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: yEy6]f+>+
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CountBean.java ?:9"X$XR
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/* [{/jI\?v
* CountData.java #,'kXj
* lH~[f
* Created on 2007年1月1日, 下午4:44 *lJxH8 \
* J]r^W)O
* To change this template, choose Tools | Options and locate the template under bpa?C
* the Source Creation and Management node. Right-click the template and choose <(! :$
* Open. You can then make changes to the template in the Source Editor. &5!8F(7
*/ ZS o)
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package com.tot.count; o^wqFX(Y
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/** %\:Wi#w>
* .x&%HA
* @author MLp9y#
*/ %!#azI
public class CountBean { ]hV*r@d
private String countType; &BSn?
int countId; iH'p>s5L
/** Creates a new instance of CountData */ hgE71H\s
public CountBean() {} akTk(
public void setCountType(String countTypes){ 1k^oS$UT
this.countType=countTypes; bvOq5Q6
} ;5AcFB
public void setCountId(int countIds){ y8xE
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this.countId=countIds; EKN~H$.
} -$g#I
public String getCountType(){ ?gXp*>Kg[
return countType; PQE=D0
} :rP=t ,
public int getCountId(){ e+=K d+:k
return countId; >8[Z.fX
} z'7]h TA
} y>ktcuML
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CountCache.java 43 :X,\~)
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/* 1B\WA8
* CountCache.java 0tJZ4(0
* tT._VK]o&R
* Created on 2007年1月1日, 下午5:01 Ew$C
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* *yGGBqd
* To change this template, choose Tools | Options and locate the template under 5`_SN74o
* the Source Creation and Management node. Right-click the template and choose qcRs$-J
* Open. You can then make changes to the template in the Source Editor. f?)-}\[IR{
*/ @E8+C8'
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package com.tot.count; u]G\H!WkQ
import java.util.*; H%{+QwzZ[j
/** A?0Nm{O;3v
* O33`+UV"W
* @author ^kSqsT"
*/ 0IWf!Sk
]
public class CountCache { Gp\
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public static LinkedList list=new LinkedList(); 4{Z)8;QX
/** Creates a new instance of CountCache */ h>bx}$q
public CountCache() {} (QiAisE
public static void add(CountBean cb){ O.JN ENZf
if(cb!=null){ UL9n-M=
list.add(cb); ,]/X\t5]D
} TJ*T:?>e
} \^1E4C\":
} . 'yCw#f
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CountControl.java M'l ;:
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/* #,v{Ihn
* CountThread.java Z #m+ObHK1
* .o}v#W+st
* Created on 2007年1月1日, 下午4:57 wS3'?PRX
* a09<!0Rp
* To change this template, choose Tools | Options and locate the template under y~HP>~Oh
* the Source Creation and Management node. Right-click the template and choose #Rr%:\*
* Open. You can then make changes to the template in the Source Editor. `wU!`\
*/ XB5DPx
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package com.tot.count; x$(f7?s] 1
import tot.db.DBUtils; HtYwEj I
import java.sql.*; e8b:)"R
/** Vf1^4t
* Dum9lj
* @author -D~%|).'
*/ |vzl. ^"-
public class CountControl{ h@wgd~X9
private static long lastExecuteTime=0;//上次更新时间 Z5]>pJFq,
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 l9H!au=
/** Creates a new instance of CountThread */ 7cMv/g^h@
public CountControl() {} uXl3k:_n
public synchronized void executeUpdate(){ An/|+r\
Connection conn=null; 3irl
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PreparedStatement ps=null; '/%H3A#L
try{ H" 7u7l
conn = DBUtils.getConnection(); k~z Iy;AZ
conn.setAutoCommit(false); g#E-pdY
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); pI<f) r
for(int i=0;i<CountCache.list.size();i++){ l}M!8:UzU
CountBean cb=(CountBean)CountCache.list.getFirst(); 1yY0dOoLG)
CountCache.list.removeFirst(); S`Rs82>
ps.setInt(1, cb.getCountId()); [=`q>|;pOv
ps.executeUpdate();⑴ hK|Ul]qI
//ps.addBatch();⑵ 8Xs8A.
} I1&aM}y{G
//int [] counts = ps.executeBatch();⑶ MnW+25=N
conn.commit(); {BU;$
}catch(Exception e){ B#1;r-^P<
e.printStackTrace(); IEvdV6{K
} finally{ Jj%K=sw
try{ ""~ajy
if(ps!=null) { Yu2Bkq+
ps.clearParameters(); ht}wEvv
ps.close(); uFga~g
ps=null; #gw]'&{8D
} seeBS/%
}catch(SQLException e){} ~4cC/"q$X
DBUtils.closeConnection(conn); {H'Y `+
} o*hF<D$Y
} FHI ;)wn=
public long getLast(){ ENY+^7
return lastExecuteTime; BTrn0
} ,UE83j8D^
public void run(){ P=G3:eX
long now = System.currentTimeMillis(); uWE^hz"
if ((now - lastExecuteTime) > executeSep) { lks!w/yCF
//System.out.print("lastExecuteTime:"+lastExecuteTime); SMK_6?MZ
//System.out.print(" now:"+now+"\n"); e\75:oQ
// System.out.print(" sep="+(now - lastExecuteTime)+"\n");
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lastExecuteTime=now; RViuJ;
executeUpdate(); }*"p?L^p{
} "g8M0[7e3
else{ X!g#T9kG
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); Uf+%W;}
} Q&bM\;Ml
} ]e@Oiq
} Pk)1WK7E
//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 -A!%*9Z
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类写好了,下面是在JSP中如下调用。
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<% uM6+?A9@l
CountBean cb=new CountBean(); k"w"hg&e
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); k|d+#u[Mj@
CountCache.add(cb); jRV/A!4
out.print(CountCache.list.size()+"<br>"); v|2T%y_
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CountControl c=new CountControl(); iAU@Yg`pt
c.run(); 0:d_Yv,D
out.print(CountCache.list.size()+"<br>"); .kfIi^z
%>