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_lF0
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CountBean.java p5\b&~
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/* apXq$wWq{D
* CountData.java 'Tn$lh
* -c
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* Created on 2007年1月1日, 下午4:44 be_t;p`3
* })Jp5vv
* To change this template, choose Tools | Options and locate the template under _]g6
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* the Source Creation and Management node. Right-click the template and choose ?`xId;}J#7
* Open. You can then make changes to the template in the Source Editor. Tym!7H2
*/ :
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package com.tot.count; y<
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/** #X+)
* YL]x>7T~4t
* @author /D12N'VaE
*/ fg2}~02n
public class CountBean { A+'j@c\&!
private String countType; (+@H !>r$$
int countId; y=CemJ[~
/** Creates a new instance of CountData */ GZ"O%:d
public CountBean() {} iiu\_ a=0b
public void setCountType(String countTypes){ No?pv"
this.countType=countTypes; Kxq~,g=t
} M1:m"#=
public void setCountId(int countIds){ L(L;z'3y
this.countId=countIds; /CP1mn6H
} :\ S3[(FV
public String getCountType(){ iH2|w
return countType; {pqm&PB04
} 8r5j~Df
public int getCountId(){ WE3l*7<@
return countId; <H.Ml>q:r
} Z1&8U=pax
} \6o
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CountCache.java W\"cp[b
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/* [30< 0
* CountCache.java *N 't ;
* 5%9&
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* Created on 2007年1月1日, 下午5:01 Gc>\L3u
* 3Cpix,Dc
* To change this template, choose Tools | Options and locate the template under 5i0<BZDTef
* the Source Creation and Management node. Right-click the template and choose B!:(*lF
* Open. You can then make changes to the template in the Source Editor. _M?:N:e
*/ }Vt5].TA
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package com.tot.count; )|:|.`H
import java.util.*; b[$>HB_Na
/** E0YXgQa
* l)?c3
* @author {w2<;YXj!
*/ F](kU#3"S
public class CountCache { "*UHit;"+{
public static LinkedList list=new LinkedList(); 1iUy*p65:
/** Creates a new instance of CountCache */ BQm H9g|2
public CountCache() {} T =:^k+
public static void add(CountBean cb){ E|No$QO)
if(cb!=null){ I)6)~[:'
list.add(cb); B!,})F$x
} T^"d%au
} b747 eR 7E
} b*$^8%
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CountControl.java 419t"1b
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/* >8ePx,+!
* CountThread.java 3]wV`mD
* c1c0b|B!U
* Created on 2007年1月1日, 下午4:57 x.'O_7c0:
* K]RkKMT,
* To change this template, choose Tools | Options and locate the template under >J4_/p>Qs
* the Source Creation and Management node. Right-click the template and choose *-2u0 %
* Open. You can then make changes to the template in the Source Editor. Q?vGg{>
*/ *'Ch(c:rtH
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package com.tot.count; )=~1m85+5B
import tot.db.DBUtils; mWtwp-
import java.sql.*; <.Pr+g
/** 0%vXPlfnY
* Tmq:,.^}
* @author BONM:(1
*/ &0M^UvO
public class CountControl{ 98x(2fCvF(
private static long lastExecuteTime=0;//上次更新时间 WFtxEIrl3j
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 $AoN,B>
/** Creates a new instance of CountThread */ =\tg$
public CountControl() {} % nJ'r?+h
public synchronized void executeUpdate(){ C0'Tua'
Connection conn=null; GMFp,Df
PreparedStatement ps=null; c" yf>0
try{ >zXw4=J
conn = DBUtils.getConnection(); V]IS(U(
conn.setAutoCommit(false); ndN8eh:OR
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); P\SE_*&
for(int i=0;i<CountCache.list.size();i++){ 9v^MZ^Y{
CountBean cb=(CountBean)CountCache.list.getFirst(); 8%Pjx7'<
CountCache.list.removeFirst(); zL1H[}[z+
ps.setInt(1, cb.getCountId()); 2OEOb,`
ps.executeUpdate();⑴ #qHo+M$"
//ps.addBatch();⑵ O GSJR`yT
} RzXxnx)]q
//int [] counts = ps.executeBatch();⑶ R:=i/P/
conn.commit(); o: TO[
}catch(Exception e){ nsYS0
e.printStackTrace(); V+_L9
} finally{ ;[&g`%-H<
try{ a Z
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if(ps!=null) { 7|\[ipVX:3
ps.clearParameters(); `XQM)A
ps.close(); ,_p_p^Ar\4
ps=null; ]ZZ7j
} JTrxh]
}catch(SQLException e){} 6X)8vQH
DBUtils.closeConnection(conn); C)Mh
} g {wDI7"<q
} JeuW/:Wv
public long getLast(){ &`{%0r[UD#
return lastExecuteTime; 5WY..60K,
} A\gj\&B0"
public void run(){ aHS.U^2
long now = System.currentTimeMillis(); R|`}z"4C
if ((now - lastExecuteTime) > executeSep) { om|M=/^
//System.out.print("lastExecuteTime:"+lastExecuteTime); yjc:+Y{5'
//System.out.print(" now:"+now+"\n"); !\^c9Pg|v
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); e%#9|/uP
lastExecuteTime=now; Bx;bc
executeUpdate(); dX` _Y
} $}N'm
else{ 9w (QM-u
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); Rax}r
} 3%>"|Ye}A
} "C%;9_ig$
} o^2.&e+dQ
//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 %/jmQ6z^
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类写好了,下面是在JSP中如下调用。 L3'o2@$
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<% 5Tkh6 s
CountBean cb=new CountBean(); =]E;wWC
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); j?#S M!f
CountCache.add(cb); 8g^OXZ
out.print(CountCache.list.size()+"<br>"); c(i-~_
CountControl c=new CountControl(); s9zdg"c'
c.run(); dyD=R
out.print(CountCache.list.size()+"<br>"); I"y=A7Nq
%>