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: -]Aqt/w"l
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CountBean.java Eg_ram`\R
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/* =A_fL{ SM
* CountData.java !{b4+!@p
* OgCz[QXr_
* Created on 2007年1月1日, 下午4:44 |+Tq[5&R
* Am"&ApK
* To change this template, choose Tools | Options and locate the template under -o@L"C>
* the Source Creation and Management node. Right-click the template and choose Cq}E5M
* Open. You can then make changes to the template in the Source Editor. xks Me
*/ 4i+H(d n
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package com.tot.count; 9D7i>e%,;-
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/** R#W=*cN
* Q6xA@"GJ
* @author V}Ce3wgvA
*/ L fZF
public class CountBean { C40o_1g
private String countType; U.N?cKv
int countId; 8;x0U`}Ez(
/** Creates a new instance of CountData */ A5Lzd
public CountBean() {} _[/#t|I}
public void setCountType(String countTypes){ W@D./Th
this.countType=countTypes; m%s:4Z%=
} M<P8u`)>4H
public void setCountId(int countIds){ v4F+^0?
this.countId=countIds; P[tYu:
} 22 feYm|
public String getCountType(){ [gj>ey8T
return countType; WJN)<+d
} 8k;il54#
public int getCountId(){ R1(3c*0f
return countId; /dHIm`. Z
} i:1
@ vo
} q`UaJ_7
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CountCache.java WWATG=
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/* e0hY
* CountCache.java &d\ y:7
* 8#/y`ul
* Created on 2007年1月1日, 下午5:01 Zpz3?VM(
* L+}<gQJ(
* To change this template, choose Tools | Options and locate the template under *D.Ajd.G
* the Source Creation and Management node. Right-click the template and choose 5GGO:
* Open. You can then make changes to the template in the Source Editor. `\f 3Ij,
*/ n}c~+0`un
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package com.tot.count; nu(7YYCM$
import java.util.*; QQv%>=_`
/** D"%>
* D}Sww5ZmP
* @author c=X+uO-
*/ QWtDZ>
public class CountCache { (>NZYPw^3
public static LinkedList list=new LinkedList(); <_#2+7Qs
/** Creates a new instance of CountCache */ dT[JVl+3=
public CountCache() {} o4wSt6gBcJ
public static void add(CountBean cb){ uqLP$At
if(cb!=null){ fH$#vRcq
list.add(cb); XK})?LTD
} SZ}=~yoD(
} IdK<:)Q
} b` va\'&3
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CountControl.java fP\q?X@]E
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/* x0WinLQ
* CountThread.java &}
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* ~clX2U8u`
* Created on 2007年1月1日, 下午4:57
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* aYDo0?kF'
* To change this template, choose Tools | Options and locate the template under -$DfnAh
* the Source Creation and Management node. Right-click the template and choose Z&U:KrFH
* Open. You can then make changes to the template in the Source Editor. 8;r #HtFM
*/ @`dlhz
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package com.tot.count; W"GW[~
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import tot.db.DBUtils; <f M}Kk
import java.sql.*; P%gA`j
/** /R&h#;l
* WTJ{M$
* @author o+7)cI
*/ tW/g0lC%
public class CountControl{ Fx|`0LI+C
private static long lastExecuteTime=0;//上次更新时间 _DH^ K9,9
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 sRA2O/yKCE
/** Creates a new instance of CountThread */ _+'!l'`
public CountControl() {} m|F1_Ggz
public synchronized void executeUpdate(){ tH44\~
Connection conn=null; "~^0
PreparedStatement ps=null; mO;QT
try{ *=.~PR6W{
conn = DBUtils.getConnection(); w.a9}GC
conn.setAutoCommit(false); IEMa/[n/
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 6#!CBY^{
for(int i=0;i<CountCache.list.size();i++){ KE@+I.x
CountBean cb=(CountBean)CountCache.list.getFirst(); 6{Q-]LOc[.
CountCache.list.removeFirst(); V`1{*PrI@L
ps.setInt(1, cb.getCountId()); bXOKC
ps.executeUpdate();⑴ ^n(FO,8c
//ps.addBatch();⑵ fg3Jv*
} Z|%h-~
//int [] counts = ps.executeBatch();⑶ >Vjn]V5y
conn.commit(); BEvY&3%l
}catch(Exception e){ "`V@?+3
e.printStackTrace(); @,TIw[p
} finally{ ,>h"~X
try{ 8c+V$rH_
if(ps!=null) { d#a/J.Z$A
ps.clearParameters(); gTXpaB<
ps.close(); Q(nTL WW
ps=null; {tUe(
} E|"SMA,
}catch(SQLException e){} _&BK4?H@b
DBUtils.closeConnection(conn); 3HpqMz
} kpIn_Ea
} C$TU
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public long getLast(){ gVfFEF.
return lastExecuteTime; t{jY@JT|
} $|- Lw!)D
public void run(){ W~;Jsd=f
long now = System.currentTimeMillis(); _d5:Y
if ((now - lastExecuteTime) > executeSep) { V;xPZ2C;
//System.out.print("lastExecuteTime:"+lastExecuteTime); Sk cK>i.[
//System.out.print(" now:"+now+"\n"); gZ$
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// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); Lz.khE<
lastExecuteTime=now; /DHgwpJ
executeUpdate(); W3tin3__
} $qQYxx@
else{ KD &nLm!
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ly17FLJ].
} Hyy b0c^=
} )bOfs*S
} C6;2Dd]"N
//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 C!*!n^qA
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类写好了,下面是在JSP中如下调用。 FfJ;r'eGs
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<% Bdw33z*m
CountBean cb=new CountBean(); KUUA>'=
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); d^aVP
CountCache.add(cb); pY"WW0p"C
out.print(CountCache.list.size()+"<br>"); ~DInd-<5
CountControl c=new CountControl(); [ ulub|
c.run(); `s
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out.print(CountCache.list.size()+"<br>"); e
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%>