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: r$<M*z5q(\
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CountBean.java 1\)C;c,
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/* A-, hm=?
* CountData.java =b8u8*ua
* B.!&z-)#
* Created on 2007年1月1日, 下午4:44 c
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* X3][C
* To change this template, choose Tools | Options and locate the template under 9e4`N"#,lI
* the Source Creation and Management node. Right-click the template and choose P$]K
* Open. You can then make changes to the template in the Source Editor. \;iOQqv0&
*/ p(cnSvg
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package com.tot.count; S|T_<FCY
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/** x |gYxZ
* %{Obhj;c
* @author Dk&(QajL
*/ noLr185
public class CountBean { e}n(mq
private String countType; xLms|jS
int countId; ArScJ\/Nwv
/** Creates a new instance of CountData */ -zWNQp$
public CountBean() {} $$SJLV
public void setCountType(String countTypes){ C$$Zwgy
this.countType=countTypes; RR|X4h0.
} VrWQ] L
public void setCountId(int countIds){ QpA$='
this.countId=countIds; #R7hk5/8n}
} 1Y%lt5,*
public String getCountType(){ -0TI7 @
return countType; HXX9D&c4R
} ?B@3A)a
public int getCountId(){ Gm &jlN
return countId; O.Y|},F
} r;{ggwY&J
} H0jbG;
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CountCache.java _v(5vx_
{
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/* 2bG92
* CountCache.java FS!9 j8
* stMxlG"d
* Created on 2007年1月1日, 下午5:01 tc{l?7P
* Ov4=!o=
* To change this template, choose Tools | Options and locate the template under @$Yk#N;&(
* the Source Creation and Management node. Right-click the template and choose {NcJL< ;tS
* Open. You can then make changes to the template in the Source Editor. VbTX;?
*/ |`pBI0Sjo
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package com.tot.count; 4.Fh4Y:$'
import java.util.*; um%s9
/** '+ mI
* 66sgs16k
* @author feH&Ug4?G
*/ nE?:nJ|%E
public class CountCache { WncHgz
public static LinkedList list=new LinkedList(); f,|;eF-Z
/** Creates a new instance of CountCache */ Y^C(<N$
public CountCache() {} 2
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public static void add(CountBean cb){ Y]Z&
if(cb!=null){ deq5u>
list.add(cb); 6)W8H X~+
} JG&E"j#q
} 0LYf0^P
} +t&+f7
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CountControl.java bKsEXS
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/* e@]m@
* CountThread.java D=Nt0y
* .mg0L\
* Created on 2007年1月1日, 下午4:57 P)XR9&o':
* S4c-i2Rq
* To change this template, choose Tools | Options and locate the template under i3KAJ@
* the Source Creation and Management node. Right-click the template and choose U#- 5",X|
* Open. You can then make changes to the template in the Source Editor. \So)g)K
*/ }'86hnW
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package com.tot.count; 6xY6EC
import tot.db.DBUtils; }eI9me@Aa
import java.sql.*; mKyF<1,m
/** 8G2QI4
* B5h)F> &G
* @author M+^ NF\
*/ 8zcSh/
public class CountControl{ f`K#=_Kq7
private static long lastExecuteTime=0;//上次更新时间 M,yxPHlN
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 I,05'edCQ
/** Creates a new instance of CountThread */ +uj;00 D
public CountControl() {} c6=XJvz
public synchronized void executeUpdate(){ 3 ]@wa!`
Connection conn=null; dd;rnev+
PreparedStatement ps=null; t;0]d7ey'
try{ 1|s`z
conn = DBUtils.getConnection(); 0v6Z4Ahpo
conn.setAutoCommit(false); ;8
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); &U CtyCz
for(int i=0;i<CountCache.list.size();i++){ tUW^dGo.
CountBean cb=(CountBean)CountCache.list.getFirst(); 6i~<,;Cn
CountCache.list.removeFirst(); UUM:*X
ps.setInt(1, cb.getCountId()); "pcr-?L
ps.executeUpdate();⑴ :8hX kQ
//ps.addBatch();⑵ &j/,8 Z*
}
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//int [] counts = ps.executeBatch();⑶ 1}SON4U
conn.commit(); k_Sm ep
}catch(Exception e){ Os].
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e.printStackTrace(); 44w
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} finally{ 3q@H8%jcw
try{ Xr4k]'Mg
if(ps!=null) { s jaaZx1
ps.clearParameters(); <lU(9)
L;&
ps.close(); R#?atL$(
ps=null; LaZ
@4/z!
} 53.jx38xS
}catch(SQLException e){} T-lP=KF=
DBUtils.closeConnection(conn); Uqx@9z(
} BZKg:;9
} ^y93h8\y
public long getLast(){ s&CK
return lastExecuteTime; 0"N4WH O
} __uk/2q
public void run(){ ar'VoL}
long now = System.currentTimeMillis(); Sj*W|n\gj
if ((now - lastExecuteTime) > executeSep) { M0e&GR8<z>
//System.out.print("lastExecuteTime:"+lastExecuteTime); kmlO}0
//System.out.print(" now:"+now+"\n"); #Aj#C>
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); `K[r5;QFKf
lastExecuteTime=now; x%T^:R
executeUpdate(); qI
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} R%t|R79I
else{ sya!VF]`
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); \{Je!#
} Lm.N
{NV'
} ;*U&lT
} &|Rww\oJ
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 7fd,I% v
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类写好了,下面是在JSP中如下调用。 o4j!:CI
L$ ^ew0C
<% v}z^M_eFm
CountBean cb=new CountBean(); .<YfnW5/K
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 3RD+;^}q3
CountCache.add(cb); gdh|X[d
out.print(CountCache.list.size()+"<br>"); muBl~6_mb2
CountControl c=new CountControl(); pN)>c,
c.run(); )(1tDQ`L>
out.print(CountCache.list.size()+"<br>"); n$>_2v
%>