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: D-7PO3F:F
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CountBean.java
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/* )$#]h]ac
* CountData.java OW(45
* cTO\Vhg
* Created on 2007年1月1日, 下午4:44 8Wn;U!qT
* wN [mU
* To change this template, choose Tools | Options and locate the template under vc.:du
* the Source Creation and Management node. Right-click the template and choose -2}-;|
* Open. You can then make changes to the template in the Source Editor. lW^bn(_gQ
*/ \Kph?l9Ww
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package com.tot.count; ~n:dHK`
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/** {shf\pm!o
* 6#S}EaWf
* @author i5 x[1
*/ bI)ItC_wf!
public class CountBean { LRO'o{4$E
private String countType; E|ce[|2
int countId; 60KhwD1
/** Creates a new instance of CountData */ tAfdbt
public CountBean() {} xtef1 8i>
public void setCountType(String countTypes){ #}50oWE
this.countType=countTypes; K1rF;7Y6
} ;=IC.<Q<}
public void setCountId(int countIds){ \\80c65-
this.countId=countIds; jd9GueV*(
} -LF0%G
public String getCountType(){
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return countType; 7\sJ=*
} `=A*ei5
public int getCountId(){ c+l1#[Dnc
return countId; c[:OK9TH
} \%nFCK0
} >[ r
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CountCache.java __p\`3(,'
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/* 3,~M`~B
* CountCache.java ^h+,Kn0@
* YqsN#E3pf
* Created on 2007年1月1日, 下午5:01 ?{s!.U[T@
* xOCHP|?
* 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 'p=5hsG
* Open. You can then make changes to the template in the Source Editor. "mbcZ5_
*/ G%
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package com.tot.count; [6@{^
import java.util.*; sY4sq5'!
/** i"=6n>\
* 1O
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* @author x`@!hJc:[e
*/ Lpw9hj|
public class CountCache { D}|PBR
public static LinkedList list=new LinkedList(); {HKd="%VG
/** Creates a new instance of CountCache */ G}aw{Vbg_
public CountCache() {} (Dr g
public static void add(CountBean cb){ IUco
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if(cb!=null){ l4+!H\2
list.add(cb); NET?Ep
} Mq-QWx"P
} 8d9&LPv
} )ndcBwQc"
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CountControl.java L8K=Q
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/* 4`F(RweGx
* CountThread.java >$=-0?.
* ?Xm!;sS0
* Created on 2007年1月1日, 下午4:57 hC ^|
* 1iq,Gd-G.
* To change this template, choose Tools | Options and locate the template under _@CY_`a
* the Source Creation and Management node. Right-click the template and choose ;Ee!vqD2
* Open. You can then make changes to the template in the Source Editor. u.(
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*/ Jy)E!{#x
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package com.tot.count;
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import tot.db.DBUtils; t0_o.S
import java.sql.*; C3kxw1*
/** m,nZrap
* a.+2h%b
* @author c|<*w[%C
*/ :fI|>I
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public class CountControl{ Js7(TFQE
private static long lastExecuteTime=0;//上次更新时间 " , c1z\
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ji(W+tQ2Y'
/** Creates a new instance of CountThread */
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public CountControl() {} 1{N73]-M:
public synchronized void executeUpdate(){ Wx#((T
Connection conn=null; <
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PreparedStatement ps=null; q[4{Xh
try{ \F]X!#&+
conn = DBUtils.getConnection(); ,L#Qy>MOb
conn.setAutoCommit(false); [Nb0&:$ay
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); `n%uvo}UT
for(int i=0;i<CountCache.list.size();i++){ '>[l1<d!G
CountBean cb=(CountBean)CountCache.list.getFirst(); CW*Kdt
CountCache.list.removeFirst(); WF0%zxg ]
ps.setInt(1, cb.getCountId()); CZB!vh0
ps.executeUpdate();⑴ /(C?3}}L
//ps.addBatch();⑵ mm-!UsT
} 3-cCdn
//int [] counts = ps.executeBatch();⑶ }ge~Nu>w
conn.commit(); 1qWIku
}catch(Exception e){ Xd%c00"U
e.printStackTrace(); !mNXPqnN
} finally{ O]{3aMs!Y
try{ VU+` yQp
if(ps!=null) { $0WO
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ps.clearParameters(); 68ce+|
ps.close(); TWF6YAQm
ps=null; RAMkTS
} x)eYqH~i
}catch(SQLException e){} ,KvF:xqA
DBUtils.closeConnection(conn); K_/8MLJQ
} $qkVu
} Wyu$J
public long getLast(){ R?"sM<3`e
return lastExecuteTime; P7GuFn/p~2
} PI{;3X}9$,
public void run(){ ;J|sH>i
long now = System.currentTimeMillis(); *,$cW,LN
if ((now - lastExecuteTime) > executeSep) { 9(?9yFbj5
//System.out.print("lastExecuteTime:"+lastExecuteTime); N3?hyR<T
//System.out.print(" now:"+now+"\n"); ~!( (?8"
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); qzk/P1{-
lastExecuteTime=now; A4RA5N/}
executeUpdate(); XWH{+c"
} W.OcmA>x
else{ 5W/!o&x~7
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); _`yd"0Ux
} :;[pl|}tM
} _ndc^OG
} ZH8O%>!
//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 V<~.:G$3H
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类写好了,下面是在JSP中如下调用。 eELJDSd
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<% =O= 0 D
CountBean cb=new CountBean(); KT1/PWa
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); oej5bAi
CountCache.add(cb); Rh!B4oB4
out.print(CountCache.list.size()+"<br>"); MfNxd
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CountControl c=new CountControl(); V1Yab#
c.run(); VC%{qal;q
out.print(CountCache.list.size()+"<br>"); ~R7F[R
%>