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: G) 37?A)
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CountBean.java n6c+Okj
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/* <?Z]h]C^o
* CountData.java eZg>]<L
* |`AJP
* Created on 2007年1月1日, 下午4:44 g-/ }*ml
* , $cpm=1
* To change this template, choose Tools | Options and locate the template under N{a=CaYi+
* the Source Creation and Management node. Right-click the template and choose :{KpnJvd
* Open. You can then make changes to the template in the Source Editor. og4mLoLA
*/ F$YT4414
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package com.tot.count; O6\c1ha
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/** v*OT[l7
* b
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* @author rWN%j)#+
*/ VwLo
public class CountBean { *c(YlfeZ#
private String countType; 'W&ewZH_h
int countId; p y%:,hi
/** Creates a new instance of CountData */ be(hY{y`
public CountBean() {} ~L_1&q^4!i
public void setCountType(String countTypes){ -^< t%{d
this.countType=countTypes; /.t1Ow
} AO(zl*4
public void setCountId(int countIds){ \[AJWyP
this.countId=countIds; g6OPYUPg
} 4Q,|7@
public String getCountType(){ j=u)
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return countType; Z~;rp`P
} DjvPeX
public int getCountId(){ Ns\};j?TU*
return countId; ^h2!u'IQ
} c1
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} CSBDSz
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CountCache.java 0W)|n9
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/* JOwu_%
* CountCache.java ,}l|_GGj
* ;Qq7@(2y
* Created on 2007年1月1日, 下午5:01 $gCN[%+j
* [|\#cVWs
* To change this template, choose Tools | Options and locate the template under KC8
* the Source Creation and Management node. Right-click the template and choose ]VS:5kOj`
* Open. You can then make changes to the template in the Source Editor. jcRe),
*/ UMK9[Iy$<M
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package com.tot.count; 4Zn [F^p
import java.util.*; ffsF], _J
/** #6C<P!]V
* I[n|#N
* @author Fv:x>qZr@
*/ ^Iqu ^n?2.
public class CountCache { equi26jhr
public static LinkedList list=new LinkedList(); v]T?xo~@'
/** Creates a new instance of CountCache */ ^E".`~R
public CountCache() {} *Xh#W7,<
public static void add(CountBean cb){ !iK{q0
if(cb!=null){ CXTtN9N9
list.add(cb); p!\GJ a",
} `r0lu_.$]4
} G7r .Jm^q
} C)QKodI
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CountControl.java 3jHE,5m
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/* *]!rT&E
* CountThread.java {4)d
* 9ZuKED
* Created on 2007年1月1日, 下午4:57 !=u=P9I
* R^"mGe\LL
* To change this template, choose Tools | Options and locate the template under $Z8riVJ7j-
* the Source Creation and Management node. Right-click the template and choose u~~ ~@p
* Open. You can then make changes to the template in the Source Editor. Emw]`
*/ v4Kf{9q#
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package com.tot.count; |\94a
import tot.db.DBUtils; #+$PD`j
import java.sql.*; S WyJ`
/** uG-S$n"7K
* 3 Zwhv+CP[
* @author T# gx2Y
*/ ^AERGB\36
public class CountControl{ zjzEmX
private static long lastExecuteTime=0;//上次更新时间 -z%->OUu
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 KEf1GU6s
/** Creates a new instance of CountThread */ ;j+*}|!
public CountControl() {} n'%cO]nSx
public synchronized void executeUpdate(){ {Z178sik
Connection conn=null; Rm~8n;7oOr
PreparedStatement ps=null; A=70UL
try{ fUZCP*7>
conn = DBUtils.getConnection(); !_W']Crb]]
conn.setAutoCommit(false); 9#kk5 )J
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); :)h4SD8Y
for(int i=0;i<CountCache.list.size();i++){
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CountBean cb=(CountBean)CountCache.list.getFirst(); [w)KNl
CountCache.list.removeFirst(); RJ{J~-q{
ps.setInt(1, cb.getCountId()); VFm)!'=I
ps.executeUpdate();⑴ `'gcF});
//ps.addBatch();⑵ lA`-"
} Pon0(:#1
//int [] counts = ps.executeBatch();⑶ jc@=
b:r=
conn.commit(); 6z'0fi|EN
}catch(Exception e){ ^ (J%)&_\3
e.printStackTrace(); 2X(2O':Uc
} finally{ &v Q5+
try{ E,ooD3$h
if(ps!=null) { J?tnS6V
ps.clearParameters(); dP#7ev]'
ps.close(); Bx.hFEL
ps=null; Yq:/dpA_
} 1f?Fuw
}catch(SQLException e){} uzLm TmM+
DBUtils.closeConnection(conn); `m$,8f%j6_
} $U(D*0+o/
} -O?A"
public long getLast(){ <TSps!(#
return lastExecuteTime; 7nM<P4\
} (&, E}{p9
public void run(){ x}x )h3e
long now = System.currentTimeMillis(); z`D|O|#q
if ((now - lastExecuteTime) > executeSep) { _^!C4?2!
//System.out.print("lastExecuteTime:"+lastExecuteTime); $XKUw"%
//System.out.print(" now:"+now+"\n"); `V.tqZF
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); `iEYq0}
lastExecuteTime=now; &v9"lR=_k
executeUpdate(); 0rif,{"
} >:0N)Pj
else{ auM1k]
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 7
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} YF %]%^n
} nhd.c2t\
} vq@"y%C4
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 "u{ymJ]t
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类写好了,下面是在JSP中如下调用。 -W:@3\{
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<% j-qg{oIJ
CountBean cb=new CountBean(); ]eTp?q%0
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); `];ne]xM
CountCache.add(cb); "g(q)u >
out.print(CountCache.list.size()+"<br>"); n"R$b:
CountControl c=new CountControl(); Qb;]4[3
c.run(); +.$:ZzH#
out.print(CountCache.list.size()+"<br>"); r8A'8g4cM
%>