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: U8{^-#(Uz
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CountBean.java 5S[:;o
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/* 7pN&fAtj/
* CountData.java #\ECQF
* tkmzOc H
* Created on 2007年1月1日, 下午4:44 p0D@O_
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* k(xB%>ns
* To change this template, choose Tools | Options and locate the template under 411z-aS
* the Source Creation and Management node. Right-click the template and choose WD5jO9Oai
* Open. You can then make changes to the template in the Source Editor. (G~M E>
*/ QRx9;!~b}
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package com.tot.count; :Dfl ,=S
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/** K+d{R=s^
* o=-Af|#b
* @author l
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*/ Y-,S_59
public class CountBean { hOYX
private String countType; E
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int countId; {b-SK5%]L
/** Creates a new instance of CountData */ 7q:;3;"9
public CountBean() {} B 74
public void setCountType(String countTypes){ 3m~,6mQ
this.countType=countTypes; P~V ^Efz{
} *\_>=sS x;
public void setCountId(int countIds){ IR?nH`V
this.countId=countIds; XjmAM/H4
} 2Ima15^+F
public String getCountType(){ (=j/"Mb
return countType; dA<SVk*0Q
} 4pZKm-dM^
public int getCountId(){ a'?LC)^
return countId; O_ vH w^
} E>:#{%
} Y/LS(b*
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CountCache.java VA`VDUG,
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/* $GOF'
* CountCache.java 2@Q5Ta#h
* ].Ra=^q
* Created on 2007年1月1日, 下午5:01 |,({$TrF
* Y\
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* To change this template, choose Tools | Options and locate the template under sLzZ}u?(
* the Source Creation and Management node. Right-click the template and choose
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* Open. You can then make changes to the template in the Source Editor. ulk/I-y
*/ s){VU2.ra
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package com.tot.count; U lCw{:#F
import java.util.*; Nr}O6IJ>Sg
/** l\!`ZhM,
* Fu% n8
* @author >"z`))9
*/ } Fli
public class CountCache { s#aane
public static LinkedList list=new LinkedList(); xgtx5tg
/** Creates a new instance of CountCache */ ~S<}q6H.
public CountCache() {} i[wnG )
public static void add(CountBean cb){ :f7:@8
if(cb!=null){ /g8nT1k
list.add(cb); Pa=xc>m^
} L>lxkq8!Q
} [h>A<O
} C0khG9,BL
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CountControl.java E 0OHl
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/* :*R+ee,&-
* CountThread.java A+}O~,mxP8
* o#D'"Tn!
* Created on 2007年1月1日, 下午4:57 l\2"u M#7
* +i}uRO
* To change this template, choose Tools | Options and locate the template under MlLM
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* the Source Creation and Management node. Right-click the template and choose ,Ww.W'#P
* Open. You can then make changes to the template in the Source Editor. 7#*`7 K'P!
*/ Fh&USn"
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package com.tot.count; P,#l~ \
import tot.db.DBUtils; : H]MMe
import java.sql.*; LG{50sP`
/** $O fZp<M
* .&Sjazk0XO
* @author .4Mc4'
*/ 0LTsWCUQ6e
public class CountControl{ a=sd&](_
private static long lastExecuteTime=0;//上次更新时间 vrh2}biCR
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 U.=TjCW
/** Creates a new instance of CountThread */ U} Pr1
public CountControl() {} #%/Jr 52<
public synchronized void executeUpdate(){ mi@uX@ #
Connection conn=null; iszVM
PreparedStatement ps=null; feM(
try{ 07\]8^/G
conn = DBUtils.getConnection(); bn=7$Ax
conn.setAutoCommit(false); f:AfM f>m
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); X|4Kdi.r@
for(int i=0;i<CountCache.list.size();i++){ tiRi_
CountBean cb=(CountBean)CountCache.list.getFirst(); J/rF4=j%xy
CountCache.list.removeFirst(); <"S`ZOn
ps.setInt(1, cb.getCountId()); j9}.U \
ps.executeUpdate();⑴ c0_512
//ps.addBatch();⑵ H2+V1J=
} -k%|sqDZj
//int [] counts = ps.executeBatch();⑶ _^$F^}{&
conn.commit(); ?\<Kb|Q
}catch(Exception e){ zs'Jgm.v
e.printStackTrace(); H1
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} finally{ Y~I0\8s-
try{ Z}IuR|=
if(ps!=null) { +O8}twt@
ps.clearParameters(); <d[GGkY]=
ps.close(); {+gK\Nz
ps=null; )/z+W[t
} 4KW_#d`t
}catch(SQLException e){} >keYx<1
DBUtils.closeConnection(conn); @mcP-
} =`!#V/=
} \SWuylE
public long getLast(){ RGBntp%
return lastExecuteTime; Y+EwBg)co
} aCyn9Y$=
public void run(){ D+h`Z]"|
long now = System.currentTimeMillis(); R0nUS<b0
if ((now - lastExecuteTime) > executeSep) { ,0?3k
//System.out.print("lastExecuteTime:"+lastExecuteTime); qg*xdefQ%
//System.out.print(" now:"+now+"\n"); xj5MKX{CJT
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); DtZ7UX\P
lastExecuteTime=now; 3'7X[{uBr
executeUpdate(); n0uL^{B
} VT;cz6"6b4
else{ _z#S8Y
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); kPSi6ci
} >^v,,R8j
} }To-c'
}
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//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 z:08;}t
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类写好了,下面是在JSP中如下调用。 JP]-a!5Ru
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<% m'2EiYX$}\
CountBean cb=new CountBean(); )-i (%;,*e
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); FX~pjM
CountCache.add(cb); , lBHA+@
out.print(CountCache.list.size()+"<br>"); h0l_9uI
CountControl c=new CountControl(); ei[, ug'
c.run(); =[)2DJC
out.print(CountCache.list.size()+"<br>"); QD
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