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: .!,T>:R
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CountBean.java {?l#*XH;
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/* z`xdRe{QP
* CountData.java o{?s\)aBa
* DK&J"0jz,
* Created on 2007年1月1日, 下午4:44 LnxJFc:1K
* *xM4nUu<~
* To change this template, choose Tools | Options and locate the template under WWc{]R^D
* the Source Creation and Management node. Right-click the template and choose P$N\o @
* Open. You can then make changes to the template in the Source Editor. RXb+"/
*/ %IW=[D6Tg
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package com.tot.count; wvcG <sj
; @-7'%(C
/** 2ME3= C
* #)hM]=,e
* @author d>)*!l2,C
*/ 9EK5#_L[=
public class CountBean { F.?^ko9d
private String countType; >"{3lDyq-
int countId; Qy*`s
/** Creates a new instance of CountData */ !CTchk<{(
public CountBean() {} I/<aY*R4
public void setCountType(String countTypes){ <E|i3\[p
this.countType=countTypes; :o&qJ%
} C\j|+s
public void setCountId(int countIds){ c#
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this.countId=countIds; ^|Of
} &o=
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public String getCountType(){ 5<GC
return countType; =" #O1$
} k!>MZ
public int getCountId(){ tVvRT*>Wb
return countId; VjBV2 x
} PiMh]
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} #Fl"#g$
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CountCache.java sikG}p0mx<
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/* w
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* CountCache.java ^9%G7J:vGO
* tz)aQ6p\X
* Created on 2007年1月1日, 下午5:01 D4ESo)15'
* p}.L]Y
* To change this template, choose Tools | Options and locate the template under S2kFdx*Zf
* the Source Creation and Management node. Right-click the template and choose T+9#P4
* Open. You can then make changes to the template in the Source Editor. -[|R\'i
*/ Nj5Mc>_
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package com.tot.count; 3u^U\xB
import java.util.*; yJ c#y
/** \ty{KAc&
* b<P9@h~:
* @author Q.>@w<[!L
*/ <[@AMd S
public class CountCache { O[U^{~iM
public static LinkedList list=new LinkedList(); |`1lCyV\tE
/** Creates a new instance of CountCache */ mQhI"3!f
public CountCache() {} 9i*t3W71]
public static void add(CountBean cb){ a"EX<6"
if(cb!=null){ PB_+:S^8
list.add(cb); B<u6Z!Pp2
} *8M0h9S$
} o|*ao2a
} l<>syHCH;L
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CountControl.java g'ha7~w(p
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/* @#hd8_)A.
* CountThread.java 7IB<0
* WUm83"
* Created on 2007年1月1日, 下午4:57 !1$QNxgi
* /bv1R5
* To change this template, choose Tools | Options and locate the template under vxhs1vh
* the Source Creation and Management node. Right-click the template and choose 7xTgG!>v
* Open. You can then make changes to the template in the Source Editor. \
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*/ brx
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package com.tot.count; Uoe;4ni
import tot.db.DBUtils; ?&
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import java.sql.*; 9fj3q>Un,
/** y3{'s>O6
* r:]t9y>$<
* @author @E
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*/ T"xq^h1\
public class CountControl{ *pK bMG#
private static long lastExecuteTime=0;//上次更新时间 8/F}vfKEN
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 AE?MEag
/** Creates a new instance of CountThread */ _y*@Hj
public CountControl() {} Mrysy)x
public synchronized void executeUpdate(){ %N$,1=0*
Connection conn=null; D!Pv`wm
PreparedStatement ps=null; v W=$C
try{ HX%lL}E
conn = DBUtils.getConnection(); F7P?*!dx
conn.setAutoCommit(false); KX D&FDkF
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); M3P\1
for(int i=0;i<CountCache.list.size();i++){ yB0xa%
CountBean cb=(CountBean)CountCache.list.getFirst(); _<s[HGA`z
CountCache.list.removeFirst(); 44C"Pl
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ps.setInt(1, cb.getCountId()); }N[|2nR'
ps.executeUpdate();⑴ r@b M3V_o
//ps.addBatch();⑵ W^#HR
} {9:[nqX
//int [] counts = ps.executeBatch();⑶ B3|h$aKC
conn.commit(); P'%#B&LZo
}catch(Exception e){ dO]N&'P7
e.printStackTrace(); E-gI'qG\(
} finally{ {w:*t)@j
try{ U4)x "s[CP
if(ps!=null) { :0@R(ct;>
ps.clearParameters(); Sk7l&B
ps.close(); nb-]fa
ps=null; %3b;`Oa
} #gn{X!;-;
}catch(SQLException e){} {9?++G"\
DBUtils.closeConnection(conn); :5|'C
} R9XISsM^
} eajctkzj
public long getLast(){ -': ;0
return lastExecuteTime; ykK21P,v
} H4RqOI
public void run(){ 2E5n07,
long now = System.currentTimeMillis(); +g %h,@
if ((now - lastExecuteTime) > executeSep) { ! |4fww
//System.out.print("lastExecuteTime:"+lastExecuteTime); cxX/ b,
//System.out.print(" now:"+now+"\n"); LX f r
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); U}f"a!
lastExecuteTime=now; DBTeV-G9~R
executeUpdate(); OM,Dy&Y
} ^97u0K3$
else{ [0c7fH`8V
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); Q/D?U[G
} JTGA\K
} /B"FGa04p(
} g
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//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 MpY/G%3
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类写好了,下面是在JSP中如下调用。 cft/;Au{
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<% hc7"0mVd{
CountBean cb=new CountBean(); X%(1C,C(
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); '`s\_Q)hG_
CountCache.add(cb); qmmQHS
out.print(CountCache.list.size()+"<br>"); ^.3(o{g
CountControl c=new CountControl(); )<ig6b%
c.run(); U$,-F**
out.print(CountCache.list.size()+"<br>"); _*iy *:(o
%>