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: %3FI>\3
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CountBean.java 2b !b-
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/* )L_jR%2j
* CountData.java `7'(U)x,F
* #+r-$N.7
* Created on 2007年1月1日, 下午4:44 {x-g?HB
* V1(eebi|
* To change this template, choose Tools | Options and locate the template under NbgP,-
* the Source Creation and Management node. Right-click the template and choose 3fBq~ Q
* Open. You can then make changes to the template in the Source Editor. `M\L6o
*/ yQ&;#`!'
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package com.tot.count; s'/ug
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/** &(wik#S
* Av/|={i
* @author .k[Ptx>
*/ I|BLAm6j
public class CountBean { Ph-3,cC
private String countType; ,/Xxj\i
int countId;
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/** Creates a new instance of CountData */ 'zRd?Z>%
public CountBean() {} F[9IHT6{
public void setCountType(String countTypes){ SU x\qz)
this.countType=countTypes; *6k
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} mQ1QJ_;
public void setCountId(int countIds){ d{DlW
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this.countId=countIds; [rGR1>U?i
} s;$
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public String getCountType(){ ! a1j c_
return countType; ]%NCKOM
} ]>x674H
public int getCountId(){ 1q/z&@+B
return countId; <f:b%Pm7
} AvH/Q_-b
} pQW^lqwZ:6
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CountCache.java b$g.">:$
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/* 8f#YUK
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* CountCache.java EMJ}tvL0Tp
* 1=#`&f5f&
* Created on 2007年1月1日, 下午5:01 gSC8qip
* mAXTO7
* To change this template, choose Tools | Options and locate the template under ox)/*c<
* the Source Creation and Management node. Right-click the template and choose sd>#Hn
* Open. You can then make changes to the template in the Source Editor. {*tewF)|
*/ RU[{!E
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package com.tot.count; @-Gf+*GZys
import java.util.*; a#KxjVM
/** nj)M$'
* k98--kc5
* @author +]UPY5:F
*/ A.y"R)G
public class CountCache { 7!Fu.Ps
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public static LinkedList list=new LinkedList(); R-Uj\M>
/** Creates a new instance of CountCache */ v]vrD2L
public CountCache() {} .\<
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public static void add(CountBean cb){ `/Z8mFs Y
if(cb!=null){
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list.add(cb); w[loV
} JQI`9$asuC
} %M~Ugv_4v
} I]TL#ywF
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CountControl.java %_}#IS1
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/* 5>$*#0%"}
* CountThread.java XIf,#9
* $D8KEkW
* Created on 2007年1月1日, 下午4:57 R%SsHu">
* 7?p%~j
* To change this template, choose Tools | Options and locate the template under +U@P+;
* the Source Creation and Management node. Right-click the template and choose i Ri1E;
* Open. You can then make changes to the template in the Source Editor. vFy/
*/ R"K{@8b
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package com.tot.count; Zni8im,_j
import tot.db.DBUtils; W._vikR
import java.sql.*; 4 YI,:
/** -.:1nI
* XWk/S $-d
* @author Tf*X\{"
*/ |+ @
public class CountControl{ +)Z,%\)Z
private static long lastExecuteTime=0;//上次更新时间 D3BX[
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 Sd}fse
/** Creates a new instance of CountThread */ (z+[4l7
public CountControl() {} oM QH-\(}
public synchronized void executeUpdate(){ Y`\zLX"_m
Connection conn=null; IjD:
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PreparedStatement ps=null; [ *R8XXuL
try{ tz._*n83
conn = DBUtils.getConnection(); CuU"s)
conn.setAutoCommit(false); ^#XxqVdPk
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ;I]TM#qGF
for(int i=0;i<CountCache.list.size();i++){ (w@|:0t^y[
CountBean cb=(CountBean)CountCache.list.getFirst(); @v@'8E Q
CountCache.list.removeFirst(); Q8T4_p[-o
ps.setInt(1, cb.getCountId()); \-`L}$
ps.executeUpdate();⑴ S ^2'O7uj
//ps.addBatch();⑵ Hq6VwQu?
} Wf>UI)^n
//int [] counts = ps.executeBatch();⑶ x&8fmUS:@;
conn.commit(); C[ <&%=
}catch(Exception e){ :cIE8<\%
e.printStackTrace(); v"y
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} finally{ ml\7JW6Rx
try{ Je+L8TB
if(ps!=null) { !|,=rM9x
ps.clearParameters(); o%Pi;8
ps.close(); >8 VfijK
ps=null; kax9RHvku
} ]Cbht\Ag"
}catch(SQLException e){} +oe
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DBUtils.closeConnection(conn); ';zLh
} ?Q:se
} /vSFQ}W
public long getLast(){ ]qhVxeUm
return lastExecuteTime; >PL/>
} `hI1
public void run(){ goWD~'\
long now = System.currentTimeMillis();
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if ((now - lastExecuteTime) > executeSep) { p;X[_h
//System.out.print("lastExecuteTime:"+lastExecuteTime); dax|4R
//System.out.print(" now:"+now+"\n"); k$3.FO"
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); c-z=(Z
lastExecuteTime=now; @DY0Lz;
executeUpdate(); 32YE%
} {tF=c0Z
else{ >-EoE;s
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); f}nGWV%,
} (;C_>EL&u
} \MK)dj5uUJ
} .#rI9op
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 'HPw5 L
#d(6q$IE
类写好了,下面是在JSP中如下调用。 XlDVJx<&J
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<% ]wdudvS@6r
CountBean cb=new CountBean(); C'*1w
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); #q(BR{A>t
CountCache.add(cb); R*VZ=i
out.print(CountCache.list.size()+"<br>"); 7A3e-51>
CountControl c=new CountControl(); (:M6*RV
c.run(); \1ys2BX
out.print(CountCache.list.size()+"<br>"); F#Z]Xq0r
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