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: sLTQm*jL
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CountBean.java gxI/MD~!>
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/* L*6<h
* CountData.java a ge8I$*`@
* 9'|k@i:
* Created on 2007年1月1日, 下午4:44 oGeV!hD
* rB(Q)N
* To change this template, choose Tools | Options and locate the template under A
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* the Source Creation and Management node. Right-click the template and choose r_bG+iw7p
* Open. You can then make changes to the template in the Source Editor. 7bGt'gvv
*/ r0&LjH&R
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package com.tot.count; %t9Kc9u3p
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/** 16z
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* 9"B;o
* @author U~7{q
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*/ lQ[JA[
public class CountBean { K'"s9b8
private String countType; Mjl,/-0 w
int countId; qnd] UUA^
/** Creates a new instance of CountData */ 9~K>c
public CountBean() {} U/v)6:j)4R
public void setCountType(String countTypes){ %M^Q{`
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this.countType=countTypes; W S9:*YH
} i8EKzW
public void setCountId(int countIds){ w}07u5
this.countId=countIds; Ut1s~b1
} MD4mh2
public String getCountType(){ ]5ibg"{S
return countType; T# tFzbr
} /d}5R@Oy
public int getCountId(){ 0&&P+adk
return countId; drwxrZt
} [%Dh0hOg
} Bz:Hp{7&
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CountCache.java h"2^`
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/* >:
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* CountCache.java kY4h-oZ
* DEfhR?v
* Created on 2007年1月1日, 下午5:01 R
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* xAn|OSe
* To change this template, choose Tools | Options and locate the template under ~7\`qH
* the Source Creation and Management node. Right-click the template and choose %hBw)3;l
* Open. You can then make changes to the template in the Source Editor. %$_?%X0=t
*/ vKkvB;F41
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package com.tot.count; b4ke'gx
import java.util.*; P=9sP:[f6
/** F*:H&,
* q}g0-Da
* @author 6,R<8a;Wn
*/ >Ij#+=
public class CountCache { l,b_'
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public static LinkedList list=new LinkedList(); t#]VR7]
/** Creates a new instance of CountCache */ 8L@@UUjr
public CountCache() {} e5ww~%,
public static void add(CountBean cb){ RD:LNl<0sh
if(cb!=null){ = j
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list.add(cb); '@QK<!%,
} ]<fZW"W<q
} }4Gn$'e
} R3BK\kf&
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CountControl.java Z3Xgi~c
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/* ZU9Rvtb KB
* CountThread.java 8Tc:TaL
* f+c{<fX
* Created on 2007年1月1日, 下午4:57 L#_QrR6Sny
* <%`z:G3
* To change this template, choose Tools | Options and locate the template under `-rtU
* the Source Creation and Management node. Right-click the template and choose :{xu_"nYr
* Open. You can then make changes to the template in the Source Editor. <S@2%%W
*/ kw1Lm1C
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package com.tot.count; x1#6~283
import tot.db.DBUtils; )YLZ"@
import java.sql.*; _p+q)#.W
/** ljh,%#95=
* ?3iN)*Ut
* @author (L<G=XC
*/ mx^rw*'JGC
public class CountControl{ F@X8a/;F-
private static long lastExecuteTime=0;//上次更新时间 YE@!`!`d:
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 %U97{y
/** Creates a new instance of CountThread */ Fi+,omB&
public CountControl() {} E{}eYU
public synchronized void executeUpdate(){ OadGwa\:s
Connection conn=null; QVR-`d/
PreparedStatement ps=null; >P ygUY
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try{ UWBR5
conn = DBUtils.getConnection(); ). HnK
conn.setAutoCommit(false); K5d>{c
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); xkz`is77Y@
for(int i=0;i<CountCache.list.size();i++){ q +c~Bd
CountBean cb=(CountBean)CountCache.list.getFirst(); Fw"x4w
CountCache.list.removeFirst(); dC">AW
ps.setInt(1, cb.getCountId()); IBv9xP]BZ
ps.executeUpdate();⑴ Sj4 @pMh4
//ps.addBatch();⑵ [#2z=Xg
} \88IFE
//int [] counts = ps.executeBatch();⑶ @,q<][q
conn.commit(); P-\T BS_O
}catch(Exception e){ }/.b@`Dh;
e.printStackTrace(); Y{m1\s/ o
} finally{ rP&.`m88n
try{ N5fMMi(O
if(ps!=null) { oVnHbvP1X
ps.clearParameters(); d[KG0E5`
ps.close(); [i N}W5
m
ps=null; 4*+)D8
} T(eNK
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}catch(SQLException e){} }nNCgH
DBUtils.closeConnection(conn); r6`KZ TU
} ,tOc+3Qz$
} ^(yU)k3pu
public long getLast(){ mINir-
return lastExecuteTime; 9=MxuBl
} ,W;2A0A?X
public void run(){ a 1pa#WC
long now = System.currentTimeMillis(); j}DG +M
if ((now - lastExecuteTime) > executeSep) { p4wXsOQ}
//System.out.print("lastExecuteTime:"+lastExecuteTime); 5A"OL6ty
//System.out.print(" now:"+now+"\n"); ~FZ=
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); H52] Zm
lastExecuteTime=now; I!,FxOM|$
executeUpdate(); I78huYAYA
} 0SWec7G
else{ p%y|w
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); }o#6g|"\sY
} / CVhvK
} (K->5rSU
} ^<'=]?xr
//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 C&KH.h/N
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类写好了,下面是在JSP中如下调用。 mmgIV&P
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<% 1'[_J
CountBean cb=new CountBean(); 3+$~l5LY
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ?e!mv}B_
CountCache.add(cb); ]W 6!Xw)[
out.print(CountCache.list.size()+"<br>"); n8>(m,
CountControl c=new CountControl(); q:ZF6o`Z83
c.run(); m]:|j[!*M
out.print(CountCache.list.size()+"<br>"); th(<S
%>