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: M,7A|?O
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CountBean.java TL-sxED,,D
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/* w]J9Kv1)-
* CountData.java GsA/pXx
*
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* Created on 2007年1月1日, 下午4:44 nlOM4fJ(
* 1JMEniB+9
* To change this template, choose Tools | Options and locate the template under p%pM3<p
* the Source Creation and Management node. Right-click the template and choose Ri =>evx
* Open. You can then make changes to the template in the Source Editor. q\cH+n)C
*/ F[BJhN*]a
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package com.tot.count; B&ItA76
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/** <csz4tL}P
* BU(:6
* @author ~za=yZo7(
*/ ?mU
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public class CountBean { ]r8t^bqe
private String countType; pC2ZN
int countId; N}HQvlLkF9
/** Creates a new instance of CountData */ $w4%JBZr
public CountBean() {} ? FGzw
public void setCountType(String countTypes){ [@fw9@_'
this.countType=countTypes; ,:Qy%k}f
} Fa:fBs{
public void setCountId(int countIds){ (99P9\[p
this.countId=countIds; |\;oFuCv##
} +[Cdd{2
public String getCountType(){ v]SHude{
return countType; A{3Aw| ;
} $<cio
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public int getCountId(){ G5a PjP
return countId; e=ZwhRP
} ARvT
} ;T0F1
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CountCache.java Z]kk.@P
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/* ky>0
* CountCache.java 3NAU|//J
* _ZX"gHx
* Created on 2007年1月1日, 下午5:01 G|MjKe4}
* ^K*uP^B=
* To change this template, choose Tools | Options and locate the template under BB@I|)9O(
* the Source Creation and Management node. Right-click the template and choose
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* Open. You can then make changes to the template in the Source Editor. U+: o y:mz
*/ 29]-s Utqv
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package com.tot.count; =%P'?(o|
import java.util.*; GO0Spf_Gh
/** AT Dm$ *
* U
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* @author E`s9SE
*/ 3jR,lEJyj
public class CountCache { {,EOSta
public static LinkedList list=new LinkedList(); l,AK
/** Creates a new instance of CountCache */ DY1?37h
public CountCache() {} v0hr ~1
public static void add(CountBean cb){ 64xq@_+
if(cb!=null){ wgfy; #
list.add(cb); 2r;^OWwr?
} 1&N|k;#QS
} :&:IZkO
} ;]YQWK
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CountControl.java o"J>MAD
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/* 7LMad%
* CountThread.java tKg\qbY&
* b*$/(2"m
* Created on 2007年1月1日, 下午4:57 ~3-2Iu^F
* 6!P];3&o\A
* To change this template, choose Tools | Options and locate the template under ^@f%A<
* the Source Creation and Management node. Right-click the template and choose 0w^\sf%s
* Open. You can then make changes to the template in the Source Editor. ZK,}3b{
*/ M7z>ugk"
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package com.tot.count; .Rl58]x~
import tot.db.DBUtils; EGMj5@>
import java.sql.*; 8was/^9;
/** 5"(AqXoq
* t95hI DtD
* @author clfi)-^{K
*/ *4}lV8
public class CountControl{ S~^0
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private static long lastExecuteTime=0;//上次更新时间 &X0/7)*"v
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 nsR^TD;
/** Creates a new instance of CountThread */ uV1H iv-
public CountControl() {} bDd$79@m
public synchronized void executeUpdate(){ bSH lR#!6
Connection conn=null; N_S>%Z+
PreparedStatement ps=null; QYDTb=h~
try{ 8\c=Un
conn = DBUtils.getConnection(); {MX_t/o=f
conn.setAutoCommit(false); XP'Mv_!Z
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); <jdS0YT
for(int i=0;i<CountCache.list.size();i++){ &We1i&w
CountBean cb=(CountBean)CountCache.list.getFirst(); u*_I7.}9
CountCache.list.removeFirst(); UJ'
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ps.setInt(1, cb.getCountId()); - bL
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ps.executeUpdate();⑴ +o&E)S}wP
//ps.addBatch();⑵ VU,\OOp
} W}B4^l
//int [] counts = ps.executeBatch();⑶ MU5@(s3B?
conn.commit(); H -('!^
}catch(Exception e){ $s2Ty1
e.printStackTrace(); etF?,^)h=g
} finally{ \ZrLh,6f.
try{ ~N+lI\K
if(ps!=null) { m(JFlO
ps.clearParameters(); xo{f"8}^
ps.close(); rhFa rm4a
ps=null; U!m-{7s$
} #sit8k`GR8
}catch(SQLException e){} :&$4&\_F
DBUtils.closeConnection(conn); Bm%.f!`
} /bA\O
} y@g{:/cmO
public long getLast(){ g;en_~g3j
return lastExecuteTime; K]dqK'
} PZ69aZ*Gs
public void run(){ t!^FWr&
long now = System.currentTimeMillis(); [;B_ENV
if ((now - lastExecuteTime) > executeSep) { &8t?OpB =h
//System.out.print("lastExecuteTime:"+lastExecuteTime); YN4P
>d
//System.out.print(" now:"+now+"\n"); 2 cfzLW(
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ]7kq@o/7
lastExecuteTime=now; ;cZ9C 1
executeUpdate(); jeb<qi>
} F=
else{ |E@G sw
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); JA7HO|
} 6 .DJRY
} b><jhbv
} G[u_Uu=>
//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 Q(m} Sr4
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类写好了,下面是在JSP中如下调用。 AG)N^yd
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<% /b@0HL?
CountBean cb=new CountBean(); >K#Z]k
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); Jl3l\I'
CountCache.add(cb); !7J;h{3Uw
out.print(CountCache.list.size()+"<br>"); Z91gAy^z<
CountControl c=new CountControl(); FM9b0qE
c.run(); W#'c6Hq2c
out.print(CountCache.list.size()+"<br>");
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%>