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: j~(rG^T
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CountBean.java p)N=
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/* G,e>dp_cPu
* CountData.java EkgS*q_
* <- Q=h?D
* Created on 2007年1月1日, 下午4:44 xI55pj*
* H`G[QC
* To change this template, choose Tools | Options and locate the template under DF-`nD
* the Source Creation and Management node. Right-click the template and choose b{=2#J-
* Open. You can then make changes to the template in the Source Editor. ~EG`[cv
*/ {O*WLZ {0
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package com.tot.count; h!?7I=p~#
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/** t>. mB@se|
* +u#;k!B/>
* @author ,OsFv}v7
*/ Eg-3GkC
public class CountBean { p [4/Nq,c
private String countType; ^\Nsx)Y;
int countId; w?d~c*4+
/** Creates a new instance of CountData */ nPj%EKdY4
public CountBean() {} 8Gzc3
public void setCountType(String countTypes){ hn#i,XnY
this.countType=countTypes; ya0L8`q
} !jL|HwlA
public void setCountId(int countIds){ O6NgI2[O
this.countId=countIds; 8rAOs\ys
} ^6bU4bA
public String getCountType(){ NOLw119K
return countType; 47ra`*
} _nOJ.G
public int getCountId(){ OW-[#r
return countId; (ec?_N0=
} abh='5H|^|
} .p NWd
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CountCache.java $73 7oV<
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/* j-8v$0'
* CountCache.java M>VT$!Lx
* N@lTn}U
* Created on 2007年1月1日, 下午5:01 ^E*W
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* sy=M#WGS
* To change this template, choose Tools | Options and locate the template under 2F[smUL
* the Source Creation and Management node. Right-click the template and choose 1Y:lFGoe
* Open. You can then make changes to the template in the Source Editor.
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*/ 3JV ENn9
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package com.tot.count; O}I8P")m
import java.util.*; =T;>$&qs
/** D0Yl?LU3
* ^AkVmsv;;
* @author 0)`{]&
*/ "K
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public class CountCache { #5-5N5-1
public static LinkedList list=new LinkedList(); u@tJu'X
/** Creates a new instance of CountCache */ 6:O3>'n
public CountCache() {} j}7as&
public static void add(CountBean cb){ ||a
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if(cb!=null){ dqMt6b\}
list.add(cb); yBqv'Y
} P,r9<
} =QFnab?N
} p\T9q
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CountControl.java qq"&Bc>
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/* 9?a-1
* CountThread.java dznHR6x
* -Zx
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* Created on 2007年1月1日, 下午4:57 ?K%&N99c!
* /fC@T
* To change this template, choose Tools | Options and locate the template under =+9.X8SP
* the Source Creation and Management node. Right-click the template and choose KKP}fN
* Open. You can then make changes to the template in the Source Editor. f_a.BTtNO
*/ xP%`QTl\
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package com.tot.count; /HbxY
import tot.db.DBUtils; $zS0]@Dj
import java.sql.*; 86igP
/** hfT HP
* ~L $B]\/A5
* @author _i{$5JJ+K2
*/ y`O !,kW
public class CountControl{ }1E'a>^|
private static long lastExecuteTime=0;//上次更新时间 P=PcO>
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 wQbN5*82
/** Creates a new instance of CountThread */ 2g5Ft
public CountControl() {} ^HYmi\`
public synchronized void executeUpdate(){ Se h[".l
Connection conn=null; tZ,vt7
PreparedStatement ps=null; u3)Oj7cX
try{ KdY3
conn = DBUtils.getConnection(); "S#4
conn.setAutoCommit(false); ru[W?O"
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 7zo)t1H1
for(int i=0;i<CountCache.list.size();i++){ vH/<!jtI
CountBean cb=(CountBean)CountCache.list.getFirst(); 37GJ}%Qs
CountCache.list.removeFirst();
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}5
ps.setInt(1, cb.getCountId()); np3$bqm
ps.executeUpdate();⑴ .J:04t1
//ps.addBatch();⑵ kXimJL_<g
} e+jp03m\W
//int [] counts = ps.executeBatch();⑶ 09z%y[z
conn.commit(); 7|4hs:4mD
}catch(Exception e){ !R*%F
e.printStackTrace(); i(R&Q;{E^
} finally{ q] g'rO'
try{ ,4W|e!
if(ps!=null) { d'ddxT$GG
ps.clearParameters(); ;AyE(|U+
ps.close(); W/_=S+CvK
ps=null; lg` Qi&
} >;V ?s]
}catch(SQLException e){} #U45H.Rz
DBUtils.closeConnection(conn); @V{s'V
}
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} ]"bkB+I
public long getLast(){ jO
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return lastExecuteTime; n5CjwLgu\b
} XQL"D)fw
public void run(){ #?%akQ+w
long now = System.currentTimeMillis(); KWtLrZ(j
if ((now - lastExecuteTime) > executeSep) { .w5#V|
//System.out.print("lastExecuteTime:"+lastExecuteTime); z
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//System.out.print(" now:"+now+"\n"); _~!*|<A_
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); l{oAqTN
lastExecuteTime=now; jR8~EI+
executeUpdate(); 8tq6.%\
} f1GV6/| m
else{ <L|eY(:
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ZqKUz5M4
} <hlH@[7!
} Y"qKe,
} Uw R,U#d
//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 H |8vW
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类写好了,下面是在JSP中如下调用。 ly`p)6#R=
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<% 6<0-GD}M
CountBean cb=new CountBean(); +g36,!q
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 'Okitq+O
CountCache.add(cb); ! K? o H
out.print(CountCache.list.size()+"<br>"); 9>~UqP9
CountControl c=new CountControl(); T&Dt;CSF
c.run(); dm3cQ<0
out.print(CountCache.list.size()+"<br>"); ^]mwL)I}
%>