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: ,#blY~h8^
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CountBean.java /gUD!@
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/* ;lU]ilYv
* CountData.java ")i>-1_H
* I]vCra
* Created on 2007年1月1日, 下午4:44 (n
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* hY[Vs5v
* To change this template, choose Tools | Options and locate the template under TW)~&;1l
* the Source Creation and Management node. Right-click the template and choose kD{qW=Lpn
* Open. You can then make changes to the template in the Source Editor. _=ziw|zI
*/ &vHfuM`
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package com.tot.count; T(4OPiKu
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/** C'oNGOEd
* ,3p$Z
* @author #24eogo~
*/ ;:#g\|(<+
public class CountBean { % >}{SS
private String countType; \$[;
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int countId; ]aqg{XdGt
/** Creates a new instance of CountData */ = k7}[!T
public CountBean() {} TL*8h7.(
public void setCountType(String countTypes){ oJ`cefcWo
this.countType=countTypes; ]^c]* O[8
} 'pQ\BH
public void setCountId(int countIds){ \
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this.countId=countIds; y>jP]LR4
} |xX>AMZc)D
public String getCountType(){ Jh!'"7
return countType; aZBb@~Y
} 4b<>gpQ
public int getCountId(){ o|O|e9m(
return countId; f zsD
} +x_9IvaW&?
} 29~Bu5
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CountCache.java NU{`eM
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/* ux=0N]lc
* CountCache.java A$;"9F@
* %IhUQ6
* Created on 2007年1月1日, 下午5:01 *!-J"h
* }<KQ+
* To change this template, choose Tools | Options and locate the template under F* h\ #?
* the Source Creation and Management node. Right-click the template and choose 9?L,DThQ
* Open. You can then make changes to the template in the Source Editor. KVA~|j B
*/ &m8Z3+Ea
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package com.tot.count; +:jx{*}jo
import java.util.*; 3Lw&HtH
/** ro`2IE>
* -lDAxp6p
* @author X^c2
*/ (>usa||
public class CountCache { iwS55o
public static LinkedList list=new LinkedList(); |z%:{
/** Creates a new instance of CountCache */ c3]X#Qa#m$
public CountCache() {} 7ElU5I<S
public static void add(CountBean cb){ I {&8iUN
if(cb!=null){ WPbG3FrL!
list.add(cb); _oBJ'8R\
} \Uh$%#}.
} #cdrobJ
} ~;uc@GGo
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CountControl.java unZYFA}(
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/* .lE7v -e
* CountThread.java UD}#c:I
* z [9f
* Created on 2007年1月1日, 下午4:57 '#Pg:v_
* W<sa6,$
* To change this template, choose Tools | Options and locate the template under (W'.vEl
* the Source Creation and Management node. Right-click the template and choose RjW<
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* Open. You can then make changes to the template in the Source Editor. M*n@djL$\~
*/ _&xi})E^O]
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package com.tot.count; 66 @#V
import tot.db.DBUtils; r>Rm=eKJ
import java.sql.*; v"3($?au0
/** Li8$Rb~q
* &K@ RTgb
* @author _C nl|'
*/ b`yb{&
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public class CountControl{ %S9YjMR@
private static long lastExecuteTime=0;//上次更新时间 wu53e= /
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 YOE!+MiO
/** Creates a new instance of CountThread */ GX-V|hLaGX
public CountControl() {} k?7V#QW(
public synchronized void executeUpdate(){ o{r<=X ysM
Connection conn=null; <A+n[h
PreparedStatement ps=null; W3aFao>!OZ
try{ s.qo/o\b
conn = DBUtils.getConnection(); W _JGJV.^f
conn.setAutoCommit(false);
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); yuA+YZ
for(int i=0;i<CountCache.list.size();i++){ TcEvUZJ"
CountBean cb=(CountBean)CountCache.list.getFirst(); x_VD9
CountCache.list.removeFirst(); yNc"E
ps.setInt(1, cb.getCountId()); {$H-7-O$
ps.executeUpdate();⑴ mA2L~=v#
//ps.addBatch();⑵ yDe6f(D
} r)xkpa5
//int [] counts = ps.executeBatch();⑶ O~~WP*N
conn.commit(); RF$2p4=[
}catch(Exception e){ sjIUW$
e.printStackTrace(); .,+TpPkc
} finally{ &'KJh+jJ
try{ 4M,Q{G|e
if(ps!=null) { (u:^4,Z
ps.clearParameters(); g*]/HS>e<G
ps.close(); 6)j4-
ps=null; {@YY8SKb9
} |f IIfYE
}catch(SQLException e){} ;%W]b
DBUtils.closeConnection(conn); YkuFt>U9,
} K~6,xZlDWM
} Ql8s7 %
public long getLast(){ |x#w8=VP-
return lastExecuteTime; vmsrypm
} %pG^8Q()
public void run(){ [ ~&yLccN
long now = System.currentTimeMillis(); ~OSgpM#O!T
if ((now - lastExecuteTime) > executeSep) { b<bj5m4fz>
//System.out.print("lastExecuteTime:"+lastExecuteTime); [Rxbb+,U
//System.out.print(" now:"+now+"\n"); p'f8?jt
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); DElrY)3O.
lastExecuteTime=now; Q/zlU@
executeUpdate(); ;eY.4/*R
} CyXFuk!R
else{ 'nRoa7v(
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); /?*GJN#
} dYxX%"J
}
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} w]O[{3"
//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 9Rd&Jq^
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类写好了,下面是在JSP中如下调用。 $s]vZ(H
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<% D`NPU
CountBean cb=new CountBean(); l' mdj!{&
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); `p'682x I
CountCache.add(cb); +S6(Fvp
out.print(CountCache.list.size()+"<br>"); ;lP/hG;`
CountControl c=new CountControl(); bGtS! 'I
c.run(); X 7R&>Pf
out.print(CountCache.list.size()+"<br>"); *YO^+]nmY
%>