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: kM,@[V
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CountBean.java k}#@8n|b
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/* 51z /
* CountData.java 3#B@83C0Z
* fH; |Rm
* Created on 2007年1月1日, 下午4:44 t={po QC~
* +<z7ds{Z
* To change this template, choose Tools | Options and locate the template under fs7~NY
* the Source Creation and Management node. Right-click the template and choose :ET x*c
* Open. You can then make changes to the template in the Source Editor. 8pd&3G+
*/ ?S8$5gA
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package com.tot.count; kF#{An)P
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/** y _6r/z^
* BL7>dZOa
* @author 'r6 cVBb}
*/ 6R L~iD;X
public class CountBean { |I(%7K
private String countType; X"wFQa
int countId; vu44 !c@
/** Creates a new instance of CountData */ UC.8DaIPN
public CountBean() {} ?l(nM+[kSL
public void setCountType(String countTypes){ z"9aAytd
this.countType=countTypes; r.?qEe8VV
} GsI[N%
public void setCountId(int countIds){ . c#90RP
this.countId=countIds; Oxpo6G
} 58 kv#;j
public String getCountType(){ 2lF WW(
return countType; aD0Q 0C+
} GpScc'a7
public int getCountId(){ wE)]
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return countId; )7tV*=?Ic8
} e<kpcF5{\
} XadG\_?t`
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CountCache.java K6ciqwUO
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/* -?[O"D"c
* CountCache.java Tq.MubaO
* $ V3n~.=
* Created on 2007年1月1日, 下午5:01 )gL&
*
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* To change this template, choose Tools | Options and locate the template under bOi};/f
* the Source Creation and Management node. Right-click the template and choose | h
* Open. You can then make changes to the template in the Source Editor. ',:3>{9
*/ XC
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package com.tot.count; hkkF1
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import java.util.*; \dC.%#
/** 9zmD6G!}t
* =`r ppO
* @author <yis
*/ 4
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public class CountCache { 6\%r6_.d
public static LinkedList list=new LinkedList(); B >ms`|q=l
/** Creates a new instance of CountCache */ xV"6d{+
public CountCache() {} ?f(pQy@V
public static void add(CountBean cb){ ~JIywzcf8
if(cb!=null){ bX a %EMF
list.add(cb); tq2-.]Y@U
} `\Uc4lRS
} Iq^~
} c(QG4.)m
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CountControl.java #(m`2Z`H
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/* PWADbu{+
* CountThread.java ^vYVl{$bT
* 3WQRN_
* Created on 2007年1月1日, 下午4:57 w:~nw;.T
* MtMvpHk
* To change this template, choose Tools | Options and locate the template under xC=
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1
* the Source Creation and Management node. Right-click the template and choose Y{+zg9L*
* Open. You can then make changes to the template in the Source Editor. 7qCJ]%)b6
*/ !#}v:~[A
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package com.tot.count; Fr1;)WV
import tot.db.DBUtils; md1EJ1\14
import java.sql.*;
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/** `V?x
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* tI/mE[W
* @author x.j Yip
*/ K0d-MC
public class CountControl{ s:-8 Z\,
private static long lastExecuteTime=0;//上次更新时间 <B|n<R<?
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 Z!q2F%02FO
/** Creates a new instance of CountThread */ AAIyr703cQ
public CountControl() {} ]>]#zu$=c
public synchronized void executeUpdate(){ <Tj"GVZAEO
Connection conn=null; 0"wbcAh)
PreparedStatement ps=null; "Nk=g~|
try{ [lDt0l5^
conn = DBUtils.getConnection(); M="WUe_
conn.setAutoCommit(false); >
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); )R
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for(int i=0;i<CountCache.list.size();i++){ q/W{PBb-2k
CountBean cb=(CountBean)CountCache.list.getFirst(); hP'~
CountCache.list.removeFirst(); \'\N"g`Fr
ps.setInt(1, cb.getCountId()); sR7{ i
ps.executeUpdate();⑴ l8hvq(,{
//ps.addBatch();⑵ .FfwY 'V
} /K2.V@T
//int [] counts = ps.executeBatch();⑶ ;o~+2Fir
conn.commit(); ~frPV8^DP
}catch(Exception e){ `dG.L
e.printStackTrace(); <> &e/
} finally{ J4Q)`Y\~
try{ T U"K#V&u
if(ps!=null) { rw}5nv
ps.clearParameters(); qv
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ps.close(); ')1}#V/I
ps=null; r|
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} ?{ 8sT-Z-L
}catch(SQLException e){} 1 $KLMW
DBUtils.closeConnection(conn); 0-;DN:>
} Lz#$_Am'H
} |k['wqn"
public long getLast(){ YoSo0fQA
return lastExecuteTime; !Vp,YN+yN
} ^C,/T2>
public void run(){ 7gZVg@
long now = System.currentTimeMillis(); {kRDegby
if ((now - lastExecuteTime) > executeSep) { Skr\a\
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//System.out.print("lastExecuteTime:"+lastExecuteTime); MA/"UV&M(
//System.out.print(" now:"+now+"\n"); VOowA^
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); !}Woo$#ND
lastExecuteTime=now; *pS7/Qe
executeUpdate(); q N[\J7Pz9
} 5'{qEZs^QU
else{ :*F3
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); PpJE|[]
} $BR=IYby
} %%-U.
} R%]9y]HQ
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 7YQK@lS
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类写好了,下面是在JSP中如下调用。 :?&WKW
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<% 61s2bt#
CountBean cb=new CountBean(); ZH`K%h0
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); *`S)@'@:(
CountCache.add(cb); 4}r\E,`*X
out.print(CountCache.list.size()+"<br>"); AK*mcTr
CountControl c=new CountControl(); j]ln
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c.run(); (to/9OrG
out.print(CountCache.list.size()+"<br>"); 0$F _hZU
%>