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: Xwg|fr+p
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CountBean.java _]"5]c&*3
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/* wff&ci28
* CountData.java $B6"fYiDk
* k,L ,
* Created on 2007年1月1日, 下午4:44
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* \dyJ=tg
* To change this template, choose Tools | Options and locate the template under _Ee`Uk
* the Source Creation and Management node. Right-click the template and choose {gE19J3
* Open. You can then make changes to the template in the Source Editor. *t;'I -1w^
*/ s!\uR.
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package com.tot.count; 73$^y)AvY
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/** r( _9_%[
* Gy9+-7"V
* @author uiO7sf6
*/ W;]*&P[[
public class CountBean { dbTPY`
private String countType; |bQX9|L
int countId; ,x| 4nk_
/** Creates a new instance of CountData */ m6BIQ(l
public CountBean() {} h[D"O6 y
public void setCountType(String countTypes){ (k9{&mPJ
this.countType=countTypes; ]Dm'J%P0}
} D nA}!s
public void setCountId(int countIds){ SxMrX C*
this.countId=countIds; vUGEzC M
} N[%^0T$
public String getCountType(){ 6i/x"vl>
return countType; ~X^L3=!vf
} [>P@3t(/
public int getCountId(){ ^$):Xz
return countId; T}(J`{9i
} .6%-Il
} FbB>
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CountCache.java tBgB>-h(
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/* od{b]HvgS
* CountCache.java y]5O45E0
* I_mnXd;n
* Created on 2007年1月1日, 下午5:01 j]EeL=H<P
* a3i4eGT -
* To change this template, choose Tools | Options and locate the template under 2R&msdF
* the Source Creation and Management node. Right-click the template and choose .__X-+^
* Open. You can then make changes to the template in the Source Editor. 5qkG~YO-
*/ _94|^
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package com.tot.count; /,'D4s:Gg
import java.util.*; O/^7TBTn<r
/** 75~>[JM
* ffK A
* @author x^kV;^ I
*/ :ND5po#(
public class CountCache { *TY?*H
public static LinkedList list=new LinkedList(); 7/lXy3B4
/** Creates a new instance of CountCache */ T:aYv;#0
public CountCache() {} c&.>SR')
public static void add(CountBean cb){ !Q!==*1H
if(cb!=null){ Hu|;cbK
list.add(cb); ahNpHTPa
} Ml1sE,BT
} <rc? EV
} 5v4
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CountControl.java K_
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/* y^:!]-+
* CountThread.java WpE\N0Yg
* bX%9'O [-
* Created on 2007年1月1日, 下午4:57 7A|n*'[T>
* hjywYd]8
* To change this template, choose Tools | Options and locate the template under
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* the Source Creation and Management node. Right-click the template and choose lz.ta!6
* Open. You can then make changes to the template in the Source Editor. MXsSF|-
*/ N;ed_!
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package com.tot.count; d^sS{m\
import tot.db.DBUtils; ~a KxwH
import java.sql.*; ?sV0T)uk
/** )IQa]A
* )%lPa|7s
* @author [V_Z9-f*
*/ bhaIi>W~G
public class CountControl{ K^j7T[pR
private static long lastExecuteTime=0;//上次更新时间 \EF^Ag
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 4$LVl
/** Creates a new instance of CountThread */ '+LbFGrO3
public CountControl() {} ca/AScL
public synchronized void executeUpdate(){ Jylav:
Connection conn=null; T)J=lw
PreparedStatement ps=null; n}cjVH5
try{ |T<t19
conn = DBUtils.getConnection(); XnmQp)nyV
conn.setAutoCommit(false); P!@b:.$
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); Q@gmtAp
for(int i=0;i<CountCache.list.size();i++){ 3B#qQ#
CountBean cb=(CountBean)CountCache.list.getFirst(); _]btsv\)f
CountCache.list.removeFirst(); `,|"rn#S
ps.setInt(1, cb.getCountId()); [%'yHb~<
ps.executeUpdate();⑴ U:xY~>
//ps.addBatch();⑵ +jQHf-l
} c3,YA,skb!
//int [] counts = ps.executeBatch();⑶ aI]EwVz-q
conn.commit(); {\3ZmF
}catch(Exception e){ F]kn4zr
e.printStackTrace(); z97RNT|Y7U
} finally{ Os--@5e
try{ tB4dkWt.}
if(ps!=null) { f& P'Kxj_
ps.clearParameters(); 0Z9>%\km_
ps.close(); ^]}+s(
ps=null; *#p}>\Y{
} T.\=R
}catch(SQLException e){} EaaLN<i@0
DBUtils.closeConnection(conn); ' jAX&7G`
} J{fTx@?(
} 7.Df2_)
public long getLast(){ M4[(.8iE
return lastExecuteTime; 8i:E$7e tH
} w1tWyKq
public void run(){ /U\k<\1~m
long now = System.currentTimeMillis(); s`Z|
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if ((now - lastExecuteTime) > executeSep) { F(+,M~
//System.out.print("lastExecuteTime:"+lastExecuteTime); g{{DC )>
//System.out.print(" now:"+now+"\n"); a=n*}.
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); @I_!q*
lastExecuteTime=now; %0 cFs'
executeUpdate(); oD1rt>k
} LsB|}_j7
else{ A=8%2UwI
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); WUnz
} e$'|EE.=q+
} |6@s6]%X}
} +/+:D9j ,
//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 4yy9m8/
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类写好了,下面是在JSP中如下调用。 +S/OMkC
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<% _Sa7+d(
CountBean cb=new CountBean(); *?Hc8y-dG,
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); aY:u-1
CountCache.add(cb); 5dwC~vn}c
out.print(CountCache.list.size()+"<br>"); Lg6;FbY?
CountControl c=new CountControl(); haNi[|
c.run(); 2>`m1q:
out.print(CountCache.list.size()+"<br>"); ~4-:;8a
%>