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: qM1)3.)[:
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CountBean.java
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/* x*R8^BA]pR
* CountData.java U.hERe~X
* *bxJ)9B
* Created on 2007年1月1日, 下午4:44 S\3AW,c]w
* .qIy7_^
* To change this template, choose Tools | Options and locate the template under ^#BGA|j
* the Source Creation and Management node. Right-click the template and choose ;N$ 0)2w
* Open. You can then make changes to the template in the Source Editor. O\4+_y
*/ JIP+ !2
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package com.tot.count; Wm$`ae
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/** G !1~i*P$u
* 4z9#M;qT
* @author `*" H/QG
*/ $h 08Z
public class CountBean { YA"Ti9-EV
private String countType; .|-l+
int countId; 0i5y(m&7
/** Creates a new instance of CountData */ R81{<q'%X
public CountBean() {} <Qcex3
public void setCountType(String countTypes){ e8AjO$49
this.countType=countTypes; ?E+:]j_
} cebs.sF:
public void setCountId(int countIds){ 7b&JX'`Mb
this.countId=countIds; 't|Un G
} '?"t<$b
public String getCountType(){ ([,vX"4
return countType; Lj&1K~U
} &Y54QE".
public int getCountId(){ +mfe*'AU
return countId; ~K~b`|1
} f0uUbJ5
} \7Gg2;TA6o
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CountCache.java lAdDu
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/* RzA2*]%a
* CountCache.java M}Nb|V09
* ;wij}y-6
* Created on 2007年1月1日, 下午5:01 J [ YtA
* =\~E n5
* To change this template, choose Tools | Options and locate the template under r]A"Og_U
* the Source Creation and Management node. Right-click the template and choose b8J@K"
* Open. You can then make changes to the template in the Source Editor. hLb;5u&!kW
*/ =?/N5O(
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package com.tot.count; :tRf@bD#
import java.util.*; )W&o?VRfO
/** j/)"QiS*?
* Ts|--,
* @author ;i<$7MR.e
*/ }JRP,YNh
public class CountCache { [Q4_WKI0T
public static LinkedList list=new LinkedList(); ^"3\iA:
/** Creates a new instance of CountCache */ 06 QU
public CountCache() {} x|]\1sb"
public static void add(CountBean cb){ )O,wRd>5
if(cb!=null){ TT'Ofvdc
list.add(cb); MaZM%W8Z
} &J8Z@^
} _i5mC,OffN
} q`XW5VV{K
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CountControl.java =EQJqj1T
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/* e# t3u_
* CountThread.java _eGT2,D5r
* l^.K'Q1~a
* Created on 2007年1月1日, 下午4:57 ^NXcLEaP*<
* ujU=JlJ7dl
* To change this template, choose Tools | Options and locate the template under )h#]iGVN}
* the Source Creation and Management node. Right-click the template and choose [+;qWfs B
* Open. You can then make changes to the template in the Source Editor. K*~]fy
*/ J^ `hbP+2
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package com.tot.count; nSS>\$
import tot.db.DBUtils; oBr.S_Qe
import java.sql.*; #O"
/** f\fdg].!
* !=3Rg-'d1
* @author BPqk"HG]T
*/ zrs<#8!Y_!
public class CountControl{ qD#VbvRc9+
private static long lastExecuteTime=0;//上次更新时间 0n.S,3|
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 s2FngAM;f
/** Creates a new instance of CountThread */ "
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public CountControl() {} b.s9p7:J
public synchronized void executeUpdate(){ ibJHU@l
Connection conn=null; {Hl[C]25X
PreparedStatement ps=null; 9Y/L?km_(
try{ FXV`9uq}Z
conn = DBUtils.getConnection(); H6gU?9%
conn.setAutoCommit(false); } VEq:^o.
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 'CXRG$D
for(int i=0;i<CountCache.list.size();i++){ Po(]rQbE
CountBean cb=(CountBean)CountCache.list.getFirst(); G/vC~6x
CountCache.list.removeFirst(); mffIf1f
ps.setInt(1, cb.getCountId()); +Ng0WS_0
ps.executeUpdate();⑴ 4,G w#@
//ps.addBatch();⑵ +E/y ~s
} ;
dd Q/
//int [] counts = ps.executeBatch();⑶ Gs
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conn.commit(); '7*=`q{
}catch(Exception e){ Z)pz,
e.printStackTrace(); PmR* }Aw
} finally{ w5KPB5/zu
try{ :m'+tGs
if(ps!=null) { B&Y_2)v
ps.clearParameters(); e8}Ezy"^
ps.close(); cu&,J#r%
ps=null; #?[.JD51l
} p@YB?#Im
}catch(SQLException e){} Vw#{C>
DBUtils.closeConnection(conn); 7\XE,;4>
} &<5+!cV=
} rR,2UZR
public long getLast(){ uS+k^
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return lastExecuteTime; U47}QDh
} _q?<at}y
public void run(){ }P9Ap3?
long now = System.currentTimeMillis(); VR5fqf|*
if ((now - lastExecuteTime) > executeSep) { 9}29&O
//System.out.print("lastExecuteTime:"+lastExecuteTime); &v!WVa?
//System.out.print(" now:"+now+"\n"); N]N4^A'
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); k(%QIJH
lastExecuteTime=now; Thr*^0$C
executeUpdate(); }fR,5|~X
} tMp=-"
else{ rw7_5l
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); _qXa=|}V.
} q<#>HjC
} !yOeW0/2[
} ]@^coj[
//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 w}R~C
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类写好了,下面是在JSP中如下调用。 S8,Z;y
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<% &PWB,BXv
CountBean cb=new CountBean(); >q~l21dUi
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); sj?3M@l95W
CountCache.add(cb); `Y=WMNy
out.print(CountCache.list.size()+"<br>"); Q&'}BeUbm
CountControl c=new CountControl(); 6
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c.run(); A'&n5)tb
out.print(CountCache.list.size()+"<br>"); '3IC*o"
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