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: j_0xE;g"]
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CountBean.java "]}?{2i;
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/* w^^8*b<
* CountData.java }=fls=c/0
* u,JUMH]@
* Created on 2007年1月1日, 下午4:44 }$` PZUw>
* cuh Z_l
* To change this template, choose Tools | Options and locate the template under }oL
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* the Source Creation and Management node. Right-click the template and choose VK%
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* Open. You can then make changes to the template in the Source Editor. J]5ZWo%
*/ OU[ FiW-E
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package com.tot.count;
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/** 3'!*/UnU
* N6BEl55 &
* @author I.- I4F)D
*/ S{nBQB<
public class CountBean { Qov*xRO6
private String countType; 4k)0OQeW6
int countId; %(B6eiA
/** Creates a new instance of CountData */ g(l:>=g]?
public CountBean() {} T U^s!Tj
public void setCountType(String countTypes){ P\%aJ'f~
this.countType=countTypes; ^!Tq(t5V
} 5l]qhi3f
public void setCountId(int countIds){ [tkP2%1
this.countId=countIds; 7X8n|NZRH7
} QB#_Wn
public String getCountType(){ +wcif-
return countType; FKy2C:R(]
} %']`t-N8
public int getCountId(){ dMK\ y4#i
return countId; W?gelu]
} lz4M)pL^
} #ds@!u+&
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CountCache.java >M7(<V
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/* %=)%$n3=-M
* CountCache.java kudXwj
* 87rHW@\](
* Created on 2007年1月1日, 下午5:01 |XJ|vQGU
* 2XrYm"6w
* To change this template, choose Tools | Options and locate the template under zKQXmyO
* the Source Creation and Management node. Right-click the template and choose c@lH
* Open. You can then make changes to the template in the Source Editor. [Uw3.CVh
*/ Mo]
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package com.tot.count; a6'T]DW0W
import java.util.*; vk<4P;A(G
/** cHon' tS
* 6|Xm8,]yRw
* @author }'4aW_ta
*/ .q'{3
public class CountCache { WfYC`e7q
public static LinkedList list=new LinkedList(); \R,8xID_t
/** Creates a new instance of CountCache */ )PvB^n
public CountCache() {} _ .xicov
public static void add(CountBean cb){ ,f$ftn\~j/
if(cb!=null){ r[P+F
list.add(cb); XhmUtbs
} vP^V3
} R(IYb%L
} [s F/sa3
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CountControl.java V eLGxc
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/* ]JlM/
* CountThread.java ldr~=<hsZ
* G"U^]$(+K
* Created on 2007年1月1日, 下午4:57 0F<$Zbe2B
* LzD,]{CC5
* To change this template, choose Tools | Options and locate the template under Bh7dAV(
* the Source Creation and Management node. Right-click the template and choose j#
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* Open. You can then make changes to the template in the Source Editor. i}v3MO\X
*/ _CG
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package com.tot.count; c"pu"t@/Z
import tot.db.DBUtils; gb/<(I )
import java.sql.*; _*n
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/** k;
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* }r|$\ms
* @author `vD.5
*/ a7"Aq:IjU
public class CountControl{ bf6:J
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private static long lastExecuteTime=0;//上次更新时间 N^zFKDJG
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 TH*}Ja^/
/** Creates a new instance of CountThread */ RU% 4~WC
public CountControl() {} 0?=a$0_C
public synchronized void executeUpdate(){ WU~L#Ih.V
Connection conn=null; c. }#.-b8
PreparedStatement ps=null; rVB\\
try{ (1Klj+"p%
conn = DBUtils.getConnection(); dg4q+
conn.setAutoCommit(false); FBS]U$1
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); uEr[' >
for(int i=0;i<CountCache.list.size();i++){ [BFPIVD)h]
CountBean cb=(CountBean)CountCache.list.getFirst(); Uwg*kJ3H
CountCache.list.removeFirst(); RAFdo
ps.setInt(1, cb.getCountId()); ; - 8]
ps.executeUpdate();⑴ $tDM
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//ps.addBatch();⑵
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} Y/y`c-VO
//int [] counts = ps.executeBatch();⑶ z|O3pQn~
conn.commit(); j{Sbf04
}catch(Exception e){ F-GH?sfvi
e.printStackTrace(); [m(n-MuF
} finally{ 6@Ir|o
try{ B4x@{rtER
if(ps!=null) { d bHxc@H
ps.clearParameters(); L4v26*P
ps.close(); |};-.}u^`h
ps=null; a'?V:3 ]
} !H~PF*,hY
}catch(SQLException e){} f*Yr*yC
DBUtils.closeConnection(conn); oq2-)F2/
} sU"sd7#A
} UL`%Xx
public long getLast(){ h}=
return lastExecuteTime; ISg-?h/
} 'LC0hoV
public void run(){ ?%Gzd(YEY
long now = System.currentTimeMillis(); f s2}a
if ((now - lastExecuteTime) > executeSep) { NV`=T?1[5
//System.out.print("lastExecuteTime:"+lastExecuteTime); \2 M{R
//System.out.print(" now:"+now+"\n"); /]9(InM9/
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); rtz ]PH
lastExecuteTime=now; 8@7leAq!
executeUpdate(); 83_vo0@<6
} \Yr&vX/[p
else{ TsY
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//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); YB376/
} LKYcE;n
} L@`:mK+;
} eJE!\ucS2W
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 l4\ !J/df
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类写好了,下面是在JSP中如下调用。 p:3
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<% b?k6-r$j
CountBean cb=new CountBean(); iVA=D&eZ
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); +<fT\Oq#
CountCache.add(cb); J9lG0
out.print(CountCache.list.size()+"<br>"); VMw[M^
CountControl c=new CountControl(); fwv.^kx
c.run(); Gp2Cwyv
out.print(CountCache.list.size()+"<br>"); NGmXF_kqN
%>