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: f0`rJ?us
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CountBean.java ;w&yGm
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/*
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* CountData.java 8t
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* ^cXL4*_=
* Created on 2007年1月1日, 下午4:44 &!EYT0=>p
* L5P}%1 _
* To change this template, choose Tools | Options and locate the template under zNTu j p
* the Source Creation and Management node. Right-click the template and choose QZq9$;>dW
* Open. You can then make changes to the template in the Source Editor. ^XB8A=xi
*/ :^L]Da3
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package com.tot.count; Br$PL&e~
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/** 1X}Tp\e
* YxqQg
* @author sN) .Jo
*/ %H~gN9Vn#@
public class CountBean { NjyIwo0
private String countType; MOeLphY
int countId; NKh{iSLm
/** Creates a new instance of CountData */ ZvKMRW
public CountBean() {} ;l4\^E1
public void setCountType(String countTypes){ 4'=N{.TtO
this.countType=countTypes; G&H"8REm
} YGmdiY:;1
public void setCountId(int countIds){ CXFAb1m
this.countId=countIds; !27]1%Aw
} YfU#kvE'
public String getCountType(){ twS3J)UH
return countType; odn`%ok
} #iDFGkK/
public int getCountId(){ =eLb"7C#0
return countId; |;-r};
} cY]Y8T)
} Xkm2C)
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CountCache.java jch8d(`?d
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/* sZDJ+
* CountCache.java E-iBA (H
* * v]UgPk
* Created on 2007年1月1日, 下午5:01 a$O]'}]`
* *
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* To change this template, choose Tools | Options and locate the template under OFbg]{ub?
* the Source Creation and Management node. Right-click the template and choose _?c.3+;s
* Open. You can then make changes to the template in the Source Editor. A\.*+k/B
*/ "?,6{\y,
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package com.tot.count; +N@F,3yNa
import java.util.*; a $%[!vF
/** .U%"oD
* mIo7 K5z{
* @author
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*/ (*BW/.Fq
public class CountCache { `0D1Nh"%k
public static LinkedList list=new LinkedList(); V,5}hQJ
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/** Creates a new instance of CountCache */ @E;pT3; )
public CountCache() {} VC7F#a*V
public static void add(CountBean cb){ i8.[d5
if(cb!=null){ nWu4HFi
list.add(cb); AMz=HN
} < z)G& h@
} RkwY3s"
} >cL2PN_y
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CountControl.java %Ege^4PE
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/* s\!vko'M
* CountThread.java -~f.>@Wb
* ):
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* Created on 2007年1月1日, 下午4:57 Jo <6M'
* tvRy8u;
* To change this template, choose Tools | Options and locate the template under 4N j?UDa
* the Source Creation and Management node. Right-click the template and choose J}CK|}
* Open. You can then make changes to the template in the Source Editor. jF9CTL<
*/ -+|[0hpw
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package com.tot.count; +~O{
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import tot.db.DBUtils; ?%Fk0E#>2
import java.sql.*; q/79'>`|ai
/** f*Js= hvO
* zX`RN)C
* @author O]eJQ4XN<
*/ gQ#T7
public class CountControl{ 06 s3
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private static long lastExecuteTime=0;//上次更新时间 |'_<(z
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ^^uD33@_
/** Creates a new instance of CountThread */ eCD,[At/
public CountControl() {} 2"mj=}y6
public synchronized void executeUpdate(){ ts>}>}@vc
Connection conn=null; P^W47
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PreparedStatement ps=null; 5&=n
try{ -74T C
conn = DBUtils.getConnection(); wkA!Jv%
conn.setAutoCommit(false); HH@xnd
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); I3Xh[% -!
for(int i=0;i<CountCache.list.size();i++){ QPE.b-S
CountBean cb=(CountBean)CountCache.list.getFirst(); 7g+ ]
CountCache.list.removeFirst(); v*'\w#
ps.setInt(1, cb.getCountId()); ,6\f4/
ps.executeUpdate();⑴ ygt)7f5
//ps.addBatch();⑵ X(28xbd|
} :/%xK"
//int [] counts = ps.executeBatch();⑶ +Q0-jS#d
conn.commit(); 6qpV53H
}catch(Exception e){ BK SK@OV
e.printStackTrace(); rd4'y~#S
} finally{ "e<.
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try{ Uy|=A7Ad
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if(ps!=null) { <OSvRWP)
ps.clearParameters(); _O9H._E
ps.close(); PGl-2Cr
ps=null; 6 <S&~q
} ^oO5t-9<!
}catch(SQLException e){} pu*u[n
DBUtils.closeConnection(conn); z>;+'>XXgx
} l0xFt
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}
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public long getLast(){ dU^<7 K:S
return lastExecuteTime; _k.bGYldk
} Ltd?#HP
public void run(){ JM lhBh
long now = System.currentTimeMillis(); y$V)^-U>fw
if ((now - lastExecuteTime) > executeSep) { E wsq0D
//System.out.print("lastExecuteTime:"+lastExecuteTime); 05I39/T%
//System.out.print(" now:"+now+"\n"); ey\{C`(__y
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 9|A-oS
lastExecuteTime=now; Cy:`pYxhd
executeUpdate(); H-KwkH`L4
} 0W%}z}/N
else{ Ss! 3{VW
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); (,c?}TP
} W)msaq,
} )-:eQ{st`
} L(2P|{C
//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 'qF3,Rw
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类写好了,下面是在JSP中如下调用。 Bd~cY/M
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<% AKCfoJ
CountBean cb=new CountBean(); Dq%r
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cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 0mD;.1:
CountCache.add(cb); Q] yT
out.print(CountCache.list.size()+"<br>"); OG^WZ.YU
CountControl c=new CountControl(); Q}?N4kg
c.run(); 2]aZe4H.
out.print(CountCache.list.size()+"<br>"); ^&';\O@)
%>