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: Ua\g*Cxh
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CountBean.java !NK8_p|X
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/* $@+\_f'bU>
* CountData.java 7*d}6\
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* Created on 2007年1月1日, 下午4:44 -MJ6~4k2
* lh3%2Dq$
* To change this template, choose Tools | Options and locate the template under ^%|{>Mz;c
* the Source Creation and Management node. Right-click the template and choose c, \TL
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* Open. You can then make changes to the template in the Source Editor. f8_5.vlw
*/ YMad]_XOP
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package com.tot.count; ]3xnq<
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/** "m0>u,HmI
* S*?'y
* @author aePhtQF
*/ R*/%+
public class CountBean { 3\|e8(bc
private String countType; }k7@
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int countId; `;*%5WD%
/** Creates a new instance of CountData */ yPn5l/pDDr
public CountBean() {} u2y?WcMv
public void setCountType(String countTypes){ S%-L!V ,
this.countType=countTypes; -7TT6+H)
} lMB^/-Y
public void setCountId(int countIds){ e(x1w&8dB
this.countId=countIds; /cexd_l|f
} GKH7Xx(
public String getCountType(){ :)t1>y>3
return countType; Qr1%"^4
} ? QwDV`
public int getCountId(){ Fl]$ql
return countId; :e ?qm7 cB
} U:c!9uhp
} G9:[W"P
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CountCache.java oOBN
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/* Sb> ;k(;`:
* CountCache.java .1.n{4z>:
* /@lXQM9T
* Created on 2007年1月1日, 下午5:01 GfD!Z3
* pY!@w0.
* To change this template, choose Tools | Options and locate the template under v)!Rir5
* the Source Creation and Management node. Right-click the template and choose 'h%)@q)J)
* Open. You can then make changes to the template in the Source Editor. &!2
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*/ ae{%*
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package com.tot.count; E@hvO%
import java.util.*; Q?L-6]pg
/** fxXZ^#2wX
* ^;$a_eR
* @author ?W1(
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*/ E).Nu
public class CountCache { L,p5:EW8.
public static LinkedList list=new LinkedList(); {tk42}8k
/** Creates a new instance of CountCache */ 5'?K(Jdmp
public CountCache() {} [mJcc
public static void add(CountBean cb){ P-ys$=
if(cb!=null){ ]MfT5#(6h
list.add(cb); PZKKbg2S
} ox{)O/aj
} H5S>|"`e`e
} Q*ZqY
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CountControl.java @ T'!;)
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/* .8uJ%'$)
* CountThread.java ce.'STm=
* (\e,,C%;
* Created on 2007年1月1日, 下午4:57 W=&\d`><k
* HtgVD~[]
* To change this template, choose Tools | Options and locate the template under 8TD:~ee
* the Source Creation and Management node. Right-click the template and choose ;iy]mPd
* Open. You can then make changes to the template in the Source Editor. 73A1+2
*/ l6:k|hrm;
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package com.tot.count; Ry,_%j3
import tot.db.DBUtils; aU<0<Dx
import java.sql.*; ow:c$Zq
/** y;keOI!
* $T8Ni!#/C
* @author <oS2a/Nd
*/ #b4`Wcrj
public class CountControl{ .wtb7U;7
private static long lastExecuteTime=0;//上次更新时间 \kF}E3~+#
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 eA$9)K1GO
/** Creates a new instance of CountThread */ J~V`"uo
public CountControl() {} e57}.pF^
public synchronized void executeUpdate(){ IfF<8~~E
Connection conn=null; 3:&!Q*i;
PreparedStatement ps=null; -8HIsRh
try{ l"*qj#FD
conn = DBUtils.getConnection(); ;VSHXU'H
conn.setAutoCommit(false); z|=l^u6uS
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); >7!4o9)c
for(int i=0;i<CountCache.list.size();i++){ Q[;!z1ur
CountBean cb=(CountBean)CountCache.list.getFirst(); T-xcd
CountCache.list.removeFirst(); pR4{}=g,
ps.setInt(1, cb.getCountId()); Yn+/yz5k_
ps.executeUpdate();⑴ _Xlf}BE
//ps.addBatch();⑵ xop9*Z$
} &dp(CH<De
//int [] counts = ps.executeBatch();⑶ B#&U5fSw+0
conn.commit(); Dp8YzWL2^
}catch(Exception e){ >(ku*
e.printStackTrace(); eG72=l)Mz
} finally{ 8wp)aGTcU
try{ f]^(|*6
if(ps!=null) { #*BcO-N
ps.clearParameters(); )a.w4dH
ps.close(); 4xk'R[v
ps=null; ?5K.#>{
} l]%_D*<Y
}catch(SQLException e){} INby0S
DBUtils.closeConnection(conn); G5|xWeNgA
} N8m|Y]^H#
} 12gcma}
public long getLast(){ PPU,o8E+
return lastExecuteTime; kG[u$[B
} yBXdj`bV
public void run(){ ^:5;H=.
long now = System.currentTimeMillis(); %a<N[H3NV@
if ((now - lastExecuteTime) > executeSep) { SouPk/-B80
//System.out.print("lastExecuteTime:"+lastExecuteTime); @aN<nd`q)
//System.out.print(" now:"+now+"\n"); n7i;^=9mM
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); IFlDw}M!9
lastExecuteTime=now; 3o9`Ko0
executeUpdate(); / *Z(;-
} T3u%V_
else{ )TnxsFC
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 0$b)@
} {-2I^Ym 5i
} ~=aD*v<3d
} 'IY?7+[
//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 <_=a1x
P#\L6EO.
类写好了,下面是在JSP中如下调用。 -^=gQ7f9
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<% 4.$<o/M
CountBean cb=new CountBean(); HUuL3lYka
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ?k<i e2
CountCache.add(cb); tH,}_Bp
out.print(CountCache.list.size()+"<br>"); v
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CountControl c=new CountControl(); EpB2?XGA
c.run(); oJK1~;:
out.print(CountCache.list.size()+"<br>"); v3x_8n$C9
%>