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: "D V.%7*^
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CountBean.java z1oikg:?4
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/* 0q%=Vs~@g
* CountData.java zw=as9z1-
* E%L]ifA9!
* Created on 2007年1月1日, 下午4:44 L|DSEth
* 7 R1;'/;
* To change this template, choose Tools | Options and locate the template under WZ"g:Khw
* the Source Creation and Management node. Right-click the template and choose aO@zeKg
* Open. You can then make changes to the template in the Source Editor. |0Kj0u8T
*/
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package com.tot.count; wzAp`Zs2Dm
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/** 1a{~B#
* -CW$p=y}
* @author @vf{_g<
*/ xBGSj[1`i
public class CountBean { hk"^3d !
private String countType; B^(0>Da\
int countId; cm]D"GFLY
/** Creates a new instance of CountData */ e=nEx Y
public CountBean() {} QsYc 9]:
public void setCountType(String countTypes){ Vxif0Bx&/d
this.countType=countTypes; DBi3 j
} g<~[k?~J
public void setCountId(int countIds){ &libC>a[
this.countId=countIds; Jrlc%,pZ
} ~..h=
public String getCountType(){ Xmy(pV!PF
return countType; UC*<]
} k}-%NkQ
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public int getCountId(){ 9;;1 "^4/
return countId; _-g:T
} 0-Xpq,0
} Qwx}e\=
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CountCache.java ja2LQe@Q
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/* ?|^1-5l3
* CountCache.java ~I/7{B|yX
* =_cWCl^5
* Created on 2007年1月1日, 下午5:01 J.":oD
* a(Z" }m
* To change this template, choose Tools | Options and locate the template under yB}y' 5
* the Source Creation and Management node. Right-click the template and choose O3*Vilx
* Open. You can then make changes to the template in the Source Editor. =}7wpTc,
*/ C%#C|X193
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package com.tot.count; oq]KOj[
import java.util.*; ]5td,2E
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/** 0*:]eM};P
* Q}]:lmqH
* @author oB3>0Pm*a.
*/ z[qM2
public class CountCache { Iu0K#.s_
public static LinkedList list=new LinkedList(); ycw'>W3.*
/** Creates a new instance of CountCache */ *goi^Xp
public CountCache() {} Q+ G=f
public static void add(CountBean cb){ 7Yj\*N
if(cb!=null){ zGZe|-
list.add(cb); U$VTk
} XrSqUD
} & PHHacp
} wrsETB
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CountControl.java D (qT$#
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/* ZWf{!L,@Z
* CountThread.java Q'~;RE%T
* [4xN:i
* Created on 2007年1月1日, 下午4:57 u#=N8
* $BH0W{S
* To change this template, choose Tools | Options and locate the template under FG#E?G
* the Source Creation and Management node. Right-click the template and choose W,Dr2$V
* Open. You can then make changes to the template in the Source Editor. (a7IxW
*/ D zDt:.JZ
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package com.tot.count; >47,Hq:2
import tot.db.DBUtils; Zb2 B5(0
import java.sql.*; d:sUh
/** 2b|vb}|t{
* wK#UFOp
* @author -ZihEyG?V
*/ HTx7._b
public class CountControl{ o'Tqqrr
private static long lastExecuteTime=0;//上次更新时间 ?wwY8e?S
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 y
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/** Creates a new instance of CountThread */ 0HxF#SlKM
public CountControl() {} fvNGGn!
public synchronized void executeUpdate(){ d\Dxmb]o
Connection conn=null; ~q|^z[7
PreparedStatement ps=null; miN(a; Q2P
try{ $ HUCp9
conn = DBUtils.getConnection(); TS3 00F
conn.setAutoCommit(false); NmtBn^t
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); p3^7Hr
for(int i=0;i<CountCache.list.size();i++){ 1YnDho;~
CountBean cb=(CountBean)CountCache.list.getFirst(); pd X9G
CountCache.list.removeFirst(); V<nzThM\
ps.setInt(1, cb.getCountId()); `VBjH]$
ps.executeUpdate();⑴ m?B@VDZ
//ps.addBatch();⑵ SZwfYY!ft0
} UhEJznfi
//int [] counts = ps.executeBatch();⑶ +%gh?
conn.commit(); 5gJQr%pS
}catch(Exception e){ ^uZ%d
e.printStackTrace();
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} finally{ +U6!
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try{ * rs_k/2(
if(ps!=null) { >/'WU79TYE
ps.clearParameters(); W
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ps.close(); 3rR(>}:[V
ps=null; C8G['aQ
} `pcjOM8u
}catch(SQLException e){} bt
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DBUtils.closeConnection(conn); J-,T^Wv
} uNx3us-
} +qS$t
public long getLast(){ C2`END;
return lastExecuteTime; AMO{?:8Y;
} "ht2X
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public void run(){ z-,U(0 .
long now = System.currentTimeMillis(); &'|bZms g
if ((now - lastExecuteTime) > executeSep) { TkQ05'Qc
//System.out.print("lastExecuteTime:"+lastExecuteTime); s}HTxY;
//System.out.print(" now:"+now+"\n"); vO&1F@
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); w93yhV?
lastExecuteTime=now; myJsRb5
executeUpdate(); oHa6fi
} s'K0C8'U
else{ (,<?Pg7v:f
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); XVI+Y
} Ii,L6c
} h<uRlTk
} ~i(*.Z)
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//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 ?. ~@ lE
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类写好了,下面是在JSP中如下调用。 WRo#ZVt9$
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<% 5B@&]-'~
CountBean cb=new CountBean(); rN>f"/J
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cb.setCountId(Integer.parseInt(request.getParameter("cid"))); F!Nx^M1
CountCache.add(cb); 4ci
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out.print(CountCache.list.size()+"<br>"); +i
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CountControl c=new CountControl(); @s@r5uR9B
c.run(); M\T6cN@m
out.print(CountCache.list.size()+"<br>"); sM-k,0z
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