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: Y+j|T`d
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CountBean.java !J'BAq[x
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/* ; v>2z!M
* CountData.java |Y2u=B
* +>37'PD
* Created on 2007年1月1日, 下午4:44 $Jx]
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*
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* To change this template, choose Tools | Options and locate the template under 6YYZ S2
* the Source Creation and Management node. Right-click the template and choose If2f7{b
* Open. You can then make changes to the template in the Source Editor. _ jF,
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*/ YDdmT7Ow
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package com.tot.count; VbJGyjx
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/** n$B=Vt,
* Ws.F=kS>h
* @author I@7^H48\
*/ #.#T+B+9
public class CountBean { WXaLKiA*(
private String countType; M)(
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int countId; B]0`b1t
/** Creates a new instance of CountData */ zc\e$MO
public CountBean() {} c9r, <TR9
public void setCountType(String countTypes){ 3Sf<oYF
this.countType=countTypes; )>C,y`,
} Kcl>uAgU
public void setCountId(int countIds){ G-9]z[\#
this.countId=countIds; l<! ?`V6}
} A0
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public String getCountType(){ m" .8-
return countType; .$L'Jt2X
} p.gi8%f`
public int getCountId(){ D3|y|Dr
return countId; @e3O=_m-
} 8v5cQ5Lc
} ,o*x\jrGw
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CountCache.java [*]&U6\j
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/* &0+;E-_
* CountCache.java M&:[3u-
* Ihw^g<X
* Created on 2007年1月1日, 下午5:01 nsuK{8}@
* H
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* To change this template, choose Tools | Options and locate the template under rp{q.fy'U
* the Source Creation and Management node. Right-click the template and choose K!0vvP2H
* Open. You can then make changes to the template in the Source Editor. DO8@/W(
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*/ I?EtU/AD
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package com.tot.count; <`+U B<K
import java.util.*; /*B-y$WQk
/** 3g0[(;
* [;
* @author Zu,rf9LMj
*/ 1#gveHm]-G
public class CountCache { 'K"V{
public static LinkedList list=new LinkedList(); -1DQO|q#
/** Creates a new instance of CountCache */ M._9/
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public CountCache() {} M]vcW
public static void add(CountBean cb){ .m9s+D]fI
if(cb!=null){ 3#!}W#xv
list.add(cb); Akb#1Ww4
} #kR8v[Z
} !c4pFQ B
} "6[fqW65
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CountControl.java ~Uz,%zU#3
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/* ^M0e 0
* CountThread.java []}E-
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* &-dyg+b3
* Created on 2007年1月1日, 下午4:57 ]N!8U_U3
* G0Eqo$W)S
* To change this template, choose Tools | Options and locate the template under W]}y:_t4
* the Source Creation and Management node. Right-click the template and choose 9nu!|reS
* Open. You can then make changes to the template in the Source Editor. &Egw94l
*/ \_bk+}WJ]s
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package com.tot.count; om@GH0o+
import tot.db.DBUtils; Z@4BTA
import java.sql.*; ,qz$6oxh\
/** ...|S]a
* |:7O
* @author IlJ!jq
*/ nYhI0q
public class CountControl{ (&H-v'a}3
private static long lastExecuteTime=0;//上次更新时间 H$bu*o-Z
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 8E`A`z
/** Creates a new instance of CountThread */ outAZy=R;
public CountControl() {} Q`j!$r
public synchronized void executeUpdate(){ b1>zGC^|
Connection conn=null; *~YU0o
PreparedStatement ps=null; %{?EfULg
try{ ixm-wZI
conn = DBUtils.getConnection(); 7:awUoV8f
conn.setAutoCommit(false); 2K[Y|.u8>q
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); U$-Gc[=|
for(int i=0;i<CountCache.list.size();i++){ OHTJQ5%zL
CountBean cb=(CountBean)CountCache.list.getFirst(); &Azfpv
CountCache.list.removeFirst(); + :4
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ps.setInt(1, cb.getCountId()); I.As{0cc
ps.executeUpdate();⑴ _Vul9=
//ps.addBatch();⑵ C^oj/}^
} v50w}w'
//int [] counts = ps.executeBatch();⑶ BC.~wNz6
conn.commit(); R~TzZ(Ah]
}catch(Exception e){ |h}/#qhR
e.printStackTrace(); lKKg n{R
} finally{ "jS@ug
try{ " iAwD8-
if(ps!=null) { }22h)){n#Y
ps.clearParameters(); L+VqTt
ps.close(); W/e6O?? O
ps=null; \JjZ _R
} b/"&E'5-`\
}catch(SQLException e){} ' b1k0 9'
DBUtils.closeConnection(conn);
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} QfPsF@+-`7
} P`^3-X/
public long getLast(){ T)4pLN
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return lastExecuteTime; PggjuPPh
} [[
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public void run(){ Lmh4ezrdH
long now = System.currentTimeMillis(); O\0]o!
if ((now - lastExecuteTime) > executeSep) { &q8oalh
//System.out.print("lastExecuteTime:"+lastExecuteTime); mcO/V-\5'
//System.out.print(" now:"+now+"\n"); drRi<7
i
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); W@S>#3,
lastExecuteTime=now; pe%$(%@v
executeUpdate(); W5a7HkM
} '$nm~z,V
else{ &}}UdJ`
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); fib#)KE
} d!>.$|b
} 8);G'7O
} l5;
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//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 J[ 0o6
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类写好了,下面是在JSP中如下调用。 R(.5Hs
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<% gu:8+/W8L
CountBean cb=new CountBean(); -]hk2Q0
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); my1FW,3
CountCache.add(cb); U0X,g(2'
out.print(CountCache.list.size()+"<br>"); *z852@
CountControl c=new CountControl(); g_8A1lt
c.run(); e 97Ll=>
out.print(CountCache.list.size()+"<br>"); nev@ykP6
%>