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: ]3Jb$Q@
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CountBean.java 6]4=8! J
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/* \XfLTv
* CountData.java 1Ve~P"w
* }FX:sa?5
* Created on 2007年1月1日, 下午4:44 >X5RRSo
* czB),vooz
* To change this template, choose Tools | Options and locate the template under GgE
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* the Source Creation and Management node. Right-click the template and choose Xo6zeLHO
* Open. You can then make changes to the template in the Source Editor. EoS6t
*/ NceK>::56
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package com.tot.count; def\=WyK
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/** 2tQ?=V(Di
* <~u-zaN<W
* @author pIKfTkSqH
*/ 8~O0P=
public class CountBean { pr1kYMrqri
private String countType; $&i8/pD
int countId; y(Em+YTD
/** Creates a new instance of CountData */ r?pN-x$M=
public CountBean() {} !LsIHDs4
public void setCountType(String countTypes){ \KKE&3=
this.countType=countTypes; 4E$d"D5]>p
} 6LqF*$+$`
public void setCountId(int countIds){ o
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this.countId=countIds; WtXf~ :R
} H8m[:K]_H
public String getCountType(){ 3PkU>+.6
return countType; OU*skc>
} cqcH1aSv
public int getCountId(){ 6.a|w}C`
return countId; 2;w> w#}>
} 4{0vdpo3F
} fVi[mH0=+
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CountCache.java b{
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/* |lyspD
* CountCache.java T iJ \J{
* 'CRjd~L
* Created on 2007年1月1日, 下午5:01 Un&rP70
* y`cL3
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* To change this template, choose Tools | Options and locate the template under o?aF
* the Source Creation and Management node. Right-click the template and choose 3(:?Z-iKe
* Open. You can then make changes to the template in the Source Editor. J8[aVG
*/ ~RV9'v4
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package com.tot.count; (aB:P03
import java.util.*; j|b$b,rF\
/** "S>VqvH3
* KYq<n& s
* @author jV<5GWq
*/ -.-@|*5
public class CountCache { ]
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public static LinkedList list=new LinkedList(); v7D0E[)~
/** Creates a new instance of CountCache */ @[Wf!8_
public CountCache() {} i6O'UzD@T
public static void add(CountBean cb){ r>rL[`p(2
if(cb!=null){ X@7:FzU9
list.add(cb); |{rhks~
} aaI5x
} aLwEz}-
} -1ci.4F&
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CountControl.java ;h#Q!M&e#
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/* khQfLA
* CountThread.java Q{
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* "M,Hm!j
* Created on 2007年1月1日, 下午4:57 j
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* VI.Cmw~S
* To change this template, choose Tools | Options and locate the template under .{(gku>g(
* the Source Creation and Management node. Right-click the template and choose #=Whh
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* Open. You can then make changes to the template in the Source Editor.
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*/ q{!ft9|K\d
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package com.tot.count; W>[TFdH?
import tot.db.DBUtils; uY3?(f#
import java.sql.*; +}BKDEb
/** yEVnG`
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* @author HYNp vK
*/ [9yy<Z5
public class CountControl{ =vL
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private static long lastExecuteTime=0;//上次更新时间 t*-_MG
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 hF1Lj=x
/** Creates a new instance of CountThread */ }3-`e3
public CountControl() {} "rpP
public synchronized void executeUpdate(){ hKems3
Connection conn=null; 3X9
PreparedStatement ps=null; }'uV{$
try{ m;vm7]5
conn = DBUtils.getConnection(); {k']nI.>
conn.setAutoCommit(false); "}0)~,{xB
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); D% 2S!
for(int i=0;i<CountCache.list.size();i++){ {$C"yksr
CountBean cb=(CountBean)CountCache.list.getFirst(); [6nN]U~ Y
CountCache.list.removeFirst(); 0uI=8j
ps.setInt(1, cb.getCountId()); d 0:;IUG
ps.executeUpdate();⑴ uao#=]?)
//ps.addBatch();⑵ o\nFSGkn
} x(:alG%#
//int [] counts = ps.executeBatch();⑶ \{o<-S;h
conn.commit(); )%hW3w
}catch(Exception e){ d;).| .}P
e.printStackTrace(); qh6Q#s>tH
} finally{ T t$]
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try{ Iz!]LW
if(ps!=null) { >{"E~U
ps.clearParameters(); &InFC5A
ps.close(); 2hb>6Z;r]K
ps=null; ,F=FM>o
} W'v
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}catch(SQLException e){} 3.Jk-:u %m
DBUtils.closeConnection(conn); 6vg` 8
} kU{a!ca4
} u_Xp\RJ
public long getLast(){ Hr*xA x
return lastExecuteTime; 1#|qT7
} gdg
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public void run(){ 7_L$ XIa
long now = System.currentTimeMillis(); _*wlK;`
if ((now - lastExecuteTime) > executeSep) { $]J<^{v
//System.out.print("lastExecuteTime:"+lastExecuteTime); sLc,Dx"+
//System.out.print(" now:"+now+"\n"); QGnUPiD^
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); Y 9BKd78Y
lastExecuteTime=now; 3E!3kSh|
executeUpdate(); pR!m
} /LLo7"
else{ "XU)(<p
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); R3*{"!O
} !fJy7Y
} Xj<xen(
} p uW
//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 }eSrJgF4M
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类写好了,下面是在JSP中如下调用。 $?DEO[p.
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<% 1 ;Uc-<
CountBean cb=new CountBean(); X#ud_+6x
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); (Y
CountCache.add(cb); Pje1,B q
out.print(CountCache.list.size()+"<br>"); 2|${2u`$&y
CountControl c=new CountControl(); 4
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c.run(); E*L5D4Kw
out.print(CountCache.list.size()+"<br>"); i4)]lWnd
%>