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: &>]c"?C*
tUPdq 0%t[
CountBean.java $xl>YYEBMH
byW9]('e
/* E0o?rgfdq
* CountData.java Sb;=YW
1<
* 8r46Wr7Q
* Created on 2007年1月1日, 下午4:44 |)pRkn8x
* GV"Hk E;
* To change this template, choose Tools | Options and locate the template under f,_EPh>
* the Source Creation and Management node. Right-click the template and choose #uzp
* Open. You can then make changes to the template in the Source Editor. v3`k?jAaI
*/ 3r]:k)J
XzBnj7E
package com.tot.count; ,4&?`Q
<@puWm[p
/** IW<nfg
* BlrZ<\-/
* @author yK3b^
*/ ~;#OQ[
public class CountBean { RMfKM!
vE
private String countType; :4V8Iz 71
int countId; %Ct^{k~1
/** Creates a new instance of CountData */ f*ICZM
public CountBean() {} #2~-I
public void setCountType(String countTypes){ th?w&;L
this.countType=countTypes; E1&9( L5
} +%%Ef]
public void setCountId(int countIds){ %gb4(~E+N
this.countId=countIds; 1K`7
} z9B""ws
public String getCountType(){ [$<\*d/
return countType; hN3*]s;/6z
} X'
,0vK
public int getCountId(){ knsTy0]
return countId; `3C dW
} [7btoo|P]
} OrJuE[R.
Tt.#O~2:9
CountCache.java {Hu@|Q\~&
}CCTz0[D"
/* H>qw@JiO!
* CountCache.java aGR!T{`
* k)t_U3i
* Created on 2007年1月1日, 下午5:01 3m#/1=@o
* ^z%ShmM&LZ
* To change this template, choose Tools | Options and locate the template under XJ3p<
* the Source Creation and Management node. Right-click the template and choose .a0]1IkatV
* Open. You can then make changes to the template in the Source Editor. $k,wA8OZ-
*/ &P@dx=6d
eq!>~: #
package com.tot.count; nbMxQODk
import java.util.*; ;
m]KKB
/** hN5?u:
* m 3Y@p$i5
* @author ~mR@L `"l
*/ t6+c"=P#
public class CountCache { !G8=S'~~
public static LinkedList list=new LinkedList(); !pqfx93R*
/** Creates a new instance of CountCache */ XDt MFig
public CountCache() {} fK %${
public static void add(CountBean cb){ u Sl&d
if(cb!=null){ L^{1dVGWNa
list.add(cb); 6Kbc:wlR
} *:+&SxL
} X^td`}F/=V
} @X?7a]+;8
?DwI>< W
CountControl.java 4Ucs9w3[
'BiR ,M$mY
/* =Lc!L
!(,b
* CountThread.java r+D ?_Lk
* OtVRhR3>
* Created on 2007年1月1日, 下午4:57 ]2 7
* 5p}ri,Y<
* To change this template, choose Tools | Options and locate the template under 0{q>'dv
* the Source Creation and Management node. Right-click the template and choose zJ=lNb?q
* Open. You can then make changes to the template in the Source Editor. NR6wNz&81
*/ +&*D7A>~p
VbG#)>"F
package com.tot.count; S <RbC
import tot.db.DBUtils; ]VCVV!G_=n
import java.sql.*; 9Ev<t\B
/** _&wrA3@/L
* Z"pCDW)
* @author Q:5^K
*/ "K9/^S_
public class CountControl{ :Rftn6!
private static long lastExecuteTime=0;//上次更新时间 nZbINhls
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 W0 n?S
"
/** Creates a new instance of CountThread */ T)Zef
public CountControl() {} '
a>YcOw
public synchronized void executeUpdate(){ V`WSZ
Connection conn=null; cs]h+yE
PreparedStatement ps=null; z]%c6ty
try{ I,lX;~xb
conn = DBUtils.getConnection(); ^ 5D%)@~
conn.setAutoCommit(false); Sk6B>O <:
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); zJ
$&`=
for(int i=0;i<CountCache.list.size();i++){ '-l.2IUyT
CountBean cb=(CountBean)CountCache.list.getFirst(); q^ w@l
CountCache.list.removeFirst(); E
xls_oSp
ps.setInt(1, cb.getCountId()); }mYxI^n
ps.executeUpdate();⑴ 3T= ?!|e
//ps.addBatch();⑵ ;(3!#4`q(]
} z8@[]6cW
//int [] counts = ps.executeBatch();⑶ K7-z.WTUR
conn.commit(); 8)o%0#;0B
}catch(Exception e){ J85S'cwZZ
e.printStackTrace(); 0Xw$l3@N^
} finally{ !0Mx Bem
try{ -\9K'8 C
if(ps!=null) { euyd(y$'k
ps.clearParameters(); j6: jN-z
ps.close(); yp!7^
ps=null; zCe[+F
} )Ggv_mc h
}catch(SQLException e){} Pxvf"SXX
DBUtils.closeConnection(conn); {44#<A<
} `9*
|Y 8:
} )
w1`<7L
public long getLast(){ Iysp)
return lastExecuteTime; lS96Z3k"SB
} Due@'
public void run(){ WqJrDj~
long now = System.currentTimeMillis(); jl"su:y
if ((now - lastExecuteTime) > executeSep) { ! }>CEE
//System.out.print("lastExecuteTime:"+lastExecuteTime);
I !J'
//System.out.print(" now:"+now+"\n"); jf^BEz5
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); EvKzpxCh
lastExecuteTime=now; rQD^O4j R
executeUpdate(); OfK>-8
} t}YT+S
else{ &e6!/y&
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ^?8/9o
} vk4Q2P
} /U
3Uuk:
} q"e]\Tb=we
//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 $3=S\jyfK
ZYS]Et[Q
类写好了,下面是在JSP中如下调用。 `*ALb|4ilG
bgYUsc*uR
<% H:F'5Zt
CountBean cb=new CountBean(); %6W%-`
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); bs&>QsI?j
CountCache.add(cb); 8Drz
i!}
out.print(CountCache.list.size()+"<br>"); gkmV;0
CountControl c=new CountControl(); .]e_je_
c.run(); )`BKEaf
out.print(CountCache.list.size()+"<br>"); p/U{*i]t
%>