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: [76m gj!K
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CountBean.java zck |jhJ6
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/* "/XS3sv"s
* CountData.java e]X9"sd0=
* &(^>}&XS.<
* Created on 2007年1月1日, 下午4:44 /0YNB)
* KF-gcRh
* To change this template, choose Tools | Options and locate the template under XY QUU0R
* the Source Creation and Management node. Right-click the template and choose <ct {D|mm
* Open. You can then make changes to the template in the Source Editor. U14dQ=~b/
*/ Z*e7W O.
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package com.tot.count; 7iJk0L$]x
.r*b+rc;]
/** U ._1'pW
* =yNHJHRA#
* @author #XY]@V\
*/ c!\y\r
public class CountBean { $BBfsaJPT
private String countType; /s*>V@Q
int countId; \T]"pE+8l
/** Creates a new instance of CountData */ G7/LY TT)
public CountBean() {} Z/RUrYeb
public void setCountType(String countTypes){ Tx_(^K
this.countType=countTypes; Iq}h}Wd
} |~CnELF)
public void setCountId(int countIds){ ng<`2XgU
this.countId=countIds; tw3d>H`
} )LhO}zQ
public String getCountType(){ =<_5gR
return countType; QBn>@jq
} Yh%wf3
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public int getCountId(){ Tk2kis(n
return countId; m[7:p{
} h'fD3Gr&
} Sf'5/9<DW+
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CountCache.java q(p0#Mk,E
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/* =K>Z{%i
* CountCache.java I2DmM"-|
* aQmL=9
* Created on 2007年1月1日, 下午5:01 d=KOV;~);
* *nW9)T
* To change this template, choose Tools | Options and locate the template under 8k`zMT
* the Source Creation and Management node. Right-click the template and choose d,+n,;6Cf
* Open. You can then make changes to the template in the Source Editor. jb![ Lp
*/ i
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package com.tot.count; d$,i?d,
import java.util.*; -pGt;
/** *(MvNN*
* *_wef/==
* @author Q%xY/xH]
*/ ?(<AT]h V:
public class CountCache { pOYtN1uN|
public static LinkedList list=new LinkedList(); YPy))>Q>cK
/** Creates a new instance of CountCache */ G([vy#p
public CountCache() {} @!'H'GvA
public static void add(CountBean cb){ #Fd([Zx#.
if(cb!=null){ bg*{1^
list.add(cb); (Sv%-8?gs
} -d3y!|\>a
} td&l T(7
} Bw=[g&+o1@
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CountControl.java bX(*f>G'
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/* C|zH {.H
* CountThread.java wf@2&vJ
* Qd4T?5 vG
* Created on 2007年1月1日, 下午4:57 &P3vcB
* LI<5;oE;
* To change this template, choose Tools | Options and locate the template under ;MJ1Q
* the Source Creation and Management node. Right-click the template and choose JAz;_wS(k
* Open. You can then make changes to the template in the Source Editor. -N(MEzAE
*/ ">9CN$]J
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package com.tot.count; NFc8"7Mz}
import tot.db.DBUtils; a!K;8#xc
import java.sql.*; \-0` %k"&
/** _MEv*Q@o
* %S#"pKE6R
* @author L>b,}w
*/ "y0A<-~
public class CountControl{ y)E2=JQA/
private static long lastExecuteTime=0;//上次更新时间 ) :@%xoF5
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 :GYv9OG
/** Creates a new instance of CountThread */ s-V$N
public CountControl() {} ,AM-cwwT:u
public synchronized void executeUpdate(){ eFI4(Y
Connection conn=null; P.B'Gh#^
PreparedStatement ps=null; ]c2| m}I{:
try{ OJ 5 !+#>
conn = DBUtils.getConnection(); mD)O\.uA
conn.setAutoCommit(false); ix+x-G
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); i|^6s87"N2
for(int i=0;i<CountCache.list.size();i++){ EvmmQ
CountBean cb=(CountBean)CountCache.list.getFirst(); 1W[(+TZ&s
CountCache.list.removeFirst(); Q9>]@DrAx
ps.setInt(1, cb.getCountId()); 3@?YTez#
ps.executeUpdate();⑴ $@kw>2
//ps.addBatch();⑵ F8Wq&X#r
} 1[`<JCFClc
//int [] counts = ps.executeBatch();⑶ c7IR06E
conn.commit(); |u;PU`^-z
}catch(Exception e){ %Ab_PAw
e.printStackTrace(); se HbwO3 b
} finally{ iGMONJRO
try{ ZG<!^tj
if(ps!=null) { p d3&AsU
ps.clearParameters(); Vb9N~v
ps.close(); RAI&;"
ps=null; :Qo
} I7^X;Q
F
}catch(SQLException e){} k&s7-yY
DBUtils.closeConnection(conn); Fd&!-`T?
} PZJ
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} X2YOD2<v
public long getLast(){ ]/Qy1,
return lastExecuteTime; MwqT`;lb
} a[g|APZz
public void run(){ CZRo{2!?U
long now = System.currentTimeMillis(); \Egc5{
if ((now - lastExecuteTime) > executeSep) { QS*cd|7J;
//System.out.print("lastExecuteTime:"+lastExecuteTime); X",0VO
//System.out.print(" now:"+now+"\n"); f94jMzH9z
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); H<}eoU.
lastExecuteTime=now; :&)/vq
executeUpdate(); ld}$Tsy0
} A i){,nh`0
else{ >wO$Vu
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//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ]GPJ(+5
} otD?J= B
} .<^YE%
} /'fDXSdP
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 {WeXURp&nF
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类写好了,下面是在JSP中如下调用。 s[@>uP
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<% A=d$ir
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CountBean cb=new CountBean(); 6H,=S`V]EK
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); /JubiLEK
CountCache.add(cb); :;;WK~*#
out.print(CountCache.list.size()+"<br>"); 6oh@$.ThG
CountControl c=new CountControl(); m<"fRT!Y
c.run(); RLOQ>vYY
out.print(CountCache.list.size()+"<br>"); yUmsE-W
%>