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: s)/i_Oe$\
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CountBean.java dP)8T
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/* h3@mN\=h'
* CountData.java %*}JDx#@
* T^A:pL1
* Created on 2007年1月1日, 下午4:44 6mRvuJ%
* MlRgdVX
* To change this template, choose Tools | Options and locate the template under Mqw&%dz'_
* the Source Creation and Management node. Right-click the template and choose \8Blq5n-O*
* Open. You can then make changes to the template in the Source Editor. 9=3V}]^M
*/ dhm;
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package com.tot.count; ?1PY]KNaK
NTAPx=!1*
/** _Seiwk&
* P7u5Ykc*
* @author <PV @JJ"
*/ 3%<ia$
public class CountBean { BvX!n"QIb
private String countType; gN mp'Lm
int countId; B>?. Nr
/** Creates a new instance of CountData */ $
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public CountBean() {} o6vm(I%
public void setCountType(String countTypes){ Ypv"u0
this.countType=countTypes; *vBcT.|,
} zI7-xqZ
public void setCountId(int countIds){ 1/le%}mK
this.countId=countIds; mi97$Cr2
} (x.K%QC)
public String getCountType(){ KsUsj3J
return countType; % j^=
} Atfon&^
public int getCountId(){ u{>5
return countId; GueqpEd2
} ?FMHK\
} fWKv3S1dT
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CountCache.java .`)ICX
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/* ^lf;Lc
* CountCache.java cHJ
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* N{Is2Ia
* Created on 2007年1月1日, 下午5:01 5,?9#n\E,
* .4-;
* To change this template, choose Tools | Options and locate the template under ;AG5WPI
* the Source Creation and Management node. Right-click the template and choose CH9#<?l
* Open. You can then make changes to the template in the Source Editor. 7qzI]
*/ [IV8
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package com.tot.count; &NGlkn
import java.util.*; ~"=nt@M]
/** 5%4:)s{4|
* }GGFJ"
* @author rvr Ok
*/ dnNc,l&g
public class CountCache { UTs0=:+,t
public static LinkedList list=new LinkedList(); Mw+]*
/** Creates a new instance of CountCache */ YO-O-NEP
public CountCache() {} 39m#
public static void add(CountBean cb){ bR;H@Fdg?
if(cb!=null){ #;^.&2Lt
list.add(cb); PeE'#&wn
} ~Dkje
} \".3x
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} I S!B$
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CountControl.java =AR'Pad
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/* 'MG)noN5
* CountThread.java mH}AVje{
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* q"]-CGAa
* Created on 2007年1月1日, 下午4:57 WVwNjQ2PM
* 0c:CA>F
* To change this template, choose Tools | Options and locate the template under -?e~S\JH
* the Source Creation and Management node. Right-click the template and choose J@yy2AZnO
* Open. You can then make changes to the template in the Source Editor. Q) FL|
*/ g7d) YUc
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package com.tot.count; /- kMzL
import tot.db.DBUtils; k (
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import java.sql.*; -M[5K/[
/** \h
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* KWN&nP
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* @author l"ih+%S
*/ tnKzg21%
public class CountControl{ 0BVMLRB
private static long lastExecuteTime=0;//上次更新时间 5IMh$!/uc
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 YHeB<v
/** Creates a new instance of CountThread */ +o_`k!
public CountControl() {} !-\*rdE{9
public synchronized void executeUpdate(){ x$M[/ID0
Connection conn=null; [0IeEjL
PreparedStatement ps=null; i-&kUG_X
try{ Ye(0'*-jyc
conn = DBUtils.getConnection(); %A64 Y<K
conn.setAutoCommit(false); e#W@ep|n
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ?rHc%H
for(int i=0;i<CountCache.list.size();i++){ pGsVO5M?
CountBean cb=(CountBean)CountCache.list.getFirst(); <cWo]T`X!
CountCache.list.removeFirst(); '5[L []A
ps.setInt(1, cb.getCountId()); Gm.v-T$
ps.executeUpdate();⑴ ]CHMkuP[k
//ps.addBatch();⑵ #Q|$&b
} }25{"R}K
//int [] counts = ps.executeBatch();⑶ %oN^1a'&)
conn.commit(); $'[(
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}catch(Exception e){ kv5D=0r
e.printStackTrace(); 9$d (`-&9p
} finally{ L!e@T'
try{ ?|8H$1
if(ps!=null) { :Eob"WH
ps.clearParameters(); 2Jj`7VH>
ps.close(); N*o+m~:y
ps=null; tpCEWdn5
} c"0CHrd
}catch(SQLException e){} sY1*WolA
DBUtils.closeConnection(conn); TYLf..i<
} orL7y&w(v:
} wBmbn=>#S
public long getLast(){ Kk??}
return lastExecuteTime; {`1zVT p[<
} E2dSOZS:)%
public void run(){ i&?~QQP`
long now = System.currentTimeMillis(); Y4b"(ZhM_
if ((now - lastExecuteTime) > executeSep) { sQt@B#;
//System.out.print("lastExecuteTime:"+lastExecuteTime); 2f~s$I&l#
//System.out.print(" now:"+now+"\n"); Ie+z"&0
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); {~d4;ht1Y
lastExecuteTime=now; bg 7b!t1F
executeUpdate(); 4I2ppz
} zM)o^Fn2
else{ vguqk!eo4
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 1zl@$ Nt
} ,,,5pCi\
} }RM?gE
}
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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 VoP(!.Ua>7
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类写好了,下面是在JSP中如下调用。 [;tbNVZK
=>BT]WK>
<% |NM.-@1
CountBean cb=new CountBean(); }*+ca>K
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); U8.DPRa
CountCache.add(cb); 5@Rf]'1B0
out.print(CountCache.list.size()+"<br>"); 0ED(e1K#B
CountControl c=new CountControl(); f#5mX&j
c.run(); sg9ZYWcL
out.print(CountCache.list.size()+"<br>"); s[Njk@y,
%>