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: PL@hsZty~c
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CountBean.java 5 qt]~v%y
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/* mHM38T9C%
* CountData.java b" 1a7
* FF0N{bY
* Created on 2007年1月1日, 下午4:44 3yszfWr
* D\}^<HW
* To change this template, choose Tools | Options and locate the template under K9njD#/
* the Source Creation and Management node. Right-click the template and choose *Cz>r}W
* Open. You can then make changes to the template in the Source Editor. /a[i:Oa#
*/ %nSm 32/t3
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package com.tot.count; 4&r[`gL
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/** 9s>q4_D
* WldlN?[j
* @author =kp#v
*/ B:\\aOEj
public class CountBean { Pv17wUB
private String countType; lG I1LUo
int countId; Aq yR+
/** Creates a new instance of CountData */ Ynl^Z
public CountBean() {} !TA6- ]1
public void setCountType(String countTypes){ (+`pEDD{X
this.countType=countTypes; 64%P}On
} aHNR0L3$}{
public void setCountId(int countIds){ [a:yKJ[
this.countId=countIds; ,|D_? D)U
} 5Ev9u),D+v
public String getCountType(){ ] JVs/
return countType; t3|If@T
} k@L},Td
public int getCountId(){ ~Z9Eb|B
return countId; lr'h
} !8 lG"l|,l
} "1FPe63\*O
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CountCache.java |`+kZ-M*
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/* Jz&a9
* CountCache.java Cc/h|4
* ,m;S-Im_Xr
* Created on 2007年1月1日, 下午5:01 Jr$,w7tQn@
* ELf cZfJ
* To change this template, choose Tools | Options and locate the template under tJ>%Xop
* the Source Creation and Management node. Right-click the template and choose N:?UA
* Open. You can then make changes to the template in the Source Editor. ]VtVw^ ir
*/ mk(O..)2
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package com.tot.count; d[E~}Dq3#
import java.util.*; #?\$*@O
/** $M{MOehZ
* Xb?:dlu3
* @author tS!FnQg4
*/ dn(I$K8
public class CountCache { [EI~/#;
public static LinkedList list=new LinkedList(); }{T9`^V:h
/** Creates a new instance of CountCache */ %sxLxx_x!
public CountCache() {} ;\ ^'}S|3Z
public static void add(CountBean cb){ Dk8
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if(cb!=null){ eG&\b-%
list.add(cb); d3-F?i
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} 2l]*><q|
} t5t,(^ ;f
} I,TJV)B
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CountControl.java R[KF${X4
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/* jBZlNEw
* CountThread.java QZ?# ixvJ
* ;wo
* Created on 2007年1月1日, 下午4:57 > %h7)}U
* % `Q[?(z
* To change this template, choose Tools | Options and locate the template under }<R,)ZV^G
* the Source Creation and Management node. Right-click the template and choose iO1ir+B\
* Open. You can then make changes to the template in the Source Editor. ;;e\"%}@=q
*/ Geyy!sr``
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package com.tot.count; [.J&@96,b
import tot.db.DBUtils; wpgO09
import java.sql.*; 1(%9)).K
/** p]h;M
* <;Q1u,Mc
* @author @Wgd(Ezd
*/ Lzmdy0!'
public class CountControl{ H#H@AY3Y
private static long lastExecuteTime=0;//上次更新时间 z=mH\!
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 W*J_PL9j
/** Creates a new instance of CountThread */ 5Ku=Xzvq
public CountControl() {}
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public synchronized void executeUpdate(){ O[}{$NXw
Connection conn=null; zs/4tNXw
PreparedStatement ps=null; `+DH@ce
try{ w`BY>Xft0
conn = DBUtils.getConnection(); K[wny0 (
conn.setAutoCommit(false); KLb"_1z
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); MWdev.m:Z
for(int i=0;i<CountCache.list.size();i++){ +85#`{ D
CountBean cb=(CountBean)CountCache.list.getFirst(); Nq]8p =e
CountCache.list.removeFirst(); o;'E("!<Z
ps.setInt(1, cb.getCountId()); CD^C}MB
ps.executeUpdate();⑴ YcQ$nZAU
//ps.addBatch();⑵ I0iTa99K
} LR:PSgy
//int [] counts = ps.executeBatch();⑶ -M]B;[^
conn.commit(); $Lj~ge3#
}catch(Exception e){ >+,w2m@0
e.printStackTrace(); Fl0(n #L
} finally{ ?'_Ty`vT
try{ 6U .A/8z
if(ps!=null) { OaTnQ|*
ps.clearParameters(); \c')9g@
ps.close(); `iHyGfm
ps=null; ]MD,{T9l\>
} u<L<o2
}catch(SQLException e){} Sg%h}]~
DBUtils.closeConnection(conn); pbCj
^
} { 6
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} -VZn`6%s
public long getLast(){ jY;T:C-T
return lastExecuteTime; Wd`*<+t]
} /esdtH$=
public void run(){ 6=cfr; BH2
long now = System.currentTimeMillis(); k8KRVXgx
if ((now - lastExecuteTime) > executeSep) { yMG(FAyu
//System.out.print("lastExecuteTime:"+lastExecuteTime); z*V 8l*
//System.out.print(" now:"+now+"\n"); su$IXI#R-&
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 9sP;s^#t7U
lastExecuteTime=now; j_I[k8z
executeUpdate(); :g%hT$,]3b
} WCNycH+1
else{ zA%YaekJ
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 2[Ofa(mkkp
} sKy3('5;
} <OH{7>V
} ` ~w|Xz
//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 =Bg $OX
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类写好了,下面是在JSP中如下调用。 jJY{np
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<% jKh:}yl4
CountBean cb=new CountBean(); }_/]f!]
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); D`|8Og
CountCache.add(cb); $e~MKLd
out.print(CountCache.list.size()+"<br>"); N#``(a
CountControl c=new CountControl(); noNJ+0S
c.run(); M)F_$
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out.print(CountCache.list.size()+"<br>"); c,2OICj
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