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: n&JP/P3Y
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CountBean.java i>}z$'X
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/* Czn7,KE8X
* CountData.java zvj\n9H
* fba3aId[
* Created on 2007年1月1日, 下午4:44 'Mtu-\
* 2e=Hjf
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* To change this template, choose Tools | Options and locate the template under Uk4">]oct
* the Source Creation and Management node. Right-click the template and choose egvWPht'_
* Open. You can then make changes to the template in the Source Editor. ]y
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*/ }% *g\%L
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package com.tot.count; 03T.Owd
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/** *qBZi;1
* /zKuVaC
* @author f
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*/ ]Re<7_xt
public class CountBean { DEhA8.v
private String countType; |Rc#Q<Vh|
int countId; &9>d
/** Creates a new instance of CountData */ Cz%ih#^b
public CountBean() {} '
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public void setCountType(String countTypes){ DSp@
this.countType=countTypes; JZ
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} +l\Dp
public void setCountId(int countIds){ Heu@{t.[!D
this.countId=countIds; 4j5 "{
} HN+z7 Q8hH
public String getCountType(){ xC(PH?_
return countType; crQuoOl7
} ;f\0GsA#
public int getCountId(){ DQd&:J@?
return countId; @,vSRns
} %qMk&1
} "fdG5|NJe
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CountCache.java @B6[RZ R
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/* /VQ<}S[k}-
* CountCache.java 9viC3bj. o
* ak zb<aT
* Created on 2007年1月1日, 下午5:01 vjb{h'v
*
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* To change this template, choose Tools | Options and locate the template under 9TLP(
* the Source Creation and Management node. Right-click the template and choose OB%y'mo7]
* Open. You can then make changes to the template in the Source Editor. 4Bz~_
*/ SL*(ZEn"
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package com.tot.count; o9CB
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import java.util.*; |8"HTBb\CW
/** -9mh|&z`
* Y`wi=(
* @author e=U7w7(s9
*/ <Ip}uy[Y
public class CountCache { YL]x>7T~4t
public static LinkedList list=new LinkedList(); yI!K
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/** Creates a new instance of CountCache */ z|Xl%8
public CountCache() {} YG_3@`-<
public static void add(CountBean cb){ I/adzLQ
if(cb!=null){ xAI<<[-
list.add(cb); JW$#~"@r
} R!O'DM+
} UU_k"D~
} >. A{=?
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CountControl.java |b@-1
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/* jm!G@k6TA
* CountThread.java li'#< "R?'
* j JW0a\0
* Created on 2007年1月1日, 下午4:57 j$,`EBf`:<
* 8p5u1 ;2
* To change this template, choose Tools | Options and locate the template under 7Y-GbG.'
* the Source Creation and Management node. Right-click the template and choose xk,E
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* Open. You can then make changes to the template in the Source Editor. B,676~I
*/ 2axH8ONMu
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package com.tot.count; B!:(*lF
import tot.db.DBUtils; OHB!ec6W
import java.sql.*; "|hmiMdGB
/** wi!Ml4Sb
*
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* @author (+_Amw!W
*/ Kh27[@s
public class CountControl{ O!a5
private static long lastExecuteTime=0;//上次更新时间 5)}xqE"x
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 yY!jkRq%w
/** Creates a new instance of CountThread */ Vry#
public CountControl() {} '1d-N[
public synchronized void executeUpdate(){ SQ@@79A
Connection conn=null; %f@]-
PreparedStatement ps=null; 9%4rO\q
try{ >4;A(s`
conn = DBUtils.getConnection(); >LjvMj ]
conn.setAutoCommit(false); _rSnp
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); R \iU)QP
for(int i=0;i<CountCache.list.size();i++){ #CM2FN:W
CountBean cb=(CountBean)CountCache.list.getFirst(); mFT[[Z#
CountCache.list.removeFirst(); c|E
ps.setInt(1, cb.getCountId()); oYu5]ry
ps.executeUpdate();⑴ b.$Gc!g
//ps.addBatch();⑵ MVV<&jho{^
} Fd2zvi
//int [] counts = ps.executeBatch();⑶ xD1w#FMlQs
conn.commit(); u ;I5n
}catch(Exception e){ mWtwp-
e.printStackTrace(); hd\iW7
} finally{ vQA: \!
try{ )4j#gHN\
if(ps!=null) { mI}'8.
ps.clearParameters(); WO]dWO6Mm
ps.close(); )5B90[M|t
ps=null; k*M1m'1
} gCd9"n-e
}catch(SQLException e){} m@OgT<E]_
DBUtils.closeConnection(conn); y>|7'M*+
} TzVNZDQ`Jl
} ndN8eh:OR
public long getLast(){ vQztD_bX%
return lastExecuteTime; =8[HC}s|$
} zL1H[}[z+
public void run(){ F`f#gpQ
long now = System.currentTimeMillis(); 1'M<{h<sP
if ((now - lastExecuteTime) > executeSep) { RzXxnx)]q
//System.out.print("lastExecuteTime:"+lastExecuteTime); yt$V<8a
//System.out.print(" now:"+now+"\n"); hb`(d_= 7F
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); V+_L9
lastExecuteTime=now; %T!UEl`v
executeUpdate(); x2;92I{5C,
} `XQM)A
else{ Z|E( !"zE9
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); )'92{-A0
} 6X)8vQH
} haS`V
} IeE+h-3p
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 ]x! vPIyq
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类写好了,下面是在JSP中如下调用。 "h\{PoG
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<% zkB_$=sbn#
CountBean cb=new CountBean(); Wk`G+VR+
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); P5kkaLzG
CountCache.add(cb); v$lP?\P;}X
out.print(CountCache.list.size()+"<br>"); 5{VrzzOK}
CountControl c=new CountControl(); {}[S,L
c.run(); gQ h;4v
out.print(CountCache.list.size()+"<br>"); 3%>"|Ye}A
%>