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: D&o~4Qvc]
DHg)]FQ/
CountBean.java Or#KF6+ut
Avww@$
/* {SF'YbY
* CountData.java wP7
E8'
* =pZ$oTR
* Created on 2007年1月1日, 下午4:44 X2|&\G9c
* (A )f
r4
* To change this template, choose Tools | Options and locate the template under tdHeZv
* the Source Creation and Management node. Right-click the template and choose Up1n0
* Open. You can then make changes to the template in the Source Editor. llN/
*/ x4i&;SP0
Bz(L}V]\k
package com.tot.count; $."DOZQ3U
ekW#|
/** n8E3w:A-
* 2:RFPK
* @author H:nO\]
*/ ce3``W/H3
public class CountBean { rf^u&f
private String countType; u9{SG^
int countId;
s)jNP\-
/** Creates a new instance of CountData */ 75pn1*"gQ
public CountBean() {} *JRM(V+IEv
public void setCountType(String countTypes){ jR9;<qT/
this.countType=countTypes; #kk5{*`
}
[b+B"f6
public void setCountId(int countIds){ O]Ey@7 &
this.countId=countIds; JXV#V7
} $O&N
public String getCountType(){ 9?q ^yy
return countType; Ei<m/v
} l,6' S8=
public int getCountId(){ 1pK(tm
return countId; "Lyb4# M
} #eF,* d
} e(?1`1
<*I*#WI&B
CountCache.java A{dqB
bk0<i*ju7(
/* r $[{sW
* CountCache.java %ikPz~(
* ~|[i64V<^
* Created on 2007年1月1日, 下午5:01 Q,M,^_
* Rh!m1Q(-
* To change this template, choose Tools | Options and locate the template under _%3p&1ld
* the Source Creation and Management node. Right-click the template and choose XqU0AbQ
* Open. You can then make changes to the template in the Source Editor. *kTj,&x[
*/ g*Pn_Yo[.
EL%P v1
package com.tot.count; p' 6h9/
import java.util.*; 6B]i}nFH{+
/** f,kV
* )gz]F_
* @author _R^ZXtypd
*/ g:.LCF
public class CountCache { IAWs}xIly
public static LinkedList list=new LinkedList(); ^F
qs,^~W
/** Creates a new instance of CountCache */ \PD%=~
public CountCache() {} ?VCp_Ji
public static void add(CountBean cb){ $> ;|
if(cb!=null){ /eT9W[a
list.add(cb); ]heVR&bQ
} xi=0kO
} qfdL *D
} qo}yEl1
PdEPDyFk h
CountControl.java RD0*]4>]
KMG}VG
/* AQtOTT$
* CountThread.java 2kOaKH[(q
* k{'<J(Hb
* Created on 2007年1月1日, 下午4:57 mq}UUk@
* uP$i2Cy
* To change this template, choose Tools | Options and locate the template under c_,pd
* the Source Creation and Management node. Right-click the template and choose j >`FZKxp
* Open. You can then make changes to the template in the Source Editor. G0kF[8Am
*/ G O"E>FyB
$2Awp@j
package com.tot.count; 8#R%jjr%T
import tot.db.DBUtils; G({5Lj gW
import java.sql.*; @=}NMoNH
/** w#_7,*6]
* |z8_]o+|r1
* @author C8do8$
*/ eY%Ep=J
public class CountControl{ I FvigDj?
private static long lastExecuteTime=0;//上次更新时间 T*S)U ;
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 2"k|IHs1
/** Creates a new instance of CountThread */ H@1qU|4
public CountControl() {} -GCU6U|
public synchronized void executeUpdate(){ cd~ QGP_C
Connection conn=null; i!fk'Yt%
PreparedStatement ps=null; {MN6JGb|'
try{ aK(e%Ed t"
conn = DBUtils.getConnection(); xb"e'Zh
conn.setAutoCommit(false); QpiDBJCL
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); h#Mx(q
for(int i=0;i<CountCache.list.size();i++){ unRFcjEa
CountBean cb=(CountBean)CountCache.list.getFirst(); J7`;l6+Gb
CountCache.list.removeFirst(); 4uh~@ Lv
ps.setInt(1, cb.getCountId()); <IBUl}|\
ps.executeUpdate();⑴ *y(UI/c
//ps.addBatch();⑵ <;@E
.I\N
} [h_d1\ Cr
//int [] counts = ps.executeBatch();⑶ i-#D c(9
conn.commit(); -;;m/QM
}catch(Exception e){ m&#D ~
e.printStackTrace(); xIV#}z0
} finally{ ]ncK M?'O
try{ U6o]7j&6
if(ps!=null) { YE:5'@Z
ps.clearParameters(); Z2-tDp(I
ps.close(); &_s^C?x
ps=null; }A[5\V^D*
} ;mr*$Iu 7|
}catch(SQLException e){} r[^O 7
DBUtils.closeConnection(conn); N/b$S@
} ~eS/gF?
} knzo 6
public long getLast(){ tkff\W[JU
return lastExecuteTime; Z^Wv(:Nr
} %tPy]{S..
public void run(){ aI|X~b
long now = System.currentTimeMillis(); ++ 5!8Nv
if ((now - lastExecuteTime) > executeSep) { a<]vHC7
//System.out.print("lastExecuteTime:"+lastExecuteTime); Ji1# >;&
//System.out.print(" now:"+now+"\n"); 3[?;s}61
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); Su[(IMw
lastExecuteTime=now; gxJ12'
m
executeUpdate(); ooCfr?E
} [jxh$}?P
else{ 0bD\`Jiv,
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 5 /T#>l<
} R:ecLbC
} jK%Lewq
} g&Uu~;jq]
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 kY9$ M8b
h0A%KL
类写好了,下面是在JSP中如下调用。 >wFn|7\)s>
'Q=(1a11
<% )c 79&S
CountBean cb=new CountBean(); bj_/
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ;!7M<T$&
CountCache.add(cb); 0zsmZ]b5E
out.print(CountCache.list.size()+"<br>"); 5^CWF|
CountControl c=new CountControl(); [@3.dd
c.run(); 7osHKO<?2
out.print(CountCache.list.size()+"<br>"); - (q7"h
%>