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: )BfAw
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CountBean.java Mrb)
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/* _h1mF<\ X^
* CountData.java S$XSei_q
* _GPl gp:
* Created on 2007年1月1日, 下午4:44 kg\>k2h
* J9S>yLQK
* To change this template, choose Tools | Options and locate the template under 6D_D' ;o
* the Source Creation and Management node. Right-click the template and choose o3}3p]S\
* Open. You can then make changes to the template in the Source Editor. UkGCyGyZ[
*/ {BU;$
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package com.tot.count; IEvdV6{K
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/** ""~ajy
* Yu2Bkq+
* @author ht}wEvv
*/ jZrq{Z<
public class CountBean { ~WV"SaA)*U
private String countType; &PtJ$0%q
int countId; "@8li^
/** Creates a new instance of CountData */ IMONgFBS
public CountBean() {} '@P^0+B!(.
public void setCountType(String countTypes){ y1L,0 ]
this.countType=countTypes; +m,yA mEEd
} 2^yU ~`#
public void setCountId(int countIds){ iO;
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this.countId=countIds; ,~W|]/b<q
} @pU)_d!pJ
public String getCountType(){ %ULr8)R;
return countType; Dv`c<+q(#
} SMK_6?MZ
public int getCountId(){ e\75:oQ
return countId;
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} RViuJ;
} }*"p?L^p{
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CountCache.java S>1Iky|
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/* 7Hu3>4<
* CountCache.java
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* K",N!koj
* Created on 2007年1月1日, 下午5:01 r]36zX v
* jrh43
\$*
* To change this template, choose Tools | Options and locate the template under v/=}B(TDF
* the Source Creation and Management node. Right-click the template and choose JqiP>4Uwm^
* Open. You can then make changes to the template in the Source Editor. jo@J}`\Zt
*/ 8Uxne2e
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package com.tot.count; du^J2m{f
import java.util.*; 8)I^ t81
/** *4Y Vv
* (Ep\Z 6*
* @author !%0 *z
*/ o{[YA}xc
public class CountCache { IPo?:1x]s
public static LinkedList list=new LinkedList(); :9 ^*
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/** Creates a new instance of CountCache */ kMd.h[X~
public CountCache() {} k$^`{6l
public static void add(CountBean cb){ `PH{syz
if(cb!=null){ VP]% Hni]
list.add(cb); B^9j@3Ux
} S{m%H{A!
} A^<iL
} PwLZkr@4^
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CountControl.java &:)Wh[
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/* ^y%T~dLkp'
* CountThread.java n.0fVV-A
* ZJs$STJ*
* Created on 2007年1月1日, 下午4:57 L;I]OC^J
* IO-Ow!
* To change this template, choose Tools | Options and locate the template under 8X|-rM{
* the Source Creation and Management node. Right-click the template and choose H_Q+&9^/
* Open. You can then make changes to the template in the Source Editor. b SU~XGPB
*/ g}',(tPMZ
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package com.tot.count; [hj6N*4y
import tot.db.DBUtils; S^ \Vgi(
import java.sql.*; /t"3!Z?BOv
/** _a T5jR=
* E~oOKQ5W
* @author Y0-n\|
*/ @I!0-OjL
public class CountControl{ *!7O~yQ
private static long lastExecuteTime=0;//上次更新时间 d-dEQKI?;
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 N<injx
/** Creates a new instance of CountThread */ e**qF=HCw
public CountControl() {} [HZv8HU|
public synchronized void executeUpdate(){ 6,{$J
Connection conn=null; ZzT9j~
PreparedStatement ps=null; Y/zj[>
try{ G<v&4/\p`M
conn = DBUtils.getConnection(); ~M4;
conn.setAutoCommit(false); ,nDaqQ-C!!
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); yaH
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for(int i=0;i<CountCache.list.size();i++){ YcpoL@ab
CountBean cb=(CountBean)CountCache.list.getFirst(); rh}J3S5vp
CountCache.list.removeFirst(); gSQJJxZ{?
ps.setInt(1, cb.getCountId()); 9mTJ|sN:e
ps.executeUpdate();⑴ pcWPH.
//ps.addBatch();⑵ v^ VitLC
} :G%61x&=Zc
//int [] counts = ps.executeBatch();⑶ wDe& 1(T^
conn.commit(); }Kbb4]t|"
}catch(Exception e){ v
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e.printStackTrace(); 0.k7oB;f(@
} finally{ W|63Ir67
try{
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if(ps!=null) { fS78>*K
ps.clearParameters(); wi6
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ps.close(); j+
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ps=null; VS8Rx.?
}
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}catch(SQLException e){} ?2Py_gkf
DBUtils.closeConnection(conn); -C?ZB}`
} L0WN\|D
} b!5~7Ub.No
public long getLast(){ XuM'_FN`A<
return lastExecuteTime; 2!=f hN
} Gu\q%'I
public void run(){ 9m~p0 ILh
long now = System.currentTimeMillis(); ;@Y;g(bw:
if ((now - lastExecuteTime) > executeSep) { 4u})+2W
//System.out.print("lastExecuteTime:"+lastExecuteTime); n8ZZ#}Nhg
//System.out.print(" now:"+now+"\n"); q'Tf,a
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); '@k+4y9q?
lastExecuteTime=now; %aVq+kC h
executeUpdate(); x-&@wMqkc
} 'kO!^6=4M
else{ 8NAON5.!
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); PBTnIU
} CN8Y\<Ar
} *mvlb
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} ;u46Z
//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 l?n\i]'
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类写好了,下面是在JSP中如下调用。 g&Vx:fOC
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<% #fn)k1
CountBean cb=new CountBean(); ,M
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cb.setCountId(Integer.parseInt(request.getParameter("cid"))); pYmk1!]/
CountCache.add(cb); %S^8c
out.print(CountCache.list.size()+"<br>"); R|87%&6']
CountControl c=new CountControl(); K} X&AJ5A
c.run(); _TQj~W<
out.print(CountCache.list.size()+"<br>"); "n5N[1bk
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