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: `(Ei-$
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CountBean.java 2lXsD;[
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/* sm\/wlbE
* CountData.java */?L_\7
* {s_0[>
* Created on 2007年1月1日, 下午4:44 b!_l(2
* d p_J*8
* To change this template, choose Tools | Options and locate the template under oLB pG1Va
* the Source Creation and Management node. Right-click the template and choose WMl_$Fd6
* Open. You can then make changes to the template in the Source Editor. .DCp)&m
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*/ }RW4
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package com.tot.count; YHCXVu<.b
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/** 0D0 #*J
* tHhY1[A8m
* @author 6S]GSS<
*/ [yjC@docH
public class CountBean { iY.~N#Q
private String countType; VJuPC
int countId; T73saeN
/** Creates a new instance of CountData */ xI_WkoI
public CountBean() {} mQ' ]0D S
public void setCountType(String countTypes){ ~+^,o_hT
this.countType=countTypes; p|Z"<
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} /"Rh
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public void setCountId(int countIds){ KasOh"W.P
this.countId=countIds; +Y 3_)
} 0-FwHDxw
public String getCountType(){
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return countType; ^W#[6]S
} @yobT,DXi
public int getCountId(){ XTHrf'BU
return countId; :GGsQ
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} K\n %&w
} $m{\<A
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CountCache.java nc@ul')
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/* 8> O'_6Joj
* CountCache.java TvM{ QGN
* VwtGHF'
* Created on 2007年1月1日, 下午5:01 c.jnPVf:
* _FAwW<S4B
* To change this template, choose Tools | Options and locate the template under T /[)U
* the Source Creation and Management node. Right-click the template and choose B(b[Dbb
* Open. You can then make changes to the template in the Source Editor. FKL}6W:
*/ "D@m/l
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package com.tot.count; @0B<b7Jv
import java.util.*; F~RUb&*/<
/** 1Kwl_jf
* ilFM+x@
* @author R Af+%h*
*/ zse!t
public class CountCache { S,Tm=} wj
public static LinkedList list=new LinkedList(); I|iI
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/** Creates a new instance of CountCache */ swlxV@NQ
public CountCache() {} f
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public static void add(CountBean cb){ ^_2Ki
if(cb!=null){ NW!e@;E+i
list.add(cb); Km\M/j|
} !M3IuDN
} :!{aey
} AO^F6Y/
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CountControl.java X3a:*1N
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/* :(I)+;M}P
* CountThread.java @JN%P}4)
* )t)tk=R9N
* Created on 2007年1月1日, 下午4:57 4Ag+
* U.>n]/&
* To change this template, choose Tools | Options and locate the template under ,9W 0fm\t
* the Source Creation and Management node. Right-click the template and choose vi lNl|
* Open. You can then make changes to the template in the Source Editor. ,wZ[Y
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*/ xB9^DURr\
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package com.tot.count; Hi.JL
import tot.db.DBUtils; >@]E1Qfe
import java.sql.*; ;'p0"\SV
/** 73N%_8DH
* nc$?tC9V
* @author 1d-j_H`s
*/ %NxNZe
public class CountControl{ <NS=<'U
private static long lastExecuteTime=0;//上次更新时间 xbn+9b
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 4b7}Sr=`
/** Creates a new instance of CountThread */ S0p]:r";x
public CountControl() {} #9
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public synchronized void executeUpdate(){ EHo"y.ODg
Connection conn=null; Qj3UO]>
PreparedStatement ps=null; 17};I7
try{ G_dia6
conn = DBUtils.getConnection(); *OsXjL`f
conn.setAutoCommit(false); O#u)~C?)8
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ~ RTjcE
for(int i=0;i<CountCache.list.size();i++){ /vU9eh"%
CountBean cb=(CountBean)CountCache.list.getFirst(); '@pav>UPD
CountCache.list.removeFirst(); p4aM`PW8>=
ps.setInt(1, cb.getCountId()); 5!y3=.j
ps.executeUpdate();⑴ W>1\f0'
//ps.addBatch();⑵ rEddX
} I-;JDC?
//int [] counts = ps.executeBatch();⑶ qD`')=
conn.commit(); @6t3Us~/
}catch(Exception e){ eb( =V*
e.printStackTrace(); 0}P&G^%"
} finally{ O\G%rp L$w
try{ *sL'6"#Cre
if(ps!=null) { CsuSg*#X+
ps.clearParameters(); H<1C5-
ps.close(); :()4eK/\
ps=null; >1joCG~
} 3zh'5qQ
}catch(SQLException e){} Q[~O`Lz
DBUtils.closeConnection(conn); p&ow\AO
} P#EqeO
} 'n>|jw)
public long getLast(){ %f:'A%'Qb
return lastExecuteTime; JTz1M~
} @&h<jM{D
public void run(){ 0*tEuJ7
long now = System.currentTimeMillis(); * z{D}L-&
if ((now - lastExecuteTime) > executeSep) { S6]D;c8GE
//System.out.print("lastExecuteTime:"+lastExecuteTime); 's&Vg09D,
//System.out.print(" now:"+now+"\n"); '*)!&4f
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); U?>zq!C&R
lastExecuteTime=now; V(w[`^I>~
executeUpdate(); faMUd#o&
} 6E_YQbdy
else{ iB]kn(2C
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); B /Dj2
} Qt@~y'O
} ]FFU,me2
} v,>q]!
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//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 br'~SXl
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类写好了,下面是在JSP中如下调用。 YjdH7.js
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<% -$T5@
CountBean cb=new CountBean(); :mg#&MZj<
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); Dvx"4EA{7{
CountCache.add(cb); _@"Y3Lqi
out.print(CountCache.list.size()+"<br>"); =U,;/f
CountControl c=new CountControl(); Ylo@
c.run(); 0Fi7|
out.print(CountCache.list.size()+"<br>"); qBCZ)JEN#U
%>