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: _:wZmZU}
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CountBean.java !"g=&Uy&
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/* i Td-n9
* CountData.java L7SEswMti
* jg~_'4f#
* Created on 2007年1月1日, 下午4:44 u$WBc\j
* CnabD{uTf
* To change this template, choose Tools | Options and locate the template under oJP<'l1
* the Source Creation and Management node. Right-click the template and choose >?S\~Y
* Open. You can then make changes to the template in the Source Editor. x Z|&/Ci
*/ =y?#^
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package com.tot.count; NNwc!x)*
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/** |WB"=PE
* WI,40&<
* @author CfQf7-
*/ fH-NU-"
public class CountBean { 5B}3GBA
private String countType; (FM4 ^#6
int countId; Hab!qWK`
/** Creates a new instance of CountData */ OZG0AX+=#
public CountBean() {} O[; +i
public void setCountType(String countTypes){ pPoH5CzcK
this.countType=countTypes; S*4f%!
} <e'P%tG'
public void setCountId(int countIds){ Af`z/:0<
this.countId=countIds; W&<g} N+
} $v FrU v
public String getCountType(){ SEYG y+#K
return countType; hO#HvW
} doLkrEm&
public int getCountId(){ Ymq3ty]Pe
return countId; d{W}p~UbH
} TW>?h=.z
} .\$Wy$ d
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CountCache.java H \ 3M
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/* *%3oyWwCd
* CountCache.java x7f:F.
* !;i*\
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* Created on 2007年1月1日, 下午5:01 USprsaj
* FS8S68
* To change this template, choose Tools | Options and locate the template under j5zFDh1(
* the Source Creation and Management node. Right-click the template and choose Z)NrhJC
* Open. You can then make changes to the template in the Source Editor. +i+tp8T+7
*/ 7k `_#
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package com.tot.count; <_t5:3HL
import java.util.*; U M@naU
/** K${}r0
* *MI)]S
* @author vEF=e
*/ PQ,+hq
public class CountCache { 2sUbiDe-
public static LinkedList list=new LinkedList(); )i @1XH"D
/** Creates a new instance of CountCache */ &RWM<6JP
public CountCache() {} KCD5*xH
public static void add(CountBean cb){ Fqo&3+J4
if(cb!=null){ J2'K?|,m
list.add(cb); 90p3V\LO
} i (0hvV>'
} Hr6wgYPi
} H "O$&
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CountControl.java f4
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/* mk\i}U>`
* CountThread.java y<|)'(
* h`lmC]X_
* Created on 2007年1月1日, 下午4:57 JPsSw
* i *B:El1
* To change this template, choose Tools | Options and locate the template under WKxm9y
V
* the Source Creation and Management node. Right-click the template and choose v`SY6;<2
* Open. You can then make changes to the template in the Source Editor. O] H=s
*/ _#FIay\ahB
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package com.tot.count; E3f9<hm
import tot.db.DBUtils; AVv#\JrRW
import java.sql.*; TMww
/** { UOhVJy
* l~['[Ub0)
* @author YN^T$,*
*/ ?gN9kd)
public class CountControl{ R4SxFp
private static long lastExecuteTime=0;//上次更新时间 kxh 5}eB
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 /~*Cp9F"]
/** Creates a new instance of CountThread */ #d% vT!Bz~
public CountControl() {} g?V&mu
public synchronized void executeUpdate(){ Y9tV%
Connection conn=null; |Ytg
PreparedStatement ps=null; 2 h<U
try{ y@`~ 9$
conn = DBUtils.getConnection(); ]H+{eJB7O
conn.setAutoCommit(false); jN6b*-2
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); y
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for(int i=0;i<CountCache.list.size();i++){ "5}%"-#
CountBean cb=(CountBean)CountCache.list.getFirst(); +2Ql~w@$^l
CountCache.list.removeFirst(); waCboK'
ps.setInt(1, cb.getCountId()); ]`d2_mu
ps.executeUpdate();⑴ f^?uY8<
//ps.addBatch();⑵ )v1CC..
} 's.~$
//int [] counts = ps.executeBatch();⑶ `NSy"6{Z
conn.commit(); %[ /<+
}catch(Exception e){ f>z`i\1oO
e.printStackTrace(); 5oJ Dux }
} finally{ .LObOR5J7
try{ h@@d{{IqT
if(ps!=null) { 4uUs7T
ps.clearParameters(); <s}|ZnGE
ps.close(); 3 Z1OX]R
ps=null; _q)!B,y-/N
} k2p'G')H
}catch(SQLException e){} (a }J$:
DBUtils.closeConnection(conn); {zP#woz2Q
} 0[)VO[
} PrSkHxm
public long getLast(){ j{;|g%5t
return lastExecuteTime; KDD@%E
} @rwU 1T33
public void run(){ $O9Xx
long now = System.currentTimeMillis(); EZib1g&:R/
if ((now - lastExecuteTime) > executeSep) { _]=9#Fg7{
//System.out.print("lastExecuteTime:"+lastExecuteTime); X>t3|h
//System.out.print(" now:"+now+"\n"); Pz@/|&]
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 94{)"w]
lastExecuteTime=now; 7Ms90oE/c
executeUpdate(); (ua q<Cvg
} rl?7W];
else{ s<&[\U
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); TsHF
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} 62kb2C
} `G?qY8
} =IHje;s
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 7tgFDLA
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类写好了,下面是在JSP中如下调用。 &g0g]G21*I
:#$F)]y'\
<% Z^#]#f
CountBean cb=new CountBean(); ^VI,C|
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); XlkGjjW#/J
CountCache.add(cb); ia4k :\
out.print(CountCache.list.size()+"<br>"); TvQ^DZbe
CountControl c=new CountControl(); })[($$f/
c.run(); ]1sNmi$T
out.print(CountCache.list.size()+"<br>"); DZs^ 2Zc
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