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: {IrJLlq
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CountBean.java ^H-QYuz:T0
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/* 6$DG.p
* CountData.java xh`Du|jvm
* _\!0t
* Created on 2007年1月1日, 下午4:44 '(XW$D
* !YIb
* To change this template, choose Tools | Options and locate the template under 5c)<'EP
* 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. w~n kNqm
*/ BPqwDjW
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package com.tot.count; 1P \up
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/** 5/k)\`
* E::<;9
* @author 4V1|jy3
*/ &62`Wr 0C
public class CountBean { p#z;cjfSt
private String countType; r.9 $y/5
int countId; J7_8$B-j7
/** Creates a new instance of CountData */ c9|I4=_K
public CountBean() {} zQn//7#-G
public void setCountType(String countTypes){ Ae.]F)w_\
this.countType=countTypes; `P#8(GU
} dbg|VoNf
public void setCountId(int countIds){ tgc@7
this.countId=countIds; ea>[BB3#
} wD}EW
public String getCountType(){ bIq-1
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return countType; <jg8y'm@0
} z}D#WWSxf
public int getCountId(){ @|Z*f\
return countId; yTP[,bM
} D)h["z|F
} 8dlInms
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CountCache.java >d'EInSF
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/* jzQ9zy_
* CountCache.java ^971<B(v
*
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* Created on 2007年1月1日, 下午5:01 EmF]W+!z%
* ]S*E
* To change this template, choose Tools | Options and locate the template under |b,zw^!e['
* the Source Creation and Management node. Right-click the template and choose Dxz5NW4
* Open. You can then make changes to the template in the Source Editor. Gi;9 S
*/ RsR] T]4
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package com.tot.count; gW/QFZjY
import java.util.*; 2Qw)-EB
/** v]l&dgoT
* \l>qY(gu
* @author %}\ vW
*/ K90D1sD
public class CountCache { {jrZ?e-q
public static LinkedList list=new LinkedList(); t7sUtmq
/** Creates a new instance of CountCache */ DS.39NY
public CountCache() {} fp,1qzU[k
public static void add(CountBean cb){ [f/vLLK
if(cb!=null){ .QNjeMu.
list.add(cb); }k4`
} Z3Bo@`&?
} (/To?`
} wVlSjk
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CountControl.java 4V!1/w
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/* M}R@ K;%
* CountThread.java Qfwwh`;
* yLV2>kq
* Created on 2007年1月1日, 下午4:57 AECxd[k$9
* XB6N[E
* To change this template, choose Tools | Options and locate the template under Ym3
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* the Source Creation and Management node. Right-click the template and choose _-g-'Hr+N
* Open. You can then make changes to the template in the Source Editor. D>psh-,1
*/ YK(XS"Kl
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package com.tot.count; ]JkpR aP$
import tot.db.DBUtils; 07~pf}
import java.sql.*; !pG+Ak?
/** 2O}s*C$Xav
* v+|@}9| Z
* @author |`N$>9qN
*/ ?v0A/68s#
public class CountControl{ XfD
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private static long lastExecuteTime=0;//上次更新时间 p_D
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private static long executeSep=60000;//定义更新间隔时间,单位毫秒 Y8x(#qp,
/** Creates a new instance of CountThread */ @1/Q
public CountControl() {} $71i+h]_
public synchronized void executeUpdate(){ zpBBnlq
Connection conn=null; !"Z."fm*
PreparedStatement ps=null; MoC*tImWR
try{ >u'/$k
conn = DBUtils.getConnection(); >#Grf)@"6
conn.setAutoCommit(false); dqIZ#;:g
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); D}=/w+
for(int i=0;i<CountCache.list.size();i++){ |JirBz
CountBean cb=(CountBean)CountCache.list.getFirst(); DQL06`pX/
CountCache.list.removeFirst(); KIXwx98
ps.setInt(1, cb.getCountId()); o06A=4I
ps.executeUpdate();⑴ 'vqj5YTj
//ps.addBatch();⑵ Qi(e`(,'
} /1[}G!
//int [] counts = ps.executeBatch();⑶ kKFuTem_3
conn.commit(); )Tyky%P+iI
}catch(Exception e){ bCJ<=X,g`K
e.printStackTrace(); ~(w=U *
} finally{ V{7lltu
try{ 5n&)q=jk=
if(ps!=null) { ==PQ-Ia
ps.clearParameters(); V{ 4i$'
ps.close(); 9Bbm7Gd
ps=null; + MOe{:/6
} CuV=C
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}catch(SQLException e){}
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DBUtils.closeConnection(conn); <lg"M;&Ht
} luP'JUq
} )]0[`iLe
public long getLast(){ ~@)-qV^~
return lastExecuteTime; Vz=j)[
} \N'hbT=
public void run(){ R{2GQB
long now = System.currentTimeMillis(); "-~D!{rS
if ((now - lastExecuteTime) > executeSep) { 5~<a>>
//System.out.print("lastExecuteTime:"+lastExecuteTime); IPr*pQ{;c
//System.out.print(" now:"+now+"\n"); (;Dn%kK
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); #*ZnA,
lastExecuteTime=now; !."%M^J
executeUpdate(); ;f\R$u-
} !ch[I#&J-
else{ )%H5iSNG$P
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); B5?c'[V9
} 2V=FWuXC"
} ?,+C!R?
} 0pZ.; /<{
//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 s)`1Rf
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类写好了,下面是在JSP中如下调用。 {Q#Fen
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<% qxg7cj2
CountBean cb=new CountBean(); 7 ~%
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); Uy_}@50"l
CountCache.add(cb); LB64W ;#h
out.print(CountCache.list.size()+"<br>"); W?4&lC^G
CountControl c=new CountControl(); /
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c.run(); TQbFI;\
out.print(CountCache.list.size()+"<br>"); jl 30\M7
%>