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: L(;WxHL
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CountBean.java X#xFFDzN
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/*
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* CountData.java _eSdnHWx
* LVIAF0kX
* Created on 2007年1月1日, 下午4:44 q:>^ "P{
* &ej8mq"\
* To change this template, choose Tools | Options and locate the template under 3>ex5
* the Source Creation and Management node. Right-click the template and choose ] U@o0
* Open. You can then make changes to the template in the Source Editor. -!RtH |P
*/ 4!62/df
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package com.tot.count; vq*Q.0 M+
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/** ]e:/"
* ubMOD<
* @author %OR|^M
*/ $lIWd
public class CountBean { _R|Ify#J
private String countType; B@Co'DV[/]
int countId; 3:/'t{ ^B
/** Creates a new instance of CountData */ xVB;s.'!
public CountBean() {} {3a&1'a0g
public void setCountType(String countTypes){ XKL3RMF9r
this.countType=countTypes; 3gWvmep1
} aIy*pmpD=
public void setCountId(int countIds){ kB:Uu}(=N
this.countId=countIds; S 6,4PP
} .%BT,$1K
public String getCountType(){ .D,p@4
return countType; |!|^ v
} Zv]x'3J#Y
public int getCountId(){ <>xJn{f0c
return countId; -Lu)'+
} 'z@ 0
} Kr'f- {
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CountCache.java hD,:w%M
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/* $yDWu"R8
* CountCache.java vgt]:$
* M4LP$N
* Created on 2007年1月1日, 下午5:01 :,;K>l^U
* l:;PXy6)
* To change this template, choose Tools | Options and locate the template under 'k;4 j|<
* the Source Creation and Management node. Right-click the template and choose B0$:b!
* Open. You can then make changes to the template in the Source Editor. _CBWb
*/ `=+^|Y}
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package com.tot.count; s..lK
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import java.util.*; c@[:V
/** k NqS8R|
* z't??6
* @author gXT9 r' k
*/ Q'l^9Bz
public class CountCache { zepop19
public static LinkedList list=new LinkedList(); ?SQE5Z
/** Creates a new instance of CountCache */ yw[ #
public CountCache() {} +cJy._pi!
public static void add(CountBean cb){ :a8 YV!X
if(cb!=null){ 7qO a
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list.add(cb); 6%`&+Lq
} |Z\R*b"
} N- e$^pST
} 3P~o"a>
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CountControl.java .M,RFC
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/* fy@avo9
* CountThread.java H>Q%"|
* &*G<a3Q
* Created on 2007年1月1日, 下午4:57 d\MLOXnLq;
* `
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* To change this template, choose Tools | Options and locate the template under lPH%Do>K
* the Source Creation and Management node. Right-click the template and choose 2Y}?P+:%>
* Open. You can then make changes to the template in the Source Editor. h'J|K^na
*/ !f>d_RG
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package com.tot.count; ]3ONFa
import tot.db.DBUtils; r`&-9"+
import java.sql.*; ?1L.:CS
/** [=O/1T
* eD$M<Eu
* @author "gd=J_Yw
*/ ^Jb
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public class CountControl{ HS'Vi9
private static long lastExecuteTime=0;//上次更新时间 Er/bO
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 Ze<K=Q%(i
/** Creates a new instance of CountThread */ UT~a&u
public CountControl() {} tqAd$:L
public synchronized void executeUpdate(){ @3fn)YQ'
Connection conn=null; W{z.?$SH
PreparedStatement ps=null; G6VF>2
try{ &<zd.~N"
conn = DBUtils.getConnection(); gh`m*@
conn.setAutoCommit(false); `&0Wv0D0
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ]v[|B
for(int i=0;i<CountCache.list.size();i++){ T|&[7%F3"
CountBean cb=(CountBean)CountCache.list.getFirst(); PFUO8>!pA\
CountCache.list.removeFirst(); }:: S0l
ps.setInt(1, cb.getCountId()); MT(o"ltQ
ps.executeUpdate();⑴ 5<I
//ps.addBatch();⑵ _X~87
} 86@c't@
//int [] counts = ps.executeBatch();⑶ 3mPjpm
conn.commit(); :^UFiUzrE
}catch(Exception e){ 'c\iK=fl
e.printStackTrace(); I%|>2}-_U
} finally{ zYXV;
try{ f}guv~K
if(ps!=null) { =U|N=/y#hJ
ps.clearParameters(); 1+b{}d
ps.close(); '
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ps=null; e \O/H<
} |AZg*T3:W
}catch(SQLException e){} yA{W
DBUtils.closeConnection(conn); zf3v5Hk
} yH][(o=2
} AM=z`0so
public long getLast(){ kq\)MQ"/X
return lastExecuteTime; .CP&bJP%
} s
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public void run(){ nRd)++
long now = System.currentTimeMillis(); 4|A>b})H
if ((now - lastExecuteTime) > executeSep) { 0$r^C6}f
//System.out.print("lastExecuteTime:"+lastExecuteTime); FP[!BUOf"
//System.out.print(" now:"+now+"\n"); }b 1cLchl
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); CJ}5T]WZ
lastExecuteTime=now; @FdSFQ/9
executeUpdate(); #plY\0E@
} ~>9_(L
else{ q2HYiH^L
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 4k./(f2+
} RN=` -*E1
} R^{)D3
} =4d (b ;
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 S/;bU:
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类写好了,下面是在JSP中如下调用。 @p\}p Y$T
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<% m%?V7-9!k
CountBean cb=new CountBean(); @F(mi1QO
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); X.`~>`8
CountCache.add(cb); !3T&4t
out.print(CountCache.list.size()+"<br>"); fM^[7;]7e
CountControl c=new CountControl(); #^+DL]*l
c.run(); "RIZV
out.print(CountCache.list.size()+"<br>"); fNGZ o
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