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^Erj# /
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CountBean.java Uqel
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/* I8gNg
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* CountData.java f7_(C0d
* G+<XYkz*
* Created on 2007年1月1日, 下午4:44 a yoC]rE
* Ku,wI86
* To change this template, choose Tools | Options and locate the template under 0/su`
* the Source Creation and Management node. Right-click the template and choose H@uu;:l<7A
* Open. You can then make changes to the template in the Source Editor. 2#.s{ Bv
*/ `"=>lu2H
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package com.tot.count; f`hZb
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/** a}%f+`z
* O{l4 f:51
* @author =>;&M)+q
*/ 3xy2ZYw
public class CountBean { x &R9m,
private String countType; =5\*Zh1
int countId; Jo {:]:
/** Creates a new instance of CountData */ b{<?E };%
public CountBean() {} Lu}jk
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public void setCountType(String countTypes){
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this.countType=countTypes; T<B}Z11R
} >aAM&4
public void setCountId(int countIds){ gq?7O<
this.countId=countIds; J#$U<`j*G
} JVIFpN" `
public String getCountType(){ vIRT$W' O}
return countType; `q36`Wn
} lOt7ij(,L
public int getCountId(){ -0^]:
return countId; tDRR 3=9pX
} a$=~1@
} hW#^H5?
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CountCache.java NBPP?\1
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/* u#Ig!7iUu
* CountCache.java OyO]; Yk
* T`E0_ZU;
* Created on 2007年1月1日, 下午5:01 4k225~GQ:C
* w^0hVrws=,
* To change this template, choose Tools | Options and locate the template under M{L- V
* the Source Creation and Management node. Right-click the template and choose Z<;W*6J
* Open. You can then make changes to the template in the Source Editor. D&):2F^9.
*/ Cx2#
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package com.tot.count; q SNCBn '
import java.util.*; 86=W}eV1r
/** |`o|;A]
* ;5ki$)v"
* @author t$$YiO
*/ "K(cDV Q
public class CountCache { 1b~21n
public static LinkedList list=new LinkedList(); Lng. X8D
/** Creates a new instance of CountCache */ GURiW42
public CountCache() {} {IgH0+z
public static void add(CountBean cb){ C][$0
if(cb!=null){ UfX~GC;B
list.add(cb); "s0,9;
}
} dy_Uh)$$|g
} @*y4uI6&
} on7
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CountControl.java gkd4)\9
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/* A&M_ J
* CountThread.java )jOa!E"
* 3Z";a
* Created on 2007年1月1日, 下午4:57 &<;T$Y
* r,JQR)l0@V
* To change this template, choose Tools | Options and locate the template under +E</A:|}S
* the Source Creation and Management node. Right-click the template and choose _|u}^MLO
* Open. You can then make changes to the template in the Source Editor. 84WDR?
*/ )9nW`d+
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package com.tot.count; %4Lo Em=U
import tot.db.DBUtils; )YAa7\Od
import java.sql.*; ,Wd=!if
/** wnC} TWxX
* S' $;
* @author S
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*/ HXU#Ux
public class CountControl{ 4MPy}yT*
private static long lastExecuteTime=0;//上次更新时间 s;I
@En
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 G[ U5R?/
/** Creates a new instance of CountThread */ >T]9.`xhK
public CountControl() {} GKFRZWXdT
public synchronized void executeUpdate(){ 6B8!}6Ojc
Connection conn=null; :f[ w
PreparedStatement ps=null; Rj";?.R*e
try{ q\<l"b z
conn = DBUtils.getConnection(); ;D~#|CB
conn.setAutoCommit(false); t}k:wzZ@
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); le \f:
for(int i=0;i<CountCache.list.size();i++){ .6`r`|=
CountBean cb=(CountBean)CountCache.list.getFirst(); y-26\eY^P
CountCache.list.removeFirst(); C_N|o|dX
ps.setInt(1, cb.getCountId()); _G'ki.[S7
ps.executeUpdate();⑴ F:m6Mf7L
//ps.addBatch();⑵ Q!q6R^5!K
} |^-D&C(Eu
//int [] counts = ps.executeBatch();⑶ Xr
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conn.commit();
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}catch(Exception e){ T*/I4"
e.printStackTrace(); 6#Z]yk+p
} finally{ gfK_g)'2U
try{ \H .Cmm^I
if(ps!=null) { !!Ww#x~k$[
ps.clearParameters(); 5)< Y3nU~
ps.close(); =
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ps=null; tn$TyCzckW
} ~u$cX1M
}catch(SQLException e){} 7R6B}B?/
DBUtils.closeConnection(conn); b|-)p+ba
} kS_#8I
} ufk2zL8y
public long getLast(){ ,+df=>$W
return lastExecuteTime; Y0g]-B
} c/+6M
public void run(){ BlpyE[h
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long now = System.currentTimeMillis(); #qVTB@d
if ((now - lastExecuteTime) > executeSep) { ,G0"T~
//System.out.print("lastExecuteTime:"+lastExecuteTime); f~W+Rt7o
//System.out.print(" now:"+now+"\n"); *jhgCm
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); N
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lastExecuteTime=now; iT&4;W=72~
executeUpdate(); =)Hu(;Yv
} 1Z
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else{ |9XoRGgXU
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 2&*#k
} =7e!'cF[
} 0p.MH~mx
} :=*G7ZyW$
//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 Njg87tKB
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类写好了,下面是在JSP中如下调用。 v76P?[
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<% Eb~vNdPo
CountBean cb=new CountBean(); *g*"bi*
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); m19\H
CountCache.add(cb); B`)sc ~u
out.print(CountCache.list.size()+"<br>"); Y7+c/co
CountControl c=new CountControl(); I`oJOLV
c.run(); mlc8q s
out.print(CountCache.list.size()+"<br>"); -3yK>\y=|
%>