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: [)kuu
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CountBean.java Z~}9^ (qc
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/* TKiYEh
* CountData.java /8Z&Y`G
* <@lj\,
* Created on 2007年1月1日, 下午4:44 6L)7Q0Z
* H/.UDz
* To change this template, choose Tools | Options and locate the template under k8l7.e*
* the Source Creation and Management node. Right-click the template and choose >;R7r|^k
* Open. You can then make changes to the template in the Source Editor. F/[m.!Eo
*/ 7 toIbC#
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package com.tot.count; d+6q%U
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/** {wgq>cb
* JT~Dr KI_
* @author TB= _r(:l+
*/ Y\+LBbB8
public class CountBean { UJ(UzKq8
private String countType; vp9wRGd
int countId; E|jU8qz>P
/** Creates a new instance of CountData */ l2YA/9.
public CountBean() {} ,?HM5c{'[Y
public void setCountType(String countTypes){ 7%[ YX
this.countType=countTypes; |.$7.8g
} .}uri1k"@k
public void setCountId(int countIds){ Y9&na&vY?
this.countId=countIds; 1 o_6WU
} HLdHyK/S
public String getCountType(){ d0&
return countType; mahNQ5 W*)
} )heHERbJ
public int getCountId(){ ,}"jiGgS4
return countId; N2Ysi$
} MJCz %zK
} ZLdIEBi=
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CountCache.java l N0u1)'2
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/* 0\s&;@xKk
* CountCache.java ^,)nuUy
* bI_MF/r''
* Created on 2007年1月1日, 下午5:01 7+IRI|d
* 9\T9pjdZE
* To change this template, choose Tools | Options and locate the template under M4CC&?6\
* the Source Creation and Management node. Right-click the template and choose @K}h4Yok
* Open. You can then make changes to the template in the Source Editor. ^zS;/%
*/ TCIbPsE
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package com.tot.count; Ta/u&t4
import java.util.*; ? STO#<a
/** MZB}O"
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* p=zTY7L
* @author y~\uS
*/ F%af05L[
public class CountCache { s&<76kwl
public static LinkedList list=new LinkedList(); Q#.E-\=^
/** Creates a new instance of CountCache */ jA[")RVG
public CountCache() {} 0&b;!N!vJ
public static void add(CountBean cb){ N8x.D-=gG
if(cb!=null){ WwWCNN~}
list.add(cb); D*?LcxX
} O6ugN-d>
} M%W#0
} 7s!rer>
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CountControl.java N93R(x)%
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/* 412E7
* CountThread.java hE$3l+
* ]mUt[Yy:z
* Created on 2007年1月1日, 下午4:57 fny6`_O
* ;sq xFF@
* To change this template, choose Tools | Options and locate the template under zK{}
* the Source Creation and Management node. Right-click the template and choose ?r5a*
* Open. You can then make changes to the template in the Source Editor. 9_e_Ne`i`?
*/ 3(vm'r&5n>
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package com.tot.count; 7zJ2n/`m*
import tot.db.DBUtils; ~C>Q+tR8
import java.sql.*; _-^mxC|M
/** U@{>+G[
* 7^mQfQv
* @author F-
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*/ -T-yt2h(
public class CountControl{ H*P+>j&
private static long lastExecuteTime=0;//上次更新时间 Zk>m!F>,p
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 W:6#0b"_#
/** Creates a new instance of CountThread */ `PvS+>q
public CountControl() {} kC6Y?g
public synchronized void executeUpdate(){ 4FZ/~Y1}
Connection conn=null; |"9vq<`
PreparedStatement ps=null; i~R+g3oi
try{ p~""1m01,D
conn = DBUtils.getConnection(); "a33m:]J
conn.setAutoCommit(false); YI > xxWA
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); HDKY7Yr
for(int i=0;i<CountCache.list.size();i++){ Fp[49
CountBean cb=(CountBean)CountCache.list.getFirst(); W
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CountCache.list.removeFirst(); q5@Nd3~h
ps.setInt(1, cb.getCountId()); 51H6
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ps.executeUpdate();⑴ _@gg,2
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//ps.addBatch();⑵ }9#GJ:x`
} bAuiMw7!
//int [] counts = ps.executeBatch();⑶ V[kn'QkWv
conn.commit(); 0uPcEpIA
}catch(Exception e){ jG)66E*"
e.printStackTrace(); Y9vVi]4
} finally{ vv<\LN0
try{ p9mGiK4!
if(ps!=null) { Q)qJ6-R|HD
ps.clearParameters(); ^Jdg%U?
ps.close(); #o9CC)q5G
ps=null; >i.$s
} !|]k2=+I
}catch(SQLException e){} ,Mi'NO
DBUtils.closeConnection(conn); cz>)6#&O
} D`X<b4e8/
} #F2DEo^0
public long getLast(){ jsr)
return lastExecuteTime; :`"-Jf
} R!WDQGR(2
public void run(){ h4MBw=Tz~
long now = System.currentTimeMillis(); 0Js5 '
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if ((now - lastExecuteTime) > executeSep) { rg]b$tL~
//System.out.print("lastExecuteTime:"+lastExecuteTime); &jQqlQ j
//System.out.print(" now:"+now+"\n"); a|[f%T<<
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 3u^wK
lastExecuteTime=now; #N64ZXz_
executeUpdate(); hE'7M;
} /6yVbo"
else{ b&1hj[`)
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n");
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} fb^R3wd$ff
} ;E5XH"L\
} )FIFf;r
//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 &TrL!9FtJ
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类写好了,下面是在JSP中如下调用。 sCQV-%9
j]5e$e{
<% KV9~L`=]i
CountBean cb=new CountBean(); DRXUQH
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); $#W^JWN1
CountCache.add(cb); TlX:05/V8
out.print(CountCache.list.size()+"<br>"); ]VtP7Y
CountControl c=new CountControl(); B4+u/hkbh?
c.run(); -49I3&
out.print(CountCache.list.size()+"<br>"); tx`^'%GMA
%>