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: *J8j_-i,R
5U3="L
CountBean.java 0}PW?t76
H]UM2.
/* Xn$]DE/r}N
* CountData.java }v0oFY$u`H
* He)v:AH
* Created on 2007年1月1日, 下午4:44 [*vk&
* +X
cB 5S>
* To change this template, choose Tools | Options and locate the template under UG&/0{j5XV
* the Source Creation and Management node. Right-click the template and choose ZaH<\`=%
* Open. You can then make changes to the template in the Source Editor. H:,rNaz7D^
*/ !(uyqplTk
2B=yT8
package com.tot.count; G0CmY43
Rc0OEs%7P
/** tE3!;
* IA$:r@QNx8
* @author p!|Wp
*/ vs7Hg)F
public class CountBean { k
U*\Fa*E
private String countType; _;v4]MU
int countId; 8g(%6 ET
/** Creates a new instance of CountData */ SD8Q_[rY
public CountBean() {} 6Nj\N oS
public void setCountType(String countTypes){ &=<x&4H+
this.countType=countTypes; (t>BO`,
} QC \8Zy
public void setCountId(int countIds){ ojT TYR{
this.countId=countIds; 8nt:peJ$+
} Y71io^td~j
public String getCountType(){ ,Tvk&<!0
return countType; &P&M6v+
} f lR6^6E
public int getCountId(){ -%5*c61
return countId; D;.-e
} ]6GdB3?UVM
} )f*&}SV
2%. A{!
CountCache.java ht!o_0{~
}_@*,
/* `rbTB3?
* CountCache.java Cc$!TZq=
* i"0^Gr
* Created on 2007年1月1日, 下午5:01 )ra_`Qdcf
* |k^'}n
* To change this template, choose Tools | Options and locate the template under F7Mf>."
* the Source Creation and Management node. Right-click the template and choose !L2R0Y:a
* Open. You can then make changes to the template in the Source Editor. Y]Vt&*{JV
*/ +Hc[5WL
0x4Xs
package com.tot.count; l"W9uS;\T
import java.util.*; QpBgG~h"
/** lr=? &>MXj
* eY-W5TgU
* @author $.a<b^.Xi
*/ blpX_N
public class CountCache { MT[V1I{LV
public static LinkedList list=new LinkedList(); P6u9Ngay
/** Creates a new instance of CountCache */ Y}&//S A
public CountCache() {} }rj.N98
public static void add(CountBean cb){ f7Y0L8D
if(cb!=null){ lG I1LUo
list.add(cb); ^ r-F@$:.
} !TA6- ]1
} ^HgQ"dD
<
} aHNR0L3$}{
(0 /,R
CountControl.java (#k>cA(}
4w\
r
`@
/* k@L},Td
* CountThread.java Dt%Gv0
* !8 lG"l|,l
* Created on 2007年1月1日, 下午4:57 z#ab
V1
Xi
* |`+kZ-M*
* To change this template, choose Tools | Options and locate the template under {Fs}8\ z
* the Source Creation and Management node. Right-click the template and choose Cc/h|4
* Open. You can then make changes to the template in the Source Editor. 5%BexIk
*/ PIR#M('
w#vSZbh
package com.tot.count; ]VtVw^ ir
import tot.db.DBUtils; #tg,%*.s
import java.sql.*; dw#K!,g
/** e/Wrm^]y
* Xb?:dlu3
* @author f4UnLig
*/ H=Scrvfx
public class CountControl{ UF0W%Z
private static long lastExecuteTime=0;//上次更新时间 ;\ ^'}S|3Z
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 s~
||Vv!
/** Creates a new instance of CountThread */ d3-F?i
5d
public CountControl() {} ^0)Mc"&{
public synchronized void executeUpdate(){ 3*)<Y}Tc
Connection conn=null; fFDI qX
PreparedStatement ps=null; zmH8^:-x
try{ 7ss Y*1b
conn = DBUtils.getConnection(); ;wo
conn.setAutoCommit(false); uu ahR
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); }<R,)ZV^G
for(int i=0;i<CountCache.list.size();i++){ x\PZ.o
CountBean cb=(CountBean)CountCache.list.getFirst(); w0qrh\3du
CountCache.list.removeFirst(); a%| I'r
ps.setInt(1, cb.getCountId()); b3R1L|@
ps.executeUpdate();⑴ 0U|t@&q
//ps.addBatch();⑵ NwAvxN<R(f
} G>Fk
)
//int [] counts = ps.executeBatch();⑶ 9{[I|
conn.commit(); # &zM.O1Q
}catch(Exception e){ H<_BnT#
e.printStackTrace(); kw)("SQ
} finally{ LLy w9y1
try{ aa|u*afWQ
if(ps!=null) { pH&*5=t}
ps.clearParameters(); MWdev.m:Z
ps.close(); 7LEB,bU
ps=null; 5k:SD7^b
} pK` 1pfih
}catch(SQLException e){} \^o8qw'pt
DBUtils.closeConnection(conn); z$g
cK>@l
} >+,w2m@0
} OlU')0Y
public long getLast(){ OaTnQ|*
return lastExecuteTime; ))T@U?r
} 8^IV`P~2M
public void run(){ CzMCd
~*7R
long now = System.currentTimeMillis(); 1O#]qZS}]
if ((now - lastExecuteTime) > executeSep) { ~7p!t%;$
//System.out.print("lastExecuteTime:"+lastExecuteTime); (vX)
<Z
!
//System.out.print(" now:"+now+"\n"); ;X_bDiG$
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 0Q7teXRM
lastExecuteTime=now; m}UcF oaO
executeUpdate(); 8F>u6Y[P
} Xr:gm`[
else{ 9Lus,l\
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 6a*?m{
} -L-#-dK'
} $-D}y:
} 3Pu8IXW
//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 V0)bPcS/
Fqt,VED
类写好了,下面是在JSP中如下调用。 z`"*60b
?F6L,
<% sX@}4[)<&
CountBean cb=new CountBean(); RWg'W,v=!
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 7vo8lnQ{
CountCache.add(cb); LC1WVK/
out.print(CountCache.list.size()+"<br>"); tJG+k)EE
CountControl c=new CountControl(); &\>=4)HB;
c.run(); a}e GB +
out.print(CountCache.list.size()+"<br>"); s.X
.SJ
%>