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: Hdn%r<+c
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CountBean.java z>6hK:27
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/* #hQ#_7
* CountData.java ld7B!_b<
* pkKcTY1Fx
* Created on 2007年1月1日, 下午4:44 gfW_S&&q
* C)a;zU;9
* To change this template, choose Tools | Options and locate the template under cm'`u&S
* the Source Creation and Management node. Right-click the template and choose DO^J=e
* Open. You can then make changes to the template in the Source Editor. GBvgVX<
*/ ROWI.|
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package com.tot.count; B1U<m=Y
sU=7)*$
/** ZHN@&Gg6)
* Zw`9B
* @author \se
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*/ #H5i$ o
public class CountBean { Fmd^9K
private String countType; (*K=&e0O
int countId; ?=dp]E{
/** Creates a new instance of CountData */ \ ";^nk*
public CountBean() {} n9w(Z=D\
public void setCountType(String countTypes){ na4^>:r~
this.countType=countTypes; V#P`FX
} eVetG,["
public void setCountId(int countIds){ 'Zket=Sm;
this.countId=countIds; r3BQo[ 't
} Qf
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public String getCountType(){ ,O'#7Dj
return countType; 0# d:<+4D
} l(<=JUO;
public int getCountId(){ [Nw%fuB
return countId; wyi%!H
} E5+-N
} j(>~:9I`
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CountCache.java }|j\QjH
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/* JnY.]:
* CountCache.java KB$SB25m
* yP^C)
* Created on 2007年1月1日, 下午5:01 T1\@4x
* O!U8"Yr$
* To change this template, choose Tools | Options and locate the template under 99YgQ Y]HO
* the Source Creation and Management node. Right-click the template and choose {2v,J]v_[
* Open. You can then make changes to the template in the Source Editor. Ds<~JfVl
*/ +I>V9%%vW_
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package com.tot.count; Mjj5~by:
import java.util.*; 1Uaj}=@M
/** 5@-[[ $dk
* sq45fRAi
* @author !K %8tr4
*/ [a[.tR38e
public class CountCache { b$JrLZs$_
public static LinkedList list=new LinkedList(); ,vh$G 7D
/** Creates a new instance of CountCache */ N87)rhXSo,
public CountCache() {} _wp_y-"
public static void add(CountBean cb){ EZee
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if(cb!=null){ TZ+- >CG
list.add(cb); =H_vRd
} 7@NV|Idtd
} &~K4I
} M?ObK#l!_
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CountControl.java 8fSY@
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/* N!~5S`
* CountThread.java dQQ!QbI(.
* 6BdK)s
* Created on 2007年1月1日, 下午4:57 ) -^(Su(!
* xh:A*ZI=7
* To change this template, choose Tools | Options and locate the template under dI?x(vw
* the Source Creation and Management node. Right-click the template and choose =3dR-3
* Open. You can then make changes to the template in the Source Editor. ]pq(Q:"P,5
*/ uefrE53
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package com.tot.count; tu:W1?
import tot.db.DBUtils; 'D:R]@eK]
import java.sql.*; $}8@?>-w
/** BA6(Owb
* 0CpE,gg
* @author wec_=EqK0
*/ v
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public class CountControl{ Xx+eGV";`
private static long lastExecuteTime=0;//上次更新时间 (&!RX.i
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 Ial"nV0>0
/** Creates a new instance of CountThread */ wM1&_%N
public CountControl() {} 5kik+
public synchronized void executeUpdate(){ &Sdf0"
Connection conn=null; 3]li3B'
PreparedStatement ps=null; <]f{X<ef
try{ cw/E?0MWb
conn = DBUtils.getConnection(); qO RL
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conn.setAutoCommit(false); Ly q[gQjr
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); Eyq4w
for(int i=0;i<CountCache.list.size();i++){ ~$jRn(2
CountBean cb=(CountBean)CountCache.list.getFirst(); H{4_,2h=m
CountCache.list.removeFirst();
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ps.setInt(1, cb.getCountId()); "DC L
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ps.executeUpdate();⑴ g-4j1yJV<
//ps.addBatch();⑵ JI[{n~bhGD
} M)"'Q6ck=
//int [] counts = ps.executeBatch();⑶ @gnLY
conn.commit(); u\q(v D.
}catch(Exception e){ O~#A )d6
e.printStackTrace(); 'mTQ=1
} finally{ _ -|+k
try{ vyvb-oz;u
if(ps!=null) { L]*5cH
ps.clearParameters(); D4O^5?F)|
ps.close(); )8`i%2i=
ps=null; -)Hc^'.
} {_R{gpj'
}catch(SQLException e){} Ei4Iv#Oi`
DBUtils.closeConnection(conn); s=>^ 8[0O
} "BZL*hHq
} ~X(2F#{<{
public long getLast(){ AD~_n^
return lastExecuteTime; B8~bx%)3T
} :(YFIW`59
public void run(){ 4YgO1}%G
long now = System.currentTimeMillis(); UCo`l~K)qg
if ((now - lastExecuteTime) > executeSep) { Z]XjN@j"
//System.out.print("lastExecuteTime:"+lastExecuteTime); ~7wLnB
//System.out.print(" now:"+now+"\n"); 8[H bg
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); :;jRAjq"
lastExecuteTime=now; i8A-h6E
executeUpdate(); jbe_r<{
} ,B#*<_?E5
else{ [D"5@
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); #wZbG|%
} Oe21noL
} `Y3\R#
} O4cBn{Dq9
//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 sD$K<nyz
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类写好了,下面是在JSP中如下调用。 b$sT`+4q
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<% 30YH}b#B
CountBean cb=new CountBean(); Ln8r~[tVE<
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ]sI\.a
CountCache.add(cb); \c1>15
out.print(CountCache.list.size()+"<br>"); bPIo9clq
CountControl c=new CountControl(); 9
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c.run(); QJSi|&Rx&?
out.print(CountCache.list.size()+"<br>"); K{9
%>