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: hMJ \a
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CountBean.java }\u~He%
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/* -<#n7b
* CountData.java i7~oZ)w
* ej,MmLu~^
* Created on 2007年1月1日, 下午4:44 NrvS/cI!t
* '4sT+q
* To change this template, choose Tools | Options and locate the template under BO\l>\)Ir
* the Source Creation and Management node. Right-click the template and choose hBsjO3n
* Open. You can then make changes to the template in the Source Editor. c: *wev
*/ >ge-yK 1
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package com.tot.count; #},]`"n\
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/** 7kn=j6I
* {CH\TmSz
* @author F dv&kK!
*/ whKr3)
public class CountBean { P7\(D`
private String countType; kSNVI-Wzu
int countId; se_zCS4Y
/** Creates a new instance of CountData */ ^F?H)[0
public CountBean() {} _0F6mg n
public void setCountType(String countTypes){ IJ,,aCj4g
this.countType=countTypes; VhSKtD1
} zi>f436-
public void setCountId(int countIds){ ~s^&*KaA
this.countId=countIds; 1,PFz
} fJv0 B*
public String getCountType(){ %8o(x 0
return countType; QBto$!})
} ! #
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public int getCountId(){ ECkfFE`
return countId; q\#3G
} @7lZ{jV$
} 54F([w
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CountCache.java l^`!:BOtR
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/* >mF`XbS
* CountCache.java Wc3!aLNx
* |[34<tIN
* Created on 2007年1月1日, 下午5:01 C,PCU <q
* j{_MDE7N
* To change this template, choose Tools | Options and locate the template under M/V
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* the Source Creation and Management node. Right-click the template and choose +G/~v`Bv
* Open. You can then make changes to the template in the Source Editor. e^'?:j
*/ M`?/QU~
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package com.tot.count; ip5s'S~
import java.util.*; 6\o.wq
/** 66L*6O4
* SgXXitg9+
* @author [RpFC4W
*/ p'w[5'
public class CountCache { [F/x U
public static LinkedList list=new LinkedList(); xC;$/u%'
/** Creates a new instance of CountCache */ n;rOH[P
public CountCache() {} F$ h/k^
public static void add(CountBean cb){ Kg](kP
if(cb!=null){ 95]%j\
list.add(cb); X<9DE!/)
} Jy|Mfl%d
} .j&jf^a5
} %oor7 -l
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CountControl.java wFqz.HoB
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/* b1*6)
* CountThread.java c7rYG]
* D 0n2r
* Created on 2007年1月1日, 下午4:57 N ZlJ_[\$C
* q',a7Tf:
* To change this template, choose Tools | Options and locate the template under u|:VQzPd-
* the Source Creation and Management node. Right-click the template and choose #kb(2Td
* Open. You can then make changes to the template in the Source Editor. !-MG"\#Wq
*/ 1~`gfHI4
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package com.tot.count; vY;Lc
import tot.db.DBUtils; JR<R8+@g_
import java.sql.*; ,}2j
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/** %ANPv =
* t#pY2!/T3
* @author Gc 8
*/ .`h+fqa
public class CountControl{ Ck^= H
private static long lastExecuteTime=0;//上次更新时间 WG}QLcP
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 @pS[_!EqYz
/** Creates a new instance of CountThread */ d?{2A84S
public CountControl() {} 8c/Ii"1
public synchronized void executeUpdate(){ nVM`&azD
Connection conn=null; }E1Eq
PreparedStatement ps=null; 50R+D0^mh
try{ W@S9}+wl*
conn = DBUtils.getConnection(); sN?:9J8
conn.setAutoCommit(false); =:0(&NCRq
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 11-uJVO~*
for(int i=0;i<CountCache.list.size();i++){ ^y6CV4T+
CountBean cb=(CountBean)CountCache.list.getFirst(); x)U;
CountCache.list.removeFirst(); R;.WOies4
ps.setInt(1, cb.getCountId()); =& lYv
ps.executeUpdate();⑴ ut,"[+J
//ps.addBatch();⑵ *|3z($*U]
} T
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//int [] counts = ps.executeBatch();⑶ T6,lk1S'=
conn.commit();
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}catch(Exception e){ J~Ph)|AiS
e.printStackTrace(); >WEg8'#O
} finally{ nagto^5X
try{ vVf!XZF
if(ps!=null) { )/pPY
ps.clearParameters(); 5(|ud)v
ps.close(); HWU{521
ps=null; ZT8j9zs
} Oxvw`a#
}catch(SQLException e){} A&7jE:Ew
DBUtils.closeConnection(conn); `&6]P :_qp
} puyL(ohem
} j w462h
public long getLast(){ >k#aB.6
return lastExecuteTime; {2Ibd i
} +=8Po'E^!d
public void run(){ x}[` -
long now = System.currentTimeMillis(); 6qDD_:F
if ((now - lastExecuteTime) > executeSep) { NNdS:(
//System.out.print("lastExecuteTime:"+lastExecuteTime); #e=^[E-yE
//System.out.print(" now:"+now+"\n"); !58JK f
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ~S6N'$^
lastExecuteTime=now; &ivIv[LV
executeUpdate(); eC39C2q\
} =+L>^w#6=
else{ R{B~No w3
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); U,S286
}
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} <am7t[G."
} KAzRFX),
//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 TDGzXJf[
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类写好了,下面是在JSP中如下调用。 c2f$:XiM
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<% b#U%aPH
CountBean cb=new CountBean(); /km3L7L%R
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); *X-$*
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CountCache.add(cb); ;CZcY] ol
out.print(CountCache.list.size()+"<br>"); BYf"l8^,
CountControl c=new CountControl(); h:NXO'
c.run(); !;a<E:
out.print(CountCache.list.size()+"<br>"); i5" q1dRQ
%>