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: i92{N$*x
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CountBean.java iH9g5G`O
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/* k)'hNk"x
* CountData.java iv?'&IUfK
* i6kW"5t
* Created on 2007年1月1日, 下午4:44 iVd*62$@$
* MnO,Cd6{%d
* To change this template, choose Tools | Options and locate the template under ^8o'\V"m^
* the Source Creation and Management node. Right-click the template and choose /1h`O@VA
* Open. You can then make changes to the template in the Source Editor. m`g%\o^6i
*/ #KXaz Zu"
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package com.tot.count; nR6~oB{-
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/** % rdW:
* ^OI
* @author -fj;9('YJ
*/ CJJ 1aM
public class CountBean { =9\=5_V
private String countType; 4(R O1VWsb
int countId; a)(j68c
/** Creates a new instance of CountData */ +N5G4t#.
public CountBean() {}
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public void setCountType(String countTypes){ m1gJ"k6
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this.countType=countTypes; :)c >5
} YdV5\!
public void setCountId(int countIds){ j^1T3 +
this.countId=countIds; [NFg9y;{h
} Ve2z= 6(
public String getCountType(){ ,YSQog
return countType; 'P)xY-15
} lT@5=ou[
public int getCountId(){ @?aNvWeavH
return countId; x]euNa
} Eof1sTpA
} "]LNw=S
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CountCache.java 7t\kof
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/* .Ap[C? mV
* CountCache.java c?}C{
* 3! dD!'
* Created on 2007年1月1日, 下午5:01 j5R= K*y
* x~$P.X7(~
* To change this template, choose Tools | Options and locate the template under 9u1_L`+b
* the Source Creation and Management node. Right-click the template and choose CHdw>/5
* Open. You can then make changes to the template in the Source Editor. NRcg~Nu
*/ 6vX+-f
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package com.tot.count; b]g}h
import java.util.*; <eO 7b6_
/** ve1jLjsB
* XEfTAW#7
* @author j*I0]!-
*/ J6hWcA6g
public class CountCache { ]g IXG`
public static LinkedList list=new LinkedList(); ,ZD!Qb
/** Creates a new instance of CountCache */ YM 7P!8Gc
public CountCache() {} U@|{RP
public static void add(CountBean cb){ 8hQ"rrj+
if(cb!=null){ #Q^mdv?
list.add(cb); Cs^o- g!L
} HNY{%D
} r;y&Wa
} jS5e"LMIq
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CountControl.java }.NR+:0
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/* bsr
* CountThread.java U>e@m?
* 3 V8SKBS
* Created on 2007年1月1日, 下午4:57 _L_SNjA_
* oMLpl3pl
* To change this template, choose Tools | Options and locate the template under PX?tD:,[-
* the Source Creation and Management node. Right-click the template and choose csRba;Z[
* Open. You can then make changes to the template in the Source Editor. PaMi5Pq
*/ WN>.+qM~8
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package com.tot.count; +O j28vR
import tot.db.DBUtils; xO/44D
import java.sql.*; 5iG|C ~
/** 0K 7-i+\#
* h6)hZ'zV
* @author MG8-1M
*/ ^[&*B#(
public class CountControl{ @`%.\_
private static long lastExecuteTime=0;//上次更新时间 #@2 `^1
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 }=?r`J+Ev;
/** Creates a new instance of CountThread */ /J/r 62
public CountControl() {} HZ[&ZNTa
public synchronized void executeUpdate(){ twf;{lZ(
Connection conn=null; \Vm{5[ :SA
PreparedStatement ps=null; xdYjl.f
try{ QdUl-(
conn = DBUtils.getConnection(); O5_E"um
conn.setAutoCommit(false); ovm*,La)g
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); |1J "r.K
for(int i=0;i<CountCache.list.size();i++){ d>@{!c-
CountBean cb=(CountBean)CountCache.list.getFirst(); m1\>v?=K
CountCache.list.removeFirst(); T1n GBl\(
ps.setInt(1, cb.getCountId()); * fSa8CV
ps.executeUpdate();⑴ }mu8fm'
//ps.addBatch();⑵ dam.D.o"
} U!3nn#!yE
//int [] counts = ps.executeBatch();⑶ `dEWP;#cp
conn.commit(); [<wy@W
}catch(Exception e){ /PPk
p9H{
e.printStackTrace(); BAX])~_
} finally{ bTO$B2eh|
try{ d`({z]W;
if(ps!=null) { fkRb;aIl
ps.clearParameters(); <u4GIi
<sm
ps.close(); &bBp`h
ps=null; /I[cj3}{+f
} lba*&j]w=
}catch(SQLException e){} G`6U t
DBUtils.closeConnection(conn); oS_'@u.5
} *eUL1m8Y
} rp=?4^(u
public long getLast(){ q69a-5q
return lastExecuteTime; eZ}FKg%2[
} LwY_6[Ef
public void run(){ xs.[]>nQN
long now = System.currentTimeMillis(); kwWO1=ikz@
if ((now - lastExecuteTime) > executeSep) { _AVCh)Zb
//System.out.print("lastExecuteTime:"+lastExecuteTime); I*K^,XY+
//System.out.print(" now:"+now+"\n"); r)+dK}xl
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); pC5-,Z;8
lastExecuteTime=now; `q$DNOrS
executeUpdate(); f8[2$i*cL
} Plm3vk=
else{ t9 &O0tpe
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); }pTw$B
} o<V-gS
} g](m& O
} Ta9;;B?$
//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 *D4H; P#
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类写好了,下面是在JSP中如下调用。 `kekc.*-[@
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<% p,kJ# I
CountBean cb=new CountBean(); tvFJ^5
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); T,WWQm
CountCache.add(cb); ?W.Y
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out.print(CountCache.list.size()+"<br>"); xl# j_d,
CountControl c=new CountControl(); KVQZ
c.run(); I,
out.print(CountCache.list.size()+"<br>"); !Y\hF|[z
%>