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: hw,nA2w\
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CountBean.java VcGl8~#9
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/* gUNhN1=
* CountData.java G &xtL
* Pr1qX5> =
* Created on 2007年1月1日, 下午4:44 _aR{B-E
* T?Kh'
* To change this template, choose Tools | Options and locate the template under 1^LdYO?g'
* the Source Creation and Management node. Right-click the template and choose <4+P37^~
* Open. You can then make changes to the template in the Source Editor. KF
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*/ Ym1vq=
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package com.tot.count; E/g"}yR
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/** yfK}1mx)j
* VxBBZsZO~
* @author kN.;;HFq#
*/ jB(+9?;1${
public class CountBean { D#UuIZ
private String countType; ''YqxJ fb
int countId; .6P.r}
/** Creates a new instance of CountData */ YZ5,K6u
public CountBean() {} `mzlOB
public void setCountType(String countTypes){ M2Jf-2
this.countType=countTypes; R|n
} (/uAn2
public void setCountId(int countIds){ 7b+r LyS0
this.countId=countIds; [02rs@c>
} tGgxI D
public String getCountType(){ /kY9z~l
return countType; db~^Gqv6k
} UB.1xcI
public int getCountId(){ UxL*I[z5
return countId; 5X20/+aT
} HwHF8#D*l
} O;~e^ <*
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CountCache.java -T,?'J0 2
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/* :D*U4<
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* CountCache.java =..Bh8P71!
* ~f h
* Created on 2007年1月1日, 下午5:01 4p,:}h
* sFc \L9 4
* To change this template, choose Tools | Options and locate the template under 0n{.96r0R
* the Source Creation and Management node. Right-click the template and choose RNi%6A1
* Open. You can then make changes to the template in the Source Editor. q2*A'C
*/ -NXxxK
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package com.tot.count; H].|K/-p
import java.util.*; 1Ng+mT
/** `G qe]ZE#"
* <Z]#vrq
* @author Z^_qXerjP
*/ !?nbB2,
public class CountCache { hyH[`wiq
public static LinkedList list=new LinkedList(); 5p (zhfuG
/** Creates a new instance of CountCache */ _K o#36.S
public CountCache() {} C`hdj/!A
public static void add(CountBean cb){ eR$@Q
if(cb!=null){ LH5Z@*0#
list.add(cb);
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} ~Q&J\'GQH
} }:0_%=)N<
} ob\-OMNs@
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CountControl.java hx9{?3#
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/* lS4r pbU_
* CountThread.java ?H=q!i
* WO_Uc_R
* Created on 2007年1月1日, 下午4:57 eX+36VG\
* w*-42r3,'
* To change this template, choose Tools | Options and locate the template under sp,-JZD
* the Source Creation and Management node. Right-click the template and choose oX|T&"&
* Open. You can then make changes to the template in the Source Editor. e9o\qEm
*/ xqt?z n
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package com.tot.count; }R%H?&P
import tot.db.DBUtils; qYC&0`:H
import java.sql.*; \baY+,Dr+
/** vqSpF6F
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* F\ B/q
* @author =rA?,74
*/ 4!IuTPmr
public class CountControl{ ./#YUIC
private static long lastExecuteTime=0;//上次更新时间
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private static long executeSep=60000;//定义更新间隔时间,单位毫秒 AELj"=RA
/** Creates a new instance of CountThread */ "+(|]q"W
public CountControl() {} N d].(_
public synchronized void executeUpdate(){ ubwM*P
Connection conn=null; ev4[4T-(@
PreparedStatement ps=null; GC')50T J
try{ 2 ? qC8eC
conn = DBUtils.getConnection(); $aV62uNf
conn.setAutoCommit(false); GbSCk}>
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ,<v0(
for(int i=0;i<CountCache.list.size();i++){ NoiB98g
CountBean cb=(CountBean)CountCache.list.getFirst(); #EH=tJgO|J
CountCache.list.removeFirst(); 1Gsh%0r3
ps.setInt(1, cb.getCountId()); ON,[!pc
ps.executeUpdate();⑴ Pk;\^DRC
//ps.addBatch();⑵ |Xt.[1
} C%z)D1-
//int [] counts = ps.executeBatch();⑶ Tqt-zX|>
conn.commit(); ;z'&$#pA
}catch(Exception e){ 8ymdg\I+L
e.printStackTrace(); BJjic% V
} finally{ ,"EaZ/Bl/
try{ 2lTt
if(ps!=null) { }J# HIE\RG
ps.clearParameters(); ]l,D,d81
ps.close(); "^#O7.oVi+
ps=null; "`qk}n-
} 8,U~ p<Gz
}catch(SQLException e){} !D=!
DBUtils.closeConnection(conn); b j&!$')
} 2FMmANH0ev
} riIubX#
public long getLast(){ 0~U#DTx0
return lastExecuteTime; \D@j`o
} Z[#8F&QV!m
public void run(){ Z)7{~xq
long now = System.currentTimeMillis(); &qx/ZT
if ((now - lastExecuteTime) > executeSep) { 9hzu!}~'I
//System.out.print("lastExecuteTime:"+lastExecuteTime); Nf| 0O\+%y
//System.out.print(" now:"+now+"\n"); 9^a|yyzL
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); Jh-yIk
lastExecuteTime=now; E=I'$*C\D
executeUpdate(); ]3 "0#Y
} &W\e 5X<A
else{ ?MH=8Cl1w
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); `i`P}W!F
} w|f+OlPXq
} "S;4hO
} j9fBl:Fr
//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 2xNR=u`
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类写好了,下面是在JSP中如下调用。 MSCH6R"5
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<% d:'{h"M6
CountBean cb=new CountBean(); *$A`+D9
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); hkPMu@BI
CountCache.add(cb); hi(b\ABx
out.print(CountCache.list.size()+"<br>"); 5iw\F!op:
CountControl c=new CountControl(); #(tdJ<HvC|
c.run(); z4YDngf=4
out.print(CountCache.list.size()+"<br>"); N3u06
%>