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: sR"zRn
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CountBean.java _HWHQF7
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/* ;[{:'^n
* CountData.java , @%C8Z
* -H1"OJ2aF
* Created on 2007年1月1日, 下午4:44 &YT_#M
* JqI6k6~Q^
* To change this template, choose Tools | Options and locate the template under v!<PDw2'
* the Source Creation and Management node. Right-click the template and choose hmK8jl<6
* Open. You can then make changes to the template in the Source Editor. j+_S$T8w
*/ >]Mq)V9
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package com.tot.count; =cf{f]N
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/** "n{9- VEmN
* c;c:Ea5
* @author *Rz{44LP&
*/ ,U6*kvHS6
public class CountBean { +M44XhT
private String countType; `pP9z;/Xq
int countId; -Wl)Lez@
/** Creates a new instance of CountData */ RH!SW2o<
public CountBean() {} V/aQ*V{
public void setCountType(String countTypes){ H|PrsGW
this.countType=countTypes; -Bo86t)F
} *'Z-OY<V
public void setCountId(int countIds){ wrH7 pd
this.countId=countIds; lZ}izl
} LQh^;
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public String getCountType(){ VDB$"T9#
return countType; a`7%A H)
} OOCQsoN
public int getCountId(){ jg~_'4f#
return countId; {iA^rv|
} CnabD{uTf
} oJP<'l1
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CountCache.java x Z|&/Ci
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/* h6g=$8E
* CountCache.java NNwc!x)*
* (N,nux(0k
* Created on 2007年1月1日, 下午5:01 |WB"=PE
* WI,40&<
* To change this template, choose Tools | Options and locate the template under 0(wf{5
* the Source Creation and Management node. Right-click the template and choose fH-NU-"
* Open. You can then make changes to the template in the Source Editor. j h;
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*/ iPMB$SdfO
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package com.tot.count; Q2*/`L}m\
import java.util.*; 66oK3%[
/** zLh Fbyn(
* ?K0U3V$s
* @author pp(H
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*/ fk+1# 7{
public class CountCache { s>T`l
public static LinkedList list=new LinkedList(); $v FrU v
/** Creates a new instance of CountCache */ {5SfE$r
public CountCache() {} hO#HvW
public static void add(CountBean cb){ ]} '^`
if(cb!=null){ 5!<o-{J[(=
list.add(cb); #-,g&)`]
} S2ark,sp6
} Zotz?jVVr
} uii7b7[w
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CountControl.java Z*9L'd"D|
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/* ?RDO] I>
* CountThread.java Ru:n~77{
* KL
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* Created on 2007年1月1日, 下午4:57 HCJ;&C73&
* p:B
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* To change this template, choose Tools | Options and locate the template under ~u!gUJ:
* the Source Creation and Management node. Right-click the template and choose Po> e kz_E
* Open. You can then make changes to the template in the Source Editor. o"RJ.w:dn
*/ Z
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package com.tot.count; [ dGO,ndE
import tot.db.DBUtils; m`'=)x|
import java.sql.*; |B
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/** [KMS<4t'
* C(s\LI!r
* @author w}d}hI
*/ l1}R2lSEO
public class CountControl{ jA,|JgN|n
private static long lastExecuteTime=0;//上次更新时间 Rxx>{+f4M
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 L.kD,'G}>
/** Creates a new instance of CountThread */ ?!H)zz6y
public CountControl() {} 9/G!0uE
public synchronized void executeUpdate(){ YX_vv!-]
Connection conn=null; A]j}'
PreparedStatement ps=null; zHV|-R
try{ zwnw'
conn = DBUtils.getConnection(); Oo
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conn.setAutoCommit(false); i-,'.w
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); Z9xR
for(int i=0;i<CountCache.list.size();i++){ ^1.7Juvb
CountBean cb=(CountBean)CountCache.list.getFirst(); $:e)$Xnn-
CountCache.list.removeFirst(); P])L8zK
ps.setInt(1, cb.getCountId()); s{ =5-:
ps.executeUpdate();⑴ +lKrj\Xj
//ps.addBatch();⑵ ^T{8uJ'kn
} ?NlSeh
//int [] counts = ps.executeBatch();⑶ :Dayv6g
conn.commit(); }C_|gd
}catch(Exception e){ b"t")U==
e.printStackTrace(); \BUqDd!
} finally{ )=Zsv40O
try{ o_O+u%y
if(ps!=null) { uWTN2jr
ps.clearParameters(); '6X%=f'^b
ps.close(); <Pio Q>~
ps=null; P% Q@9kO>
} .liyC~YW
}catch(SQLException e){} *="m3:c'J
DBUtils.closeConnection(conn); V}SyD(8~
} iD<6t_8),
} \e|U9;Mf
public long getLast(){ Mb/L~gd"
return lastExecuteTime; Z:|9N/>T
} VJg,~lQN#t
public void run(){ 7G"7wYc>R
long now = System.currentTimeMillis(); UQ~4c,
if ((now - lastExecuteTime) > executeSep) { AFm,CINa
//System.out.print("lastExecuteTime:"+lastExecuteTime); XIRR Al(,
//System.out.print(" now:"+now+"\n"); }%x}fu#
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); gD6tHg>_
lastExecuteTime=now; H<Hrwy~
executeUpdate(); Pcdf$a"`
} Ft)
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else{ 5z~\5x
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); <BPRV> 0X
} (f~gEKcB2u
} waCboK'
} 69/?7r
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 ;E#\
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类写好了,下面是在JSP中如下调用。 MRs,l'
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<% IA2GUnUhu
CountBean cb=new CountBean(); b=1%pX_
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); z,x"a
CountCache.add(cb); 1ef'7a7e8
out.print(CountCache.list.size()+"<br>"); w;+ br
CountControl c=new CountControl(); _f3
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c.run(); (Y2mmd
out.print(CountCache.list.size()+"<br>"); .T$D^?G!D
%>