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: OY@ %p}l
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CountBean.java )q3p-)@kQ
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/* fXQNHZ|4
* CountData.java }U5yQ%N
* 'K,:j 388
* Created on 2007年1月1日, 下午4:44 UU0,!?o4
* 8E]F$.6U
* To change this template, choose Tools | Options and locate the template under RhLVg~x
* the Source Creation and Management node. Right-click the template and choose "wh ,Ue
* Open. You can then make changes to the template in the Source Editor. q;)JISf.
*/ 0v$~90)
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package com.tot.count; s.NGA.]$
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/** %FI E\9
* _b;{_g
* @author hTi$.y!k
*/ #|PS&}6wU
public class CountBean { Z!X0U7&U
private String countType; KRDmY+
int countId; m$T-s|SY
/** Creates a new instance of CountData */ &H:(z4/
public CountBean() {} 3n}?bY8@5_
public void setCountType(String countTypes){ yd`mG{Z
this.countType=countTypes; 'u<juFr
} y;@:ulv[
public void setCountId(int countIds){ "o}+Ciul
this.countId=countIds; =P
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} 3
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public String getCountType(){ pr UM-u8
return countType;
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} x>`%DwoRI
public int getCountId(){ (mt k 4
return countId; _MX>#!l
} O55 xS+3^k
} !5uGd`^I
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CountCache.java 03S]8l
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/* #';:2Nyq
* CountCache.java xbYi.
* dT1H
* Created on 2007年1月1日, 下午5:01 v^iL5y!
* Is?La
* To change this template, choose Tools | Options and locate the template under 2JcjZn
* the Source Creation and Management node. Right-click the template and choose CooQ>f
* Open. You can then make changes to the template in the Source Editor. mZ"4&U
*/ (|1A?@sJ#h
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package com.tot.count; 2Gaa(rJ5o
import java.util.*; 6]%sFy2
/** *U=s\
* ;&-k#PE]/H
* @author ;
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*/ rK]Cr9W M
public class CountCache { =CVB BuVy
public static LinkedList list=new LinkedList(); }"!I[Ek> y
/** Creates a new instance of CountCache */ q\p:X"j|
public CountCache() {} tQYM&6g
public static void add(CountBean cb){ ILShd)]Rw
if(cb!=null){ RcU}}V
list.add(cb); ' x35=@
} !s?nJ(p
} I(7NQ8Hx
} VYImI>.t{
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CountControl.java !AfHk|
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/* J B]q
* CountThread.java (uZ&V7l
* wLJ:\_Jaf
* Created on 2007年1月1日, 下午4:57 "J8vjr1/
* Pax|x15
* To change this template, choose Tools | Options and locate the template under MC:@U~}6
* the Source Creation and Management node. Right-click the template and choose
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* Open. You can then make changes to the template in the Source Editor. !"/n/jz
*/ @wo(tf=@P
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package com.tot.count; 90*5
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import tot.db.DBUtils; `gf0l /d
import java.sql.*; D}8[bWF
/** 8MzVOF{"
* kw%};;
* @author "PTZ%7YH}
*/ (~wqa 3
public class CountControl{ X1-'COQS%&
private static long lastExecuteTime=0;//上次更新时间 qPy1;maXP
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 kN4{13Qs*
/** Creates a new instance of CountThread */ 64G[|" j D
public CountControl() {} .ndCfdy~
public synchronized void executeUpdate(){ |\IN.W[EL
Connection conn=null; K<Iv:5-2
PreparedStatement ps=null; 4\u1TYR
try{ "x*egI
conn = DBUtils.getConnection(); ]<rkxgMW>
conn.setAutoCommit(false); oO|KEY(
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ,UGRrS
for(int i=0;i<CountCache.list.size();i++){ %r}{hq4
CountBean cb=(CountBean)CountCache.list.getFirst(); %'7lbpy,f
CountCache.list.removeFirst(); WR yaKM
ps.setInt(1, cb.getCountId()); yiC^aY=-
ps.executeUpdate();⑴ ?6un4EVL{
//ps.addBatch();⑵ UK O[r;
} wFsyD3
//int [] counts = ps.executeBatch();⑶ ';jYOVe
conn.commit(); Q)"Nu.m
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}catch(Exception e){ 7k9G(i[-+
e.printStackTrace(); c[4i9I3v
} finally{ `e|0g"oP
try{ <[\`qX
if(ps!=null) { v|%Z+w
ps.clearParameters(); '~[d=fwH
ps.close(); kG@@ot" n
ps=null; au+kNF|Q
} dDGgvi|[Mz
}catch(SQLException e){} jW3!6*93
DBUtils.closeConnection(conn); Xr$J9*Jk-
} u:gN?O/G
} 9-
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public long getLast(){ ^O<&f D
return lastExecuteTime; J|kR5'?x
} ()Y4v
public void run(){ +)<wDDC_
long now = System.currentTimeMillis(); wKYZa# u
if ((now - lastExecuteTime) > executeSep) { KB`!Sj\
//System.out.print("lastExecuteTime:"+lastExecuteTime); n%C>E.Tq
//System.out.print(" now:"+now+"\n"); NS%xTLow-
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); I E&!YP(U(
lastExecuteTime=now; t2I5hSf
executeUpdate(); hjB@o#S
} 8I8
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else{
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//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 'y2nN=CN
} PQnF
} !^=*Jq>
} ,dov<U[ia
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 (-xS?8x$
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类写好了,下面是在JSP中如下调用。 , 5kKimTt
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<% bRJMYs
CountBean cb=new CountBean();
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cb.setCountId(Integer.parseInt(request.getParameter("cid"))); t2"O
CountCache.add(cb); qnJt5
out.print(CountCache.list.size()+"<br>"); ?NR A:t(}
CountControl c=new CountControl(); wF,UE_
c.run(); iH@yCNE"
out.print(CountCache.list.size()+"<br>"); +!z{5:
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