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: /7fd"U$Lh
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CountBean.java e`q*'u1?
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/* -GM"gkz
* CountData.java hQlyqTP|2
* h+A+>kC5
* Created on 2007年1月1日, 下午4:44 t\TxK7i
* El: @l%
* To change this template, choose Tools | Options and locate the template under &fl RrJ
* the Source Creation and Management node. Right-click the template and choose EU04U
* Open. You can then make changes to the template in the Source Editor. #TC}paIpj
*/ y)a)VvU":
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package com.tot.count; 1N:~5S}s>
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/** rHk,OC
* ek]nLN
* @author E@n~ @|10
*/ lI+^}-<
public class CountBean { 8n-Xt7z
private String countType; IV1Y+Z )
int countId; Dln1 R[
/** Creates a new instance of CountData */ TbN{ex*
public CountBean() {} ,D]g]#Lq
public void setCountType(String countTypes){ 72.Msnn
this.countType=countTypes; \=]`X2Ld
} ~8"oH5
public void setCountId(int countIds){ #NYHwO<0-
this.countId=countIds; ';c 6
} oveK;\7/m
public String getCountType(){ 9q
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return countType; *Ms"{+C
} ICr.Gwe3_
public int getCountId(){ 6}!1a?X
return countId; aM(#J7;
} P=6d<no&<
} G_,9h!e
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CountCache.java I,`;#Q)nx
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/* eU,FYJt9
* CountCache.java CV_M |
* OK8Ho"
* Created on 2007年1月1日, 下午5:01 cofdDHXfQI
* `wQs$!a
* To change this template, choose Tools | Options and locate the template under }f14# y;
* the Source Creation and Management node. Right-click the template and choose s=F[.X9lp
* Open. You can then make changes to the template in the Source Editor. G6}&k[d5%
*/ DwZRx@
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package com.tot.count; q=D8 Nz
import java.util.*; &;)B
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/** 'GX x|.
* zy nX9t
* @author `j9\]50Z>
*/ ,UNk]vd
public class CountCache { R=&-nC5e
public static LinkedList list=new LinkedList(); 4Orq;8!BW
/** Creates a new instance of CountCache */ Y:L[Iz95o
public CountCache() {} ]8DTk!
public static void add(CountBean cb){ /<IWdy]$3
if(cb!=null){ F:q8.^HTJ
list.add(cb); bt_c$TN
} :]]x^wony~
} ;1{=t!z=
} #;W4$q
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CountControl.java V$O 6m|q
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/* X0-PJ-\aD@
* CountThread.java >u(^v@Ejf
* :vzIc3~c:`
* Created on 2007年1月1日, 下午4:57 }LKD9U5;8
* ;UM(y@
* To change this template, choose Tools | Options and locate the template under S50}]5K
* the Source Creation and Management node. Right-click the template and choose VltM{-k^
* Open. You can then make changes to the template in the Source Editor. 6)ln,{
*/ W=w]`'
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package com.tot.count; Q"nw.FjUG
import tot.db.DBUtils; s-+-?$K
import java.sql.*; C.ji]P#
/** 4%w<Ekd
* ,Xfu?Yan
* @author 6$=>ck P
*/ Z`MpH
public class CountControl{ ]@<VLP?
private static long lastExecuteTime=0;//上次更新时间 KYJP`va6k
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 <FBBR2
/** Creates a new instance of CountThread */ SZ9DT
public CountControl() {} 3Il._]#
public synchronized void executeUpdate(){ E;x-O)(&
Connection conn=null; vYb4&VV
PreparedStatement ps=null; v<g=uEpN
try{ l~f3J$OkJ
conn = DBUtils.getConnection(); 4g8o~JI:v
conn.setAutoCommit(false); B5vLV@>]
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); j~K(xf
for(int i=0;i<CountCache.list.size();i++){ ;nQ=!
.#Q
CountBean cb=(CountBean)CountCache.list.getFirst(); njg0MZBqA
CountCache.list.removeFirst(); `[(XZhN
ps.setInt(1, cb.getCountId()); >yXhP6
ps.executeUpdate();⑴ 1Q!^*D
//ps.addBatch();⑵ 2EZ7Vdz2
} n7K%lj-.P
//int [] counts = ps.executeBatch();⑶ 0F%8d@Y2
conn.commit(); d=%NFCIV
}catch(Exception e){ `iM%R3&
e.printStackTrace(); zPqJeYK
} finally{ M9BEG6E9
try{ SO(BkxV@
if(ps!=null) { w43b=7
ps.clearParameters(); 4:NMZ `~
ps.close(); [f6BA|
ps=null; }u3|w0~c)
} U&u6356
}catch(SQLException e){} VrP{U-`
DBUtils.closeConnection(conn); T1.U (::
} M'<% d[
} zEtsMU
public long getLast(){ :??W3ROn
return lastExecuteTime; b~:)d>s8wY
} KB|mtsi
public void run(){ 7<MEM NYX
long now = System.currentTimeMillis(); ;hO6 p
if ((now - lastExecuteTime) > executeSep) { _.V5-iN
//System.out.print("lastExecuteTime:"+lastExecuteTime); EJTM
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//System.out.print(" now:"+now+"\n"); nb=mY&q}~
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 6)*fr'P
lastExecuteTime=now; )1M2}11uS
executeUpdate(); 4s9@4
} j,^&U|!
else{ b3R(O|
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); K;sC#9m
} 3mAiz q3
} IJ2'
} YSt*uOZK
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 wzju)q S
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类写好了,下面是在JSP中如下调用。 !(? 7V
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<% ~nmFZ]y
CountBean cb=new CountBean(); T*%GeY
[
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); lqmQQ*Z
CountCache.add(cb); axvZA:l
out.print(CountCache.list.size()+"<br>"); 5Ex[}y9L`
CountControl c=new CountControl(); ZJZSt% r
c.run(); a<\n$E#q
out.print(CountCache.list.size()+"<br>"); p:y\{k"
%>