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: }we"IqLb
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CountBean.java $D45X<
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/* `yxk
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* CountData.java ZLO_5#<
* BgE]xm
* Created on 2007年1月1日, 下午4:44 b?Vu9!
* Y@pa+~[{h3
* To change this template, choose Tools | Options and locate the template under 7#<|``]zNf
* the Source Creation and Management node. Right-click the template and choose $x 2t0@
* Open. You can then make changes to the template in the Source Editor. S#ven&
*/ !Hgq7vZG
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package com.tot.count; [y:6vC
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/** u2F
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* 7&+Gv6E
* @author 20K<}:5t1
*/ H{+U; 6b
public class CountBean { NcPzmW{#;g
private String countType; 9,F(f}(t
int countId; LxG :?=O.
/** Creates a new instance of CountData */ zS?L3*u
public CountBean() {} m@yaF:
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public void setCountType(String countTypes){ K J~f ~2;
this.countType=countTypes; 8Y4YE(x5
} Bg34YmZ
public void setCountId(int countIds){ 1ra}^H}
this.countId=countIds; HM<V$
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} bbnAF*7s8
public String getCountType(){ ukZL
return countType; yyZjMnuD
} 6vmkDL8{A8
public int getCountId(){ 8T1`TGSFC
return countId; `
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} 6v.*%E*P
} {9)LHX7dN
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CountCache.java VGe/;&1h
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/* [y'jz~9c
* CountCache.java 9}": }!
* ^&.F!
* Created on 2007年1月1日, 下午5:01 fPspJug
* C~:aol i;
* To change this template, choose Tools | Options and locate the template under {)`5*sd
* the Source Creation and Management node. Right-click the template and choose &hZcjdB
* Open. You can then make changes to the template in the Source Editor. =n$,Vv4A
*/ Gd"lB*^Ht
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package com.tot.count; <FGM/e4
import java.util.*; S"fnT*:.%
/** gmrjCLj
* KUB"@wUr
* @author $H-s(3vq
*/ B_:K.]DK`
public class CountCache { lZb1kq%9g
public static LinkedList list=new LinkedList(); .'SM|r$
/** Creates a new instance of CountCache */ {U&Mo97rzX
public CountCache() {} S6Kaw
public static void add(CountBean cb){ N>@AsI
if(cb!=null){ F-2HE><+
list.add(cb); Oa*/jZjr
} A 8&%G8d
} r$*k-c9Bf
} F[Peil+|`
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CountControl.java B<_T"n'#b
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/* o%CBSm]
* CountThread.java G*Qk9bk9
* Vrz<DB^-e
* Created on 2007年1月1日, 下午4:57 ;)UZT^f`)K
* EV]exYWB
* To change this template, choose Tools | Options and locate the template under =#uXO<
* the Source Creation and Management node. Right-click the template and choose "j~=YW+l
* Open. You can then make changes to the template in the Source Editor. 9t;aJFI
*/ cITQ,ah
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package com.tot.count; AEEy49e
import tot.db.DBUtils; |f`!{=?
import java.sql.*; As78yfK
/** pcL02W|J
* Px)VDs=k
* @author lQ)ZsFs=
*/ :#b[gWl0Ru
public class CountControl{ utRvE(IbmV
private static long lastExecuteTime=0;//上次更新时间 a_FJN zL
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 {iHC;a5gb$
/** Creates a new instance of CountThread */ S[* e K
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public CountControl() {} MYjDO>(_
public synchronized void executeUpdate(){ |L0 s
Connection conn=null; $JcU0tPq0
PreparedStatement ps=null; {Uu7 @1@n
try{ tpA7"JD
conn = DBUtils.getConnection(); ,]Hn*\@p[c
conn.setAutoCommit(false); l6)*u[}E
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); i1u &-#k
for(int i=0;i<CountCache.list.size();i++){ TB1 1crE
CountBean cb=(CountBean)CountCache.list.getFirst(); {s4:V=J
CountCache.list.removeFirst(); Z+Z`J;
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ps.setInt(1, cb.getCountId()); <L:v2 8c
ps.executeUpdate();⑴ 6`F_js.a
//ps.addBatch();⑵ #|2w^Kn
} +-HaYB|p
//int [] counts = ps.executeBatch();⑶ q!}&<w~|
conn.commit(); 5Ss=z
}catch(Exception e){ .wYx_
e.printStackTrace(); %z1WdiC
} finally{ IOt!A
try{ RM QlciG
if(ps!=null) { [ bE9Y;
ps.clearParameters(); -s4qm)\
ps.close(); zn@tLLX
ps=null; F5&4x"c
} L
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}catch(SQLException e){} { 5h6nYu
DBUtils.closeConnection(conn); Zj!S('hSY
} &eyFApM[Z
} TQYud'u/
public long getLast(){ mtmtOG_/=
return lastExecuteTime; ~(G]-__B<
} F|Jo|02
public void run(){ kXv
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long now = System.currentTimeMillis(); 4z?6[Cg<
if ((now - lastExecuteTime) > executeSep) { %p@A8'b
//System.out.print("lastExecuteTime:"+lastExecuteTime); 1+Ja4`o,iS
//System.out.print(" now:"+now+"\n"); RIb<
7
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); l$MX\
lastExecuteTime=now; &vd9\Pp
executeUpdate(); [WC-EDO2lb
} v5 $"v?PT
else{ c tTbvXP
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); )|'? uN7
} CP/`ON
} jbfMTb4
} :^! wQ""
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 rzY7f: '
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类写好了,下面是在JSP中如下调用。 L 'H1\'
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<% CKrh14ul
CountBean cb=new CountBean(); @(&ki~+
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 3| g'1X}
CountCache.add(cb); b8Y1 .y"#
out.print(CountCache.list.size()+"<br>"); nA5v+d-<T
CountControl c=new CountControl(); 2'_Oi-&
c.run(); E #8 `X
out.print(CountCache.list.size()+"<br>"); A]ciox$AjW
%>