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: %1}6q`:w
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CountBean.java EX
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/* P+(i^=S
* CountData.java ^[q /Mw
* Xs$Ufi
* Created on 2007年1月1日, 下午4:44 j8$Zv%Ca%
* @;^Y7po6u
* To change this template, choose Tools | Options and locate the template under 8]"(!i_;)
* the Source Creation and Management node. Right-click the template and choose r4{<Z3*N
* Open. You can then make changes to the template in the Source Editor. |g&ymFc
*/ [EZYsOr.
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package com.tot.count; PLR0#).n
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/** 4IsG=7
* Pqp *
* @author w"zE_9I\
*/ Q!'qC*Gyfn
public class CountBean { Ew,T 5GG
private String countType; d8x%SQ!V
int countId; `8g7q 5
/** Creates a new instance of CountData */ )&W**!(C
public CountBean() {} WFv!Pbq,
public void setCountType(String countTypes){ ,.mBJSE3
this.countType=countTypes; }iiHr|l3
} 0kDBE3i#
public void setCountId(int countIds){ R: Z_g!h
this.countId=countIds; 1~yZ T
} iEHh{H(
public String getCountType(){ f~h~5
return countType; (-^bj
} gS9>N/b|
public int getCountId(){ gK1g]Tc @G
return countId; !iu5OX7K|
} ?=On%bh
} 4<S'
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CountCache.java t~p
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/* k&6I f0i
* CountCache.java 2}WDw>V
* m
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* Created on 2007年1月1日, 下午5:01 ZFn(x*L
* k$7Z^~?Fz
* To change this template, choose Tools | Options and locate the template under T0QvnIaP
* the Source Creation and Management node. Right-click the template and choose PlxIfL
* Open. You can then make changes to the template in the Source Editor. ~(X(&
*/ Af-UScD%G
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package com.tot.count; uh3)0.nR
import java.util.*; xBM>u,0.F
/** 4_=Ja2v8;`
* nWYCh7
* @author @F5f"8!.\
*/ <nHkg<O6Y
public class CountCache { yI;"9G
public static LinkedList list=new LinkedList(); pV\YG B+
/** Creates a new instance of CountCache */ 6(V
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public CountCache() {} +}kgQ^
public static void add(CountBean cb){ >,5i60Q
if(cb!=null){ #/-_1H
list.add(cb); `dkV_ O0
} 2Aq~D@,9=:
} N/F$bv
} h0 |}TV^UJ
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CountControl.java 2W<n5o
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/* g.DLfwI|
* CountThread.java z~oDWANP
* l]LxL
* Created on 2007年1月1日, 下午4:57 xTV{^=\rS
* ]7YNIS
* To change this template, choose Tools | Options and locate the template under *VeW?mY,P
* the Source Creation and Management node. Right-click the template and choose <=um1P3X
* Open. You can then make changes to the template in the Source Editor. %&blJ6b
*/ I["j=r
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package com.tot.count; X&\d)/Y
import tot.db.DBUtils; kI\tqNJ i
import java.sql.*; Fd$!wBL
/** ?+C V1 ]
* =?Fkn4t
* @author \Ad7
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*/ t%VDRZo7
public class CountControl{ ]`o!1( GA
private static long lastExecuteTime=0;//上次更新时间 > 0>
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ?A*Kg;IU
/** Creates a new instance of CountThread */ wxQ>ifi9Z
public CountControl() {} )0 Z! n
public synchronized void executeUpdate(){ x_w~G]! /
Connection conn=null; 0BU=)Swku
PreparedStatement ps=null; ja=w5
try{ h1D?=M\9
conn = DBUtils.getConnection(); |L3X_Me
conn.setAutoCommit(false); |`rJJFA
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); #@.-B,]
for(int i=0;i<CountCache.list.size();i++){ n> w`26MMp
CountBean cb=(CountBean)CountCache.list.getFirst(); cNK)5-
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CountCache.list.removeFirst(); )]6hy9<
ps.setInt(1, cb.getCountId()); ).412I
ps.executeUpdate();⑴ :py\|
//ps.addBatch();⑵ !7p}C-RZp
} 2b@tj
5
//int [] counts = ps.executeBatch();⑶ |F$BvCg
conn.commit();
#=c`of6
}catch(Exception e){ ^q[gxuL_
e.printStackTrace(); 2a=sm1?
} finally{ Rd&9E
try{ T2'RATfG
if(ps!=null) { 8G^<[`.@j
ps.clearParameters(); mqtg[~dNc
ps.close(); s}5+3f$f
ps=null; .8gl< vX
} f i~I@KJ>
}catch(SQLException e){} ]wn/BG)
DBUtils.closeConnection(conn); /8yn vhF#
} QrYa%D+
} 0JyVNuHn
public long getLast(){ XVVD 0^ Q
return lastExecuteTime; "E*e2W
} |}&RXD
public void run(){ /%rq
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long now = System.currentTimeMillis(); \1%l^dE@
if ((now - lastExecuteTime) > executeSep) { ,T{<vRj7_
//System.out.print("lastExecuteTime:"+lastExecuteTime); x34f9!
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//System.out.print(" now:"+now+"\n"); %CnxjtTo
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); OEhHR
lastExecuteTime=now; @\P4/+"9
executeUpdate(); *<4Em{rZ5
} q?j|K|%
else{ c@(&[/q!
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); <v
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} /#LW"4;*
} cDEJk?3+
} b{M7w
//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 n`7f"'/:
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类写好了,下面是在JSP中如下调用。 ^_+XDO
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<% NaUr!s
CountBean cb=new CountBean(); L{{CAB!
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); d3Di/Iej
CountCache.add(cb); !vD{Df>
out.print(CountCache.list.size()+"<br>"); aG`;OgrH
CountControl c=new CountControl(); R=j% S!
c.run(); M" lg%j
out.print(CountCache.list.size()+"<br>"); 3.Gj4/f
%>