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: @{y[2M} %]
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CountBean.java j6{9XIRo_
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/* 4!
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* CountData.java u!WjG@
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* Created on 2007年1月1日, 下午4:44 {E+o+2L
* idh5neyL
* To change this template, choose Tools | Options and locate the template under } :8{z`4H
* the Source Creation and Management node. Right-click the template and choose vpl>
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* Open. You can then make changes to the template in the Source Editor. 3BWYSJ|
*/ y&$v@]t1
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package com.tot.count; .q^+llM
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/** <;
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* BYBf`F)4
* @author Q-M"+ HO
*/ +:&,Ts/
public class CountBean { W8R"X~!V
private String countType; _R?:?{r,
int countId; ic_q<Y}
/** Creates a new instance of CountData */ [b<AQFh<c
public CountBean() {} bzt(;>_8
public void setCountType(String countTypes){ P5^<c\Mr,Y
this.countType=countTypes; C0$KpUB
} Lupug"p0
public void setCountId(int countIds){ 3HP o*~"]
this.countId=countIds; y6*9, CF
} 6+hx64 =
public String getCountType(){ 2,,t+8"`
return countType; b^~"4 fU
} !.nyIA(
public int getCountId(){ ^k7`:@
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return countId; ;m[-yqX
} -U"h3Ye^
} 3h-C&C
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CountCache.java <$]=Vaq
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/* ^t{2k[@
* CountCache.java t kJw}W1@
* KDODUohC
* Created on 2007年1月1日, 下午5:01 d?uN6JH9
* ogrh"
* To change this template, choose Tools | Options and locate the template under PfRe)JuB
* the Source Creation and Management node. Right-click the template and choose bm+
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* Open. You can then make changes to the template in the Source Editor. E0Y>2HOuL
*/ xy$agt>j>
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package com.tot.count; XpLK0YI
import java.util.*; r#xq 8H=_m
/** T3W?-,
* Jbrjt/OG#I
* @author \<bar ~
*/ a2MFZe
public class CountCache { XDWR]
public static LinkedList list=new LinkedList(); 0+]ol:i
/** Creates a new instance of CountCache */ K~ 6[zJ4
public CountCache() {} <lBY
public static void add(CountBean cb){ -t:~d:
if(cb!=null){ GV1SKa
list.add(cb); eiJ13`T
} )S;pYVVAl
} l".LtUf-
} 2!u4nxZ.
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CountControl.java MY[QYBkn}
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/* #H;yXsR`
* CountThread.java y]5c!N %8
* j6NK7Li
* Created on 2007年1月1日, 下午4:57 9 ^G.]W]
* iIe\m V
* To change this template, choose Tools | Options and locate the template under $T)EJe
* the Source Creation and Management node. Right-click the template and choose rk$$gXg9/
* Open. You can then make changes to the template in the Source Editor. z ]@ Q
*/ bh9!OqK9K
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package com.tot.count; iAOm[=W
import tot.db.DBUtils; 9HjtWQn
import java.sql.*; Z+qTMm
/** +~6Nq(kV
* 1m52vQSo3l
* @author jgfl|;I?pg
*/ w*E0f?s
public class CountControl{ Q>,EYb>wI
private static long lastExecuteTime=0;//上次更新时间 L1'#wH
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ^+hqGu]M
/** Creates a new instance of CountThread */ O$2= Z
public CountControl() {} ]CFh0N|(L
public synchronized void executeUpdate(){ nbVlP
Connection conn=null; b xU13ESv
PreparedStatement ps=null; PW[NW-S`c
try{ `H_.<``>
conn = DBUtils.getConnection(); P2q'P&
conn.setAutoCommit(false); `pHlGbrW
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); nMniHB'
for(int i=0;i<CountCache.list.size();i++){ &rcC7v K9
CountBean cb=(CountBean)CountCache.list.getFirst(); HR/"Nwr
CountCache.list.removeFirst(); "o=*f/M
ps.setInt(1, cb.getCountId()); A1mxM5N
ps.executeUpdate();⑴ )@X
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//ps.addBatch();⑵ Vz"Ja
} K,VN?t<h
//int [] counts = ps.executeBatch();⑶
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conn.commit(); w4S0aR:yL
}catch(Exception e){ AS}
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e.printStackTrace(); UJqDZIvC
} finally{ vbDSNm#Yv
try{ 8op,;Z7Y
if(ps!=null) { ugZ-*e7
ps.clearParameters(); FXHcy:)}G
ps.close(); {Q&@vbw'
ps=null; zjzW;bo( d
} >O{[w'sWa
}catch(SQLException e){} [_jd
DBUtils.closeConnection(conn); 8f^QO:
} (dL;A0L
} u9t@%H)lZ
public long getLast(){ XzX-Q'i=n0
return lastExecuteTime; O[N}@%HMW
} *bl*R';
public void run(){ k,~I>qg
long now = System.currentTimeMillis(); HF3W,eaqK
if ((now - lastExecuteTime) > executeSep) { b
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//System.out.print("lastExecuteTime:"+lastExecuteTime); xHA6
//System.out.print(" now:"+now+"\n"); b"au9:F4@7
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); IEx`W;V]K
lastExecuteTime=now; Tn$/9<Q
executeUpdate(); syEWc(5
} R3HfE*;Z
else{ qhKW6v
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); B{#*PAK=
} Q:
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} bJ[{[|yEd
} G lz0`z
//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 {HJzhIgCf
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类写好了,下面是在JSP中如下调用。 cGevFlnh
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<% ~f.fg@v`+v
CountBean cb=new CountBean(); B1EI'<S
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); DrG9Kky{
CountCache.add(cb); Rmq8lU
out.print(CountCache.list.size()+"<br>"); X&B2&e;
CountControl c=new CountControl(); $_j\b4]%
c.run(); qdlz#-B
out.print(CountCache.list.size()+"<br>"); kIm)Um
%>