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: rS8 w\`_
nH-V{=**
CountBean.java O XP\R
g(4bBa9y
/* n/4i|-^
* CountData.java mY7>(M{
* qxOi>v0\H
* Created on 2007年1月1日, 下午4:44 gl%`qf6:O
* B&?sF" Y
* To change this template, choose Tools | Options and locate the template under &[[K"aM1
* the Source Creation and Management node. Right-click the template and choose N.do "
* Open. You can then make changes to the template in the Source Editor. j+IrqPKC^
*/ &qM[g9
gABr@>Vv
package com.tot.count; >SbK.Q@ei
)Kd%\PP
/** |CFRJN-J"
* 3G}AH E4
* @author 5Wx~ZQZ
*/ aHzHvl
public class CountBean { b;cMl'
private String countType; q(M:QWA q
int countId; zZ-\a[F
/** Creates a new instance of CountData */ r(A.<`\
public CountBean() {} \}0-^(9zd
public void setCountType(String countTypes){ @OpNHQat9
this.countType=countTypes; /0MDISQy9
} *#
{z 3{+
public void setCountId(int countIds){ R:aa+MX(1
this.countId=countIds; V^s0fWa
} gb|Q%LS9R
public String getCountType(){ =n(3o$r(
return countType; TI|/u$SJ<Z
} PJ4(}a
public int getCountId(){ @~td`Z?1y
return countId; *Mc7f ?H
} 0MF}^"R
} \*t~==WB
_QOZsEe
CountCache.java ,F6=b/eZ
pc]J[ S?P
/* XRN+`J
* CountCache.java ^Q<mV*~
* W i.5Y{
* Created on 2007年1月1日, 下午5:01 t<iEj"5
* X;F8_+Np
* To change this template, choose Tools | Options and locate the template under I^\&y(LJF
* the Source Creation and Management node. Right-click the template and choose *XOJnyC_H
* Open. You can then make changes to the template in the Source Editor. &EGqgNl
*/ q'[}9e`Q
w*9br SK
package com.tot.count; 26?W
nu60
import java.util.*; WiL2
/** lCd@jB{
* 5K%SL1N
* @author nuQ]8- ,
*/ NE2pL@sk
public class CountCache { -_OS%ARa
public static LinkedList list=new LinkedList(); &
WOiik
/** Creates a new instance of CountCache */ Elj_,z
public CountCache() {} {y= W6uP
public static void add(CountBean cb){ >4` dy
if(cb!=null){ w'4AJ Q|;
list.add(cb); :nN1e
} W*DVi_\$y
} CBYX]
} PQmq5N6
$lA
V 6I.
CountControl.java rf:XRJ<4
VXBY8;+Yp
/* pO Iq%0]
* CountThread.java {@Yb%{+
* B_`y|sn
* Created on 2007年1月1日, 下午4:57 ~T7B$$
* WUc#)EEM)
* To change this template, choose Tools | Options and locate the template under NH<gU_s8{9
* the Source Creation and Management node. Right-click the template and choose Rgy-OA
* Open. You can then make changes to the template in the Source Editor. f>o,N{|
*/ inb^$v
9I7\D8r
package com.tot.count; }GMbBZ:nKK
import tot.db.DBUtils; ^jB8Q
import java.sql.*; RrZM&lXY
/** }kHdK vZ
* ZIR0PQh\
* @author P;[OWSR[d
*/ 1F'1>Bu~
public class CountControl{ WO5O?jo'
private static long lastExecuteTime=0;//上次更新时间 b3-eR5U/
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 }TQ{`a@
/** Creates a new instance of CountThread */ Am0{8
'
public CountControl() {} Qhi '')Q
public synchronized void executeUpdate(){ Y/<lWbj*A
Connection conn=null; '+>fFM,*B
PreparedStatement ps=null; F7L &=K$2y
try{ d6{Gt"
conn = DBUtils.getConnection(); f*{
YFg?*&
conn.setAutoCommit(false); sxKf&p;
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ?^mi3VM
for(int i=0;i<CountCache.list.size();i++){ `nXVE+E@
CountBean cb=(CountBean)CountCache.list.getFirst(); MTER(L
CountCache.list.removeFirst(); mP38T{
ps.setInt(1, cb.getCountId()); Jb)#fH$L
ps.executeUpdate();⑴ hf/2vt
m
//ps.addBatch();⑵ F;ZSzWq
} ,d+fDmm3
//int [] counts = ps.executeBatch();⑶ WO4=Mte?
conn.commit(); Zv_.na/^K
}catch(Exception e){ c}*2$1
e.printStackTrace(); %D$,;{ew
} finally{ V-I(WzR9y
try{ XfE?C:v
if(ps!=null) { 1be %G [*
ps.clearParameters(); {CG_P,FO
ps.close(); 3nZ9m
ps=null; >SN|?|2U/
} Xv <G-N4
}catch(SQLException e){} "vYE+
DBUtils.closeConnection(conn); @ l1
} +x?#DH-
} $8USyGi3J
public long getLast(){ aV o;~h~
return lastExecuteTime; *%w69#D
} U t-B^x)gl
public void run(){ {qW~"z*
long now = System.currentTimeMillis(); P&d"V<
if ((now - lastExecuteTime) > executeSep) { b*;"q9u5
//System.out.print("lastExecuteTime:"+lastExecuteTime); 2$_9cF Wm
//System.out.print(" now:"+now+"\n"); ^,F;M`[
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 6$a$K,dZ
lastExecuteTime=now; $WYbm}j
executeUpdate(); I$NhXZ)KT
} EV#MQM
else{ tt?58dm|
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); -7/s]9o'
} O1 .w,U
} <^b7cOFQ
} G2LK]
//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 <H1`
n,eJ$2!J
类写好了,下面是在JSP中如下调用。 YSJy`
F/m^?{==~*
<% -LDCBc"
CountBean cb=new CountBean(); *#%9Rp2|
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); PkE5|d*,
CountCache.add(cb); SvN9aD1
out.print(CountCache.list.size()+"<br>"); {U
'd}Q
CountControl c=new CountControl(); 4Wy<?O2
c.run(); A7!g
out.print(CountCache.list.size()+"<br>"); 72sD0)?A
%>