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: P%>? O :a
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CountBean.java $DC*&hqpt
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/* {e[S?1t=l
* CountData.java $enh>!mU
* f&t]O$
* Created on 2007年1月1日, 下午4:44 _GK^ 7}u
* BR\%aU$u
* To change this template, choose Tools | Options and locate the template under &|P@$O>
* the Source Creation and Management node. Right-click the template and choose 9Qp39(l:
* Open. You can then make changes to the template in the Source Editor. Y."ujo #bB
*/ 94%gg0azp
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package com.tot.count; (utm+*V,
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/** EDvK9J
* "s2?cQv{#
* @author A|tee@H*0
*/ ~\/>b}^uf'
public class CountBean { Ld? tVi
private String countType; VB*N;bM^
int countId; C1P{4 U
/** Creates a new instance of CountData */ wXDF7tJh
public CountBean() {} ?UQVmE&
public void setCountType(String countTypes){ 3tI=?E#
this.countType=countTypes; N+l~r]: &
} )gV+BHK
public void setCountId(int countIds){ Y5=~>*e
this.countId=countIds; 0IBVR,q
} JU:!lyd
public String getCountType(){ 8-cG[/|0
return countType; $-"AMZ899
}
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public int getCountId(){ y?<[g;MuT
return countId; b>E%&sf
} MLY19 ;e
} E!Hq%L!/
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CountCache.java hSaS2RLF
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/* 2 *n2!7jZ*
* CountCache.java x@2rfs
* x+|Fw d
* Created on 2007年1月1日, 下午5:01
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* F^_d8=67h
* To change this template, choose Tools | Options and locate the template under \l{*1lQ`
* the Source Creation and Management node. Right-click the template and choose 0{v?
* Open. You can then make changes to the template in the Source Editor. 9~zh]deH
*/ 4DEsB)%X
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package com.tot.count; b@^M|h.Va
import java.util.*; /`hr)
/** V-A^9AAPm
* 3{Ze>yFE
* @author /`\-.S9
*/ 0-0 )E&2
public class CountCache { 7EY~5U/4
public static LinkedList list=new LinkedList(); aen(Mcd3bg
/** Creates a new instance of CountCache */ ro@Zbm;P
public CountCache() {} jCW>=1:JGY
public static void add(CountBean cb){ Yp 6;Y7^
if(cb!=null){ #lltXqvD?
list.add(cb); 'e3y|
} tt[P{mMQ
} l4U& CA y
} HCHP15otfe
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CountControl.java M42Zpb].
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/* KrMIJA4>
* CountThread.java Vnh
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* ;zs*Zd7h M
* Created on 2007年1月1日, 下午4:57 lx$Y-Tb^F
* T~"tex]
* To change this template, choose Tools | Options and locate the template under vlyq2>TfR
* the Source Creation and Management node. Right-click the template and choose UgJlXB|a%2
* Open. You can then make changes to the template in the Source Editor. n,PHfydqX
*/ Z ;%
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package com.tot.count; sB0+21'R
import tot.db.DBUtils; Lom%eoH)
import java.sql.*; rO]C`bg
/** /lr RbZ
* $k'f)E
* @author V.y+u7<3}
*/ n!eg"pL
public class CountControl{ X'kw5P!sq
private static long lastExecuteTime=0;//上次更新时间 dC( 6s=4
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 #H!~:Xu
/** Creates a new instance of CountThread */ 30DpIkf
public CountControl() {} S
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public synchronized void executeUpdate(){ P* aD2("Z
Connection conn=null; cYbO)?mC_
PreparedStatement ps=null; 3M%EK2 ,
try{ {_q2kk
conn = DBUtils.getConnection(); bzJKoxU
conn.setAutoCommit(false);
}rO4b>J
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); V ?_%Y<|L
for(int i=0;i<CountCache.list.size();i++){ d\)v62P
CountBean cb=(CountBean)CountCache.list.getFirst(); dH`a|SVW9
CountCache.list.removeFirst(); cU{LyZp
ps.setInt(1, cb.getCountId()); PU'v o4
ps.executeUpdate();⑴ fLD9RZ8_
//ps.addBatch();⑵ Qb(CH
} whLske-
//int [] counts = ps.executeBatch();⑶ QlXy9-oJ"
conn.commit(); e<p$Op
}catch(Exception e){ (vI7qD_
e.printStackTrace(); kBONP^xI
} finally{ wR;l"*j
try{ Z(<ul<?r
if(ps!=null) { ~(Tz <
ps.clearParameters(); ,7QnZ=F
ps.close(); F;b|A`M
ps=null; t[Q^Xp
} #-@{ rgH
}catch(SQLException e){} iF%q6R
DBUtils.closeConnection(conn); TWs|lhC7!
} "|Pl(HX
} t
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public long getLast(){ NNfCJ|
return lastExecuteTime; .H>Rqikj
} {$EXI]f
public void run(){ o?b%L
long now = System.currentTimeMillis(); Gg!))I+
if ((now - lastExecuteTime) > executeSep) { %b*%'#iK
//System.out.print("lastExecuteTime:"+lastExecuteTime); MO D4O4z&
//System.out.print(" now:"+now+"\n"); jqLyX
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); o}%fs
*
lastExecuteTime=now; =CVw0'yZ
executeUpdate(); i i@1!o
} qMES<UL>
else{ NcBe|qxQ
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); :$i:8lz
} MW$H/:3
} @:+n6
} Q\#{2!I
//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 )]>G,.9C}
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类写好了,下面是在JSP中如下调用。 *rcuhw"^b#
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<% xPMyG);
CountBean cb=new CountBean(); (SsH uNt.
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ~Oq,[,W
CountCache.add(cb); >'-w%H/
out.print(CountCache.list.size()+"<br>"); r@[VY g~
CountControl c=new CountControl(); &1E~ \8U
c.run(); 'SU9NQS
out.print(CountCache.list.size()+"<br>"); nj^q@h
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