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: DZ%8 |PmB
DzE E:&*=
CountBean.java .Map
K_FBy
/* Y}ky/?q
* CountData.java @QX4 \
* 5 Af?Yxv
* Created on 2007年1月1日, 下午4:44 acy"ct*I
* 4zwif&
* To change this template, choose Tools | Options and locate the template under 4NI'(#l
* the Source Creation and Management node. Right-click the template and choose !&6-(q9
* Open. You can then make changes to the template in the Source Editor. 65t[vi*C
*/ MKe *f%
I'P.K| "R
package com.tot.count; P1e5uJkd
~"\P~cg0J
/** .;j"+Ef
* /:^tc/5U]
* @author h4h d<,
*/ ![j(o!6&
public class CountBean { |:}L<9Sq
private String countType; 0x6@{0
int countId; }:"R-s
/** Creates a new instance of CountData */ ELD
+:b
public CountBean() {} P0Aas)!
public void setCountType(String countTypes){ sbpu
qOL
this.countType=countTypes; ,qYf#fU#7
} ={OCa1
public void setCountId(int countIds){ KM E XT$p
this.countId=countIds; gMCy$+?
} &9k"9
public String getCountType(){ i /C'0
return countType; })q]gMj
} OY$7`8M[
public int getCountId(){ S[ i$e
return countId; \:C%>
.VG
} rC~_:uXtE
} ,Qga|n8C
^75pV%<%
CountCache.java .!9Vt#
C?bXrG\
/* m2wp m_vV#
* CountCache.java 5NFq7&rJ6
* e-1;dX HL
* Created on 2007年1月1日, 下午5:01 g+VRT,r
* +~@7"
|d
* To change this template, choose Tools | Options and locate the template under tYF$#Nor#k
* the Source Creation and Management node. Right-click the template and choose K T%i,T
* Open. You can then make changes to the template in the Source Editor. x!Y( Y=i>
*/ wbo{JQ
F1zT )wW
package com.tot.count; 3@%BA(M
import java.util.*; pFG]IM7o/u
/** 6
bYC
* uF.Q " ,<
* @author elNB7%Y/
*/ oM-b96
public class CountCache { 0oXK&Z
public static LinkedList list=new LinkedList(); Ug%<b
/** Creates a new instance of CountCache */ /abmjV0
public CountCache() {} USH@:c#t
public static void add(CountBean cb){ /YS@[\j4
if(cb!=null){ Jx)~kK
list.add(cb); $gXkx D
} `4se7{'UK`
} +!D=SnBGs
} tuX =o
`"i^'VL,
CountControl.java EolE?g@l8
B!$V\Gs
/* cu)@P 0I
* CountThread.java [%HYh7ua<
* IY-(-
a8
* Created on 2007年1月1日, 下午4:57 "v*oga%
* Cij$GYkv
* To change this template, choose Tools | Options and locate the template under >aNbp
* the Source Creation and Management node. Right-click the template and choose B:B0p+$I
* Open. You can then make changes to the template in the Source Editor. }x{rTEq
*/ ]t8{)r
sDW"j\
package com.tot.count; {Q}!NkF1
import tot.db.DBUtils; : Bdi pc
import java.sql.*; #JHy[!4
/** (jD'+ "?
* cg>!<T*
* @author k8!hvJ)?
*/ UUt~W
public class CountControl{ ay!6T`U`
private static long lastExecuteTime=0;//上次更新时间 <L[T'ZE+
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 yBUZVqqDa
/** Creates a new instance of CountThread */ r@N39O*Wq
public CountControl() {} Q"x`+?!
public synchronized void executeUpdate(){ L{+&z7M
Connection conn=null; &ryl$!!3H
PreparedStatement ps=null; oAIY=z
try{ *93l${'
conn = DBUtils.getConnection(); Tw`F?i~
conn.setAutoCommit(false); IBn'iE[>
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); TyxU6<>4J4
for(int i=0;i<CountCache.list.size();i++){ 9;;]q?*
CountBean cb=(CountBean)CountCache.list.getFirst(); ,(1vEE[9-
CountCache.list.removeFirst(); ]<&B
BQ
ps.setInt(1, cb.getCountId()); @]?? +f}#
ps.executeUpdate();⑴ :mCw.Jz<h
//ps.addBatch();⑵ K|P9uHD
} u K+9gTv
//int [] counts = ps.executeBatch();⑶ iX0]g45o
conn.commit(); # CP9^R S
}catch(Exception e){ 7UeE(=Hr5
e.printStackTrace(); uD0(aqAZ
} finally{ )&b}^1
try{ x9FLr}e
if(ps!=null) { /h.:br?M#P
ps.clearParameters(); E7d~#
ps.close(); 48*Oh2BA
ps=null; Gd]5xl
HRU
} ^+.+IcH
}catch(SQLException e){} C}M0XW
DBUtils.closeConnection(conn); _RA{SO
} j3sz*:
} >x|A7iWn{,
public long getLast(){ (6b?ir ~
return lastExecuteTime; !3b|*].B
} I{*.htt{
public void run(){ tkm~KLWV&7
long now = System.currentTimeMillis(); |IyM"UH
if ((now - lastExecuteTime) > executeSep) { yH0yO*RZ
//System.out.print("lastExecuteTime:"+lastExecuteTime); vu
!j{%GO
//System.out.print(" now:"+now+"\n"); 9XJ9~I?
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); .P|+oYT&g
lastExecuteTime=now; , u8ZS|9
executeUpdate(); >S-N|uR6
} t
wa(M?
else{ S20 nk.x
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); '/gxjr&
} #'G7mAoA
} 2yi*eR
} &k%wOz1vM
//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 2ZTyo7P
#Of<1
类写好了,下面是在JSP中如下调用。 #2ZrdD"5kQ
x`j$9XN5
<% Eb4< 26A
CountBean cb=new CountBean();
Xv?
S
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); $w";*">:0
CountCache.add(cb); ?vL^:f["
out.print(CountCache.list.size()+"<br>"); }5fI*v
CountControl c=new CountControl(); )Bm^aMVl3
c.run(); f//j{P[
out.print(CountCache.list.size()+"<br>"); &\WkJ}&PnA
%>