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: gSS2)Sd}
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CountBean.java *^+8_%;1
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/* QYl
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* CountData.java ."HDUo2D7
* $hND!T+;
* Created on 2007年1月1日, 下午4:44 w +pK=R
* ~8fy
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* To change this template, choose Tools | Options and locate the template under k
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* the Source Creation and Management node. Right-click the template and choose c*fMWtPp
* Open. You can then make changes to the template in the Source Editor. g7Xjo )
*/ 'MF|(`
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package com.tot.count; hDPZj#(c
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/** 0#$<2
* QkY]z~P4
* @author ,drbj.0-
*/ ^a ,Oi%
public class CountBean { 2kG(\+\
private String countType; kfb*|
int countId; ,Z_aZD4
/** Creates a new instance of CountData */ A@:h\<
public CountBean() {} p=fj1*
public void setCountType(String countTypes){ ;_bZH%o.
this.countType=countTypes; ,}8|[)"
} ]x;*Z&
public void setCountId(int countIds){ q 4Rvr[
this.countId=countIds; |+-D@22y
} ]H%SGQPn
public String getCountType(){ "xr=:[n[
return countType; 3izGMH_`
} s2IjZF {
public int getCountId(){ v|]1x2191
return countId; T6Oah:50EM
} bi:TX<K+
} KR49Y>s<
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CountCache.java xAZ-_}'tW
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/* #0:N$'SZ
* CountCache.java :"ta#g'
* [5"F=tT7WP
* Created on 2007年1月1日, 下午5:01 {/u}
* g`n5-D@3
* To change this template, choose Tools | Options and locate the template under xJNV^u
* the Source Creation and Management node. Right-click the template and choose ],?$&
* Open. You can then make changes to the template in the Source Editor. 6=aXz2.f
*/ !0}SZ
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package com.tot.count; p?6`mH
import java.util.*; y;$
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/** 1:.I0x!
* bF"1M#u:
* @author XCP/e p
*/ "/#=8_f
public class CountCache { .XZq6iF9
public static LinkedList list=new LinkedList(); -zSkon2Y^
/** Creates a new instance of CountCache */ Q
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public CountCache() {} ]b+Nsr~
public static void add(CountBean cb){ 'xG:v)(
if(cb!=null){ =N~*`5|rk
list.add(cb); GN=ugP 9
} lL$no7HBy
} kGkfLY6B
} x("V+y*
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CountControl.java XwlF[3VbiX
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/* c H7Gb|,M
* CountThread.java "NMSLqO
* Mr}K-C?ge
* Created on 2007年1月1日, 下午4:57 ` 0z8J*T]
* OMz_xm.UPi
* To change this template, choose Tools | Options and locate the template under 4\pUA4
* the Source Creation and Management node. Right-click the template and choose "BvAiT{u
* Open. You can then make changes to the template in the Source Editor. J+:gIszsWT
*/ "0sk(kT
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package com.tot.count; ] v8 .ym
import tot.db.DBUtils; sVNM#,
import java.sql.*; cxB{EH,2Um
/** hVl^vw7o
* JO =kfWW
* @author Fs 95^T
*/ C_rA'Hy
public class CountControl{ lWRRB&8
private static long lastExecuteTime=0;//上次更新时间 H]<@\g*l@P
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 6xT"j)h
/** Creates a new instance of CountThread */ JIh:IR(ta
public CountControl() {} }}q_QD_
public synchronized void executeUpdate(){ SMMvRF`7
Connection conn=null; 8Ben}j)H
PreparedStatement ps=null; 1b LY1
try{ AD0pmD
conn = DBUtils.getConnection(); tGVC"a
conn.setAutoCommit(false); P7|x=Ew;`
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); Pgo^$xn'6
for(int i=0;i<CountCache.list.size();i++){ 5LVzT1j|
CountBean cb=(CountBean)CountCache.list.getFirst(); %VsIg
CountCache.list.removeFirst(); 0~GtK8^B
ps.setInt(1, cb.getCountId()); 2(s-8E:
ps.executeUpdate();⑴
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//ps.addBatch();⑵ fKkH
[
} d'UCPg<Y
//int [] counts = ps.executeBatch();⑶ Cj3C%W
conn.commit(); >sl#2,br
}catch(Exception e){ -+,3aK<[
e.printStackTrace(); Jd-u?
} finally{ \ Q E?.Fx
try{ :@c\a99Kx
if(ps!=null) { *L+)R*|:&
ps.clearParameters(); *)82iD
ps.close(); Nt/#Qu2#br
ps=null; kW.it5Z#
} >og-
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}catch(SQLException e){} 0hoi=W6AQ
DBUtils.closeConnection(conn); q-5U,!!W/
} E,$5V^
9
} +S
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public long getLast(){ [W,} &
return lastExecuteTime; 3 6-Sw
} tZ*z.3\<
public void run(){ 2nkUvb%=
long now = System.currentTimeMillis(); k*$[V17
if ((now - lastExecuteTime) > executeSep) { qpZR-O
//System.out.print("lastExecuteTime:"+lastExecuteTime); 9TZ4ffXV*
//System.out.print(" now:"+now+"\n"); ,#blY~h8^
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ffgb3
lastExecuteTime=now; #z&@f
executeUpdate(); ZMn~QU_5
} $5v:z
else{ rc ()Eo50
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); IuN:*P
} "4[8pZO/
} i-E/#zni
} hY[Vs5v
//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 :W*']8 M-
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类写好了,下面是在JSP中如下调用。 _=ziw|zI
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<% $CP_oEb
CountBean cb=new CountBean(); ,HHCgN
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); A2{s?L,
CountCache.add(cb); [)KLmL%
out.print(CountCache.list.size()+"<br>"); u~\I
CountControl c=new CountControl(); o@j)clf
c.run(); +L>?kr[i[
out.print(CountCache.list.size()+"<br>"); WB(Gx_o3
%>