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: |0vV?f$
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CountBean.java 2 w2JFdm
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/* je6H}eWTC6
* CountData.java Sq,ZzMw
* P>/n!1c
* Created on 2007年1月1日, 下午4:44 >}`q4U6$
* d^"<Tz!
* To change this template, choose Tools | Options and locate the template under a)'^'jm)4
* the Source Creation and Management node. Right-click the template and choose Fa`/i v
* Open. You can then make changes to the template in the Source Editor. &BnK[Q8X
*/ _Y'+E
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package com.tot.count; F0O"rN{
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/** 1*{` .
* yk1syN_
* @author ` V}e$
*/ k23*F0Dv
public class CountBean { }~Z1C0t
private String countType; bKsl'3~ k
int countId; W-9^Ncp
/** Creates a new instance of CountData */ Fj<#*2{]B
public CountBean() {} ek~bXy{O`
public void setCountType(String countTypes){ ;h>s=D,r
this.countType=countTypes; f(Q-W6
} TY[{)aH{S
public void setCountId(int countIds){ RX.n7Tb
this.countId=countIds; ^a~^$PUqI
} z}v6!u|iZu
public String getCountType(){ 5bZf$$b
return countType; W]p)}#FR
} p!<Y 'G
public int getCountId(){ V3&_ST
return countId; ydOJ^Yty
} ?9#}p
}
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CountCache.java #% PnZ
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/* Iuk!A?XV
* CountCache.java fI@4 v\
* 4J3cQ;z
* Created on 2007年1月1日, 下午5:01 CO!K[q#
*
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* To change this template, choose Tools | Options and locate the template under W$=MuF7R
* the Source Creation and Management node. Right-click the template and choose ndEW$?W,
* Open. You can then make changes to the template in the Source Editor. Jwzkd"D
*/ {VqcZhqy/l
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package com.tot.count; NMYkEz(&R
import java.util.*;
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/** bgs2~50
* bd],fNgJ
* @author 5(kRFb'31F
*/ tkrRdCq
public class CountCache { nzI}w7>VU
public static LinkedList list=new LinkedList(); 7XLz Ewa
/** Creates a new instance of CountCache */ L=zt\L
public CountCache() {} _:|/4.]`_
public static void add(CountBean cb){ |pB[g>~V
if(cb!=null){ o'S&YD
list.add(cb); lTOO`g
} K1c@]]y)
} 0mj^Tms
} V 4Y w"J
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CountControl.java W~sP7&sp
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/* PfKIaW<
* CountThread.java cY1d6P0
* H% c:f
* Created on 2007年1月1日, 下午4:57 ~x`BV+R
* Gb]t%\
* To change this template, choose Tools | Options and locate the template under fbaQXM
* the Source Creation and Management node. Right-click the template and choose u*/.
* Open. You can then make changes to the template in the Source Editor. 6{/HNEI*1
*/ D,Ft*(|T
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package com.tot.count; rOC2 S(m
import tot.db.DBUtils; v6B}ov[Y2
import java.sql.*; bnS"@^M
/** Cnp\2Fu/
* ;E? Z<3{
* @author g~EJja;
*/ :sD/IM",},
public class CountControl{ ,U9gg-.Lp
private static long lastExecuteTime=0;//上次更新时间 }F'B!8n
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 "P O>@tY
/** Creates a new instance of CountThread */ =?Y%w%2
public CountControl() {}
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public synchronized void executeUpdate(){ 8sm8L\-
Connection conn=null; x|
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PreparedStatement ps=null; Qs(WyP#
try{ $ekJs/I&
conn = DBUtils.getConnection(); `Oxo@G*@}W
conn.setAutoCommit(false); &m@~R|
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); <[9{Lg*D
for(int i=0;i<CountCache.list.size();i++){ @k_xA-a
CountBean cb=(CountBean)CountCache.list.getFirst(); q$>/~aVM
CountCache.list.removeFirst(); iQry X(z
ps.setInt(1, cb.getCountId()); l#!p?l
ps.executeUpdate();⑴ 6ybpPls
//ps.addBatch();⑵ fI:j@Wug
} NYS|fa
//int [] counts = ps.executeBatch();⑶ E .2b@
conn.commit(); ~y@,d
}catch(Exception e){ `Mj>t(
e.printStackTrace(); B J,U,!
} finally{ P GTi-o}
try{ KjK.Sv{N
if(ps!=null) { .L;M-`^
ps.clearParameters(); Gn}G$uk61
ps.close(); Gj Ds,9@f
ps=null; F'eV%g
} Oj6PmUK4
}catch(SQLException e){} Uy8r
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DBUtils.closeConnection(conn); tqdw
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} r`? bYoz
} <[7
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public long getLast(){ 3yT7;~vPj
return lastExecuteTime; l/|bU9o /u
} sxac(L
public void run(){ GEJEhwO;H
long now = System.currentTimeMillis(); x8L$T (^
if ((now - lastExecuteTime) > executeSep) { NkWU5E!
//System.out.print("lastExecuteTime:"+lastExecuteTime); R*m=V{iu`
//System.out.print(" now:"+now+"\n"); <B,z)c
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); pDW4DF:`(
lastExecuteTime=now; >]DnEF&
executeUpdate(); '`.bmiM
} nJEm&"AI
else{ H}TzNs
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); J|vriI;
} gQXB=ywF
} 7WuhYJbf
} VK7lm|J+
//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 )~(( 6?k4e
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类写好了,下面是在JSP中如下调用。 N{6
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<% C_c*21X
CountBean cb=new CountBean(); 3`V#ImV>
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); s@Q,
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CountCache.add(cb); Yv}V =O%
out.print(CountCache.list.size()+"<br>"); (QARle(i
CountControl c=new CountControl(); -kFPmM;
c.run(); l!6^xMhYk
out.print(CountCache.list.size()+"<br>"); XeGtge/}T
%>