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: ;k
b^mJE
[&NF0c[i
CountBean.java nt;A7pI`
}QJE9;<e
/* Slv}6at5
* CountData.java ~fCD#D2KU
* Fg#*rzA
* Created on 2007年1月1日, 下午4:44 0RoI`>j'
* 8w2+t>?
* To change this template, choose Tools | Options and locate the template under SF_kap%JM
* the Source Creation and Management node. Right-click the template and choose ; UrwK
* Open. You can then make changes to the template in the Source Editor. DVSYH{U4
*/ A1Q]KS@
2#+@bk>^{
package com.tot.count; xmiF!R
uU5:,Wy+dg
/** &<_sXHg<x
* iZjvO`@[
* @author E/U1g4S
*/ t:=Ui/!q
public class CountBean { Mqc[IAcd]
private String countType; 9!9 Gpi
int countId; Ch;EnN<
/** Creates a new instance of CountData */ gEi"m5po
public CountBean() {} q,:\i+>K*
public void setCountType(String countTypes){ 9,y&?GLP
this.countType=countTypes; 42m`7uQ
} 8 6L&u:o:
public void setCountId(int countIds){ h)y"?Jj
this.countId=countIds; _^a.kF
} m@zxjIwT
public String getCountType(){ ^S<Z'S
return countType; QyHUuG|g
} y|MW-|0=!
public int getCountId(){ =HoiQWQs`
return countId; Mm6
(Q
} 7FMHz.ZRE
} 4uNcp0
k ,<L#?,a
CountCache.java v11mu2
H[>_LYZ8
/* }Bc6:a
* CountCache.java ~7~nU>Vv
* i6X/`XW'
* Created on 2007年1月1日, 下午5:01 c&0IJ7fZG
* Pi8U}lG;
* To change this template, choose Tools | Options and locate the template under a?JU(
* the Source Creation and Management node. Right-click the template and choose x(S064
* Open. You can then make changes to the template in the Source Editor. tY[y? DJ
*/
wh*OD
q1?2
U<
package com.tot.count; ~(%G;fZ?x
import java.util.*; pM#:OlqC
/** m7RWu I,
* ,Y`C7Px
* @author ?<nz2 piP,
*/ |_w*:NCV5
public class CountCache { @'}X&TN<a
public static LinkedList list=new LinkedList(); -TD6s:'
/** Creates a new instance of CountCache */
Kjf#uU.7
public CountCache() {} "\>3mVOb
public static void add(CountBean cb){ nmSpNkJ5
if(cb!=null){ }VFSF/\^
list.add(cb); c89RuI `B~
} Hy `r}+
} @EZXPU
} jM7}LV1Ck
+u)'
CountControl.java (yX Vp2k
f ~Fus
/* g:2/!tujL
* CountThread.java mB1)!
* "n8_Ag@r
* Created on 2007年1月1日, 下午4:57 ;l`8w3fDt
* ~Yr.0i.W
* To change this template, choose Tools | Options and locate the template under EI_J7J+
* the Source Creation and Management node. Right-click the template and choose IsRsjhg8x
* Open. You can then make changes to the template in the Source Editor. @ym7hk.
*/ Yb?#vp I
o&CvjE
package com.tot.count; \/$v@5
import tot.db.DBUtils; F(XWnfUv
import java.sql.*; ,U7hzBj8k
/** `nizGg~1
* |RjjP 7
* @author R 7{r Y
*/ :ZzG5[o3
public class CountControl{ O!j@8~='
private static long lastExecuteTime=0;//上次更新时间 p[/n[@<8=
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 "^trHh8=
/** Creates a new instance of CountThread */ d@w
I:
7
public CountControl() {} {==Q6BG*
public synchronized void executeUpdate(){ qkBnEPWZy
Connection conn=null; qb9%Y/xy
PreparedStatement ps=null; v$mA7|(t!
try{ ~cZ1=,P
conn = DBUtils.getConnection(); 19=Dd#Nf
conn.setAutoCommit(false); sV*Q8b*
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); |
'z)RFqj
for(int i=0;i<CountCache.list.size();i++){ I+<; Dsp
CountBean cb=(CountBean)CountCache.list.getFirst(); =k8A7P
CountCache.list.removeFirst(); +L49
pv5
ps.setInt(1, cb.getCountId()); ~}M{[6!
ps.executeUpdate();⑴ keWgbj
//ps.addBatch();⑵
"Km`B1f`
} CjST*(,b
//int [] counts = ps.executeBatch();⑶ <y'ttxeS
conn.commit(); Fj&vWj`*
}catch(Exception e){ %(e=Q^=
e.printStackTrace(); *FAg^G&1
} finally{ N&ddO-r[s
try{ HwGtLeB"
if(ps!=null) { jxoEOEA
ps.clearParameters(); 9z-"JnM
ps.close(); ?Z!KV=
ps=null; zCQv:.0L
} *o>E{
}catch(SQLException e){} B#gmT2L
DBUtils.closeConnection(conn); es6e-y@e
} \GWq0z&
} +X?jf.4
public long getLast(){ `C()H@;
return lastExecuteTime; MUo?ajbqOd
} ~ACB#D%
public void run(){ >Y,7>ahyt
long now = System.currentTimeMillis(); *PI3L/*
if ((now - lastExecuteTime) > executeSep) { #2MwmIeA
//System.out.print("lastExecuteTime:"+lastExecuteTime); h\dIp`H
//System.out.print(" now:"+now+"\n");
h!Q>h7
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); _AO0:&
lastExecuteTime=now; 'v,W
gPe
executeUpdate(); =DCQ!02
} /#
eBDo
else{ >:xnjEsi$/
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); >2|#b
} [L\w]6
} "s*{0'jo
} !kIw835U
//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 4v!@9.!vQ
:C&?(HJ&r
类写好了,下面是在JSP中如下调用。 af_zZf!0
_m&VdIPO
<% zZRqb/20
CountBean cb=new CountBean(); j[HKC0C6
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 42C:cl} ."
CountCache.add(cb); tb
i;X=5
out.print(CountCache.list.size()+"<br>"); /qCYNwWH9
CountControl c=new CountControl(); P o_9M4kU
c.run(); 4H,DG`[Mo
out.print(CountCache.list.size()+"<br>"); f"tO*/|`
%>