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: BK'!WX
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CountBean.java tp.qh]2c
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/* y\Z-x
* CountData.java 8fdK|l w
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* Created on 2007年1月1日, 下午4:44 }q( IKH\&
* iw(\]tMt
* To change this template, choose Tools | Options and locate the template under V\kf6E
* the Source Creation and Management node. Right-click the template and choose qb
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* Open. You can then make changes to the template in the Source Editor. v5t`?+e
*/ y )v'0q
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package com.tot.count; Qko}rd_M
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/** *4^!e/
* 'B"kUh%3$5
* @author (o\:rLZu
*/ '7W?VipU
public class CountBean { fwI Zr~l
private String countType; U3^T.i"R
int countId; eN%Ks
/** Creates a new instance of CountData */ Y:VM5r)
public CountBean() {} I ,AI$A
public void setCountType(String countTypes){ 3yXF|
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this.countType=countTypes; &,fBg6A%
} Z$,1Tk"O/s
public void setCountId(int countIds){ dox QS ohS
this.countId=countIds; "$#x+|PyC
} 'W$jHs
public String getCountType(){ f$k#\=2%
return countType; )4a&OlEI
} CPGXwM=
public int getCountId(){ e@L'H)w,
return countId; h2KXW}y"4
} 6kjBd3
} |J`YFv
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CountCache.java ^G#=>&,
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/* ;=Bf&hY&
* CountCache.java -Tk~c1I#`
* ha'oLm#
* Created on 2007年1月1日, 下午5:01 @yB!? x
* gB<p
* To change this template, choose Tools | Options and locate the template under Gn;eh~uw;l
* the Source Creation and Management node. Right-click the template and choose +
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* Open. You can then make changes to the template in the Source Editor. `ivr$b#
*/ m7e$Z
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package com.tot.count; "aP>}5<h
import java.util.*; E+"INX7
/** @}x)>tqD
* bsPw Tp^
* @author 1(!QutEb
*/ [ WZ<d^L
public class CountCache { G_[|N>
public static LinkedList list=new LinkedList(); *Yvfp{B
/** Creates a new instance of CountCache */ $Kb-mFR
public CountCache() {} 788q<7E
public static void add(CountBean cb){ ,+*8@>c
if(cb!=null){ r,MgIv(L
list.add(cb); iAT&C`,(&
} #0L:h?L
} !HqIi@>8
} ,US~p_M!
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CountControl.java *=S\jek
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/* K~@-*8%
* CountThread.java X&M4c5Li
* =YZp,{T
* Created on 2007年1月1日, 下午4:57 Sd^e!?bp
* ,h5.Si>
* To change this template, choose Tools | Options and locate the template under 3VA8K@QiRm
* the Source Creation and Management node. Right-click the template and choose S5v>WI^0h
* Open. You can then make changes to the template in the Source Editor. Q_6./.GQ
*/ P}&7G-
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package com.tot.count; |RAi6;
import tot.db.DBUtils; yi# Nrc5B
import java.sql.*; `-s+ zG
/** J}`K&DtM9
* 9T|7edl
* @author D/{Tl
*/ o|l)oc6{
public class CountControl{ n1uJQt
private static long lastExecuteTime=0;//上次更新时间 v2EM| Q xp
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 w>H!H6Q
/** Creates a new instance of CountThread */ \fU{$
public CountControl() {} x7Ly,
public synchronized void executeUpdate(){ zmf5!77
Connection conn=null; A>OL5TCl
PreparedStatement ps=null; w*#k&N[X
try{ WqY:XE+?\
conn = DBUtils.getConnection(); ;csAhkf:S
conn.setAutoCommit(false); xYM/{[
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ^lRXc.c z
for(int i=0;i<CountCache.list.size();i++){ x}N+vK
CountBean cb=(CountBean)CountCache.list.getFirst(); fPK|Nw]b
CountCache.list.removeFirst(); ]v94U b
ps.setInt(1, cb.getCountId()); ID'@}69.S
ps.executeUpdate();⑴ !&E>8h
//ps.addBatch();⑵ cKF02?)TX
} lUCdnp;w'
//int [] counts = ps.executeBatch();⑶ %~^R Iwm
conn.commit(); [JMz~~F
}catch(Exception e){ }%$9nq3
e.printStackTrace(); 0gO2^m)W
} finally{ kZ`60X%wE
try{ b
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if(ps!=null) { 8DLR
ps.clearParameters(); U@m<
ps.close(); \~jt7 Q
ps=null; MZ+8wr/y
} 3Eiy/
}catch(SQLException e){} fn#b3ee
DBUtils.closeConnection(conn); dWD9YIYf
} }Ss#0Gee
} >\}2("bv
public long getLast(){ lJKhP
return lastExecuteTime; N1P[&lR
} k@4]s_2
public void run(){ `x6 i5mp
long now = System.currentTimeMillis(); a2Q9tt>Q
if ((now - lastExecuteTime) > executeSep) { fRaVY`|wK
//System.out.print("lastExecuteTime:"+lastExecuteTime); b%,5B
//System.out.print(" now:"+now+"\n"); A{9Hm:)
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); |%&WYm6
lastExecuteTime=now; jW2z3.w
executeUpdate(); pl
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} VC>KW{&J0
else{ dldM hT$
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); nm %ka4
} Rc?wIL)
} G*ym[
} pgU54Ef
//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 te" 8ZmJ
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类写好了,下面是在JSP中如下调用。 vWe)c J
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<% _~Lhc'^p*
CountBean cb=new CountBean(); s}`=pk/FM
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); V%e'H>EC
CountCache.add(cb); YaSwn3i/@S
out.print(CountCache.list.size()+"<br>"); v[m/>l2[P
CountControl c=new CountControl(); ZwO&G\A^
c.run(); n8zUL1:R
out.print(CountCache.list.size()+"<br>"); S5m1~fz
%>