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
0X.pI1jCO
CountBean.java u[})|x*N
2ACN5lyUS
/* L'.7V ~b{
* CountData.java I6~.sTl
* =
oQ-I
* Created on 2007年1月1日, 下午4:44 Y`w+?}(M
* _uID3N%
* To change this template, choose Tools | Options and locate the template under >HXT:0
* the Source Creation and Management node. Right-click the template and choose $o0o5 ^Z-
* Open. You can then make changes to the template in the Source Editor. M#UW#+*g!
*/ lo Oh }y+
J;HkR9<C
package com.tot.count; eVS6#R]'m
[?^,,.Dd
/** V0XQG}
* h#a,<B|
* @author xM'bb5
*/ b 'jZ4{+W
public class CountBean { /{6PwlP5
private String countType; P-.>vi^+
int countId; 7']n_-fu
/** Creates a new instance of CountData */ IOtSAf
public CountBean() {} '(r/@%=U
public void setCountType(String countTypes){ !K'j[cA^
this.countType=countTypes; P;C3{>G9
} h,"K+$
public void setCountId(int countIds){ LY(YgqL
this.countId=countIds; W{<_gD9
} &]iiBp#2
public String getCountType(){ B/6wp^#VX
return countType; 1^jGSB.%A
} yHsmX2s
public int getCountId(){ ,3 =|a|p
return countId; },lHa!<^
} 8>%:MS"
} $hXhq*5|c
PRg^E4
CountCache.java &'Pwz
rOHU)2
/* J'jwRn
* CountCache.java BIqZg$
* TCWy^8LA
* Created on 2007年1月1日, 下午5:01 F
jsnFX;
* tJ;<=.n
* To change this template, choose Tools | Options and locate the template under WBvh<wTw;
* the Source Creation and Management node. Right-click the template and choose ge
%ytrst
* Open. You can then make changes to the template in the Source Editor. /}t>o*
x
*/ p~Di\AQ/
&@NTedg!
package com.tot.count; aNs~Uad1U
import java.util.*; }8`W%_Yk
/**
[uqe|< :
* Q8OA{EUtq
* @author ,T&=*q
*/ ,rc?,J1l
public class CountCache { [$:M/5y9
public static LinkedList list=new LinkedList(); dY[ XNP
/** Creates a new instance of CountCache */ B)>r~v]
public CountCache() {} cAnL,?_v
public static void add(CountBean cb){ Q$u&/g3NvL
if(cb!=null){ mCah{~
list.add(cb); O|wu;1pQ
} )IQ5Qu
} bS7rG$n [
} >ka*-8?
4IfOvAN%
CountControl.java "x~VXU%xU
])Rs.Y{Q5
/* VAPRI\uM;
* CountThread.java A8tzIh8
* YD>5zV%!D
* Created on 2007年1月1日, 下午4:57 3h N?l
:/b
* Zcst$Aro
* To change this template, choose Tools | Options and locate the template under =ie8{j2:
* the Source Creation and Management node. Right-click the template and choose Lxz!>JO>
* Open. You can then make changes to the template in the Source Editor. c$fi3O
*/ su:~Xd
WRIOj Q:
package com.tot.count; ]$Ud`<Xnx
import tot.db.DBUtils;
/,Unp1D
import java.sql.*; Y%$@ZYW
/** GY% ^!r
* v|~&I%S7
* @author [&H$Su}$0
*/ ^hL?.xj
public class CountControl{ F3uR:)4<M
private static long lastExecuteTime=0;//上次更新时间 Fs+
CY
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 uT1xvXfqP
/** Creates a new instance of CountThread */ /1D]\k()
public CountControl() {} )\K ;Ncp[
public synchronized void executeUpdate(){ Tx)!qpZ
Connection conn=null; {p.D E
PreparedStatement ps=null; 3QM; K^$
try{ itotn!Wb`
conn = DBUtils.getConnection(); Z:_ wE62'
conn.setAutoCommit(false); !W\Zq+^^J3
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); cl\Gh
for(int i=0;i<CountCache.list.size();i++){ @9$u!ny0
CountBean cb=(CountBean)CountCache.list.getFirst(); %3SBs*?
CountCache.list.removeFirst(); Lvco9
Ak
ps.setInt(1, cb.getCountId()); o4Ny9s
ps.executeUpdate();⑴ VT@,RlB0
//ps.addBatch();⑵ WxE^S ??|
} VKGH+j[
//int [] counts = ps.executeBatch();⑶ HV0! G-h
conn.commit(); &>%R)?SZh
}catch(Exception e){ nrFuhW\r
e.printStackTrace(); J]h$4"
} finally{ {Tr5M o
try{ ko7*9`
if(ps!=null) { [l`_2{:
ps.clearParameters(); #k}x} rn<'
ps.close(); 6I8A[
ps=null; ,q_'l?Pn
} :6h$1
+6
}catch(SQLException e){} J~jxmh
DBUtils.closeConnection(conn); 322)r$!"
} N"',
} nO;*Peob
public long getLast(){ O\~/J/u
<
return lastExecuteTime; ^k#.;Q#4
} D6Q6yNE
public void run(){ 5>S=f{ghFw
long now = System.currentTimeMillis(); |M;tAG$,"y
if ((now - lastExecuteTime) > executeSep) { 6x]x>:8
//System.out.print("lastExecuteTime:"+lastExecuteTime); 76'@}wNnw
//System.out.print(" now:"+now+"\n"); 6_rgj{L
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); cu|S|]g
lastExecuteTime=now; YZ0y_it)
executeUpdate(); \Ei(HmEU
} bY@ S[
else{ ;~^9$Z@%Q
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); BI|BfO%F$j
} 1K&_t
} N'5AU (
} @gc|Z]CV
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 Gd%X> ~
B)L=)N
类写好了,下面是在JSP中如下调用。 &gv{LJd5b
%)t9b@c!}
<% J 7/)XS
CountBean cb=new CountBean(); Q$`u=-h|
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); \gU=B|W
CountCache.add(cb); s3Wjg
out.print(CountCache.list.size()+"<br>"); 0`H)c)
pP
CountControl c=new CountControl(); eV"Za.a.
c.run(); iHYvH
out.print(CountCache.list.size()+"<br>"); arQEi
%>