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: bN&DotG
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CountBean.java [x%8l,O
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/* y(*5qa<>
* CountData.java x6Tpt^N}
* 2uT@jfj:r
* Created on 2007年1月1日, 下午4:44 Y=i_2R2e2
* KGf@d*ZOMz
* To change this template, choose Tools | Options and locate the template under k$.l^H u
* the Source Creation and Management node. Right-click the template and choose {z9,CwJan?
* Open. You can then make changes to the template in the Source Editor. I* PxQ
*/ Uw?25+[b
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package com.tot.count; g7w#;E
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/** BC85#sbl
* q&&uX-ez5W
* @author ,g 1~4,hqQ
*/ VVEJE$
public class CountBean { \'X-><1
private String countType; M<x><U#]A
int countId; ?y@;=x!'
/** Creates a new instance of CountData */ |RBL5,t^
public CountBean() {} a# Uk:O!
public void setCountType(String countTypes){ C,8@V`
this.countType=countTypes; g2vt(Gf ;
} pf#R]
public void setCountId(int countIds){ 4<- E0
this.countId=countIds; *c(J4
} s]HJcgI
public String getCountType(){ Gx|/
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return countType; #4AqWyp#f
} ivSpi?
public int getCountId(){ ?btX&:j2P
return countId; vos-[$
} ZSB;4 ?:h
} fc<,kRp
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CountCache.java rW)}$|-Z
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/* SbobXTbG
* CountCache.java mp0s>R
* SwO8d;e
* Created on 2007年1月1日, 下午5:01 BOl*. t
* ()fYhk|W
* To change this template, choose Tools | Options and locate the template under ?QcS$i
* the Source Creation and Management node. Right-click the template and choose IFXn GDG$
* Open. You can then make changes to the template in the Source Editor. 'h>l_A
*/ i7?OZh*f
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package com.tot.count; {!t6&
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import java.util.*; OYOczb]
/** BO 3z$c1yU
* ^C8f(
* @author TrVQ]9;jWk
*/ 6f
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public class CountCache { OSK:Cb.-?F
public static LinkedList list=new LinkedList(); i;J*9B_U
/** Creates a new instance of CountCache */
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public CountCache() {} ]Gl5Qf:+z
public static void add(CountBean cb){ R;w1& Z
if(cb!=null){ s="cg0PD
list.add(cb); j[w5#]&%
} nB |fw"
} n* z;%'0
} jYh.$g<`0+
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CountControl.java <$%Y#I'zX
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/* &RlYw#*1.
* CountThread.java 6 w0r)
* ~gEd(
* Created on 2007年1月1日, 下午4:57 )7F$:*e
* s=XqI@
* To change this template, choose Tools | Options and locate the template under Ucj>gc=
* the Source Creation and Management node. Right-click the template and choose V/8yW3]Xy
* Open. You can then make changes to the template in the Source Editor. <h~_7Dn
*/ "'c
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package com.tot.count; *L5L.: Ze
import tot.db.DBUtils; z"!=A}i
import java.sql.*; B 3eNvUFZg
/** L_AQS9a^D
* c`V~?]I>
* @author M'xG.'
*/ Lw{'mtm
public class CountControl{ HTP~5J
private static long lastExecuteTime=0;//上次更新时间 vFGVz
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ,)}-mu
/** Creates a new instance of CountThread */ iu'r c/=V
public CountControl() {} 84-7!< 6i
public synchronized void executeUpdate(){ -axmfE?g0
Connection conn=null; SA6.g2pFz
PreparedStatement ps=null; j"<F?k@`Q
try{ [u8JqX
conn = DBUtils.getConnection(); V[">SiOg
conn.setAutoCommit(false); 1L.yh U\
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); <V*M%YWs
for(int i=0;i<CountCache.list.size();i++){ h!1CsLd[
CountBean cb=(CountBean)CountCache.list.getFirst(); K/LoHWy+n*
CountCache.list.removeFirst(); jF%l\$)/
ps.setInt(1, cb.getCountId()); @xAfD{}f!
ps.executeUpdate();⑴ g8;JpP w
//ps.addBatch();⑵ SZC1$..2T
} 5,?Au
//int [] counts = ps.executeBatch();⑶ j=w`%nh4"f
conn.commit(); qo0]7m7|
}catch(Exception e){ q*{Dy1Tj
e.printStackTrace(); a EqDxr6
} finally{ -cWxS{vO
try{ n]%yf9,w
if(ps!=null) { E9S&UU,K
ps.clearParameters(); [3hOc/]s
ps.close(); f<( ysl1[
ps=null; n5 jzVv
} ,xIWyI.
}catch(SQLException e){} 3.I:`>;EO
DBUtils.closeConnection(conn); s&WHKCb
} 9@z"~H
} TWJ%? /d
public long getLast(){ ?1MaA
return lastExecuteTime; v]BMET[w
} )WazbT@
public void run(){ (:T\<
long now = System.currentTimeMillis(); n>I
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if ((now - lastExecuteTime) > executeSep) { *.Ceb%W7C
//System.out.print("lastExecuteTime:"+lastExecuteTime); T>s3s5Y
//System.out.print(" now:"+now+"\n"); JIU=^6^2'
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); R>.
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lastExecuteTime=now; `}fwR
executeUpdate(); qQUCK
} 38eeRo
else{ +t PqU6
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); [0mg\n?
} Mi_/
^
}
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} fP:g}Z
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 )%&~CW+
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类写好了,下面是在JSP中如下调用。 {QTnVS't 0
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<% 7{e*isV
CountBean cb=new CountBean(); 4q\bnt
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); K PSHBv-#
CountCache.add(cb); k),.
out.print(CountCache.list.size()+"<br>"); J -g<-!>RM
CountControl c=new CountControl(); Ljjuf=]
c.run(); BSB;0O M
out.print(CountCache.list.size()+"<br>"); /<$\)|r
%>