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: #g~]2x
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CountBean.java FpZ5@
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/* >nO[5
* CountData.java 1rV9dM#F
* 7pM&))R
* Created on 2007年1月1日, 下午4:44 b6g/SIae
* -qG7, t
* To change this template, choose Tools | Options and locate the template under 1;HL=F
* the Source Creation and Management node. Right-click the template and choose irMBd8WG
* Open. You can then make changes to the template in the Source Editor. Ct]? /
*/ /w2NO9Q
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package com.tot.count; m}t`43}QE
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/** wsgT`M'J[
* -BH T'zq1S
* @author \~.elKw<U
*/ n<Ki.;-ZE
public class CountBean { rB_ESNx
private String countType; Mo\nY5
int countId; z8
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/** Creates a new instance of CountData */
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public CountBean() {} |;R-q8
public void setCountType(String countTypes){ lHO.pN`2
this.countType=countTypes; jV' tcFr4
} mxICQ>s
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public void setCountId(int countIds){ 1-PFM-
this.countId=countIds; W=4|ahk$
} k[\JT[Mp
public String getCountType(){ .jl^"{@6
return countType; !X 0 (4^
} zKGr(9I
public int getCountId(){ |sB L(9
return countId; -v=tM6
} ZVz*1]}
} *}Rd%'
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CountCache.java -l{ wB"
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/* \b?O+;5Cj
* CountCache.java D!D}mPi[
* 1~[GGl
* Created on 2007年1月1日, 下午5:01 ~e=KBYDBu
* $it>*%
* To change this template, choose Tools | Options and locate the template under gXB&Sgjo
* the Source Creation and Management node. Right-click the template and choose yn04[PN2
* Open. You can then make changes to the template in the Source Editor. jR{t=da
*/ ;V^ I>-fnm
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package com.tot.count; 29NP!W
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import java.util.*; EHm:&w
/** 2>im'x 5
* MJ.Kor
* @author x)T07,3:
*/ U!T#'H5'-
public class CountCache { m^4O jik
public static LinkedList list=new LinkedList(); 3Z74&a$
/** Creates a new instance of CountCache */ ]o`FF="at
public CountCache() {} ar@ysBy
public static void add(CountBean cb){ M+lI,j+
if(cb!=null){ uR82},r$m
list.add(cb); to)Pl}9QkK
} &sGLm~m#
} 7G_OFD
} 8TO5j
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CountControl.java b2YOnV
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/* = %wBC;
* CountThread.java cX5t x]
* E /V`NqC
* Created on 2007年1月1日, 下午4:57 sJ|IW0Mr
* 7/BA!V(na
* To change this template, choose Tools | Options and locate the template under 4<U6jB5
* the Source Creation and Management node. Right-click the template and choose @fd{5 >\
* Open. You can then make changes to the template in the Source Editor. F=yE>[! LB
*/ Ls NJ3oy
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package com.tot.count; cQ/T:E7$`
import tot.db.DBUtils; ~q{QquYV
import java.sql.*; l%7^'nDn
/** n7d`J_%s
* yj9Ad*.
* @author e{0O"Jd`
*/ RueL~$*6.~
public class CountControl{ XU$\.g p-
private static long lastExecuteTime=0;//上次更新时间 \>4x7mF!
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 WI54xu1M
/** Creates a new instance of CountThread */ *JVJKqed
public CountControl() {} 6
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public synchronized void executeUpdate(){ #^q@ra
Connection conn=null; %$F\o1S
PreparedStatement ps=null; !Ly1!;<
try{ j,#R?Ig
conn = DBUtils.getConnection(); 7,3v,N|
conn.setAutoCommit(false); BO;LK-V
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); I^S{V^Ty
for(int i=0;i<CountCache.list.size();i++){ <nn!9V\C
CountBean cb=(CountBean)CountCache.list.getFirst(); RQ[6svfP
CountCache.list.removeFirst(); JP 8v2)
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ps.setInt(1, cb.getCountId()); =JB1 ]b{|
ps.executeUpdate();⑴ 1iE*-K%Q
//ps.addBatch();⑵ U
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} 5VW*h
//int [] counts = ps.executeBatch();⑶ cin3)lm
conn.commit(); 6Q9S~YYq
}catch(Exception e){ V$ac}A,!
e.printStackTrace(); |HK/*B
} finally{ ;,:w%.
try{ $-f(.S
if(ps!=null) { u1(8a%ZC
ps.clearParameters(); oOK&+r7
ps.close(); WG3 .qLH%
ps=null; - Tr*G4
}
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}catch(SQLException e){} ,?s:s&4
DBUtils.closeConnection(conn); >"+bL6#
} 44cy_
} ]}dAm S/
public long getLast(){ NeY,Of|
return lastExecuteTime; Q
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} 8BwJWxBQ
public void run(){ h-[FUPfuw
long now = System.currentTimeMillis(); :KJZo,\
if ((now - lastExecuteTime) > executeSep) { N^K@$bs4^
//System.out.print("lastExecuteTime:"+lastExecuteTime); G7H'OB
&
//System.out.print(" now:"+now+"\n"); rfxLCiV
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); Hf$LWPL)lM
lastExecuteTime=now; KmRxbf
executeUpdate(); JZB@K6 ~dO
} d!]_n|B@9
else{ X7&
^"|:
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); Y/<
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} V .VV:`S
} M]OZS\9.B
} *1
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//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 BA|*V[HBE
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类写好了,下面是在JSP中如下调用。 I%31MU9
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<% _D?`'zN
CountBean cb=new CountBean(); Ie8jBf -
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); .\+%Q)?h:
CountCache.add(cb); '; Z!(r
out.print(CountCache.list.size()+"<br>"); Kzgnhgc
CountControl c=new CountControl(); Smlf9h&
c.run(); w@ =U f7
out.print(CountCache.list.size()+"<br>"); Og~3eL[1%C
%>