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: /._wXH
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CountBean.java 9z,?DBMvc
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/* C,w$)x5kls
* CountData.java ztG_::QtG]
* DB yRP-TH
* Created on 2007年1月1日, 下午4:44 +>oVc\$
* aT#R#7<Eg
* To change this template, choose Tools | Options and locate the template under 5w`v
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* the Source Creation and Management node. Right-click the template and choose G1Cn[F;e
* Open. You can then make changes to the template in the Source Editor. }0T1* .Cz
*/ f4zd(J
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package com.tot.count; .h^."+TJ
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/** x~}RL-Y2o
* Q^8C*ekfg!
* @author v"L<{HN
*/ 2Ni$
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public class CountBean { Jjz:-Uqq2
private String countType; +E QRNbA
int countId; )L`0VTw'M
/** Creates a new instance of CountData */ 16 o3ER
public CountBean() {} z@cL<.0CE
public void setCountType(String countTypes){ &gkloP@
this.countType=countTypes; pd,5.d
} kzGD*
public void setCountId(int countIds){ fw_V'l#\
this.countId=countIds; `ejE)VL=8h
} 2_0OSbFv'P
public String getCountType(){ UGEC_
return countType; q]tPsX5{*
} J;+iW*E:
public int getCountId(){ L
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return countId; g^1M]1.f
} jR\T\r4
} ;*+jCL2F
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CountCache.java ?T70C9
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/* @q2Yka
* CountCache.java `Y/DttjL
* )oa6;=go
* Created on 2007年1月1日, 下午5:01 &&|*GAjJ
* ow
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* To change this template, choose Tools | Options and locate the template under _ EHr?b2
* the Source Creation and Management node. Right-click the template and choose yjpV71!M
* Open. You can then make changes to the template in the Source Editor. ?K{CjwE.M
*/ ycRy!0l
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package com.tot.count; qr(SAIX"
import java.util.*; <O>r e3s
/** 9>qR6k?
* waW2$9O
* @author 5FnWlFc
*/ z:|4S@9
public class CountCache { R\MM2_I
public static LinkedList list=new LinkedList(); Tul_/` An
/** Creates a new instance of CountCache */ VLN=9
public CountCache() {} 8\`]T%h
public static void add(CountBean cb){ 3*3WO,9
if(cb!=null){ ~DVAk|fc
list.add(cb); &2MW.,e7s
} #5N#^#r"
} 93[c^sc9*a
} MMD4b}p
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CountControl.java 0eQyzn*98
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/* n!&DLB1z
* CountThread.java &
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* ]k_@F6 A
* Created on 2007年1月1日, 下午4:57 'u{m37ZJ
* y1(smZU
* To change this template, choose Tools | Options and locate the template under I7nt<l!
* the Source Creation and Management node. Right-click the template and choose s$:F^sxb
* Open. You can then make changes to the template in the Source Editor. x,STt{I=
*/ WsTbqR)W%
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package com.tot.count; .:*V
CDOM
import tot.db.DBUtils; Ti!j
import java.sql.*; OOGqtA;
/** B5IS-d
* O$E3ry+?
* @author 0"kNn5
*/ ?0WJB[/
public class CountControl{ ,o]"G[Jk
private static long lastExecuteTime=0;//上次更新时间 G7DEavtr
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 '%yWz)P
/** Creates a new instance of CountThread */ ^TJn&k
public CountControl() {} =4"D8UaHr
public synchronized void executeUpdate(){ Pk7Yq:avL
Connection conn=null; **d3uc4y
PreparedStatement ps=null; 3<1Uq3Pa
try{ w-2p'u['Z
conn = DBUtils.getConnection(); ns9iTU)
conn.setAutoCommit(false); znw\Dn?g
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); @Nn9-#iW
for(int i=0;i<CountCache.list.size();i++){ Pdmfn8I]%
CountBean cb=(CountBean)CountCache.list.getFirst(); :[m;#b
CountCache.list.removeFirst(); rJ4O_a5/
ps.setInt(1, cb.getCountId()); Ig t:M[
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ps.executeUpdate();⑴
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//ps.addBatch();⑵ YQvN;W
} y~w2^VN=
//int [] counts = ps.executeBatch();⑶ w7$*J:{
conn.commit(); Q9H~B`\nQ
}catch(Exception e){ D'F=v\P
e.printStackTrace(); f ."bq43(
} finally{ ~C6d5\
try{ ?1K|.lr
if(ps!=null) { 3xWeN#T0
ps.clearParameters(); v}!eJzeH
ps.close(); >t&Frw/Bl
ps=null; 8 sZ~3
} 4pq@o
}catch(SQLException e){} \?{nP6=
DBUtils.closeConnection(conn); ?~$0;5)QC
} )Ge.1B$8h
} "~0m_brf
public long getLast(){ cH?j@-pY
return lastExecuteTime; Q"n*`#Yt'
} + pZ, RW.D
public void run(){ q{HfT
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long now = System.currentTimeMillis(); $NC1>83
if ((now - lastExecuteTime) > executeSep) { X}Bo[YoY$
//System.out.print("lastExecuteTime:"+lastExecuteTime); &u( eu'Q3
//System.out.print(" now:"+now+"\n");
jhjb)r.
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); oA%8k51>~K
lastExecuteTime=now; CvKXVhf0$J
executeUpdate(); BoE;,s>]NW
} 9E4H`[EQ
else{ i[/g&fx
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 3zo]*6p0
} Gkv<)}G
} n#[-1(P
} k3h,c;
//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 l5F>v!NA
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类写好了,下面是在JSP中如下调用。 _]a8lr+_-
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<% "Lk-R5iFd
CountBean cb=new CountBean(); @.;] $N&J
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ,)e&u1'
CountCache.add(cb); &Ed7|k]H
out.print(CountCache.list.size()+"<br>"); Gx
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CountControl c=new CountControl(); `mXbF
c.run(); D1o<:jOj
out.print(CountCache.list.size()+"<br>"); k
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%>