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: e3UGYwQ
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CountBean.java Nt9M$?\P
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/* *x2+sgSf_0
* CountData.java |Xk'd@<
* _>%P};G{>
* Created on 2007年1月1日, 下午4:44 RrRrB"!8nR
* N_lQz(nG/2
* To change this template, choose Tools | Options and locate the template under la>:%SD
* the Source Creation and Management node. Right-click the template and choose ;BUJ5
* Open. You can then make changes to the template in the Source Editor. 4=td}%
*/ CTQF+Oe8O
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package com.tot.count; hC?:XVt
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/** @|v4B[/
* <61T)7
* @author Vrzx;V%
*/ eTemRNz
public class CountBean { n~l9`4wJY
private String countType; 9&fS<Hk
int countId; A(2_hl-
/** Creates a new instance of CountData */ 0]?} kY
public CountBean() {} #g*U\y
public void setCountType(String countTypes){ ]/hF!eO
this.countType=countTypes; VliX'.-
} :0x,%V74_!
public void setCountId(int countIds){ |9T3" _MmJ
this.countId=countIds; nfET;:{
} KWbnSL8
public String getCountType(){ ?pn<lW8d
return countType; D*BZp0x
} .|iMKRq
public int getCountId(){ iZ
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return countId; "{1`~pDj?
} r:lv[/D
} 'g.9
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CountCache.java v7&oHOk!
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/* Z&9MtpC+N3
* CountCache.java g"aWt%
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* nf=*KS\v
* Created on 2007年1月1日, 下午5:01 CZ"~N`
* P,U$
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* To change this template, choose Tools | Options and locate the template under yW5/Y02
* the Source Creation and Management node. Right-click the template and choose C4wJSQl_I
* Open. You can then make changes to the template in the Source Editor. ya7PF~:E-
*/ n " ?It
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package com.tot.count; vFKX@wV S
import java.util.*; "~- H]9
/** /orpQUHA
* Bu|Uz0Y
* @author vM )2F
*/ /Iht,@%E
public class CountCache { mG4$
public static LinkedList list=new LinkedList(); !kCMw%[
/** Creates a new instance of CountCache */ uG<VQ2LM
public CountCache() {} k\->uSU9
public static void add(CountBean cb){ JHQc)@E}
if(cb!=null){ lO=+V 6
list.add(cb); !Rp
} qZw4"&,j$
} \i1>/`F
} ;VM',40
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CountControl.java |]=. ^
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/* 'lmZ{a6
* CountThread.java BCnf'0q
* 7C~qAI6Eg
* Created on 2007年1月1日, 下午4:57 "s-e)svB
* p }p1>-j
* To change this template, choose Tools | Options and locate the template under _<Hx1l~
* the Source Creation and Management node. Right-click the template and choose F:$Dz?F0v
* Open. You can then make changes to the template in the Source Editor. Bfh[C]yy
*/ iV+'p->/
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package com.tot.count; -^A=U7
import tot.db.DBUtils; Y)D~@|D,
import java.sql.*; $7Sbz&)y3
/** aJh=4j~.
* JiFy.Pf
* @author D@]gc&JN[
*/ t:A,pT3
public class CountControl{ ?gZJ v
private static long lastExecuteTime=0;//上次更新时间 1-z*'Ghys
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 Zmx[u_NG
/** Creates a new instance of CountThread */ Znl&.,c)
public CountControl() {} 'vgO`
public synchronized void executeUpdate(){ _-NS-E
Connection conn=null; 9C$#A +~C
PreparedStatement ps=null; $`nKq4Y
try{ 79.J`}#
conn = DBUtils.getConnection(); ONx|c'0g
conn.setAutoCommit(false); `i{k^Q
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ~&E|;\G
for(int i=0;i<CountCache.list.size();i++){ O5"o/Y~m
CountBean cb=(CountBean)CountCache.list.getFirst(); 7e,<$PH
CountCache.list.removeFirst(); U3ygFW%
ps.setInt(1, cb.getCountId()); +n1jP<[<N
ps.executeUpdate();⑴ !*46@sb:
//ps.addBatch();⑵ OtopA)
} d2H&@80
//int [] counts = ps.executeBatch();⑶ >M` swEj
conn.commit(); FV[6">;g
}catch(Exception e){ j/zD`ydj
e.printStackTrace(); WY@x2bBi
} finally{ X,- '
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try{ C,C=W]G
if(ps!=null) { <`dF~
ps.clearParameters(); qA- ya6
ps.close(); rT`D@
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ps=null; D\Y)E#%,
} Xco$
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}catch(SQLException e){} &`rV{%N"
DBUtils.closeConnection(conn); y)3(
} MDkIaz\U
} }9C5U>?
public long getLast(){ "X']_:F1a
return lastExecuteTime; Ow\9vf6H
} >l$vu-k)~4
public void run(){ ~L(_q]
long now = System.currentTimeMillis(); c ;3bX6RD*
if ((now - lastExecuteTime) > executeSep) { PN:8H>
//System.out.print("lastExecuteTime:"+lastExecuteTime); /p,D01Ws}(
//System.out.print(" now:"+now+"\n"); 3)f=Z2U>
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); (PYUfiOf
lastExecuteTime=now; LvpHR#K)F5
executeUpdate(); T0_9:I`&
} wAHb5>!
else{ syh0E=If_
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); |-7<?aw"
} GS{:7%=j
} 6RZ[X[R[}
} x7e
//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 D} 0>x~
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类写好了,下面是在JSP中如下调用。 &Q