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: bk;uKV+<
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CountBean.java kd\Hj~*
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/* |2@*?o"ll
* CountData.java ; :q
* m4m|?
* Created on 2007年1月1日, 下午4:44 4OQ,|Wm4G
* h.F=Fhx/1
* To change this template, choose Tools | Options and locate the template under k4hk*
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* the Source Creation and Management node. Right-click the template and choose +xU( {/
* Open. You can then make changes to the template in the Source Editor. l"1D'Hk
*/ Ox&G
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package com.tot.count; 5oSp/M
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/** vNrn]v=|}7
* Z
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* @author Qubu;[0+a
*/ 6]d]0TW_
public class CountBean { qP<D9k>
private String countType; X<Z(,B
int countId; 3X1 1Gl
/** Creates a new instance of CountData */ R3l{.{3p2
public CountBean() {} zxCx2.7
public void setCountType(String countTypes){ $7c,<=
this.countType=countTypes; 3\Q 9>>
} /e?0Iv"
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public void setCountId(int countIds){ dt,Z^z+"E
this.countId=countIds; d[J_iD{ &
} ^r(My}
public String getCountType(){ D9A%8[Yo
return countType; jVQ89vf
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} RR
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public int getCountId(){ DyiJ4m}kh
return countId; `o295eiY(b
} la_c:#ho
} C !Srv7
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CountCache.java 1ONkmVtL
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/* t(-,mw
* CountCache.java c>{QTI:]
* M3O !jN~
* Created on 2007年1月1日, 下午5:01 $*iovam>^]
* vno/V#e$WX
* To change this template, choose Tools | Options and locate the template under e]1Zey
* the Source Creation and Management node. Right-click the template and choose ^N|8
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* Open. You can then make changes to the template in the Source Editor.
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*/ 9 %4:eTcp
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package com.tot.count; G%t>Ll``C
import java.util.*; PC<_1!M]
/** @r/~Y]0Ye5
* ]lBCK
* @author dp'[I:X
*/ ceJi|`F
public class CountCache { `(0B09~7
public static LinkedList list=new LinkedList(); z<vh8dNl
/** Creates a new instance of CountCache */ 4,c6VCw3+
public CountCache() {} Z%B6J>;u M
public static void add(CountBean cb){ X(*O$B{
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if(cb!=null){ YnU)f@b#
list.add(cb); T!KwRxJ23
} HdI)Z<Krp
} 9%iQ~
} BB(6[V"SV
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CountControl.java D\-\U
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/* CL4N/[UM
* CountThread.java 8Ejb/W_
* ~8u *sy
* Created on 2007年1月1日, 下午4:57 "^\q{S&q2P
* s) shq3O
* To change this template, choose Tools | Options and locate the template under @:9Gs!!
* the Source Creation and Management node. Right-click the template and choose Gb\PubJ
* Open. You can then make changes to the template in the Source Editor. diY7<u#
*/ R8Vf6]s_
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package com.tot.count; n@p@@
import tot.db.DBUtils; ={zTQ+7S`
import java.sql.*; > ]^'h
/** uI/
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* G#GZt\)F
* @author tj[E!
*/ &~H ed_
public class CountControl{ znwKwc8,
private static long lastExecuteTime=0;//上次更新时间 Nb`qM]&
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 (;},~( 2B
/** Creates a new instance of CountThread */ IUFc_uL@\
public CountControl() {} @nY]S\if
public synchronized void executeUpdate(){ src+z#
Connection conn=null; 5MAfuHq^
PreparedStatement ps=null; ^F+7<$2
try{ TjEXR$:<
conn = DBUtils.getConnection(); 7}UG&t{
conn.setAutoCommit(false); 6_bL<:xtY
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); =zcvR {Dkp
for(int i=0;i<CountCache.list.size();i++){ CC`_e^~y=F
CountBean cb=(CountBean)CountCache.list.getFirst(); \toU zTT
CountCache.list.removeFirst(); $3g{9)}
ps.setInt(1, cb.getCountId()); g=56|G7n
ps.executeUpdate();⑴ i#`q<+/q
//ps.addBatch();⑵ \H@1VgmR;
} c_D(%Vf5
//int [] counts = ps.executeBatch();⑶ _b~{/[s
conn.commit(); aLGq<6Ja
}catch(Exception e){ Lr$Mk#'B
e.printStackTrace(); {4G/HW28
} finally{
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try{ jfY7ich
if(ps!=null) { Ey|_e3Lf[
ps.clearParameters(); Qw}1q!89
ps.close(); !ka* rd
ps=null; -$Hu$Y}>
} wgS,U}/i
}catch(SQLException e){} F#sm^% _2
DBUtils.closeConnection(conn); dWvVK("Wj
} '|zrzU=
} 5FoZ$I
public long getLast(){ W8^m-B&
return lastExecuteTime; zl|z4j'Irc
} YOD.y!.zq7
public void run(){ TQF+aP8[L
long now = System.currentTimeMillis(); GBbnR:hM
if ((now - lastExecuteTime) > executeSep) { qJrT
//System.out.print("lastExecuteTime:"+lastExecuteTime); c>B1cR
//System.out.print(" now:"+now+"\n"); :x*)o+
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); T`ibulp
lastExecuteTime=now; P9
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executeUpdate(); |h\7Q1,1~2
} bx8](cT_
else{ 4VwF\
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); TmQIpeych
} M Irx,d
} rGyAzL]
} P2-&Im`+
//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 {_O!mI*
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类写好了,下面是在JSP中如下调用。 E^axLp>(I
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<% >1Z"5F7=
CountBean cb=new CountBean(); ?BnU0R_r]
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); (j&:
CountCache.add(cb); \!-BR0+y;
out.print(CountCache.list.size()+"<br>"); "+F'WCJ-(*
CountControl c=new CountControl(); (jM0YtrD
c.run(); [ >O!~
out.print(CountCache.list.size()+"<br>"); CJ
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