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: :H]d1
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CountBean.java \W*L9azr
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/* ^\}qq>_
* CountData.java H!IVbL`a{
* 9#z$GO|<
* Created on 2007年1月1日, 下午4:44 '[#y|
* AT&K> NG
* To change this template, choose Tools | Options and locate the template under s47R,K$
* the Source Creation and Management node. Right-click the template and choose wKM9fs
* Open. You can then make changes to the template in the Source Editor. D;R~!3f./b
*/ /QQRy_Z1)
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package com.tot.count; a}yb~:TC
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/** q/b+V)V
* IhNX~Jg'^
* @author K%J?'-
*/ -.h)CM@L
public class CountBean { Yz/Blh%V
private String countType; ^\ [p6>
int countId; l eC!Yj
/** Creates a new instance of CountData */ [.}qi[=n
public CountBean() {} 1$0Kvvg[
public void setCountType(String countTypes){ +pR,BjY
this.countType=countTypes; x9 > ho
} GB$`b'x@S
public void setCountId(int countIds){ F!X0Wo=
this.countId=countIds; @;4;72@O
} s;vt2>;q+e
public String getCountType(){ =Kkqk
return countType; AX v
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} uyYV_Q0~;
public int getCountId(){ Qf~>5(,h
return countId; V}s/knd
} _.JQ h
} :BPgDLL,
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CountCache.java (%B{=w}8
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/*
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* CountCache.java NTu|cX\R
* )gdeFA V
* Created on 2007年1月1日, 下午5:01 .aNh>`OT'
* :M"+
* To change this template, choose Tools | Options and locate the template under F=qILwd
* the Source Creation and Management node. Right-click the template and choose #Pg#\v|7#>
* Open. You can then make changes to the template in the Source Editor. rCw4a?YS
*/ 6BV 6<PHJ
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package com.tot.count; FsED9+/m
import java.util.*; !/p|~K
/** 0Q{lyu
* }+!"mJx@
* @author in1rDN%Vi
*/ D)-LZbPa
public class CountCache { Jt[ug26
public static LinkedList list=new LinkedList(); |?88EG@05
/** Creates a new instance of CountCache */ 4;YP\{u
public CountCache() {} QGpj$ _b
public static void add(CountBean cb){ N?qETp -:
if(cb!=null){ _x.2&S89
list.add(cb); .+9*5
} .:?v;rYk{
} ZN}`A7
} l!,tssQ
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CountControl.java |XB<vj07G
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/* 'UX^]
* CountThread.java eX$KH;M
* toY_1
* Created on 2007年1月1日, 下午4:57 V48_aL
* ?$/::uo
* To change this template, choose Tools | Options and locate the template under ]H/,Q6Q
* the Source Creation and Management node. Right-click the template and choose gkmof^
* Open. You can then make changes to the template in the Source Editor. UCVYO.
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*/ )xcjQkb
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package com.tot.count; &4OJJ9S
import tot.db.DBUtils; =aVvv+T
import java.sql.*; 7]rIq\bM
/** *P' X[z
* p7YYAh@x\
* @author Osqk#Oh
*/ lj]M 1zEz&
public class CountControl{ "e-Y?_S7R8
private static long lastExecuteTime=0;//上次更新时间 .JKH=?~\
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 fn<dr(Dx
/** Creates a new instance of CountThread */ JzEg`Sn^
public CountControl() {} 4pL'c@'
public synchronized void executeUpdate(){ :P-H8*n""
Connection conn=null; Zz} o t
PreparedStatement ps=null; &n1Vv_Lb
try{ [k
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conn = DBUtils.getConnection(); Y^]n>X
conn.setAutoCommit(false); o`CM15d*7o
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 3f5YPf2u
for(int i=0;i<CountCache.list.size();i++){ N_g=,E=U%
CountBean cb=(CountBean)CountCache.list.getFirst(); "w"a0nv
CountCache.list.removeFirst(); XgxO:"B
ps.setInt(1, cb.getCountId()); W<q<}RSn
ps.executeUpdate();⑴ %i?
//ps.addBatch();⑵ G+=Gc(J
} bg|$1ue
//int [] counts = ps.executeBatch();⑶ j*QdD\)
conn.commit(); S5JMt;O
}catch(Exception e){ )L&y@dy)
e.printStackTrace(); H{=]94
} finally{ q&:7R
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try{ 4Y?fbb<
if(ps!=null) { &~eCDlX/
ps.clearParameters(); [lIX&!T"
ps.close(); d>Tv?'o`q
ps=null; <7y/)b@
} o+x%q<e;c
}catch(SQLException e){} pS8\ B
DBUtils.closeConnection(conn); E#P#{_BR^
} ;C-ds
} }h1BAKg
public long getLast(){ FtJaX])b
return lastExecuteTime; !Mw/j`*
} ,xU#uyB
public void run(){ S(3h{Y"#
long now = System.currentTimeMillis(); E0qJ.v
if ((now - lastExecuteTime) > executeSep) { 3sV$#l P
//System.out.print("lastExecuteTime:"+lastExecuteTime); &7'=t6
//System.out.print(" now:"+now+"\n"); F+Kju2
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); T
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lastExecuteTime=now; 7s%D(;W_Mo
executeUpdate(); 3z0Bg
} QV."ZhL5 =
else{ KF&8l/f
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); npeL1zO-$
} O$z"`'&j#
} d %}?%VH
} $/^Y(0
//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 GQg
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类写好了,下面是在JSP中如下调用。 1[OY -G
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<% :[l}Bb,
CountBean cb=new CountBean(); G!`%.tH
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); zji9\
CountCache.add(cb); eLT3b6'"?
out.print(CountCache.list.size()+"<br>"); ty!DMg#
CountControl c=new CountControl(); 6\l F
c.run(); Q:)4
out.print(CountCache.list.size()+"<br>"); nGGw(6c%>
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