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: [?6+ r
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CountBean.java c@lF*"4
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/* M\ wCZG
* CountData.java :"Vmy.xq
* &OvA[<qT
* Created on 2007年1月1日, 下午4:44 #x;d+Q@
* f3;[ZS
* To change this template, choose Tools | Options and locate the template under 3
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* the Source Creation and Management node. Right-click the template and choose dM"5obEb
* Open. You can then make changes to the template in the Source Editor. 9n5uO[D
*/ \]FPv7!
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package com.tot.count; 9QD+
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/** !FK)iQy$0
* 2*W|s7cc
* @author $U&p&pgH=W
*/ W T @XHwt
public class CountBean { rZAP3)dA
private String countType; [:izej(\
int countId; =BD|uIR
/** Creates a new instance of CountData */ D3tcwjXoW_
public CountBean() {} ^S|}<6~6b
public void setCountType(String countTypes){ M )v='O<H8
this.countType=countTypes; [$]-W$j+
} ocS}4.a@
public void setCountId(int countIds){ Dl?:Mh
this.countId=countIds; 1n)YCSA
} ?>R(;B|ER
public String getCountType(){ tI0D{Xrc
return countType; ~1Ffu x
} OSJL,F,
public int getCountId(){ $|@-u0sv
return countId; H.Z<T{y;
} i:&$I=
} /*6[Itm_h
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CountCache.java eS%8WmCV9<
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/* ~A(^<
* CountCache.java 8NWuhRRrw
* 4?_^7(%p
* Created on 2007年1月1日, 下午5:01 xjYH[PgfX
* $m-@ICG#
* To change this template, choose Tools | Options and locate the template under $}H,g}@0
* the Source Creation and Management node. Right-click the template and choose S2
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* Open. You can then make changes to the template in the Source Editor. JGYJ;j{E]
*/ T#}"?A|
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package com.tot.count; a 4?c~bs
import java.util.*; u`*1OqU
/** B}I9+/|{
* w,1*dn
* @author K7,Sr1O `
*/ F\<{:wu
public class CountCache { OL.{lKJ3DV
public static LinkedList list=new LinkedList(); %YG[?"P'
/** Creates a new instance of CountCache */ 2\"T&
public CountCache() {} K;R!>p}t
public static void add(CountBean cb){ S<I9`k G
if(cb!=null){ TOx@Y$_9Q8
list.add(cb); `nd$6i^#W
} mW3IR3b
} N8*QAekN
} \5#eBJ
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CountControl.java 9$ixjkIg
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/* {T5u"U4
* CountThread.java DNRWE1P2bg
* QOv@rP/
* Created on 2007年1月1日, 下午4:57 %/r:iD
* xeRoif\4c
* To change this template, choose Tools | Options and locate the template under >B$B|g~
* the Source Creation and Management node. Right-click the template and choose *3(mNpi{_
* Open. You can then make changes to the template in the Source Editor. N1JM[<PP
*/ ' $"RQ=
nz/cs n
package com.tot.count; fjqd16{Q
import tot.db.DBUtils; Yo}QW;,g
import java.sql.*; b%xG^jUXsX
/** Pu,2a+0N
* D1wONss
* @author @lCyH(c%
*/ _rW75n=3b7
public class CountControl{ Eu[/* t+l
private static long lastExecuteTime=0;//上次更新时间 $OaxetPH
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 $v1_M1
/** Creates a new instance of CountThread */ +EH"A
public CountControl() {} O&@CT] )8
public synchronized void executeUpdate(){ \$xj>b;
Connection conn=null; 3yLJWHO%W
PreparedStatement ps=null; 1P G"IaOb
try{ ?DKY;:dZF
conn = DBUtils.getConnection(); SnY{|
conn.setAutoCommit(false); se29IhS!e
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 5I/lF oy7
for(int i=0;i<CountCache.list.size();i++){ /1b7f'
CountBean cb=(CountBean)CountCache.list.getFirst(); {n(/ c33
CountCache.list.removeFirst(); 1/J6<FVq
ps.setInt(1, cb.getCountId()); ,hE989x<iI
ps.executeUpdate();⑴ a:F\4x=
//ps.addBatch();⑵ /])P{"v$^
} EvF[h:C2
//int [] counts = ps.executeBatch();⑶ @iN"]GFjS
conn.commit(); =G`g-E2
}catch(Exception e){ (btmg<WT"
e.printStackTrace(); m%s:4Z%=
} finally{ wJh/tb=$o
try{ N t\ZM
if(ps!=null) { dd*p_4;
ps.clearParameters(); ^95njE`>t`
ps.close(); W"&,=wvg2
ps=null; #Sg"/Cc
} "6Z(0 iu:{
}catch(SQLException e){} T@a|*.V
DBUtils.closeConnection(conn); Pk;YM}
} |mcc?*%t8
} e(Rbq8D
public long getLast(){ J|`.d46
return lastExecuteTime; Nt/hF>"7
} 9+3 VK
public void run(){ 5<YL^m{/L
long now = System.currentTimeMillis(); )W&{OMr
if ((now - lastExecuteTime) > executeSep) { 45WJb+$
//System.out.print("lastExecuteTime:"+lastExecuteTime); U*?`tdXJ$
//System.out.print(" now:"+now+"\n"); ^!gq_x
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); =nqHVRA
lastExecuteTime=now; (p<pF].
executeUpdate(); bAwKmk9C
} gFsqCx<q
else{ o7@C$R_#
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); Udq!YXE0
} 73Hm:"Eqd
} P>(FCX
} <~uzKs0
//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 M=3gV?N
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类写好了,下面是在JSP中如下调用。 Je}0KW3G9L
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<% I&31jn_o
/
CountBean cb=new CountBean(); gtePo[ZH.P
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 7*"Jx}eM
CountCache.add(cb); XK})?LTD
out.print(CountCache.list.size()+"<br>"); 3R0ioi 7
CountControl c=new CountControl(); ESYF4-d+
c.run(); {Wu[e,p
out.print(CountCache.list.size()+"<br>"); 72 |O&`O
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