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: |1z?#@BH
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CountBean.java Frxim
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/* D;RZE
* CountData.java aOWfu^&H:
* ImnN&[Cu
* Created on 2007年1月1日, 下午4:44 IC[iCrB
* f:)%+)U<Xm
* To change this template, choose Tools | Options and locate the template under h9J%NH
* the Source Creation and Management node. Right-click the template and choose Ny
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* Open. You can then make changes to the template in the Source Editor. F9Y/Z5 Ea
*/ h%0hryGB
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package com.tot.count; .&Rj2d
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/** [`'[)B
* L4w KG&
* @author %?`TyVt&0
*/ `tZ-8f
public class CountBean { _t+.I9kQ
private String countType; "h >B`S
int countId; `VB]4i}u
/** Creates a new instance of CountData */ =5PNH 2
public CountBean() {} f-M 9OI
public void setCountType(String countTypes){ D. _*p
this.countType=countTypes; iCK p"(kf
} >AsrPU[
public void setCountId(int countIds){ 9~FB^3Nz_
this.countId=countIds; [p7cgHSMt
} }RT#V8oc
public String getCountType(){ .JG> /+
return countType; FSp57W$
}
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public int getCountId(){ m:{ws~
return countId; @}Y,A~
} <+%#xi/_
} k-
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CountCache.java 6,D)o/_
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/* = @UgCu>=
* CountCache.java N8s2v W
* Oy,`tG0
* Created on 2007年1月1日, 下午5:01 JkiMrpkuk
* ls<7Qe"a
* To change this template, choose Tools | Options and locate the template under 'aFj yY?%
* the Source Creation and Management node. Right-click the template and choose j![ ; ;
* Open. You can then make changes to the template in the Source Editor. 4kZ9]5#.
*/ X 9lh@`3
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package com.tot.count; RkW)B^#
import java.util.*; %#^)hX,+Q
/** p%_m!
* Ul41RNy)
* @author ,2I8,MOg
*/ c,\!<4
public class CountCache { ?uq7K"B
public static LinkedList list=new LinkedList(); Wg3\hv29
/** Creates a new instance of CountCache */ ~S='~ g)
public CountCache() {} jZ;dY~fE
public static void add(CountBean cb){ jw^Pt~@
if(cb!=null){ svBT~P0x
list.add(cb); 2?)bpp$WZ
} xq.HR_\
} rTR4j>Ua~
} Ai 9UB=[R
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CountControl.java `k>h2(@9S
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/* %S2^i3
* CountThread.java /%fa_+,|-
* 0%9Nf!j
* Created on 2007年1月1日, 下午4:57 iyRB}[y
* .Y?/J,Ch
* To change this template, choose Tools | Options and locate the template under 6@2 S*\&
* the Source Creation and Management node. Right-click the template and choose 2`-y zm
* Open. You can then make changes to the template in the Source Editor. Xg](V.B6
*/ RnA>oKc
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package com.tot.count; ,s?7EHtC
import tot.db.DBUtils; LHt{y3l]
import java.sql.*; ]Gm$0uS
/** ~sI$xX!
* {u1Rc/Lw
* @author 6__#n`
*/ T2nbU6H
public class CountControl{ 7H1 ii
private static long lastExecuteTime=0;//上次更新时间 5g{L
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private static long executeSep=60000;//定义更新间隔时间,单位毫秒 `3v!i
/** Creates a new instance of CountThread */ I^5T9}>Q
public CountControl() {} ]G0`W6;$]
public synchronized void executeUpdate(){ YEEgDw]BQ
Connection conn=null;
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PreparedStatement ps=null; g' xR$6t
try{ q=M\#MlL0'
conn = DBUtils.getConnection(); q 16jL,i
conn.setAutoCommit(false); a!;]9}u7
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); =s2dD3Fr|
for(int i=0;i<CountCache.list.size();i++){ t5%\`Yo?
CountBean cb=(CountBean)CountCache.list.getFirst(); *mc]Oa
CountCache.list.removeFirst(); &*}NN5Sv
ps.setInt(1, cb.getCountId()); [I`r[u
ps.executeUpdate();⑴ ;FO1b*
//ps.addBatch();⑵ k{fCU%
} o4)^U t+
//int [] counts = ps.executeBatch();⑶ wW7W+,{o
conn.commit(); pP4i0mO{Dv
}catch(Exception e){ N@M(Iw
e.printStackTrace(); sGf\!w
} finally{ iaqhP7!
try{ \LFRu
if(ps!=null) { q/o|uAq
ps.clearParameters(); GP%83T
ps.close(); nt/+?Sj
ps=null; f PoC
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} d2Z kchf
}catch(SQLException e){} 6AZJ,Q\E@
DBUtils.closeConnection(conn); +DWmutL
} B%v2)+?@
} X(-e-:B4;
public long getLast(){ Y *
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return lastExecuteTime; kAbkhZ1^
} z2m%L0
public void run(){ %SRUHx[D
long now = System.currentTimeMillis(); 1PMBo=SUe8
if ((now - lastExecuteTime) > executeSep) { d9zI
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//System.out.print("lastExecuteTime:"+lastExecuteTime); >uok\sX
//System.out.print(" now:"+now+"\n"); @#T*OH
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); dQ=mg#(
lastExecuteTime=now; hcw)qB,s
executeUpdate(); KzQ\A!qG
} _YXk,ME!Q
else{ ?|8QL9Q"|
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); dOm#NSJVd
} f`5e0;zm
} uzO%+B!
} f\Bd lOJ>
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 AsRS7V
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类写好了,下面是在JSP中如下调用。 i$)`U]
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<% [sC]<2 r
CountBean cb=new CountBean(); {Gnji] v
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); w][1C\8m
CountCache.add(cb); +Y!9)~f}7X
out.print(CountCache.list.size()+"<br>"); KzeTf?G
CountControl c=new CountControl(); 360V
c.run(); O a_2J#~$
out.print(CountCache.list.size()+"<br>"); >EFjyhVE
%>