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: J$F nm\
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CountBean.java f1mHN7hxW
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/* $r\"6e
* CountData.java <} ,1Ncl
* x4m 5JDC
* Created on 2007年1月1日, 下午4:44 k=[pm5ZvT~
* 0GZq`a7[
* To change this template, choose Tools | Options and locate the template under DAdYg0efex
* the Source Creation and Management node. Right-click the template and choose M;+IZr Wkl
* Open. You can then make changes to the template in the Source Editor. fkjeR
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*/ nnwJYEi
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package com.tot.count; hN
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/** )%mg(O8uL
* g5+7p@'fV
* @author S]^`woD
*/ { p;shs5
public class CountBean { h >-'-Hx+
private String countType; |;+qld[4z
int countId; a?F!,=F
/** Creates a new instance of CountData */ PU1,DU
public CountBean() {} h[kU<mU"T
public void setCountType(String countTypes){ x5}lgyt
this.countType=countTypes; )I`if(fG
} rn8cdMN
public void setCountId(int countIds){ xzsdG?P
this.countId=countIds; IA4N@ijRxh
} .2W"w)$nuq
public String getCountType(){ mT@nn,
return countType; n[,XU|2
} |a-fE]{7
public int getCountId(){
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return countId; rh!;|xB|+
} 7"4z+w
} -)v@jlg02
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CountCache.java \OQkZ.cU;
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/* H4:&%"j7
* CountCache.java s$w;q\1z
* LlHa5]E@6
* Created on 2007年1月1日, 下午5:01 edipA
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* kJ{+M] pW
* To change this template, choose Tools | Options and locate the template under %Jp|z? [/
* the Source Creation and Management node. Right-click the template and choose vDFGd-S
* Open. You can then make changes to the template in the Source Editor. AiP!hw/V$
*/ /vxm"CJR
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package com.tot.count; u5B:^.:p
import java.util.*; dtZE67KS
/** 4;<ut$G
* Dnw| %6Y
* @author Fh8lmOL;?
*/ )1
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public class CountCache { (W[V?!1
public static LinkedList list=new LinkedList(); DF_X
/** Creates a new instance of CountCache */ lk3=4|?zsE
public CountCache() {} !4(zp;WY^
public static void add(CountBean cb){ o]ePP,
if(cb!=null){ ]fBUT6
list.add(cb); :YP #
} d\]Yk]r
} M}O}:1Par
} wSEWwU[
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CountControl.java v6GPS1:a
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/* !|
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* CountThread.java Ts.wh>`
*
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* Created on 2007年1月1日, 下午4:57 $q$7^r@
* i/H+xrCK
* To change this template, choose Tools | Options and locate the template under C0jj(ku&
* the Source Creation and Management node. Right-click the template and choose |'d>JT:
* Open. You can then make changes to the template in the Source Editor. I_1e?\
*/ I%j_"r9-I
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package com.tot.count; >UDd @
import tot.db.DBUtils; ~PnTaAPJ
import java.sql.*; Fv74bC%
/** =WIJ>#Go<
* 1v zb8.
* @author #bX9Tu0
*/ *v
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public class CountControl{ A A^{B
private static long lastExecuteTime=0;//上次更新时间 2ZcKK8X;7
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 zK|i='XSf
/** Creates a new instance of CountThread */ ^r6!l.
public CountControl() {} w[tmCn+
public synchronized void executeUpdate(){ ag-f{UsTy
Connection conn=null; #T w@wfaq)
PreparedStatement ps=null; c;?fMX
try{ f>`dF?^6
conn = DBUtils.getConnection(); HpZ1xT
conn.setAutoCommit(false); N@ \&1I`c$
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); EU7|,>a
for(int i=0;i<CountCache.list.size();i++){ #>lG7Ns|4
CountBean cb=(CountBean)CountCache.list.getFirst(); #J (~_%Wi
CountCache.list.removeFirst(); JN+_|`
ps.setInt(1, cb.getCountId()); jhu 07HX_
ps.executeUpdate();⑴ kQ1w5mCh
//ps.addBatch();⑵ ^9Qy/Er'
} R;,g1m|]
//int [] counts = ps.executeBatch();⑶ >/[GTqi
conn.commit(); vM:cWat
}catch(Exception e){ a=cvCf
e.printStackTrace(); Ar*^;/
} finally{ |L2SFB?d=
try{ ?;[w" `"
if(ps!=null) { wLc4Dm*V
ps.clearParameters(); W-NDBP:
ps.close(); Ym%xx!9
ps=null; wE+${B03
} X+UJzR90
}catch(SQLException e){} (e(:P~Ry
DBUtils.closeConnection(conn); A,sr[Pa@
} V |(H|9
} 8J$|NYv_b
public long getLast(){ 9mA{K
return lastExecuteTime; .X# `k
} vz.>~HBP
public void run(){ Po%LE]v,
long now = System.currentTimeMillis(); [sB 9gY(
if ((now - lastExecuteTime) > executeSep) { F*"}aP$
//System.out.print("lastExecuteTime:"+lastExecuteTime); &f-Uyr7?
//System.out.print(" now:"+now+"\n"); S<'[%ihx
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); F~h7{@\
lastExecuteTime=now; .o) `m9/
executeUpdate(); C74a(Bk}H
} /c
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else{ lpz2 m\
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n");
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} Fu!RhsW5j
} CHe>OreiS
} 89r DyRJ;
//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 dFKM
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类写好了,下面是在JSP中如下调用。 ;L']e"G
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<% _/i4MtM
CountBean cb=new CountBean(); n2iJ%_zp
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ty8v
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CountCache.add(cb); ")d`dj\o
out.print(CountCache.list.size()+"<br>"); d_IAs
CountControl c=new CountControl(); &mb{.=
c.run(); Na:w]r:y
out.print(CountCache.list.size()+"<br>"); ,7<f9 EVY
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