} F&D,y-CQ
public String getCountType(){ ~R~MC(5N[
return countType; Gn 1
} #e&LyYx4
public int getCountId(){ snyA
return countId; 7O'u5N
} 9K=K,6
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} /Ca
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CountCache.java C@9K`N[*
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/* e@g=wN"@
* CountCache.java !+n'0{
* >,c'Z<TM
* Created on 2007年1月1日, 下午5:01 M~g@y$
* {R7m qzt
* To change this template, choose Tools | Options and locate the template under 92 1s'"
* the Source Creation and Management node. Right-click the template and choose cC TTjx{
* Open. You can then make changes to the template in the Source Editor.
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*/ K,H xe;-
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package com.tot.count; OwLJS5r@<-
import java.util.*; fTd":F
/** OTmr-l6
* Q*R9OF
* @author qex::Qf
*/ Eg$Er*)h8
public class CountCache { 5$/Me=g<
public static LinkedList list=new LinkedList(); :-cqC|Y
/** Creates a new instance of CountCache */ \1#~]1~
s
public CountCache() {} FES0lw{G#
public static void add(CountBean cb){ r-&* `Jh
if(cb!=null){ o>yo9n%t
list.add(cb); b:x*Hjf
} WWv.kglz
} kvam`8SeL
} -
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CountControl.java Mqm9i
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/* `6{4?v
* CountThread.java OQ4rJ#b
* +@anYtv%7
* Created on 2007年1月1日, 下午4:57 0|]qWcD
* JUTlJyx8
* To change this template, choose Tools | Options and locate the template under r,wC5%&Za
* the Source Creation and Management node. Right-click the template and choose Q-||A
* Open. You can then make changes to the template in the Source Editor. Q57Z~EsF
*/ ?7w7Y;FuR
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package com.tot.count; HUx-8<ws
import tot.db.DBUtils; L%/atl!
import java.sql.*; 7h\U}!
/** QX+&[G!DZH
* dSbz$Fc t
* @author sUpSXG-W/@
*/ 6x@4gPy[
public class CountControl{ ~oeX0l>F
private static long lastExecuteTime=0;//上次更新时间 6tup^Rlo;$
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 n/+G^:~_
/** Creates a new instance of CountThread */ LEY k
public CountControl() {} k<%y+v
public synchronized void executeUpdate(){ (^^}Ke{J
Connection conn=null; oC(.u ?
PreparedStatement ps=null; RHuc#b0
try{ Enqs|fkbN
conn = DBUtils.getConnection(); #6nuiSF
conn.setAutoCommit(false); }Hb_8P
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 3q`Uq`t4mR
for(int i=0;i<CountCache.list.size();i++){ 36yIfC,
CountBean cb=(CountBean)CountCache.list.getFirst(); FK;2u$:
CountCache.list.removeFirst(); !FeNx*31i
ps.setInt(1, cb.getCountId()); y@dTdR2Wc
ps.executeUpdate();⑴ 9+:<RFJ
//ps.addBatch();⑵ M|qJZ#{4>
} Zu/1:8x
//int [] counts = ps.executeBatch();⑶ Z xR
conn.commit(); Qz([\Xx:
}catch(Exception e){ 8%^W<.Y
e.printStackTrace(); r&nEM6
} finally{ 6o]>lQ}
try{ \`8?=_ST
if(ps!=null) { iG=XRctgj)
ps.clearParameters(); }dG>_/3
ps.close(); 3y*dBw
ps=null; [ejl #'*5
} S5wkBdr{
}catch(SQLException e){} PAv<J<d
DBUtils.closeConnection(conn); H2E'i\
} xWKUti i
} w/Wd^+IIn
public long getLast(){ `+GiSj8'G
return lastExecuteTime; p+Icq!aH5
} iL3k8:x
public void run(){ T0K*!j}O
long now = System.currentTimeMillis(); p.!p6ve){
if ((now - lastExecuteTime) > executeSep) { ivPX_#QI
//System.out.print("lastExecuteTime:"+lastExecuteTime); _6C,w`[[6
//System.out.print(" now:"+now+"\n"); T_~xDQ` v
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); CMHg]la
lastExecuteTime=now; p\r V 6+
executeUpdate(); W";Po)YC
} WRN}>]NgQ
else{ GD#W=O
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); `qa>6`\
} {0Ej*%
} >RKepV(X7
} bdvVPjGc&
//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 OCI{)r<O2m
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类写好了,下面是在JSP中如下调用。 ou[Wz{
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<% .
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CountBean cb=new CountBean(); OZE.T-{
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); E# *`u
CountCache.add(cb); dlc'=M
out.print(CountCache.list.size()+"<br>");
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CountControl c=new CountControl(); B[[1=
c.run(); !tuK.?q|l
out.print(CountCache.list.size()+"<br>"); vXibg
%>