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: wrJQkven-
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CountBean.java Q%aF~
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/* ]Qe~|9I
* CountData.java ,'c%S|]U7
* T+XcEI6w
* Created on 2007年1月1日, 下午4:44 ?T73BL=
* >
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* To change this template, choose Tools | Options and locate the template under z&!o1uq
* the Source Creation and Management node. Right-click the template and choose JL_(%._J
* Open. You can then make changes to the template in the Source Editor. `GqF/?i
*/ aEdMZ+P.
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package com.tot.count; d
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/** P:6K
* 51s\)d%l
* @author rs4:jS$)
*/ ;,Vdj[W$>
public class CountBean { _RcEfT
private String countType; * g+v*q X
int countId; wa[J\lW
/** Creates a new instance of CountData */ N/-(~r[
public CountBean() {} CPa+?__B
public void setCountType(String countTypes){ EM<W+YU
this.countType=countTypes; u^C\aujg
} K'8o'S_bF
public void setCountId(int countIds){ R5MN;xG^
this.countId=countIds; d.ywH;
} @ ~{TL
public String getCountType(){ f4<~_ZGr
return countType; 7]u_
} ZD50-w;
public int getCountId(){ :Dr4?6hdr
return countId; ,^4"e
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} b?=r%D->w
} Sy.%>$ z
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CountCache.java q@1A2L\Om
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/* "nJMS6HJ[
* CountCache.java uR")@Tc
* xg%{p``
* Created on 2007年1月1日, 下午5:01 B7A.~'=
* :zC=JvKT
* To change this template, choose Tools | Options and locate the template under MeV4s%*O+
* the Source Creation and Management node. Right-click the template and choose 56."&0
* Open. You can then make changes to the template in the Source Editor. ^38kxwh
*/ 9&kY>M>z0
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package com.tot.count; x2~fc
import java.util.*; r_ 9"^Er
/** 'lC=k7@x
* (
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* @author P[`>*C\9c
*/ z4.|N
public class CountCache { 8oHIXnK
public static LinkedList list=new LinkedList(); mFpj@=^_G
/** Creates a new instance of CountCache */ Yo5ged]i
public CountCache() {} N+R{&v7=F%
public static void add(CountBean cb){ lh0G/8+C
if(cb!=null){ #I ,c'Vj
list.add(cb); brE%/%!e
} !`U #Pjp.
} KPK`C0mg@k
} ,iiI5FR
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CountControl.java ctb
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/* M(^IRI-
* CountThread.java qsN}KgTjg
* 1:h(8%H@"
* Created on 2007年1月1日, 下午4:57 y}QqS/
* M;-FW5O't
* To change this template, choose Tools | Options and locate the template under Oa5-^&I
* the Source Creation and Management node. Right-click the template and choose <+ <o
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* Open. You can then make changes to the template in the Source Editor. @ bvWqMa
*/ {dl@#Tu
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package com.tot.count; s0Y7`uD^
import tot.db.DBUtils; Sr6iQxE
import java.sql.*; }D~m%%,
/** $H,9GIivD
* [eF|2:
* @author -RThd"
*/ E&vCzQ
public class CountControl{ cJ,`71xop,
private static long lastExecuteTime=0;//上次更新时间 "g!/^A!!
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 9zehwl]~
/** Creates a new instance of CountThread */ gcM(K.n
public CountControl() {} kvN6K6
public synchronized void executeUpdate(){ S@L%X<Vm
Connection conn=null; IgF#f%|Q
PreparedStatement ps=null; >vfLlYx
try{ )/v`k>E
conn = DBUtils.getConnection(); ijNI6_eU
conn.setAutoCommit(false); A.P*@}9
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); H~<wAer,Op
for(int i=0;i<CountCache.list.size();i++){ e $5s],,n
CountBean cb=(CountBean)CountCache.list.getFirst(); '(:R-u!pp
CountCache.list.removeFirst(); RoD9
ps.setInt(1, cb.getCountId()); z\IZ5'
ps.executeUpdate();⑴ ~r]$(V n
//ps.addBatch();⑵ >&qaT*_g
} 3A b_Z
//int [] counts = ps.executeBatch();⑶ /P{'nI
conn.commit(); 0pe*DbYP5
}catch(Exception e){ mc6W"
e.printStackTrace(); s[*I210
} finally{ Ac,bf 8C
try{ PPtJ/
}\
if(ps!=null) { XOY\NMo
ps.clearParameters(); wB*}XJah
ps.close(); P6ugbq[x#e
ps=null; SQ`ec95',
} ;xE1#ZT
}catch(SQLException e){} +m6acu)N.
DBUtils.closeConnection(conn); ukXKUYNm8
} YP}r15P
} )%?SWuS?N
public long getLast(){ u z>V
return lastExecuteTime; QTI^?@+N>
} Z5>}
public void run(){ !:dhK
long now = System.currentTimeMillis(); zU>bT20x/
if ((now - lastExecuteTime) > executeSep) { 8x6{[Tx
//System.out.print("lastExecuteTime:"+lastExecuteTime); Z@>WUw@F
//System.out.print(" now:"+now+"\n"); +3;[1dpgf
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); \o!B:Vb<
lastExecuteTime=now; ^t)alNGos
executeUpdate(); O$&4{h`
} k{C|{m
else{ v/C*?/ ~
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ^$\#aTyFK
} {[FJkP2l
} Hh;o<N>U
} R 9Yk9v
//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 yCye3z.
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类写好了,下面是在JSP中如下调用。 2W`<P2IA
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<% \M-$|04Qt
CountBean cb=new CountBean(); LfS]m>>e
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); `lq[6[n
CountCache.add(cb); yNmzRH u
out.print(CountCache.list.size()+"<br>"); vn=0=(
CountControl c=new CountControl(); GI*2*m!u
c.run(); h]okY49hY
out.print(CountCache.list.size()+"<br>"); *}`D2_uP
%>