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?)v#]<-
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CountBean.java 1OJD!juL$
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/* S
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* CountData.java kwU~kcM
* rxH*h`Xx@
* Created on 2007年1月1日, 下午4:44 3e4; '5q;
* e6f:@ O?
* To change this template, choose Tools | Options and locate the template under 8d|omqe~P
* the Source Creation and Management node. Right-click the template and choose *{8<4CVv
* Open. You can then make changes to the template in the Source Editor. bCr) 3,
*/ <NZ^*]
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package com.tot.count; ,e{( r0
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/** .VG$`g"
* P0NGjS|Z{
* @author _PD RUJ
*/ F(c~D0
public class CountBean { ~V&4<=r`
private String countType; gpW3zDJ
int countId; JRt^YX
/** Creates a new instance of CountData */ Pw
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public CountBean() {} q"xIW0Pc
public void setCountType(String countTypes){ 7?a@i;E<
this.countType=countTypes; T\ZWKx*#
} D%GB2-j R
public void setCountId(int countIds){ ^j&'2n@9a
this.countId=countIds; /nEt%YYh;x
} mL/]an@Y
public String getCountType(){ 7hwl[knyB
return countType; =<mpZ'9gW
} hT4u;3xE
public int getCountId(){ gdkl,z3N3
return countId; q$FwO"dC
}
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} k~f3~- "
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CountCache.java u&/[sqx
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/* r2A%.bL#
* CountCache.java ,CqJ((
* 37GJ}%Qs
* Created on 2007年1月1日, 下午5:01
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* np3$bqm
* To change this template, choose Tools | Options and locate the template under .J:04t1
* the Source Creation and Management node. Right-click the template and choose kXimJL_<g
* Open. You can then make changes to the template in the Source Editor. e+jp03m\W
*/ 09z%y[z
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package com.tot.count; !R*%F
import java.util.*; ,FRFH8p
/** l9"4"+?j<
* ,4W|e!
* @author ^2Sa_.
*/ 0I_A$Z,x
public class CountCache { 'PPVM@)fU
public static LinkedList list=new LinkedList(); W:D'k^u
/** Creates a new instance of CountCache */
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public CountCache() {} Y@x }b{3
public static void add(CountBean cb){ jO
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if(cb!=null){ n5CjwLgu\b
list.add(cb); MG ,exN
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} i'&KoR?
} KWtLrZ(j
} .w5#V|
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CountControl.java o=i)s2
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/* )6mx\t
* CountThread.java 8tq6.%\
* -L e:%q2
* Created on 2007年1月1日, 下午4:57 3=o^Vv
* !z@QoD
* To change this template, choose Tools | Options and locate the template under =f'MiU!p6
* the Source Creation and Management node. Right-click the template and choose *zoAD|0N
* Open. You can then make changes to the template in the Source Editor. Fx#0
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*/ )=VSERs
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package com.tot.count; N)'oX3?x
import tot.db.DBUtils; 86Q\G.h7
import java.sql.*; }#~@HM>6Z
/** 5Pmmt/Z
* `L<f15][
* @author 7oY}=281
*/ klHOAb1
public class CountControl{ 4T#B7wVoM
private static long lastExecuteTime=0;//上次更新时间 g-^Cf
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 g7*c wu
/** Creates a new instance of CountThread */ Z}bUvr XP
public CountControl() {} ECHl9;
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public synchronized void executeUpdate(){ |rJ1/T.9
Connection conn=null; .5=Qfvi*
PreparedStatement ps=null; (?MRbX]@
try{ &1O[N*$e
conn = DBUtils.getConnection(); Abr:UEG
conn.setAutoCommit(false); 4k'2FkDA
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); hgCF!eud
for(int i=0;i<CountCache.list.size();i++){ tBEZ4 W>67
CountBean cb=(CountBean)CountCache.list.getFirst(); A:Y]<jt
CountCache.list.removeFirst(); \+OP!`
ps.setInt(1, cb.getCountId()); \m @8$MK
ps.executeUpdate();⑴ N<wy"N{iS
//ps.addBatch();⑵ zt/p'khP3
} gb
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//int [] counts = ps.executeBatch();⑶ `>:ozN#)\
conn.commit(); 7{=<_
}catch(Exception e){ Kj[X1X5
e.printStackTrace(); &.k'Dj2hf
} finally{ |~mq+:44+
try{ I#(D.\P
if(ps!=null) { ^bpxhf
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ps.clearParameters(); ',-4o-
ps.close();
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ps=null; $Yfm>4
} `q Sfo`
}catch(SQLException e){} }\5^$[p
DBUtils.closeConnection(conn); vn;_|NeSf
} F 7+Gt
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} |a@$KF$
public long getLast(){ (Bs0/C
return lastExecuteTime; W]|;ZzZ=m
} e6s-;
public void run(){ :nki6Rkowt
long now = System.currentTimeMillis(); <p<jXwl
if ((now - lastExecuteTime) > executeSep) { }>:v
//System.out.print("lastExecuteTime:"+lastExecuteTime); _2{i}L
//System.out.print(" now:"+now+"\n"); .S/W_R
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); dP0!?J Y
lastExecuteTime=now;
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executeUpdate(); :CEhc7gU
} ;6aTt2BQ
else{ "kyy>H9)
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 75vd ]45as
} hg7`jE&2
} d!)
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} ,sPsL9]$
//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 rtcY(5Q
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类写好了,下面是在JSP中如下调用。 =8OPjcX.V
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<% H?8uy_Sc
CountBean cb=new CountBean(); "Yw-1h`fR
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); kE QT[Lo
CountCache.add(cb); =!3G ,qV
out.print(CountCache.list.size()+"<br>"); {UT>>
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CountControl c=new CountControl(); |YjuaXd7N
c.run(); RW
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out.print(CountCache.list.size()+"<br>"); jYKs| J)[
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