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: `uA&w}(G
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CountBean.java 9Oyi:2A
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/* {Ch"zuPX
* CountData.java >-lL-%N_
* IGT_
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* Created on 2007年1月1日, 下午4:44 8$U ZL
* [E
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* To change this template, choose Tools | Options and locate the template under ~#_$?_/(
* the Source Creation and Management node. Right-click the template and choose (B,t
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* Open. You can then make changes to the template in the Source Editor. ?]D+H%3[$i
*/ )]>
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package com.tot.count; r/sRXM:3cZ
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/** H)T# R?
* 1r&
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* @author l=~99mE
*/ ?>jArzI
public class CountBean { X1[R*a/p
private String countType; e=;@L3f
int countId; G!LNP&~
/** Creates a new instance of CountData */ a~>0JmM+N
public CountBean() {} zw0 r
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public void setCountType(String countTypes){ zGd*Q5l
this.countType=countTypes; 9Q7cUoxY
} 1qKxg
public void setCountId(int countIds){ #u5;utY:F
this.countId=countIds; Q0uO49sg
} D3AtYt
public String getCountType(){ gc:p@<
return countType; IcA\3j
} 9
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public int getCountId(){ p F*~)e
return countId; LOUKURe E
} *o\Y~U-so
} _KhEwd
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CountCache.java <\9Ijuq}k
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/* OK2/k_jXN'
* CountCache.java ]G
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* I;.!
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* Created on 2007年1月1日, 下午5:01 \%?8jQ'tX
* Hs`#{W{.
* To change this template, choose Tools | Options and locate the template under Y=Ar3O*F
* the Source Creation and Management node. Right-click the template and choose 031.u<_
* Open. You can then make changes to the template in the Source Editor. Or#+E2%1E
*/ )"c]FI[}
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package com.tot.count; -G<2R"Q#N
import java.util.*; >7(~'#x8A"
/** 5)n:<U*
* -2jBs-z
* @author Wh'_slDH+
*/ qfP"UAc{/
public class CountCache { #nf%ojh
public static LinkedList list=new LinkedList(); vLK\X$4
/** Creates a new instance of CountCache */ bHQKRV
public CountCache() {} <j1d~XU}
public static void add(CountBean cb){ Xm^h5jAr
if(cb!=null){ eYD9#y
list.add(cb); e"s {_V
} N} x/&e
} 6aF'^6+a
} hA1gkEM2o
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CountControl.java JPT I6"/
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/* c]aK
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* CountThread.java zmL~]!~&
* C@UJOB
* Created on 2007年1月1日, 下午4:57 y5AXL5
* H6PXx
* To change this template, choose Tools | Options and locate the template under 6Er0o{iI
* the Source Creation and Management node. Right-click the template and choose S`2mtg
* Open. You can then make changes to the template in the Source Editor. (4{ C7
*/ 4Fr7jD,#k
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package com.tot.count; 5fj
import tot.db.DBUtils; r_V2 J{B
import java.sql.*; Fyh?4!/.
/** u.pKK
* S4{ Mu(^xT
* @author 0,~6TV<K
*/ ;1R?9JN"
public class CountControl{ ]4 K1%ZV
private static long lastExecuteTime=0;//上次更新时间 _r<zSH%
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 7{Ki;1B[w
/** Creates a new instance of CountThread */ b5n]Gp
public CountControl() {} _']%qd"%
public synchronized void executeUpdate(){ B.Zm$JZ:
Connection conn=null; dIk8TJ
PreparedStatement ps=null; !HdvCYB>
try{ :p\(y
conn = DBUtils.getConnection(); f- k|w%R@
conn.setAutoCommit(false); 20.-;jK
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); d Y:|Ef|v(
for(int i=0;i<CountCache.list.size();i++){ >2| [EZ
CountBean cb=(CountBean)CountCache.list.getFirst(); =$)4:
CountCache.list.removeFirst(); ]M+VSU
ps.setInt(1, cb.getCountId()); H4}%;m%
ps.executeUpdate();⑴ *gM,x4 Y
//ps.addBatch();⑵ S/nj5Lh
} \ifK~?
//int [] counts = ps.executeBatch();⑶ I9[1U
conn.commit(); >op:0on]}
}catch(Exception e){ $S6HZG:N
e.printStackTrace(); *]}CSZ[>
} finally{ M1/M}~
try{ H{\.g=01
if(ps!=null) { Ge^zX$.'
ps.clearParameters(); FGDGWcRw~
ps.close(); z.2r@Psk
ps=null; *PSvHXNi
} kCaO\#ta
}catch(SQLException e){} AfbB~Ll Bq
DBUtils.closeConnection(conn); y*VQ]aJ
} ^wx%CdFm'P
} [%j?.N
public long getLast(){ qj~flw1:
return lastExecuteTime; ADv^eJJ|
}
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public void run(){ z-EwXE
long now = System.currentTimeMillis(); @4IW=V
if ((now - lastExecuteTime) > executeSep) { Zg
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//System.out.print("lastExecuteTime:"+lastExecuteTime); .]W;2G
//System.out.print(" now:"+now+"\n"); ;y>S7n>n:
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); _j:UGMTi(U
lastExecuteTime=now; o! aLZ3#X
executeUpdate(); Nls83 W
} Y3#Nux%
else{ S~KS9E~\
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 2v0!` &?M{
} aWyUu/g<A`
} 21r==
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} +c^_^Z$_4o
//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 _fcS>/<a
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类写好了,下面是在JSP中如下调用。 Og,Y)a;=
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<% \|CPR6I
CountBean cb=new CountBean(); f}^I=pS&
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); yL0f1nS
CountCache.add(cb); `E@kFJ(<On
out.print(CountCache.list.size()+"<br>"); ~12_D'8D[
CountControl c=new CountControl(); 1N8;)HLIBJ
c.run(); 'T\dkSJv;V
out.print(CountCache.list.size()+"<br>"); QV7,G9
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