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: {vLTeIxf.G
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CountBean.java |GuKU!
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/* ;FcExg|k
* CountData.java U%h7h`=F?
* db<q-u
* Created on 2007年1月1日, 下午4:44 (eki X*y
* >H)^6sJ;%b
* To change this template, choose Tools | Options and locate the template under {zY`h6d
* the Source Creation and Management node. Right-click the template and choose @T5YsX]qb7
* Open. You can then make changes to the template in the Source Editor. sE-x"c
*/ xcw%RUC-
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package com.tot.count; Y:rJK|m
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/** I Jqv w
* 692Rw}/
* @author &3WkH W
*/ Mp^^!AP 9
public class CountBean { -g9^0V`G
private String countType; mMV2h|W
int countId; dFx2>6AZt
/** Creates a new instance of CountData */ fV*}c`
public CountBean() {} Go-wAJ>
public void setCountType(String countTypes){ Y+!Ouc!$
this.countType=countTypes; wH+FFXGJs
} 4=~ 9v
public void setCountId(int countIds){ W)|c[Q\
this.countId=countIds; t3pZjdLJd
} HE*7\"9
public String getCountType(){ (QhGxuC
return countType;
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} C:rRK*
public int getCountId(){ YW'{|9KnI
return countId; t'dHCp}
} (D0C#<4P
} 7U&5^s
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CountCache.java aB=vu=hF
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/* a#YuKh?
* CountCache.java ;I[ht
* Sjw2 j#Q
* Created on 2007年1月1日, 下午5:01 1RCXc>}/
* lr-12-D%-
* To change this template, choose Tools | Options and locate the template under 2T//%ys=
* the Source Creation and Management node. Right-click the template and choose AQB1gzE
* Open. You can then make changes to the template in the Source Editor. ?@3#c
*/ /&*m1EN#o
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package com.tot.count; kw6cFz
import java.util.*; j#7wyi5q
/** }A^1q5
* 7fap*
* @author c9\B[@-q
*/ os}b?I*K
public class CountCache { yT[Lzv#
public static LinkedList list=new LinkedList(); <sgZ3*,A
/** Creates a new instance of CountCache */ \_lG#p|
public CountCache() {} |P^]@om
public static void add(CountBean cb){ B jH ~Ml2
if(cb!=null){ =Dh$yC-Zr
list.add(cb); oP+kAV#]
} TTeA a
} "Q3PC!7X:5
} xN e_qO
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CountControl.java 3DxZ#/!
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/* b ^uP^](J
* CountThread.java >r;ABz/
* R#"U/8b>z
* Created on 2007年1月1日, 下午4:57 %T`4!:vy
* q:TZ=bs^
* To change this template, choose Tools | Options and locate the template under fn1 ?Qp|
* 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. tn"Y9
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*/ ATKYjhc _
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package com.tot.count; JN{<oxI
import tot.db.DBUtils; :hC
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import java.sql.*; v9Z lNA7m!
/** 1 ;_{US5FR
* HF*j`}
* @author B`g<Ge~
*/ Q
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public class CountControl{ Rf)'HT
private static long lastExecuteTime=0;//上次更新时间 S1D9AcK
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 % MfGVx}nG
/** Creates a new instance of CountThread */ 1bV 2
public CountControl() {} T
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public synchronized void executeUpdate(){ @J~lV\
Connection conn=null; k)N2 +/
PreparedStatement ps=null; <bEN8b
try{ n%83jep9
conn = DBUtils.getConnection(); E\{^0vNc
conn.setAutoCommit(false); Vpug"aR&_
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); wm); aWP
for(int i=0;i<CountCache.list.size();i++){ s,eld@
CountBean cb=(CountBean)CountCache.list.getFirst(); >/7KL2*
CountCache.list.removeFirst(); 2uvQf&,
ps.setInt(1, cb.getCountId()); s(1_:
ps.executeUpdate();⑴ }ZEfT]
//ps.addBatch();⑵ w o-O_uZB
} #2_o[/&}x@
//int [] counts = ps.executeBatch();⑶ YWt"|
conn.commit(); qR [}EX&3
}catch(Exception e){ =q_&*'
e.printStackTrace();
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} finally{ [<#<:h&\
try{ O, bfdc[g4
if(ps!=null) { 5uQv
ps.clearParameters(); v\vE^|-\/
ps.close(); qT4I Y$h
ps=null; zznPD%#Sc
} K$MJ#Zx^
}catch(SQLException e){} ;whFaQi 4
DBUtils.closeConnection(conn); #JJp:S~`
} xFsB?d
} kWZ/ej
public long getLast(){ jOoIF/So
return lastExecuteTime; "|.+L
} 8\qCj.>S
public void run(){ WmT}t
long now = System.currentTimeMillis(); $$2S*qY
if ((now - lastExecuteTime) > executeSep) {
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//System.out.print("lastExecuteTime:"+lastExecuteTime); % j[O&[s}
//System.out.print(" now:"+now+"\n"); cCo07R
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); GW>7R6i
lastExecuteTime=now; Gt\K Ln
executeUpdate(); /RA1d<~$q
} jSeA%Te
else{ $I}Hk^X
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); xJ[k#?T'
} 4b3 F9
} 'k-u9
} <|KKv5[
//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 ]MqH13`)A
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类写好了,下面是在JSP中如下调用。 @e.OU(Bf
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<% V e$5w}a4
CountBean cb=new CountBean(); "oE^R?m
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); D,}'E0
CountCache.add(cb); $nGbT4sc
out.print(CountCache.list.size()+"<br>"); Z,|1G6f@
CountControl c=new CountControl(); f_re"d 3u
c.run(); 5{R#h :
out.print(CountCache.list.size()+"<br>"); dI#8CO
%>