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: $ aBSr1
,+evP=(cX
CountBean.java p%_
:(
F09AX'nj
/* RLX^'g+P
* CountData.java Gf.o{
* #u(,#(P'#
* Created on 2007年1月1日, 下午4:44 AdW7 vn
* Pu*UZcXY
* To change this template, choose Tools | Options and locate the template under |W];v@b\y
* the Source Creation and Management node. Right-click the template and choose X,CFY
* Open. You can then make changes to the template in the Source Editor. LMj'?SuH
*/ f=Y9a$.:M
;P#*R3
package com.tot.count; [<$d@}O
8uW:_t]q
/** PX/0 jv
* 7u0R=q
* @author 5!p'n#_
*/ l~c>jm8.
public class CountBean { e!'u{>u
private String countType; (19<8a9G
int countId; u6d~d\
/** Creates a new instance of CountData */ 4=cq 76
public CountBean() {} YIqfGXu8
public void setCountType(String countTypes){ ^PpFI
this.countType=countTypes; BVeNK=7m%
} k;X1x65uP
public void setCountId(int countIds){ kfECC&"
this.countId=countIds; ]`9K|v
} =%G[vm/-)
public String getCountType(){ qE=OQs9
return countType; Vtk|WV?>P+
} bUL9*{>G
public int getCountId(){ ' "
yl>"
return countId; be@uHikp;v
} 3o^M%
} <-aI%'?*
TnAX;+u
CountCache.java _@76eZd
z*1K<w8
/* uS,$P34^oy
* CountCache.java f/m6q8!L{
* uMZf9XUE
* Created on 2007年1月1日, 下午5:01 W<l(C!{
* 7?#32B
Gr
* To change this template, choose Tools | Options and locate the template under 54%}JA][
* the Source Creation and Management node. Right-click the template and choose JFdzA
* Open. You can then make changes to the template in the Source Editor. hKYPH?b%
*/ I%xJ)fIK
8
\Oiv$r
package com.tot.count; 4tWI)}+ak
import java.util.*; )CQ}LbX Zy
/** 3Re\ T
* Ev#aMK
* @author \(L^ /]}G)
*/ LXl! !i%
public class CountCache { 9B0"GEwrs
public static LinkedList list=new LinkedList(); [hbIv
/** Creates a new instance of CountCache */ *h9vMks
o
public CountCache() {} s50ln&2
public static void add(CountBean cb){ #IDCCD^1=
if(cb!=null){ ^123.Ru|t
list.add(cb); w7u >|x!
} ^Yz05\
} uD3_'a
} e vuP4-[y
$S{j}74[
CountControl.java cIjsUqKa
A4h/oMis
/* 1fZ:^|\
* CountThread.java IrC=9%pd$R
* L;`t%1
* Created on 2007年1月1日, 下午4:57 c
@R6p+
* Fwqf4&/
* To change this template, choose Tools | Options and locate the template under 9f`Pi:*+/
* the Source Creation and Management node. Right-click the template and choose yjzNU5F
* Open. You can then make changes to the template in the Source Editor. Xi.?9J`@
*/ 2O/_hv.
W9"I++~f
package com.tot.count; *6tN o-)^
import tot.db.DBUtils; ak[)+_k_
import java.sql.*; @( l`_Wx
/** ?f&I"\y
* W[s>TDc`v
* @author EM}z-@A>
*/ ba13^;fm#
public class CountControl{ H=C;g)R
private static long lastExecuteTime=0;//上次更新时间 cK&oC$[r-
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 =@o}
/** Creates a new instance of CountThread */ 63=m11Z4
public CountControl() {} KHtY
+93
public synchronized void executeUpdate(){ AAcbY;
Connection conn=null; I"4B1g
PreparedStatement ps=null; Ip0q&i<6
try{ =d}3>YHS
conn = DBUtils.getConnection(); v!Z 9T
conn.setAutoCommit(false); CgC wM=!r
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ej+!|97M
for(int i=0;i<CountCache.list.size();i++){ 3I+pe;
CountBean cb=(CountBean)CountCache.list.getFirst(); @@jdF-Utj;
CountCache.list.removeFirst(); `Fj(g!`
ps.setInt(1, cb.getCountId()); 1S.~-K*X
ps.executeUpdate();⑴ ':3KZ4/C
//ps.addBatch();⑵
2X_ef
} lDeWs%n
//int [] counts = ps.executeBatch();⑶ )RFeF!("
conn.commit(); Sqs`E[G*
}catch(Exception e){ _rd{cvdR
e.printStackTrace(); -}@9lhS,
} finally{ {W]jVh p
try{ xFZq6si?
if(ps!=null) { s? Kn,6Y
ps.clearParameters(); UZ#2*PH2E
ps.close(); d/1XL[&
ps=null; s9iM hCu|
} \BL9}5y
}catch(SQLException e){} @#apOoVW>
DBUtils.closeConnection(conn); Sls>
OIc
} VzesqVx
} 5oS\uX|
public long getLast(){ o6 /?WR 9
return lastExecuteTime; VM[8w`
} @d\F; o<
public void run(){ il~,y8WTU{
long now = System.currentTimeMillis(); jPfoI-
if ((now - lastExecuteTime) > executeSep) { $$a"A(Y
//System.out.print("lastExecuteTime:"+lastExecuteTime); H;2pk
//System.out.print(" now:"+now+"\n"); (&(f`c@I
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); PW}.`
lastExecuteTime=now; Cp%|Q.?
executeUpdate(); EeO{G*pq
} 0*)79Sz
else{
U{EW +>
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); q<VhP2R
} (P ?9Jct
} T (qu~}
} -g0>>{M'
//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 i(WWF#N5
2xX7dl(cC
类写好了,下面是在JSP中如下调用。 7F.,Xvw&@
art{PV4-
<% ]G:xT v8
CountBean cb=new CountBean(); m|
Z)h{&
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); [C$ 0HW
CountCache.add(cb); #_d%hr~d
out.print(CountCache.list.size()+"<br>"); <CFur
CountControl c=new CountControl(); $dR%8@.H
c.run(); XebCl{HHp
out.print(CountCache.list.size()+"<br>"); uT1x\Rt|e
%>