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: 2K<rK(
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CountBean.java Dww]D|M
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/* H=])o21
* CountData.java Be}e%Rk
* v ~.X
* Created on 2007年1月1日, 下午4:44 .+>w0FG.
* :,"dno7OQ
* To change this template, choose Tools | Options and locate the template under )hmU/E@
* the Source Creation and Management node. Right-click the template and choose geU-T\1[l
* Open. You can then make changes to the template in the Source Editor. i3t=4[~oL
*/ LSb3w/3M
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package com.tot.count; r)Ts(#Z
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/** sv\'XarM
* :zfnp,Gv
* @author v#&r3ZW0
*/ 0fA42*s;
public class CountBean { ]#R'hL%f
private String countType; ^@ s!"c
int countId; :J]S+tQ)
/** Creates a new instance of CountData */ +Q_(wR"FS
public CountBean() {} =Xze ).g
public void setCountType(String countTypes){ # m?GBr%k
this.countType=countTypes; W[PZQCL}K)
} @Tb
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public void setCountId(int countIds){ :0IxnK(r&
this.countId=countIds; _'<V<OjVM!
} tk"L2t
public String getCountType(){ ;KJJK#j
return countType; { 6Lkh
} [:sP Z{
public int getCountId(){ L>+g;GJ
return countId; rt$zM
} 11}sRu/
} 7vUfA"
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CountCache.java 9XWF&6w6yf
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/* c:I1XC
* CountCache.java =<fH RX`
* H6E@C}cyM
* Created on 2007年1月1日, 下午5:01 *}R5=r0
* lnL&v'{
* To change this template, choose Tools | Options and locate the template under h h}%Z=
* the Source Creation and Management node. Right-click the template and choose vLn<=.
* Open. You can then make changes to the template in the Source Editor. XSt5s06TM
*/ ;wND?:
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package com.tot.count; 0h!2--Aur
import java.util.*; BF8n: }9U
/** S+>&O3m
* `%;nHQ"
* @author MK9?81xd
*/ Fn$/ K
public class CountCache { u_.V]Rjc
public static LinkedList list=new LinkedList(); vLR)B@O,2
/** Creates a new instance of CountCache */ r5Ej
public CountCache() {} zk5sAHQ
public static void add(CountBean cb){ @z"Zj 3ti
if(cb!=null){ ^ L'8:
list.add(cb); hY+3PNiI@
} 2n+j.
} C0/s/p'
} (bt^L3}a
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CountControl.java X5 lB],t"=
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/* VOwt2&mZ
* CountThread.java ?2[=llS4
* z:9
* Created on 2007年1月1日, 下午4:57 xou7j
* l2GMVAca
* To change this template, choose Tools | Options and locate the template under ]Vhhx`0
* the Source Creation and Management node. Right-click the template and choose ASY
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* Open. You can then make changes to the template in the Source Editor. /b6Y~YbgU
*/ S<Q8kW:
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package com.tot.count; AKx\U?ei7
import tot.db.DBUtils; dgd&ymRm
:
import java.sql.*; {l{p
/** 2T5@~^:7u
* s=#IoNh
* @author R<LW*8
*/ %_u*5,w
public class CountControl{ F`8A!|cIy
private static long lastExecuteTime=0;//上次更新时间 Uo(\1&?
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 "Nd$sZk=
/** Creates a new instance of CountThread */ |[D~7|?
public CountControl() {} ;Fcdjy
public synchronized void executeUpdate(){ +A
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Connection conn=null; a$#,'UB
PreparedStatement ps=null; [UNfft=K3P
try{ hDmtBdE
conn = DBUtils.getConnection(); As@~%0 S
conn.setAutoCommit(false); J x-^WB
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); %r6LU<;1@
for(int i=0;i<CountCache.list.size();i++){ F<BhN+U
CountBean cb=(CountBean)CountCache.list.getFirst(); 1w+OnJI?
CountCache.list.removeFirst(); JeMhiY}
ps.setInt(1, cb.getCountId()); ^*C6]*C}te
ps.executeUpdate();⑴ SZg+5MD;X
//ps.addBatch();⑵ "V~U{(Z
} RUf,)]Vvk
//int [] counts = ps.executeBatch();⑶ /7@@CG6b
conn.commit();
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}catch(Exception e){ v3S{dX<
e.printStackTrace(); 25ul,t_Du
} finally{ GEA@AD=^f
try{ %xxe U
if(ps!=null) { L3Ry#uw
ps.clearParameters(); =N<Hc:<t4
ps.close(); L"zOa90ig
ps=null; ,!kyrk6
} [rTV)JsTb
}catch(SQLException e){} 9L%&4V}BIS
DBUtils.closeConnection(conn); 9^0 'VRG
} 5gF}7D@
} JC{}iG6r+
public long getLast(){ Y~=5umNSX
return lastExecuteTime; x0.&fCh%
} z-[Jbjhd
public void run(){ w|Zq5|[
long now = System.currentTimeMillis(); aEXV^5;,pJ
if ((now - lastExecuteTime) > executeSep) { $f1L<euH
//System.out.print("lastExecuteTime:"+lastExecuteTime); DetBZ.
//System.out.print(" now:"+now+"\n"); g%j z,|
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); s`C#=l4
lastExecuteTime=now; f:7Y
executeUpdate(); ++,mM7a
} -2> L*"^
else{ Uo^s]H#:
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); (4ow0}1
} G2a fHL<
} FD|R4 V*3
} G D[~4G
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 n$`Nx\ v
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类写好了,下面是在JSP中如下调用。 d q:M!F
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<% NXeo&+F
CountBean cb=new CountBean(); TM!R[-\
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); U{>!`RN
CountCache.add(cb); m{%_5 nW
out.print(CountCache.list.size()+"<br>"); 5`x9+XvoN
CountControl c=new CountControl(); UeHS4cW
c.run(); >z^T~@m7l
out.print(CountCache.list.size()+"<br>"); 8H;TPa
%>