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: pH.&C 5kA
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CountBean.java TDbSK&w :s
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/* Ywv\9KL
* CountData.java $j(d`@.DN~
* hr&&b3W3p
* Created on 2007年1月1日, 下午4:44 %WKBd\O
* y$bY
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* To change this template, choose Tools | Options and locate the template under $T#fCx/
* the Source Creation and Management node. Right-click the template and choose 5-ED\-
* Open. You can then make changes to the template in the Source Editor. {tl{j1d|
*/ _yJz:pa
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package com.tot.count; %'i_iF8.
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/** SrB>_0**
* f8SO:ihXL
* @author IY8<^Q']
*/ i].E1},%
public class CountBean { TmftEw>u
private String countType; z;P#
int countId; F!g1.49""
/** Creates a new instance of CountData */ rNJU &
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public CountBean() {} v0!|TI3s
public void setCountType(String countTypes){ !hM`Oe`S
this.countType=countTypes; ;-JF b$m
} !ht2*8$lQ
public void setCountId(int countIds){ Wu<;QY($5
this.countId=countIds; @k)J
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} P7zUf
public String getCountType(){ 6M`gy|"(~
return countType; )eT>[['fm
} hu} vYA7ZH
public int getCountId(){ :j .:t
return countId; tY]?2u%)
} N>YSXh`W`y
} ?;htK_E\*
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CountCache.java DnJ `]r
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/* Nu?A>Q
* CountCache.java %*!6R:gAp
* n"aF#HR?0d
* Created on 2007年1月1日, 下午5:01 gm,AH85
* i ]8bj5j{
* To change this template, choose Tools | Options and locate the template under Vt3*~Beb
* the Source Creation and Management node. Right-click the template and choose ?wlRHVZ
* Open. You can then make changes to the template in the Source Editor. yQ[ ;.<%v
*/ 9XtO#!+48
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package com.tot.count; h!JyFc
import java.util.*; %AtT(G(n
/** L7aVj&xM
* s@iY'11
* @author o6;
*/ Z2yO /$<
public class CountCache { Cw(yp u
public static LinkedList list=new LinkedList(); D@9 +yu=S
/** Creates a new instance of CountCache */ 2)}*'_E9
public CountCache() {} 'h0>]A 2|X
public static void add(CountBean cb){ mRC3w(W
if(cb!=null){ -6I*k |%8T
list.add(cb); EVZ1Z
} `pCy:J?d>l
} LTzdg >\oJ
} @v@F%JCZ
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CountControl.java #BcUE?K*N
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/* xR%NiYNQz
* CountThread.java [^ r8P:Ad
*
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* Created on 2007年1月1日, 下午4:57 [pp|*@1T
* C7vBa<a
* To change this template, choose Tools | Options and locate the template under 0M&n3s{5I
* the Source Creation and Management node. Right-click the template and choose 1hCU"|VH:
* Open. You can then make changes to the template in the Source Editor. 0iZeU:FE
*/ ,G46i)E\
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package com.tot.count; BF2U$-k4
import tot.db.DBUtils; l4+ `x[^
import java.sql.*; e21J9e6z
/** '"\n,3h
* tbR
* @author elhP!"G
*/ aACPyfGQ
public class CountControl{ a?nK|Q=e
private static long lastExecuteTime=0;//上次更新时间 YJHb\Cf.
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 `Rfe*oAf
/** Creates a new instance of CountThread */ 5NN;Fw+
public CountControl() {} (!5Pl`:j"
public synchronized void executeUpdate(){ \/j,
Connection conn=null; s+fxv(,"c
PreparedStatement ps=null; <yEApWd;
try{ 7<)
conn = DBUtils.getConnection(); &xB9;v3
conn.setAutoCommit(false); xrBM`Bj0@
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); Kf[.@_TD<1
for(int i=0;i<CountCache.list.size();i++){ q'+ARW48
CountBean cb=(CountBean)CountCache.list.getFirst(); SE' |||B
CountCache.list.removeFirst(); DMsqTB`
ps.setInt(1, cb.getCountId()); !e<2o2~.
ps.executeUpdate();⑴ z8"1*V
//ps.addBatch();⑵ ReM]I<WuY
} v9r.w-
//int [] counts = ps.executeBatch();⑶ :;hg :Q:
conn.commit(); [sk n9$
}catch(Exception e){ ({C[RsY=6
e.printStackTrace(); p.8
} finally{ [kN_b<Pc,
try{ c-(dm:
if(ps!=null) { H<fi,"X^
ps.clearParameters(); # }}6JM
ps.close(); r^msJ|k8[
ps=null; >0ZG&W9
} 0U*f"5F
}catch(SQLException e){} *tRsm"}
DBUtils.closeConnection(conn); b+ycEs=_
} L"dN
$ A
} j}/).O
public long getLast(){ `W+-0F@Y?@
return lastExecuteTime; bfncO[Q,?
} `S-l.zSZ4B
public void run(){ hg0{x/Dgny
long now = System.currentTimeMillis(); l1<=3+d
if ((now - lastExecuteTime) > executeSep) {
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//System.out.print("lastExecuteTime:"+lastExecuteTime); .xT{Rz
//System.out.print(" now:"+now+"\n"); P/[RH e
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); `@1e{?$
lastExecuteTime=now; KGc.YUoE
executeUpdate(); J
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} u1UCe
else{ (n>Gi;u(R
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); p9 ,[kb
} 5RWqHPw+
} cH5
} sm{0o$\Z
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 A_E2v{*n
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类写好了,下面是在JSP中如下调用。 yevJA?C4 v
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<% `<v$+mG
CountBean cb=new CountBean(); Z}vDP^rf
cb.setCountId(Integer.parseInt(request.getParameter("cid")));
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CountCache.add(cb); &v;fK$=2C
out.print(CountCache.list.size()+"<br>"); .s4v*bng
CountControl c=new CountControl(); F Xr\
c.run(); _U4@W+lhX_
out.print(CountCache.list.size()+"<br>"); 5HHf3E [
%>