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: gi`K^L=C
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CountBean.java 66\0JsT?3
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/* DQg:W |A
* CountData.java 7e&R6j
* Oq{&hH/'}
* Created on 2007年1月1日, 下午4:44 9IL#\:d1
* p},6W,f
* To change this template, choose Tools | Options and locate the template under iKB8V<[\T
* the Source Creation and Management node. Right-click the template and choose +Q, 0kv
* Open. You can then make changes to the template in the Source Editor. LV:oNK(
*/ )>LQ{X.
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package com.tot.count; 9GS<d.#Nvc
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/** L1u
* ,hK0F3?H>
* @author lo:]r.lX{
*/ :oF\?e
public class CountBean { yWIM,2x}
private String countType; P,RCbPC4
int countId; g#ZR,q
/** Creates a new instance of CountData */ zypZ3g{vz
public CountBean() {} gf+Kr02~
public void setCountType(String countTypes){ *IzcW6 [9
this.countType=countTypes;
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} `>RJ*_aKEI
public void setCountId(int countIds){ HzB&+c?Z
this.countId=countIds; 76[aOC2Ad
} /_rAy
public String getCountType(){ dQ^>,(
return countType; @f0~a
} CAY^ `K!
public int getCountId(){ daBu<0\
return countId; Kzxzz6R?
} CogLo&.
} !TY4C`/
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CountCache.java ,[+
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/* `"[VkQFB/
* CountCache.java aPB %6c=
* wP1dPl_j:0
* Created on 2007年1月1日, 下午5:01 ~fsAPIQ
* MxxY MR
* To change this template, choose Tools | Options and locate the template under r&"}zyL
* the Source Creation and Management node. Right-click the template and choose </<_e0
* Open. You can then make changes to the template in the Source Editor. wd*i~A3+?
*/ ;9c3IK@
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package com.tot.count; 7"=
import java.util.*; ,oDZ:";
/** ]M{SM`Ya
* }Evy fc#D
* @author 2uw%0r3Vi6
*/ n4)G g~PE
public class CountCache { ;^:~xJFx|
public static LinkedList list=new LinkedList();
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/** Creates a new instance of CountCache */
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public CountCache() {} wpY%"x#-+=
public static void add(CountBean cb){ .CI]8O"3y
if(cb!=null){ ~=%eOoZP;c
list.add(cb); {a_=4a
} z>k6 T4(
} >0+m
} RrLQM!~
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CountControl.java N!;Y;<Ro_
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/* 6fPuTQ}fY>
* CountThread.java ,e>C)wq;
* i>T{s-3v
* Created on 2007年1月1日, 下午4:57 IJq$GR
* ^/R@bp#<
* To change this template, choose Tools | Options and locate the template under -'{ioHt&X/
* the Source Creation and Management node. Right-click the template and choose jD_(im5
* Open. You can then make changes to the template in the Source Editor. KK]AX;
*/ 9`.b
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package com.tot.count; 6luCi$bL
import tot.db.DBUtils; )QaJYC^+
import java.sql.*; 0$&Z_oJ
/** ?`\<t$M
* >?M:oUVDU
* @author #x#.@
*/ 60~{sk~E
public class CountControl{ *~ 4uF
private static long lastExecuteTime=0;//上次更新时间 ekI1j%fO
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ` ]WU=Ss
/** Creates a new instance of CountThread */ (0D0G-r:
public CountControl() {} S3hJL:3c
public synchronized void executeUpdate(){ F#4?@W
Connection conn=null; ?Pl>sCFm~
PreparedStatement ps=null; &Z=}H0y
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try{ ]S,I}NP
conn = DBUtils.getConnection(); \I#lLP
conn.setAutoCommit(false); UN|"D]>/
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); H|F>BjXn5
for(int i=0;i<CountCache.list.size();i++){ \R&`bAd k
CountBean cb=(CountBean)CountCache.list.getFirst(); 8<)[+@$0
CountCache.list.removeFirst(); k4pvp5}%
ps.setInt(1, cb.getCountId()); +ls *04
ps.executeUpdate();⑴ HJBUN1n
//ps.addBatch();⑵ nT|fDD|
} ('
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//int [] counts = ps.executeBatch();⑶ dSIMwu6u
conn.commit(); R9S7p)B
}catch(Exception e){ L4.yrA-]C%
e.printStackTrace(); bvEk.~tC'
} finally{ *KxV;H8/
try{ wi*Ke2YKP
if(ps!=null) { Jd1eOeS
ps.clearParameters(); D6bCC;
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ps.close(); 'ycs{}'
ps=null; k>VP<Zm13
} z(1h ^.
}catch(SQLException e){} CNbrXN
DBUtils.closeConnection(conn); J;m[1Mae&
} 6xnJyEQUM
} M P0ww$(
public long getLast(){ 76 =uk!#3{
return lastExecuteTime; ixiRFBUcF~
} 2)[81a
public void run(){ w'M0Rd]
long now = System.currentTimeMillis(); v .r$]O
if ((now - lastExecuteTime) > executeSep) { @H&Aj..
//System.out.print("lastExecuteTime:"+lastExecuteTime); #:' P3)&
//System.out.print(" now:"+now+"\n"); %PlPXoG=
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); .h~)|"uzW
lastExecuteTime=now; ~ D3'-,n[
executeUpdate(); ]3
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7.
} sS5#Q
else{ nkN]z
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//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); =5dv38
} XFK$p^qu
} \iowAo$
} !nuXK
//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
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类写好了,下面是在JSP中如下调用。 JEJ]'3
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<% j?w7X?1(
CountBean cb=new CountBean(); D
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cb.setCountId(Integer.parseInt(request.getParameter("cid"))); >Cd%tIie*
CountCache.add(cb); q;kMeE*
out.print(CountCache.list.size()+"<br>"); F;q I^{m2
CountControl c=new CountControl(); .^JID~<?#
c.run(); >)#*}JI
out.print(CountCache.list.size()+"<br>"); -fUz$Df/R
%>