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: L%!jj7,9-
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CountBean.java c1c0b|B!U
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/* oYu5]ry
* CountData.java JMoWA0f
* *-2u0 %
* Created on 2007年1月1日, 下午4:44 wsM5TB
* Fd2zvi
* To change this template, choose Tools | Options and locate the template under `74A'(u_
* the Source Creation and Management node. Right-click the template and choose (HY|0Bgr
* Open. You can then make changes to the template in the Source Editor. x;ujR<
*/ mWtwp-
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package com.tot.count; hF6EOCY6D
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/** /QTGZb
* ~dC^|
* @author 3dXyKi
*/ Hq=RtW2
public class CountBean { %6 Bt%H
private String countType; Ehg5u'cj
int countId; Y]P]^3
/** Creates a new instance of CountData */ Dk:Zeo]+my
public CountBean() {} F`'e/
public void setCountType(String countTypes){ B6,"S5@
this.countType=countTypes; 9v^MZ^Y{
} 8%Pjx7'<
public void setCountId(int countIds){ zL1H[}[z+
this.countId=countIds; fY\QI
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} _uL m !ku
public String getCountType(){ Uc\\..Cf
return countType; <UeO+M(
} 7)~/`w)P
public int getCountId(){ y!!p:3
return countId; |FH/Q-7[
} W*gu*H^s~
} [&6l=a
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CountCache.java +,If|5>(
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/* aM~M@wS
* CountCache.java <vOljo
* pS9CtQqvgy
* Created on 2007年1月1日, 下午5:01 Ju+r@/y%
* v]c1|?9p'
* To change this template, choose Tools | Options and locate the template under M++*AZ
* the Source Creation and Management node. Right-click the template and choose 87y$=eZ
* Open. You can then make changes to the template in the Source Editor. Jo_h?{"L{
*/ wC;N*0Th
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package com.tot.count; ^qGH77#z
import java.util.*; zS]Yd9;X1
/** J=5G<
* )N<>L/R
* @author &!a[rvtZ+
*/ %=%jy
public class CountCache { Gb\}e}TB[
public static LinkedList list=new LinkedList(); Q lql(*
/** Creates a new instance of CountCache */ $GPenQ~},
public CountCache() {} -fn["R]
public static void add(CountBean cb){ ++BVn[ 1
if(cb!=null){ ybcQ,e
list.add(cb); D:M0_4S
} >i-cR4=LL{
} Ggsfr;m\`
} qK#\k@E
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CountControl.java yD$rls:v<
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/* P8piXG
* CountThread.java PKty'}KF
* 3@_je)s
* Created on 2007年1月1日, 下午4:57 Jcy
* Jx(%t<2
* To change this template, choose Tools | Options and locate the template under Q];+?Pu.
* the Source Creation and Management node. Right-click the template and choose UeX3cD
* Open. You can then make changes to the template in the Source Editor. kL{2az3"c
*/ rU%\ 8T0f
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package com.tot.count; esWgYAc3{
import tot.db.DBUtils; ySL 31%
import java.sql.*; 32:q'
/** 8it|yK.G@&
* M n3cIGL
* @author ts
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*/ /m(vIl
public class CountControl{ U_y)p Cd
private static long lastExecuteTime=0;//上次更新时间 :;#Kg_bz
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 L00,{g6wqb
/** Creates a new instance of CountThread */ $*{PUj
public CountControl() {} 8!'#B^
public synchronized void executeUpdate(){ ;a*i*{\Rm
Connection conn=null; T1LtO O
PreparedStatement ps=null; @I_A\ U{
try{ J#!:Z8b
conn = DBUtils.getConnection(); eOE7A'X
conn.setAutoCommit(false); P
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); `[2nxP>w`
for(int i=0;i<CountCache.list.size();i++){ H'P1EZtq
CountBean cb=(CountBean)CountCache.list.getFirst(); z<hy#BIjnd
CountCache.list.removeFirst(); [}N?'foLb
ps.setInt(1, cb.getCountId()); ]+{Cy\*kR
ps.executeUpdate();⑴ bo4 :|Z
//ps.addBatch();⑵ 1BmevEa)
} i\XOk!
//int [] counts = ps.executeBatch();⑶ t=d~\_Oa
conn.commit(); >| rID
}catch(Exception e){ _A;jtS)SY
e.printStackTrace(); l%oie1g l
} finally{ ]Jq1b210
try{ eh&? BP?
if(ps!=null) { mTwz&N\
ps.clearParameters(); !FX;QD@"
ps.close(); *}$T:kTH
ps=null;
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} g>CF|Wj
}catch(SQLException e){} i-vhX4:bd
DBUtils.closeConnection(conn); x~?,Wv|cm
} x@;XyQq
} =\eM
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public long getLast(){ EgFV
return lastExecuteTime; 6Y>MW 4q
} &&\ h%-Jc
public void run(){ tz4MT_f
long now = System.currentTimeMillis(); VrD?[&2pE
if ((now - lastExecuteTime) > executeSep) { n{6XtIoYq
//System.out.print("lastExecuteTime:"+lastExecuteTime); 6@t4pML
//System.out.print(" now:"+now+"\n"); U"v(9m@
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); No=Ig-It
lastExecuteTime=now; G^ZL,{
executeUpdate(); @kenv3[Lc
} a]>gDDF
else{ 7<<pP
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ;O}%_ef@
} bjmUU6VLT
} q&B'peT
} Xw(e@:
//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 Z2_eTC
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类写好了,下面是在JSP中如下调用。 z | Hl*T
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<% #I'W[\l~+
CountBean cb=new CountBean(); `(vgBz`e[
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); v7&e,:r2E@
CountCache.add(cb); |"8Az0[!
out.print(CountCache.list.size()+"<br>"); $W<H[k&(B
CountControl c=new CountControl(); dE7 kd=.o
c.run(); [rC-3sGar
out.print(CountCache.list.size()+"<br>"); rRRiqmq
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