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: W&%,XwkQ
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CountBean.java t(uvc{K*
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/* PgT8
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* CountData.java ?u@jedQ
* =f{v:n6
* Created on 2007年1月1日, 下午4:44 rz
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* sg2% BkTI
* To change this template, choose Tools | Options and locate the template under 6WGg_x?3
* the Source Creation and Management node. Right-click the template and choose }P.Z}n;Uj
* Open. You can then make changes to the template in the Source Editor. ;<m`mb4x[
*/ 7_76X)gIV
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package com.tot.count; xn503,5G*7
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/** ~h;
* PRaVe,5a
* @author d9;&Y?fp
*/ c:7F
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public class CountBean { ?<C(ga
private String countType; (b<0=U
int countId; 7)r]h?
/** Creates a new instance of CountData */ ~ a`[p\
public CountBean() {} D^US2B
public void setCountType(String countTypes){ _r{H)}9
this.countType=countTypes; \?T9v
} zHX\h[0f
public void setCountId(int countIds){ Jl`^`Yv
this.countId=countIds; =zK4jiM1
} 4hwb]
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public String getCountType(){ J#F5by%8
return countType; b2UDP W
} YxJQ^D`
public int getCountId(){ :#^qn|{e
return countId; u5k{.&
} L4m Vk
} 4i)5=H
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CountCache.java 5buW\_G)
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/* _Ik?WA_;
* CountCache.java bAZoi0LR
* kP&I}RY
* Created on 2007年1月1日, 下午5:01 e!*]y&W
* QTi@yT:
* To change this template, choose Tools | Options and locate the template under 9Sxr9FLW~
* the Source Creation and Management node. Right-click the template and choose 6Qt(Yu*s
* Open. You can then make changes to the template in the Source Editor. [_(J8~va
*/ @NRN#~S,_]
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package com.tot.count; |du%c`wl
import java.util.*; B=a+cT
/** )
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* )/;+aDk
* @author _)
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*/ fOHbgnL>
public class CountCache { &`l\Q\_[@
public static LinkedList list=new LinkedList(); B&6NjLV
/** Creates a new instance of CountCache */ =?6c&Z
public CountCache() {} 2MRd
public static void add(CountBean cb){ OVi<d
if(cb!=null){ Ul_Zn
list.add(cb); 1 #,4P1"
} rx gSQ+G_
} $lf/Mg_H
} t2(X
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CountControl.java =eU=\td^
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/* "@eGgQ
* CountThread.java I 0~'z f
* .h=n [`RB
* Created on 2007年1月1日, 下午4:57 @c]KHWI
* {S{ %KkAV
* To change this template, choose Tools | Options and locate the template under rzAf {2
* the Source Creation and Management node. Right-click the template and choose 9Q4{ cB
* Open. You can then make changes to the template in the Source Editor. {fACfSW6
*/ F(ydqgH~a
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package com.tot.count; -a)1L'R
import tot.db.DBUtils; A
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import java.sql.*; s`bGW1#io
/** 6~%><C
* ?;CIS$$r
* @author R QQ'Wg
*/ D#&9zR86F
public class CountControl{ LVB wWlJ
private static long lastExecuteTime=0;//上次更新时间 spfW)v/T!
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 D wJ^ W&*
/** Creates a new instance of CountThread */ mBErU6?X,A
public CountControl() {} vYV!8o.I
public synchronized void executeUpdate(){ BrE#.g Jq
Connection conn=null; paIjXaU1Mb
PreparedStatement ps=null; o(SPT?ao~
try{ GB|>eZLv<
conn = DBUtils.getConnection(); >k\pSV[
conn.setAutoCommit(false); @\ y{q;
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); L8h3kT
for(int i=0;i<CountCache.list.size();i++){ uMw6b=/U
CountBean cb=(CountBean)CountCache.list.getFirst(); Q&]|W
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CountCache.list.removeFirst(); w/*G!o-<
ps.setInt(1, cb.getCountId()); toPbFU'
ps.executeUpdate();⑴ 7?whxi Qs
//ps.addBatch();⑵ #]jl{K\f#X
} ,6{z
//int [] counts = ps.executeBatch();⑶ MWv@]P_0p!
conn.commit(); -n 9&W
}catch(Exception e){ ^\ x'4!W
e.printStackTrace(); fY&TI}Y
} finally{ #!F>cez
try{ xA
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if(ps!=null) { bHG<B
ps.clearParameters(); v-z%3x.f
ps.close(); 2/4zg
ps=null; t<` As6}
} p$\>3\
}catch(SQLException e){} ]oV{JR]
DBUtils.closeConnection(conn);
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} RdPk1?}K
} i4|R0>b
public long getLast(){ \lQ3j8U
return lastExecuteTime; [L+*pW+$\.
} k4V3.i!E
public void run(){ ?-)!dl%N
long now = System.currentTimeMillis(); VG
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if ((now - lastExecuteTime) > executeSep) { -r sbSt ?_
//System.out.print("lastExecuteTime:"+lastExecuteTime); (Y)2[j
//System.out.print(" now:"+now+"\n"); &K0b3AWc
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); `CVkjLiy
lastExecuteTime=now; &'>m;W
executeUpdate(); hEB5=~A_
} z='%NZY
else{ 0beP7}$
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); b~vV++ou_
} #Q!Xz2z2
} m:h6J''<Z*
} o+Jnn"8
//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 AZQQge
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类写好了,下面是在JSP中如下调用。 a|z-EKV
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<% "HJ^>%ia
CountBean cb=new CountBean(); ?{ExBZNa
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); v%qOW)].
CountCache.add(cb); ! eZls
out.print(CountCache.list.size()+"<br>"); i=#`7pt%'a
CountControl c=new CountControl(); E\!X$
c.run(); \~*<[.8~
out.print(CountCache.list.size()+"<br>"); "M5
%>