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: R:R@sU
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CountBean.java xAz4ZXj=q
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/* wXZY5-h4
* CountData.java KC-aLq/
* _vLT!y
* Created on 2007年1月1日, 下午4:44 WI!z92qq[
* [k=9 +0p
* To change this template, choose Tools | Options and locate the template under !cq|g
* the Source Creation and Management node. Right-click the template and choose Tc(v\|F,
* Open. You can then make changes to the template in the Source Editor. r=||sZs
*/ p33GKg0i+(
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package com.tot.count; `LU,uz
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/** JI,hy
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* .*f4e3
* @author #R PB;#{
*/ W!B4<'Fjc
public class CountBean { wP':B
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private String countType; 2^ZPO4|
int countId; a[cH@7W.#
/** Creates a new instance of CountData */ E=*Q\3G~
public CountBean() {} wEc5{ b5M
public void setCountType(String countTypes){ 3M*[a~
this.countType=countTypes; wP1VQUL
} [f(^vlK
public void setCountId(int countIds){ ~wg^>!E
this.countId=countIds; Q4:r$
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} QGj5\{E_
public String getCountType(){ wXGFq3`
return countType; |M>k &p,B-
} L Hz<=]?@
public int getCountId(){ W}_}<rlF
return countId; HU+H0S~g
} _rJSkZO
} :{uUc
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CountCache.java ZxPAu% Y
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/* 1O7ss_E
* CountCache.java ^ED>{UiNI
* jtr=8OiL
* Created on 2007年1月1日, 下午5:01 h1o+7
* h#ot)m|I
* To change this template, choose Tools | Options and locate the template under
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* the Source Creation and Management node. Right-click the template and choose $rYu4^
* Open. You can then make changes to the template in the Source Editor. m8^2k2
*/ V\hct$ 7Vm
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package com.tot.count; M%^laf
import java.util.*; 7uNI
/** be#"517
* -y*+G&
* @author (UT*T
*/ .T-p]9*p
public class CountCache { (
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public static LinkedList list=new LinkedList(); 8N_rJ)f
/** Creates a new instance of CountCache */ cGp 6yf
public CountCache() {} 6e|5qKr
public static void add(CountBean cb){ $*-L8An?
if(cb!=null){ :P"Gym
list.add(cb); PW4Wn`u
} 2U{RA's
} .Q)"F /
} K+OU~SED%F
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CountControl.java
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/* ;_&L^)~P$
* CountThread.java bQjHQ"G
* 3*JybMo"
* Created on 2007年1月1日, 下午4:57 >G~;2K[
* 1&"1pH
* To change this template, choose Tools | Options and locate the template under 0^Cx`xdX:
* the Source Creation and Management node. Right-click the template and choose 4344PBj
* Open. You can then make changes to the template in the Source Editor. @cGql=t
*/ bM3e7olWS
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package com.tot.count; liP{Mu/LO
import tot.db.DBUtils; e,UgTxZ
import java.sql.*; q~_jF$9SX
/** i=QhXCM
* ,jcp"-5#j
* @author ttVSgKAsm
*/ BIyG[y?qO
public class CountControl{ QLG,r^
private static long lastExecuteTime=0;//上次更新时间 hDMp^^$
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 }>U03aa!
/** Creates a new instance of CountThread */ "iGc'?/+
public CountControl() {} -h`0v
public synchronized void executeUpdate(){ n#/m7
Connection conn=null; our5k
PreparedStatement ps=null; 3R.cj
try{ fBOG#-a}
conn = DBUtils.getConnection(); ,[#f}|s_
conn.setAutoCommit(false); s%|J(0
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); nHjwT5Q+Q
for(int i=0;i<CountCache.list.size();i++){ gMn)<u >
CountBean cb=(CountBean)CountCache.list.getFirst(); jQ}|]pj+
CountCache.list.removeFirst(); >WX'oP(<
ps.setInt(1, cb.getCountId()); mIodD)?{
ps.executeUpdate();⑴ ~vFo 0k(
//ps.addBatch();⑵ a$8?0`(
} ,-kZ5&r
//int [] counts = ps.executeBatch();⑶ i( HhL&
conn.commit(); t%@pyK
}catch(Exception e){ ek!N eu>
e.printStackTrace(); miSC'!
} finally{ 8:NHPHxB
try{ Yg.u8{H
if(ps!=null) { :tG5~sK
ps.clearParameters(); }3lF;k(2g
ps.close(); 7yl'!uz)9
ps=null; 92Iv'(1ba
} "O
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}catch(SQLException e){} -',Y;0b%
DBUtils.closeConnection(conn); h %S#+t(Bf
} kGP?Jx\PkH
} 6suc:rp";
public long getLast(){ .`XA6e(8KR
return lastExecuteTime; $@;[K\
} IRa*}MJe
public void run(){ cgOoQP/#
long now = System.currentTimeMillis(); K?
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if ((now - lastExecuteTime) > executeSep) { FG\?_G
//System.out.print("lastExecuteTime:"+lastExecuteTime); +%v4Ci"%y
//System.out.print(" now:"+now+"\n"); ;7>--_?=
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); S(l^TF
lastExecuteTime=now; iI0 'z=J
executeUpdate(); \-y i#N
} jN0v<_PJED
else{ I|H mbTXa
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); e>.xXg6Zn
} 5H5Kt9DoW
} ]3'd/v@fT
} M(f'qFY=K
//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 v%^H9aK_
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类写好了,下面是在JSP中如下调用。 j Xf-+;ZQ
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<% f?6=H^_>
CountBean cb=new CountBean(); bX1ip2X
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cb.setCountId(Integer.parseInt(request.getParameter("cid"))); FC#Qtu~J
CountCache.add(cb); 9h8G2J
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out.print(CountCache.list.size()+"<br>"); /([aD~.
CountControl c=new CountControl(); x;Q2/YZ#
c.run(); hlZjk0ez
out.print(CountCache.list.size()+"<br>"); J:a^''
%>