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: rnAQwm-8O%
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CountBean.java l9{}nz
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/* T.d1?
* CountData.java ,f*Q3 S/I
* ZZ'5BfI"I%
* Created on 2007年1月1日, 下午4:44 lo!^h]iE !
* +G:CR,Z>+
* To change this template, choose Tools | Options and locate the template under >lPWji'4;
* the Source Creation and Management node. Right-click the template and choose (8"advc6
* Open. You can then make changes to the template in the Source Editor. s#Ayl]8r
*/ p"@[2hK
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package com.tot.count; &|9K~#LVS
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/** KBC?SxJSJc
* Nyx)&T&I
* @author *jQ?(Tf
*/ '[WVP=M<XV
public class CountBean { !d.bCE~
private String countType; x-nO; L-2p
int countId; '`s+e#rs4{
/** Creates a new instance of CountData */ >U\1*F,Om,
public CountBean() {} XoNBq9Iu
public void setCountType(String countTypes){ vKO/hZBh
this.countType=countTypes; Oa.84a
} VW`SqUl
public void setCountId(int countIds){ WuuF&0?8C
this.countId=countIds; X 0vcBHh
} g1kYL$ o4
public String getCountType(){ %T6
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return countType; <uG6!P
} 5Z@0XI
public int getCountId(){ )L/0X40<.
return countId; qdnwaJ;&
} &J?:wC=E
} 2A=q{7s
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CountCache.java r'(*#
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/* c_4K
* CountCache.java b(_f{R7PY
* do.AesdXaq
* Created on 2007年1月1日, 下午5:01 ;\g0*b(
* "5HSCl$r%
* To change this template, choose Tools | Options and locate the template under W1Vy5V|M
* the Source Creation and Management node. Right-click the template and choose <k?pnBI_
* Open. You can then make changes to the template in the Source Editor. vnN0o5
*/ H)k V8wU
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package com.tot.count; baoyU#X9
import java.util.*; +)hxYLk&I
/** +OI <0
* xp? YM35
* @author ;kzjx%h
*/ {E[t(Ig
public class CountCache { j7BLMTF3v
public static LinkedList list=new LinkedList(); VUi> ]v/e
/** Creates a new instance of CountCache */ \,xa_zeO
public CountCache() {} H+{@VB
public static void add(CountBean cb){ iE?yvtr8
if(cb!=null){ b>2{F6F
list.add(cb); VqUCcT
} "Zfm4Nx"
} xa'^:H $X
} *Z$W"JP
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CountControl.java ~t<G gNI
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/* j{j5TvsrY
* CountThread.java -UM|u_
* zpD?5
* Created on 2007年1月1日, 下午4:57 k Nvb>v
* +MZI \>
* To change this template, choose Tools | Options and locate the template under D;&\)
* the Source Creation and Management node. Right-click the template and choose G^sx/H76J
* Open. You can then make changes to the template in the Source Editor. dS8ydG2
*/ g< xE}[gF
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package com.tot.count; k;B[wEW@
import tot.db.DBUtils; ]$uC~b
import java.sql.*; -{}h6r
/** y/E:6w
* 's.e"F#
* @author NB4Q,iq$
*/ UZdGV?o ?
public class CountControl{ 3G[|4v?[<_
private static long lastExecuteTime=0;//上次更新时间 "=w:LRw
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 Er;q s *f
/** Creates a new instance of CountThread */ F$-f j "jC
public CountControl() {} t.+)g-X
public synchronized void executeUpdate(){ #mU<]O
Connection conn=null; #UE}JR3g
PreparedStatement ps=null; wfv\xHG
try{ :C>iV+B j
conn = DBUtils.getConnection(); C1fd@6
conn.setAutoCommit(false); b}DC|?~M
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ,]@K,|pC)
for(int i=0;i<CountCache.list.size();i++){ t7xJ$^p[|K
CountBean cb=(CountBean)CountCache.list.getFirst(); m_;fj~m
CountCache.list.removeFirst(); O,Tp,wT
ps.setInt(1, cb.getCountId()); q9dplEe5
ps.executeUpdate();⑴ {i+
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//ps.addBatch();⑵ s=]NKJaQH
} HUMy\u84H
//int [] counts = ps.executeBatch();⑶ gV-*z}`U
conn.commit(); q1q9W@H
}catch(Exception e){ +;\w'dBi,
e.printStackTrace(); }K={HW1>
} finally{ sE'c$H
try{ b*(K;`9)B
if(ps!=null) { 8Ji`wnkXe
ps.clearParameters(); =IW!ZN_
ps.close(); ^r-d.1
ps=null; QJj='+R>
} v)T#
iw[
}catch(SQLException e){} oN[}i6^,e
DBUtils.closeConnection(conn); ]tXIe?>9
} `<|tC#<z
} \gA<yz-;N
public long getLast(){ 0zA;%oP
return lastExecuteTime; >DUTmJxv
} n
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public void run(){ UOFb.FRP>
long now = System.currentTimeMillis(); _
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if ((now - lastExecuteTime) > executeSep) { n807?FORB
//System.out.print("lastExecuteTime:"+lastExecuteTime); J;NIa[a
//System.out.print(" now:"+now+"\n"); KJV8y"^=Q
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); tT!'qL.*
lastExecuteTime=now; [|ZFei)r
executeUpdate(); yuy\T(7BN
} Pjk2tf0j`
else{ ]E-3/r$_cO
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 1I`F?MT
} 24nNRTI
} :{N*Z }]
} U#cGd\b
//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 'iF%mnJ
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类写好了,下面是在JSP中如下调用。 u178vby;l
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<% i%!<6K6UT
CountBean cb=new CountBean(); pHoHngyi&
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); r-wCAk}m*?
CountCache.add(cb); %'ah,2a%
out.print(CountCache.list.size()+"<br>"); 4~3
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CountControl c=new CountControl(); *~g*J^R}
c.run(); faDS!E' +
out.print(CountCache.list.size()+"<br>"); \HbZ~I-
%>