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: "zYlddh
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CountBean.java 8?ZK^+]y
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/* rFGbp8(2
* CountData.java ?a(ApD\
* 4D0"Y#&G
* Created on 2007年1月1日, 下午4:44 $_NVy>\&
* Z~v.!j0
* To change this template, choose Tools | Options and locate the template under ;Q\Duj
* the Source Creation and Management node. Right-click the template and choose $2\OBc=
* Open. You can then make changes to the template in the Source Editor. `rQA9;Tn2
*/ 2jaR_``=:
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package com.tot.count; {&m^*YN/
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/** Z}WMpp^r
* )$Mgp*?
* @author JH5ckgdZ
*/ <AzvVSA,
public class CountBean { MsfY|(/m
private String countType; l&[ x)W
int countId; Ij4oH
/** Creates a new instance of CountData */ j^>J*gLM}W
public CountBean() {} ^Qq_|{vynf
public void setCountType(String countTypes){ IL&Mf9m
this.countType=countTypes; *ewE{$UpK
} fgq#Oi}
public void setCountId(int countIds){ L`tr7EEr
this.countId=countIds; [>v.#:YM^
} +Y6=;*j$
public String getCountType(){ E]i3E[T
return countType; ]w"r4HlCx
} [Jwo,?w
public int getCountId(){ 7<=xc'*8t
return countId; Il,2^54q
} Qv|A^%Ub!
} 7$Jb"s
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CountCache.java 3Oy?_a$
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/* COZ<^*=A#p
* CountCache.java ;&oS=6$
* P|l62!m<
* Created on 2007年1月1日, 下午5:01 I^emH+!MW
* I&
DEF*
* To change this template, choose Tools | Options and locate the template under "sdzm%
* the Source Creation and Management node. Right-click the template and choose Ho2#'lSKM
* Open. You can then make changes to the template in the Source Editor. &Y4S[-
*/ %`?IY <
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package com.tot.count; krFuEaO
import java.util.*; 6* (6>F5
/** a~>+I~^K5q
* 9'Le}`Gf
* @author N8#wQ*MM>
*/ tZB"(\
public class CountCache { p
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public static LinkedList list=new LinkedList(); (_ HwU/
/** Creates a new instance of CountCache */ ,(
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public CountCache() {} qs6r9?KP
public static void add(CountBean cb){ Y w7txp`i
if(cb!=null){ '1'De^%6W
list.add(cb); bbCH(fYbu
} NO+.n)etGb
} AY<(`J{
} HRn
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CountControl.java m:SG1m_6
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/* #ue WU
* CountThread.java `tw[{Wb
* i&= I5$
* Created on 2007年1月1日, 下午4:57 <Nwqt[.
* JFewOt3
* To change this template, choose Tools | Options and locate the template under I&vD >a5#
* the Source Creation and Management node. Right-click the template and choose 5$$ Yce=k
* Open. You can then make changes to the template in the Source Editor. ]{^'{ z$i
*/ + Nn
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package com.tot.count; T+1:[bqK
import tot.db.DBUtils; G9 v'a&
import java.sql.*; :{BD/6
/** uGt}H n
* Gj!9#on$7R
* @author C.4r`F$p
*/ rZ'&'#Q
public class CountControl{ 4}.PQ{
private static long lastExecuteTime=0;//上次更新时间 /Z^"[Ke
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 [J{\Ke0<e1
/** Creates a new instance of CountThread */ Y&wtF8
public CountControl() {} 1K{u>T
public synchronized void executeUpdate(){ IyK^` y
Connection conn=null; Is&0h|
PreparedStatement ps=null; 8z1#Q#5
try{ WVZ](D8Gc]
conn = DBUtils.getConnection(); [`J91=
conn.setAutoCommit(false); lDsT?yHS`Z
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); nQ*9E|Vx
for(int i=0;i<CountCache.list.size();i++){ X\4d|VJ?m
CountBean cb=(CountBean)CountCache.list.getFirst(); fJ<I|ZZ
CountCache.list.removeFirst(); Q3"{v0
ps.setInt(1, cb.getCountId()); zbY2gq@?
ps.executeUpdate();⑴ 7XzhKA6
//ps.addBatch();⑵ p+7G
} ;z2\ Q$
//int [] counts = ps.executeBatch();⑶ ?qC6p|H
conn.commit(); vbBNXy/
}catch(Exception e){ ahICx{hK
e.printStackTrace(); ^#( B4l!
} finally{ ty ESDp%
try{ u:]c
if(ps!=null) { C GN=kQ
ps.clearParameters(); f |%II,!3
ps.close(); $|"Y|3&X
ps=null; ZNDn! Sj
} +}VaQ8ti4
}catch(SQLException e){} OCW0$V6;D-
DBUtils.closeConnection(conn); @6lw_E_5
} *qa.hqas
} S4 j5-
public long getLast(){ Jn7T5$pJ
return lastExecuteTime; #B2a?
} IN8G4\r
public void run(){ lQl!TW"aO
long now = System.currentTimeMillis(); 8NnGN(a*D
if ((now - lastExecuteTime) > executeSep) { ,Iv eKk5W
//System.out.print("lastExecuteTime:"+lastExecuteTime); ~k"r
//System.out.print(" now:"+now+"\n"); ^yLhL^Y
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ThvgYv--B
lastExecuteTime=now; _ sqj~|K
executeUpdate(); &L[i"1a
} +$}3=n34)
else{ Bo,>blspw
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); whi#\>i
} *O|_)G
} %<)!]8}P*
} Ko|m<;LX
//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 gU&y5s~
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类写好了,下面是在JSP中如下调用。 ]z#+3DaH
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<% oBO4a^D
CountBean cb=new CountBean(); 9r.h^
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); PZ>(cvX&
CountCache.add(cb); `5Bv2wlIV
out.print(CountCache.list.size()+"<br>"); X L3m#zW&
CountControl c=new CountControl(); J Bgq2
c.run(); ["fUSQ
out.print(CountCache.list.size()+"<br>"); tVv/G~(
%>