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: U< G 2tn(
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CountBean.java M)+p H
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/* Jg[Ao#,==
* CountData.java =/46;844T
* $U]T8;5Q
* Created on 2007年1月1日, 下午4:44 #DFi-o&-
* [z2UfHpt~
* To change this template, choose Tools | Options and locate the template under E3O^Tg?j
* 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. ;\2Z?Kq
*/ T9Q3I
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package com.tot.count; &Q~W{.
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/** q/U-6A[0
* $xZ ~bE9
* @author Pn OWQ8=
*/ hk4t #Km
public class CountBean { 8i`>],,ch
private String countType; ( ~5M{Xh
int countId; zVw5 (Tc
/** Creates a new instance of CountData */ kaekH*m~
public CountBean() {} rMx Iujx
public void setCountType(String countTypes){ ulIEx~qP
this.countType=countTypes; A,DBq9Z+4R
} Yw3'9m^
public void setCountId(int countIds){ I61S0lz/
this.countId=countIds; vlbZ5
} h:362&?]
public String getCountType(){ !="q"X/*
return countType; v5S9h[gT
} (~^fx\-S
public int getCountId(){ ,<tJ`,0X
return countId; 6I@j$edZ
} (4L/I
} Y\-xX:n.\
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CountCache.java pVy=rS-
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/* mfQ#n!{ZH
* CountCache.java Re8x!e'>
* !Rl|o^Vw>{
* Created on 2007年1月1日, 下午5:01 NAvR^"I~
* *pJGp:{6V?
* To change this template, choose Tools | Options and locate the template under Yao}Xo9}
* the Source Creation and Management node. Right-click the template and choose f?sm~PwC-
* Open. You can then make changes to the template in the Source Editor. R}Lk$#S#
*/ Dd5
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package com.tot.count; >5~#BrpwG
import java.util.*; NVv
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/** T(7`$<TQ
* 29RP$$gR
* @author xGwImF$r
*/ BUBx}dbCM
public class CountCache { eTS}-
public static LinkedList list=new LinkedList(); A ]A{HEX
/** Creates a new instance of CountCache */ sh$-}1 ;
public CountCache() {} H>EM3cFU
public static void add(CountBean cb){ TBBnsj6e
if(cb!=null){ ;9T}h2^`B
list.add(cb); %f1%9YH
} >s{I@#9
} D9oNYF-V
} &ry*~"xoh
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CountControl.java elCYH9W^
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/* k
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* CountThread.java |NfFe*q0;8
* ?J\&yJ_B
* Created on 2007年1月1日, 下午4:57 }]vUr}Els
* sW]^YT>?
* To change this template, choose Tools | Options and locate the template under -XV,r<''
* the Source Creation and Management node. Right-click the template and choose +'?Qph6o,7
* Open. You can then make changes to the template in the Source Editor. {q0+PzgP
*/ u<BU4c/p
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package com.tot.count; nHm}^.B*+
import tot.db.DBUtils; FXof9fa_B
import java.sql.*; YJ _eE
/** |RiJ>/MK\
* !2LX+*;
* @author K|7"YNohfG
*/ 15g!Q
*v
public class CountControl{ uDDa>Ka#+
private static long lastExecuteTime=0;//上次更新时间 te+} j7SU
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 R{#< NE
/** Creates a new instance of CountThread */ l$;"yVdks
public CountControl() {} {[oNUzcd
public synchronized void executeUpdate(){ ff#7}9_mh
Connection conn=null; \Z]+j@9
PreparedStatement ps=null; ?gE=hh
try{ dDa V2:4E
conn = DBUtils.getConnection(); ~`OX}h/Z
conn.setAutoCommit(false);
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); y7,fFUKl
for(int i=0;i<CountCache.list.size();i++){ p&<Ssc
CountBean cb=(CountBean)CountCache.list.getFirst(); ~R!1{8HP
CountCache.list.removeFirst(); buGBqx[
ps.setInt(1, cb.getCountId()); u;`]U$Qq9
ps.executeUpdate();⑴ OpUfK4U)
//ps.addBatch();⑵ Dl;hOHvKk
} 7AqgX0)
//int [] counts = ps.executeBatch();⑶ JmI%7bH@
conn.commit(); 7Q .Su
}catch(Exception e){ !Z!)$3bB
e.printStackTrace(); *d1BpR%
} finally{ Ma^jy.
try{ _\WR3Q!V
if(ps!=null) { 4era5=
ps.clearParameters(); ) O0Cz n
ps.close(); YJJ1N/Z1
ps=null; AjVC{\Ik
} m!V,W*RNr
}catch(SQLException e){} k"N>pjgd$
DBUtils.closeConnection(conn); yE$PLM
} uBm"Xkxe|w
} \<LCp;- K
public long getLast(){
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return lastExecuteTime; G]K1X"W?
} )pWgt5:7~
public void run(){ oB:7R^a
long now = System.currentTimeMillis(); 1V%tev9a
if ((now - lastExecuteTime) > executeSep) { l;; 2\mL?
//System.out.print("lastExecuteTime:"+lastExecuteTime); Y6jyU1>
//System.out.print(" now:"+now+"\n"); 6j%%CWU{~
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); U4 !bW
lastExecuteTime=now; my'nDi
executeUpdate(); "<CM'R
} dfDjOZSL
else{ I5Vn#_q+b
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); p*g Fr hm
} 02J/=AC5
} S,&LH-ps
} VE|:k:};
//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 p _gN}v
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类写好了,下面是在JSP中如下调用。
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<% L AQ@y-K3
CountBean cb=new CountBean(); 7+jxf[(XQ
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); q)q3p
CountCache.add(cb); xWLvx'8W
out.print(CountCache.list.size()+"<br>"); CNB
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CountControl c=new CountControl(); N1 t4o~
c.run(); q*hn5 K*
out.print(CountCache.list.size()+"<br>"); m06'T2 I
%>