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: (BZd%!
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CountBean.java [W8?ww%qT
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/* qFwAzW;"
* CountData.java !4}Wp.
* HEs .pET\
* Created on 2007年1月1日, 下午4:44 13MB1n
* d$PQb9Q+f
* To change this template, choose Tools | Options and locate the template under Df}3^J~JX
* the Source Creation and Management node. Right-click the template and choose "[2D&\$
* Open. You can then make changes to the template in the Source Editor. znNv;-q
*/ t}2M8ue(&
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package com.tot.count; HC
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/** F>"B7:P1:Q
* O/lu0acI
* @author o(Q='kK
*/ U>a~V"5,u
public class CountBean { $j'8Z^
private String countType; BF(Kaf;<t.
int countId; PaBqv]
/** Creates a new instance of CountData */ fK5iOj'Q
public CountBean() {} @iaz_;
public void setCountType(String countTypes){ ke5_lr(
this.countType=countTypes; %VGQ{:
} 4FcY NJq
public void setCountId(int countIds){ Wq/0 }W.
this.countId=countIds; ($s%B
} r95$( N
public String getCountType(){ ? W2Wy\
return countType; r&O:Bt}x
} csms8J
public int getCountId(){ 3.?B')
return countId; E>N L/[1d
} v$EgVcK
} j?s+#t
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CountCache.java cQ`+ A|q
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/* Vf`9[*j
* CountCache.java cB2jf</
* fXB64MNo
* Created on 2007年1月1日, 下午5:01 =d1i<iw?-
*
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* To change this template, choose Tools | Options and locate the template under C:P.+AU"`
* the Source Creation and Management node. Right-click the template and choose d>jRw
* Open. You can then make changes to the template in the Source Editor. W*Ce1
*/ ZsL-vlv
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package com.tot.count; -LMO
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import java.util.*;
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/** GFO(O
* #)28ESj
* @author 0?\d%J!"S
*/ 4e9'yi
public class CountCache { \I~9%QJ>
public static LinkedList list=new LinkedList(); TDjjaO
/** Creates a new instance of CountCache */ N0']t Gh2
public CountCache() {} rR3(yy0L
public static void add(CountBean cb){ YLe$Vv735
if(cb!=null){ 6)Dp2
list.add(cb); =U<6TP]{
} O{44GB3
} h2fTG
} x#&%lJT
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CountControl.java PU{7s
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/* 9lCZi?
* CountThread.java 1
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* {;Ispx0m
* Created on 2007年1月1日, 下午4:57 cb9q0sdf
* Q.`O;D}x
* To change this template, choose Tools | Options and locate the template under 09C[B+>h
* the Source Creation and Management node. Right-click the template and choose 8A3!XA
* Open. You can then make changes to the template in the Source Editor. eWwI@ASaA
*/ `PeWV[?
*kWrF* )J
package com.tot.count; B:QAG
import tot.db.DBUtils; O)WduhlGQ
import java.sql.*; YF(TG]?6
/** UXN!iU)
* 7s-ZRb[)1
* @author ]U,f}T"e
*/ VLfE3i4Vwl
public class CountControl{ <j$n7#qk
private static long lastExecuteTime=0;//上次更新时间 .j_YVYu1&
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 =a3qpPkx
/** Creates a new instance of CountThread */ czHbdEh
public CountControl() {} *C n `pfO
public synchronized void executeUpdate(){ jM DG
Connection conn=null; wa}\bNKQk
PreparedStatement ps=null; K\]I@UTwq
try{ >"q~9b
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conn = DBUtils.getConnection(); :D !}jN/)
conn.setAutoCommit(false); tlz)V1L
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); K=mW`XXup
for(int i=0;i<CountCache.list.size();i++){ WQT;k0;T]
CountBean cb=(CountBean)CountCache.list.getFirst(); _N&]w*ce
CountCache.list.removeFirst(); m?=9j~F*
ps.setInt(1, cb.getCountId()); B)cVbjTn
ps.executeUpdate();⑴ N#? Ohz
//ps.addBatch();⑵ $Q!J.}P@
} p4-bD_
//int [] counts = ps.executeBatch();⑶ 4,pS C
conn.commit(); 7ZVW7%,zF
}catch(Exception e){ _N-JRM m<
e.printStackTrace(); #`9D,+2iB%
} finally{ xX]92Q
try{ ;'x\L<b/)
if(ps!=null) { EO[UezuU
ps.clearParameters(); MGzuQrl{H
ps.close(); (o5+9'y"9
ps=null; h#iFp9N
} A&~<qgBTp
}catch(SQLException e){} E6NrBPm
DBUtils.closeConnection(conn); >9v?p=
} 7>Oa, \
} |:?JSi0
public long getLast(){ (Mw<E<f
return lastExecuteTime; !@<>S>uGG
} >nL9%W}8M
public void run(){ `*nK@:
long now = System.currentTimeMillis(); M~1 n#
if ((now - lastExecuteTime) > executeSep) { ix=H=U]Q{
//System.out.print("lastExecuteTime:"+lastExecuteTime); :U7m@3czU
//System.out.print(" now:"+now+"\n"); P_f>a?OL:
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 5wws8w
lastExecuteTime=now; ;f8$vW];
executeUpdate(); Rr'^l]
} /:j9#kj
else{ 8v)PDO~D}A
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); uJP9J U
} `RG_FS"v
} &E>zvRBQ
} 8I'Am"bc\
//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 J0hY~B~X
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类写好了,下面是在JSP中如下调用。 8VwByk8
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<% A%G
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CountBean cb=new CountBean(); 'h6Vj6
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); Gv};mkX[N
CountCache.add(cb); aDik1Q
out.print(CountCache.list.size()+"<br>"); h*qoe(+ZD
CountControl c=new CountControl(); 'e(`2
c.run(); {|jG_
out.print(CountCache.list.size()+"<br>"); z mxrz[
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