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: w] =q>p
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CountBean.java /swNhDQ"o
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/* N6wCCXd
* CountData.java ]> 36{k]&
* `R+I(Cb
* Created on 2007年1月1日, 下午4:44 \C eP.,<
* >Qg 9KGk'
* To change this template, choose Tools | Options and locate the template under W]U},g8Z
* the Source Creation and Management node. Right-click the template and choose _)6 N&u8
* Open. You can then make changes to the template in the Source Editor. {
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*/ L}x,>hbT
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package com.tot.count; 3sy|pa
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/** "0edk"hk
* z6+D=<
* @author gV\{Qoj
*/ L/sMAB
public class CountBean { QqU>V0y"w(
private String countType; xJSK"
int countId; 4UV<Q*B\F
/** Creates a new instance of CountData */ )%T<Mw2u
public CountBean() {} M7JQw/,xs
public void setCountType(String countTypes){ KqNbIw*sR
this.countType=countTypes; Sh+$w=vC
} jQIb :\0#
public void setCountId(int countIds){ 4>I >y@^
this.countId=countIds; J jp)%c#_
} A;\1`_i0
public String getCountType(){ quGvq"Y>
return countType; ejjL>'G/|%
} -xk.wWpV
public int getCountId(){ |1[3RnGS
return countId; UBZ37P
} ?!Bf# "TY
} 6+s10?
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CountCache.java <*'%Xgm
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/* znxP.=GB
* CountCache.java Ub_!~tb}?
* ].e4a;pt
* Created on 2007年1月1日, 下午5:01 9z0G0QW[
* 7u|X
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* To change this template, choose Tools | Options and locate the template under Z|k>)pv@
* the Source Creation and Management node. Right-click the template and choose h]{V/
* Open. You can then make changes to the template in the Source Editor. ZD(VH6<g%
*/ C ks;f6G
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package com.tot.count; yur5"$n
import java.util.*; a6<UMJ
/** Q2(K+!Oe
* ^/V>^9CZ
* @author !`h^S)$
*/ E@(nKe&6T_
public class CountCache { Jdc{H/10
public static LinkedList list=new LinkedList(); gFQ\zOlY8a
/** Creates a new instance of CountCache */ .%x%b6EI
public CountCache() {} :Ou[LF.O
public static void add(CountBean cb){ b:6NVHb%
if(cb!=null){ V }?MP-.c
list.add(cb); rTmVHt
} (Q4hm ]<
} XGCjB{IV
} }8e_
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CountControl.java RNMd,?dj
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/* bMp[:dw`y
* CountThread.java i]
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* P1u(0t
* Created on 2007年1月1日, 下午4:57 5HqvSfq>?
* !CGpE=V
* To change this template, choose Tools | Options and locate the template under Z&![W@m@0N
* the Source Creation and Management node. Right-click the template and choose L%Mj{fJ>Wm
* Open. You can then make changes to the template in the Source Editor. \)'5V!B|s
*/ FMNT0
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package com.tot.count; L#6!W
import tot.db.DBUtils; ^1mnw@04
import java.sql.*; CAT{)*xc
/** 5"WI^"6b:
* f]C`]qg
* @author hC
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*/ ,%X"Caz
public class CountControl{ $2J[lt?%
private static long lastExecuteTime=0;//上次更新时间 h%UM<TZ]"
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 qe<xH#6
/** Creates a new instance of CountThread */ "PePiW(i+
public CountControl() {} &rbkw<=j
public synchronized void executeUpdate(){ %5yP^BL0
Connection conn=null; ~4V-{-=0a7
PreparedStatement ps=null; j' }4ZwEh
try{ 4Wk`P]?^
conn = DBUtils.getConnection(); -%)S~R
conn.setAutoCommit(false); 3n3$? oV
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?");
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for(int i=0;i<CountCache.list.size();i++){ ?[!_f$50]P
CountBean cb=(CountBean)CountCache.list.getFirst(); y)K!l:X
CountCache.list.removeFirst(); -SlAt$IJ
ps.setInt(1, cb.getCountId()); i[4t`v'Dk
ps.executeUpdate();⑴ @=NTr
//ps.addBatch();⑵ GvTA/zA
} k@
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//int [] counts = ps.executeBatch();⑶ `P/87=h
conn.commit(); ^9zlxs`<d
}catch(Exception e){ U)6Ew4uRxV
e.printStackTrace(); \ !qe@h<
} finally{ $g&_7SJ@
try{ EL^j}P
if(ps!=null) { Ov~vK\
ps.clearParameters(); "UUoT
ps.close(); &ev#C%Nu
ps=null; }Dx5W9Ri"
} fJK;[*&Y
}catch(SQLException e){} ;;}}uW=
DBUtils.closeConnection(conn); #B6$r/%
} 8'-E>+L
} KSve_CBOh
public long getLast(){ 6ee1^>
return lastExecuteTime; rKkFflOVO
} Xk?Y
public void run(){ XYze*8xUb
long now = System.currentTimeMillis(); j*_>/gi
if ((now - lastExecuteTime) > executeSep) { q"-+`;^7(-
//System.out.print("lastExecuteTime:"+lastExecuteTime); U]PsL3:
//System.out.print(" now:"+now+"\n"); kIJ=]wU|v
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); _T(77KLn;
lastExecuteTime=now; b>@fHmpwD
executeUpdate(); #:E^($v
} x }.&?m
else{ Ch'e'EmI
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ]vjMfT%]W
} T?KM}<$(O
} },%,v2}
} V( =3K"j
//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 R,+"^:}
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类写好了,下面是在JSP中如下调用。 J?/NJ-F
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<% c?}{>ig/)
CountBean cb=new CountBean(); ?OBB)hj
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 0~Iq9}{*P
CountCache.add(cb); G7k.YtW
out.print(CountCache.list.size()+"<br>"); bW2Msv/H
CountControl c=new CountControl(); :a*F>S!
c.run(); c|F2 6$rv
out.print(CountCache.list.size()+"<br>"); F#Bi*YY
%>