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: Iwd"f
aC
$h_
CountBean.java F!DrZd>\
YB(#]H|8S
/* L>|A6S#y8/
* CountData.java 2b vYF;<r
* 6PVlZ
* Created on 2007年1月1日, 下午4:44 4jI*Y6Wkz
* |qFN~ !
* To change this template, choose Tools | Options and locate the template under 476M` gA
* the Source Creation and Management node. Right-click the template and choose >-o?S O(M,
* Open. You can then make changes to the template in the Source Editor. 'Y6(4|w
(
*/ hNgcE,67q
GLoL4el
package com.tot.count; lBYS>4~
{RWahnr{
/**
*{L<BB^
* CVn;RF6
* @author oQE_?">w
*/ &AkzSgP
public class CountBean { Wl}G[>P
private String countType; Fp* &os
int countId; lS Kv*
/** Creates a new instance of CountData */ HvL9;^!
public CountBean() {} *>R/(Q
public void setCountType(String countTypes){ l-JKcsM
this.countType=countTypes; 'JXN*YO
} ?j
; ,q
public void setCountId(int countIds){ @5POgQ8
this.countId=countIds; [K^q:3R
} ./z"P]$
public String getCountType(){ ]MBJ"1F
return countType; TO8\4p*tE
} P7^TRrMF
public int getCountId(){ }pU!1GsO
return countId; `^@g2c+d
} 4%Wn}@
} h_}BmJ h_
?7uStqa
CountCache.java KH CdO
M 2U@gC|{
/* wN%DM)*k
* CountCache.java Z2Y583D
* |R|U z`
* Created on 2007年1月1日, 下午5:01 V%Z[,C
u+
* 5#A1u
Nb
* To change this template, choose Tools | Options and locate the template under 3]5&&=#
* the Source Creation and Management node. Right-click the template and choose cUX]tiC0
* Open. You can then make changes to the template in the Source Editor. HEW9YC"
*/ VA*79I#_q
zke~!"iq
package com.tot.count; +P<w<GfQ
import java.util.*; JhhT7\h(
/** )r-|T&Sn
* *~MiL9m+?
* @author X_Of k
*/ EKI+Dq,
public class CountCache { qhHRR/p
public static LinkedList list=new LinkedList(); ~N+/ZVo&y
/** Creates a new instance of CountCache */ }<x!95
public CountCache() {} V-o`L`(F`
public static void add(CountBean cb){ #h|,GvmF<b
if(cb!=null){ lQ(BEv"2G[
list.add(cb); Tef3
Z6
} ^?l-YnQqm?
} "=0lcbC
} j,V$vK P
lyc{Z%!3
CountControl.java Z~.]ZWj-
E;+OD&|
/* MsVI <+JZ
* CountThread.java ?5+KHG*)
* GF,|;)ly
* Created on 2007年1月1日, 下午4:57 z]R!l%`
* UEdl"FwM4
* To change this template, choose Tools | Options and locate the template under !n?*vN=S
* the Source Creation and Management node. Right-click the template and choose 77[;J
* Open. You can then make changes to the template in the Source Editor. K^1O =1gY
*/ cbHn\m)J,
B7QtB3bn
package com.tot.count; lr= !:D=K
import tot.db.DBUtils; %BP)m(S7
import java.sql.*; ^zs4tCW %
/** 2$/gg"g+
* dJ"xW;"
* @author
{83He@
*/ , $F0D
public class CountControl{ X
+
private static long lastExecuteTime=0;//上次更新时间 N X#/1=
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 9G\3hL]
/** Creates a new instance of CountThread */ b"3T(#2<*
public CountControl() {} 88LbO(q\d
public synchronized void executeUpdate(){ OgpH{"
Connection conn=null; .}u(&
PreparedStatement ps=null; =D:R'0YH
try{ 7&S|y]$~
conn = DBUtils.getConnection(); x~Esu}x7
conn.setAutoCommit(false); e, 3(i!47
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); F/,<dNJ
for(int i=0;i<CountCache.list.size();i++){ ;<ma K*f\S
CountBean cb=(CountBean)CountCache.list.getFirst(); d+| !6
CountCache.list.removeFirst(); Q)i`.mHfFI
ps.setInt(1, cb.getCountId()); eX),B
ps.executeUpdate();⑴ R;m0eG`
//ps.addBatch();⑵ .Yv.-A=ZIg
} {~{s =c0
//int [] counts = ps.executeBatch();⑶ f0'Wq^^
conn.commit(); WT? U~.U
}catch(Exception e){ jQBdS. }'v
e.printStackTrace(); A2FU}Ym0=
} finally{ Kgio}y
try{ ;{C{V{
if(ps!=null) { H_r'q9@<>
ps.clearParameters(); ZN]c>w[
)I
ps.close(); 4 ~|TKd{
ps=null; .6A:t?.
} Pj5#G0i%
}catch(SQLException e){} a/`Yh>ou
DBUtils.closeConnection(conn); Pw0 KQUs
} 2A;[Ek6{q
} cg5{o|x
public long getLast(){ 7%x+7
return lastExecuteTime; uTloj.
} aI#n+PW
public void run(){ 'ah0IYe
long now = System.currentTimeMillis(); U[ungvU1U
if ((now - lastExecuteTime) > executeSep) { ?cxK~Y\
//System.out.print("lastExecuteTime:"+lastExecuteTime); }4ju2K
//System.out.print(" now:"+now+"\n"); a9_KQ=&CI
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); JBJ7k19;
lastExecuteTime=now; ]O `
[v
executeUpdate(); <UL|%9=~
} J7] 60H#P
else{ #.t{g8W\C
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); Y,"MQFr(o
} NB#*`|qt
} 2cL)sP}
} NKh{iSLm
//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 ~"YNG?Rre
bHT@]`@@
类写好了,下面是在JSP中如下调用。 %hb5C 4q
RL)3k8pk
<% 4'=N{.TtO
CountBean cb=new CountBean(); \uPTk)oaB
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); >o=p5#{
CountCache.add(cb); EQhV}9
out.print(CountCache.list.size()+"<br>"); #C7j|9Ew1]
CountControl c=new CountControl(); 3^UsyZS)
c.run(); P&^7wud-sb
out.print(CountCache.list.size()+"<br>"); ? UDvFQ&
%>