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: U+K_eEI0_I
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CountBean.java M1^pW63
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/* i@2?5U>h
* CountData.java e1H.2n{y^
* %>f:m!.
* Created on 2007年1月1日, 下午4:44 sB6UlX;b:
* 4U((dx*m
* To change this template, choose Tools | Options and locate the template under u+Li'Ug
* the Source Creation and Management node. Right-click the template and choose Nk7Q
* Open. You can then make changes to the template in the Source Editor. mJT7e
*/ p5*i
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package com.tot.count; "8-]6p3u
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/** xT@\FwPr
* O9opX\9
* @author [P[syi#]t
*/ 3&}wfK]X
public class CountBean { sl)_HA7G
private String countType; >iq^Ts
int countId; sI~{it#
/** Creates a new instance of CountData */ u~G,=n
public CountBean() {} 13B[mp4
public void setCountType(String countTypes){ r:u5+A
this.countType=countTypes; %N!Y}$y
} bJ9>,,D
public void setCountId(int countIds){ vHao
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this.countId=countIds; w7O(I"
} ;X\!*Loe
public String getCountType(){ ?bbguwo~F
return countType; N 4Dyec\
} = uOFaZ4
public int getCountId(){ WhvO-WF
return countId; u{I)C0
} h8n J$jg
} ]92@&J0w
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CountCache.java e`Yx]3;u(
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/* Y(<>[8S m
* CountCache.java HmQuRW
* kRG-~'f%`
* Created on 2007年1月1日, 下午5:01 N>VA`+aFR
* 0e3aWn
* To change this template, choose Tools | Options and locate the template under Dtelr=/s
* the Source Creation and Management node. Right-click the template and choose W<kJ%42^j
* Open. You can then make changes to the template in the Source Editor. l^fz
*/ .4U::j}
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package com.tot.count; KbSIKj
import java.util.*; xez~Yw2
/** /f_lWr:9l
* 5y@JMQSO
* @author wz;IKdk[
*/ 'kPShZS$b
public class CountCache { g3j@o/Y
public static LinkedList list=new LinkedList(); w,D(zk$
/** Creates a new instance of CountCache */ jiz"`,-},O
public CountCache() {} y~;Kf0~
public static void add(CountBean cb){ %KRAcCa7
if(cb!=null){ ]M>mwnt+
list.add(cb); Z&YW9de@
} H$WuT;cTE
} Q+gQ"l,95
} YWjw`,EA(
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CountControl.java u Q. m[y
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/* DTPYCG&%
* CountThread.java ho;Km
* *tO7A$LDT
* Created on 2007年1月1日, 下午4:57 V)oUSHillH
* e@F9'z4
* To change this template, choose Tools | Options and locate the template under =i4 Ds
* the Source Creation and Management node. Right-click the template and choose 1Y_Cd
* Open. You can then make changes to the template in the Source Editor. 6$lj$8\
*/ ,GA2K .:#
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package com.tot.count; ~8o's`
import tot.db.DBUtils; 0jF~cV
import java.sql.*; D4?5% s
/** 5^~%10=
* 2xN1=ug
* @author LkD$\i
*/ h S/oOeG<Y
public class CountControl{ G>qzAgA
private static long lastExecuteTime=0;//上次更新时间 b)tvXiO1>
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 S~.:B2=5K
/** Creates a new instance of CountThread */ %qfql
public CountControl() {} qM~ev E$%
public synchronized void executeUpdate(){ Q-k{Lqa-
Connection conn=null; \cP\I5IW:s
PreparedStatement ps=null; :n4?
try{ bwR24>8lP
conn = DBUtils.getConnection(); hiZE8?0+~N
conn.setAutoCommit(false); !~u;CMR
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); L1
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for(int i=0;i<CountCache.list.size();i++){ gNY}`'~hr
CountBean cb=(CountBean)CountCache.list.getFirst(); T0J"Wr>WY
CountCache.list.removeFirst(); 7{e0^V,\k
ps.setInt(1, cb.getCountId()); `j{q$Y=AG
ps.executeUpdate();⑴ y w)q3zC
//ps.addBatch();⑵ YKk?BQ"
} /B73|KB+
//int [] counts = ps.executeBatch();⑶ dq}60
conn.commit(); B#9rqC
}catch(Exception e){ (\}>+qS[
e.printStackTrace(); 5}@6euT5$
} finally{ @.T(\Dq^
try{ P#m/b<
if(ps!=null) { _-$O6eZ
ps.clearParameters(); xs_l+/cZ
ps.close(); yNMnByg3?
ps=null; Nn5z
} i>#[*.|P
}catch(SQLException e){} o_>id^$>B
DBUtils.closeConnection(conn); !g{9]"Z1T
} 5|&8MGW-$
} P[6@1
public long getLast(){ 7714}%Z
return lastExecuteTime; oace!si
} N%
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public void run(){ 8@S7_x
long now = System.currentTimeMillis(); U+gOojRy{
if ((now - lastExecuteTime) > executeSep) { 22lC^)`TE
//System.out.print("lastExecuteTime:"+lastExecuteTime); vX|ZPn#
//System.out.print(" now:"+now+"\n"); +Gv{Apd"
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); *ILx-D5qr
lastExecuteTime=now; EooQLZ
executeUpdate(); fZ!fwg$
} e]R`B}vO
else{ Mr'P0^^
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); )2t!=
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} P[{qp8(g
} &iCE/
} "'/:Tp)
//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 l1BbL5#1Q>
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类写好了,下面是在JSP中如下调用。 m:|jv|f
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<% $OOZ-+8
CountBean cb=new CountBean(); J!r,ktO^U?
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ^3B)i=
CountCache.add(cb); vowU+Y
out.print(CountCache.list.size()+"<br>"); |Y#KMi ~
CountControl c=new CountControl(); Omy4Rkj8bh
c.run(); wcz|Zy
out.print(CountCache.list.size()+"<br>"); t<S]YA~N'
%>