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: g}6M+QNj
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CountBean.java u-.5rH l
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/* \v:Z;EbX
* CountData.java D)4#AI
* =j w?*
* Created on 2007年1月1日, 下午4:44 /!5cf;kl*l
* 7ko}X,aC
* To change this template, choose Tools | Options and locate the template under oP7)
* the Source Creation and Management node. Right-click the template and choose _o?aO C
* Open. You can then make changes to the template in the Source Editor. t#f-3zd9
*/ =<(6yu_
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package com.tot.count; :zIB3nT^
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/** |w~*p
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* (:H4
* @author oKkDG|IE
*/ wE9z@\z]
public class CountBean { vfDX~_N
private String countType; Iza#v0
int countId; yHf^6|$8
/** Creates a new instance of CountData */ {J)gS
public CountBean() {} m(xyEU
public void setCountType(String countTypes){ Y*jkUQ
this.countType=countTypes; C@XnV=J
} 4%yeEc;z
public void setCountId(int countIds){ R Ee~\n+P^
this.countId=countIds; BUI#y `J
} ;x|?N*
public String getCountType(){ _Nz?fJ:$@
return countType; Z~w?Qm:/
} `}
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public int getCountId(){ Xa'b@*o&
return countId; UBnHtsM
} xOxyz6B\
} LDo~
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CountCache.java FgP{
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/* !8
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* CountCache.java r;waT@&C
* 8v^AVg
* Created on 2007年1月1日, 下午5:01 N#Nc{WU'B
* >A L^y(G
* To change this template, choose Tools | Options and locate the template under j=Q ?d]
* the Source Creation and Management node. Right-click the template and choose @&E7Pg5
* Open. You can then make changes to the template in the Source Editor. SrdCLT8
*/ "5sUE!)f
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package com.tot.count; }lx'NY~(W
import java.util.*; }vF=XA
/** apxq] !
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* U6nC
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* @author KAT^v bR
*/ ll"6KI'X
public class CountCache { KAy uv
public static LinkedList list=new LinkedList(); ;,KT+!H$
/** Creates a new instance of CountCache */ 4kNSF
public CountCache() {} ^!(tc=sr
public static void add(CountBean cb){ M}" KAa
if(cb!=null){ )Y1+F,C
list.add(cb); '<C#"2
} W H+Sd
} .,p@ee$q
} 'A/{7*,
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CountControl.java {4R;C~E8
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/* ?,Wm|xY
* CountThread.java UPuG&A#VV
* &:C(,`~
* Created on 2007年1月1日, 下午4:57 6se[>'5
* srU*1jD)
* To change this template, choose Tools | Options and locate the template under :?3y)*J!
* the Source Creation and Management node. Right-click the template and choose ~05(92bK
* Open. You can then make changes to the template in the Source Editor. 8\`otJY
*/ *U,W4>(B
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package com.tot.count; 1[?xf4EMG
import tot.db.DBUtils; ARB^]
import java.sql.*; <5c^DA
/** cn$0^7?
* p!LaR.8]
* @author 'yAHB* rQR
*/ a/q8v P
public class CountControl{ v`"BXSmp{
private static long lastExecuteTime=0;//上次更新时间 u9}LvQh_6,
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 #|cr\\2*
/** Creates a new instance of CountThread */ G'_5UP!
public CountControl() {} s(Fxi|v;
public synchronized void executeUpdate(){ S#ud<=@!9
Connection conn=null; 1u~.^O}J
PreparedStatement ps=null; {*qz<U>
try{ HqA~q
conn = DBUtils.getConnection(); ?trqe/
conn.setAutoCommit(false); W^9=z~-h
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); (=D^BXtH|
for(int i=0;i<CountCache.list.size();i++){ aD?ySc}
CountBean cb=(CountBean)CountCache.list.getFirst(); K./L'Me
CountCache.list.removeFirst(); J35[GZ';D
ps.setInt(1, cb.getCountId()); >D$NEO^
ps.executeUpdate();⑴ ozG!OiRW
//ps.addBatch();⑵ lJ4&kF=t
} 3)~z~p7
//int [] counts = ps.executeBatch();⑶ 3%V VG~[
conn.commit(); 1GgG9I
}catch(Exception e){ z]Mu8
e.printStackTrace(); EDGAaN*Q
} finally{ p~t5PU*(
try{ +JBYGYN&K
if(ps!=null) { b@N*W]
ps.clearParameters(); McQWZ<
ps.close(); }mQh^
ps=null; v0~*?m4
} @{^6_n+gT%
}catch(SQLException e){} rt!Uix&
DBUtils.closeConnection(conn); vqBT^Q_q;
} G2_l}q~
} kF"G {5
public long getLast(){ k/#321Z
return lastExecuteTime; JclG*/Wjg4
} =M/($PA
public void run(){ 'uV;)~
long now = System.currentTimeMillis(); -]vPF|
if ((now - lastExecuteTime) > executeSep) { zE4TdT1y|
//System.out.print("lastExecuteTime:"+lastExecuteTime); vZ2/>}!Z=
//System.out.print(" now:"+now+"\n"); 4>8'.8S
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); tv7A&Z)Rh
lastExecuteTime=now; dpcFS0
executeUpdate(); Ft$tL;
} f{u3RCfX~2
else{ &H@OLyC
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); )3KQ
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} "DNiVL.
} :k.C|V!W
} Nm=\~LP90
//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 UZRCJ
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类写好了,下面是在JSP中如下调用。 O'<cEv'B*
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<% roG f
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CountBean cb=new CountBean(); n g?kl|VG
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ZzV%+n7<Vx
CountCache.add(cb); :f58JLX
out.print(CountCache.list.size()+"<br>"); sa>}wz<o
CountControl c=new CountControl(); ZA/:\6gm
c.run(); xp"5L8:C
out.print(CountCache.list.size()+"<br>"); N| L Ey
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