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: #$W0%7
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CountBean.java GA/afc,V
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/* O^ui+44wp
* CountData.java <1Sj_HCT
* zK1]o-wSAT
* Created on 2007年1月1日, 下午4:44 %.]#3tW
* GCiG50Z=
* To change this template, choose Tools | Options and locate the template under GoAh{=s
* the Source Creation and Management node. Right-click the template and choose 3A[<LnKR^E
* Open. You can then make changes to the template in the Source Editor. :dRC$?f4
*/ i=]R1yP
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package com.tot.count; <uJ
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/** TQNdBq5I6
* Scm45"wB+
* @author ZWGX*F#}P
*/ WAR!#E#J7
public class CountBean { ~TXu20c
private String countType; Mp!1xx
int countId; 3D!7,@&>3
/** Creates a new instance of CountData */ DEhR\Z!
public CountBean() {} LklE,W
public void setCountType(String countTypes){ aG~zMO_)]
this.countType=countTypes; ;S$
} WQ.{Ag?1
public void setCountId(int countIds){ bma.RCyY<
this.countId=countIds; 2-N7%]h
} R@5eHP^
public String getCountType(){ :AFU5mR4&
return countType; s-'~t#h
} N~IAm:G}[
public int getCountId(){ ;r~1TUKb
return countId; Pi |Z\j)
} nvLdgu4P>
}
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CountCache.java pO5j-d*
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/* ar,v/l>d4N
* CountCache.java wme#8/eUk
* q UmSB"#Z
* Created on 2007年1月1日, 下午5:01 %3TioM[B
* m-tn|m!J
* To change this template, choose Tools | Options and locate the template under ~}d\sQF.
* the Source Creation and Management node. Right-click the template and choose dMsS OP0E
* Open. You can then make changes to the template in the Source Editor. a3w6&e`
*/ QJVB:>A
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package com.tot.count; }Rh%bf7,
import java.util.*; 2ib,33 Z
/** _[(EsIqc(F
* Zos.WS#
* @author 8rlf9m
*/ bo<.pK$
public class CountCache { fibudkg'>
public static LinkedList list=new LinkedList(); 'q~<ZO
/** Creates a new instance of CountCache */ FNOsw\Bo
public CountCache() {} 8mRZ(B>% X
public static void add(CountBean cb){ RyukQY~<W
if(cb!=null){ [N~-9
list.add(cb); 3dbaCusT$
}
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} ;r6YIS4@
} <"`f!k#[
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CountControl.java )!E:
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/* >7cj.%
* CountThread.java ]}l.*v\uK
* T]1.":
* Created on 2007年1月1日, 下午4:57 gpzFY"MS=
* ecH7")
* To change this template, choose Tools | Options and locate the template under ZBx,'ph}4
* the Source Creation and Management node. Right-click the template and choose "M2WK6?O5
* Open. You can then make changes to the template in the Source Editor. }1V+8'D
*/ 6(htpT%J
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package com.tot.count; ;@gI*i
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import tot.db.DBUtils; |x&4vHXR0
import java.sql.*; _dAn/rj
/** 3$K[(>s
* 4Wa$>vz
* @author ?z-nY,'^uq
*/ ^qBm%R(
public class CountControl{ {c]dz7'?
private static long lastExecuteTime=0;//上次更新时间 ;*FY+jM
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 HfP<hQmN'
/** Creates a new instance of CountThread */ aL;zN%Tw
public CountControl() {} ^2%)Nq; O
public synchronized void executeUpdate(){ XH*(zTd(?
Connection conn=null; };"_Ku4#-
PreparedStatement ps=null; jVGAgR=[G
try{ "7Kw]8mRR
conn = DBUtils.getConnection(); AA ~7"2e
conn.setAutoCommit(false); YKayaI\*
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); &6Lh>n(
for(int i=0;i<CountCache.list.size();i++){ ?/hS1yD;
CountBean cb=(CountBean)CountCache.list.getFirst(); pjV70D8$A
CountCache.list.removeFirst(); [9~EH8
ps.setInt(1, cb.getCountId()); i
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ps.executeUpdate();⑴ ^e =xEZD
//ps.addBatch();⑵ m432,8 K3r
} ;H71A[M
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//int [] counts = ps.executeBatch();⑶ QFhyidm=]
conn.commit(); v1}ijls
}catch(Exception e){ .),9a,
e.printStackTrace(); Rw[!Jq
} finally{ >}]bKq
try{ {IBbN05 ;
if(ps!=null) { 9<P%?Q
ps.clearParameters(); k`[>Bk%b
ps.close(); g%m-*v*
ps=null; eDNY|}$}v
} A93(} V7I
}catch(SQLException e){} 0lYP!\J3]%
DBUtils.closeConnection(conn); ,?%Y*?v
} &,l7w K
} P&Xy6@%[Z
public long getLast(){ m%"=sX7/9
return lastExecuteTime; 8/,s8u
} -{d(~XIo
public void run(){ [6.<#_~{
long now = System.currentTimeMillis(); F60m]NUM)c
if ((now - lastExecuteTime) > executeSep) { }I`o%GL
//System.out.print("lastExecuteTime:"+lastExecuteTime); `\3RFr
//System.out.print(" now:"+now+"\n"); {Q]7!/>>
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); n36@&q+B&
lastExecuteTime=now; S4(?=,^-
executeUpdate(); TDg<&ND3
} =ty{ugM<
else{ B*QLKO:)i
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); QT1oU P#*
} P$clSJW
} %,Y^Tp
} !|ic{1!_
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 mwz!7Q
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类写好了,下面是在JSP中如下调用。 "Nq5FcS9
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<% y{tM|
CountBean cb=new CountBean(); #Wv8+&n
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); |*]<*qnZt
CountCache.add(cb); [e:ccm
out.print(CountCache.list.size()+"<br>"); AVc|(~V
CountControl c=new CountControl(); YQO9$g0%
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c.run(); 8D^ iQBA
out.print(CountCache.list.size()+"<br>"); OG7U+d6
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