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: V3a6QcG
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CountBean.java m9&%A0
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/* P7/Xh3
* CountData.java E?BF8t_fTE
* hy$VG%b;#
* Created on 2007年1月1日, 下午4:44 f4+wP/n&
* m^TN6/])
* To change this template, choose Tools | Options and locate the template under ObS#aRq
* the Source Creation and Management node. Right-click the template and choose a{rUk%x
* Open. You can then make changes to the template in the Source Editor. J}#2Wy^{
*/ W5:fY>7
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package com.tot.count; }? c%L8\
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/** =9^}>u
* w8J8III\~
* @author Zt=P 0
*/ +KNd%AJ
public class CountBean { EdSUBoWF}
private String countType; zM<L_l&
int countId; +qT+iHa|n
/** Creates a new instance of CountData */ R?- zJ ;
public CountBean() {} y"U)&1 c%
public void setCountType(String countTypes){ BB(v,W
this.countType=countTypes; DVKb`KJ"
} `R.Pz _oe
public void setCountId(int countIds){ hk
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this.countId=countIds; UTN[!0[
} .P?n<n#
public String getCountType(){ g)|vS>^~
return countType; k"/Rjd(;
} 9e
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public int getCountId(){ [fo#){3K
return countId; A^LS^!Jz
} ucU7
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} N`N?1!fM<}
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CountCache.java *W>, 98
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/* "5sA&^_#_
* CountCache.java +*Uv+oC|
* KU+\fwYpnk
* Created on 2007年1月1日, 下午5:01 9$C?)XKXB
* X')l04P@%
* 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 DQ[7p(
* Open. You can then make changes to the template in the Source Editor. d&f!\n_~
*/ 3?L[ohKH?:
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package com.tot.count; >+Iph2]
import java.util.*; nLv~)IQ}:
/** Fpeokr"i
* de.f?y
* @author n4}e!
*/ twbxi{8e.
public class CountCache { 8ZM#.yBB
public static LinkedList list=new LinkedList(); GU/-L<g
/** Creates a new instance of CountCache */ P4eH:0=#
public CountCache() {} Q7<VuXy
public static void add(CountBean cb){ U|\ .)h=
if(cb!=null){ 6KXW]a `
list.add(cb); c14d0x{
} B
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} <hTHY E=
} #M+_Lk3
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CountControl.java .]JIo&>5
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/* n~}[/ly
* CountThread.java k)X\z@I'
* W3\E;C-g0
* Created on 2007年1月1日, 下午4:57 2 >j0,2
* YPNW%N!$|
* To change this template, choose Tools | Options and locate the template under -/0\_zq7
* the Source Creation and Management node. Right-click the template and choose e5n]@mu%
* Open. You can then make changes to the template in the Source Editor. <mVFC
*/ 3
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package com.tot.count; MuP>#Vk
import tot.db.DBUtils; 3]9Rmx
import java.sql.*; ,9_O4O%
/** %N`_g' r!
* z9g6%RbwX
* @author fiD,HGx
i
*/ B$x@I\(M
public class CountControl{ i'"#{4I
private static long lastExecuteTime=0;//上次更新时间 Rt&5s)O'
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 y@1QVt04
/** Creates a new instance of CountThread */ (6:.u.b
public CountControl() {} Th*}U&
public synchronized void executeUpdate(){ 0chpC)#Q3;
Connection conn=null; l}/&6hI+d
PreparedStatement ps=null; 8TP~=qU
try{ '`2MxRP
conn = DBUtils.getConnection(); xa<KF
conn.setAutoCommit(false); O"\_%=X9
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); bGK*1FlH
for(int i=0;i<CountCache.list.size();i++){ k<+Sj
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CountBean cb=(CountBean)CountCache.list.getFirst(); d
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CountCache.list.removeFirst(); U=69q]
ps.setInt(1, cb.getCountId()); B7|%N=S%/
ps.executeUpdate();⑴ <j,3Dn
//ps.addBatch();⑵ e.%I#rNI
} &ni#(
//int [] counts = ps.executeBatch();⑶ WG,1%=M@
conn.commit(); ^,AE;ZT7
}catch(Exception e){ Q@>1z*'I
e.printStackTrace(); C<I?4WM
} finally{ Qzo -Yw`=
try{ H.'9]*
if(ps!=null) { C7* YZe
ps.clearParameters(); W;UPA~nT~
ps.close(); !X~NL+
ps=null; 7iwck.*
} j%-Ems*H
}catch(SQLException e){} SOM? 0.
DBUtils.closeConnection(conn); C/qKa[mg
} @fp@1n
} k3@d
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public long getLast(){ i$@xb_
return lastExecuteTime; yI#qkl-
} jl(D;JnF
public void run(){ E QU@';~8
long now = System.currentTimeMillis(); fDplYn#
if ((now - lastExecuteTime) > executeSep) { *ls6k`ymL
//System.out.print("lastExecuteTime:"+lastExecuteTime); .!Z5A9^
//System.out.print(" now:"+now+"\n"); KW[y+c u.#
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); Us'JMZ~
lastExecuteTime=now; 3Wbd=^hRvq
executeUpdate(); etiUt~W
} 1Td`S1'#yg
else{ .S#i/A'x
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); R.HvqO
} zF[Xem
} !-470J
} i7r)9^y
//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 7 =}tJ
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类写好了,下面是在JSP中如下调用。 Tgtym"=xd
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<% Y<VX.S2kf
CountBean cb=new CountBean(); eaDZ^Z
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cb.setCountId(Integer.parseInt(request.getParameter("cid"))); MZ-;'w&Z
CountCache.add(cb); 'l~7u({u
out.print(CountCache.list.size()+"<br>"); Kb<c||2Nh5
CountControl c=new CountControl(); ]1d)jWG
c.run(); _BJ:GDz>
out.print(CountCache.list.size()+"<br>"); A>upT'
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