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: M h}m;NI
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CountBean.java i)#dWFDTv
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/* lNh70G8^p
* CountData.java AKfDXy
* 8MtGlW%Eh
* Created on 2007年1月1日, 下午4:44 Eyqa?$R
* @n /nH?L
* To change this template, choose Tools | Options and locate the template under 'sKk"bi;0
* the Source Creation and Management node. Right-click the template and choose $( kF#
* Open. You can then make changes to the template in the Source Editor. ]:- mbgW
*/ M"Hf :9Rk
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package com.tot.count; "Gzz4D
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/** Lg.gfny[(t
* s^9Voi.y
* @author Y\P8v
*/ #p&qUw
public class CountBean { 7Q9 w?y~c
private String countType; "+nRGEs6
int countId; U9 s&
/** Creates a new instance of CountData */ 4e7-0}0
public CountBean() {} Iyn(?w
public void setCountType(String countTypes){ #gN&lY:CFn
this.countType=countTypes; bsli0FJSh'
} V)k4:H
public void setCountId(int countIds){ pYEMmZ?L
this.countId=countIds; 7xlkZF
} X`K<>0.N
public String getCountType(){ lrE5^;/s1
return countType; ? :%@vM
} ec;o\erPG
public int getCountId(){ I$G['`XX/
return countId; gz9j&W.
} JPHL#sKyz
} +3BN}
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CountCache.java SKN`2[ahD
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/* [|$h*YK
* CountCache.java {}przrU^c
* &Z@o Q
* Created on 2007年1月1日, 下午5:01 RbnVL$c
* ,[KD,)3y
* To change this template, choose Tools | Options and locate the template under &6!)jIWJ
* the Source Creation and Management node. Right-click the template and choose
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* Open. You can then make changes to the template in the Source Editor. #zs~," dRv
*/ K5h
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package com.tot.count; H%tdhu\e
import java.util.*; (%6P0*
/** >]TWXmx/w
* 9.-S(ZO
* @author C{rcs'
*/ hi(;;C9
public class CountCache { 2F.;;Ab
public static LinkedList list=new LinkedList(); ADzhNfS
/** Creates a new instance of CountCache */ 9cF[seE"0
public CountCache() {} ]%H`_8<gc
public static void add(CountBean cb){ >tr}|>
if(cb!=null){ cuITY^6
list.add(cb); q<|AZ2Ai
} tcI*a>
} (?c"$|^J
} Rhs/3O8k
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CountControl.java !Ai@$tl[S
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/* Zu[su>\
* CountThread.java q]-r@yF
* b8UO,fY q
* Created on 2007年1月1日, 下午4:57 #c!lS<z
* Ld~/u]K%V
* To change this template, choose Tools | Options and locate the template under C&%_a~
* the Source Creation and Management node. Right-click the template and choose {VRf0c
* Open. You can then make changes to the template in the Source Editor. CHX #^0m.
*/ Wac&b
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package com.tot.count; va@Lz&sAE%
import tot.db.DBUtils; k4J+J.|
import java.sql.*; r#a=@
/** oG\Vxg*
* 2[W&s&
* @author a;+9mDXx:
*/ 24eLB?H
public class CountControl{ lymCH
private static long lastExecuteTime=0;//上次更新时间 *GPiOA
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private static long executeSep=60000;//定义更新间隔时间,单位毫秒 99QU3c<.
/** Creates a new instance of CountThread */ TvbE2Q;/UL
public CountControl() {} kl:Bfs)b
public synchronized void executeUpdate(){ onzxx4bax
Connection conn=null; ON(kt3.h
PreparedStatement ps=null; qX{+oy5
try{ F JyT+
conn = DBUtils.getConnection(); q_58;Bv
conn.setAutoCommit(false); (!WD1w
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); xb8!B
for(int i=0;i<CountCache.list.size();i++){ kffcm/
CountBean cb=(CountBean)CountCache.list.getFirst(); ~]2K^bh8&
CountCache.list.removeFirst(); + ePS14G
ps.setInt(1, cb.getCountId()); kxv1Hn"`{E
ps.executeUpdate();⑴ .ioEIs g
//ps.addBatch();⑵ hwv/AnX~O
} R\[e!g*I
//int [] counts = ps.executeBatch();⑶ XSLFPTDEc
conn.commit(); 3!]rmZ-W
}catch(Exception e){ (GfZ*
e.printStackTrace(); =Xr.'(U
} finally{ KZf+MSq?
B
try{ Q~Wqy~tS
if(ps!=null) { s$j,9uRr
ps.clearParameters(); InI$:kJ
ps.close(); ww1[rCh\+
ps=null; ]/L0,^RI
} d2$IH#~9B
}catch(SQLException e){} OneY_<*a<
DBUtils.closeConnection(conn); Q=$2c[Uk
} J|7 3.&B
} >hIu2jm
public long getLast(){ &};zvo~P.
return lastExecuteTime; +NUG
} abVmkdP_s
public void run(){ eHUOU>&P]
long now = System.currentTimeMillis(); W"{N Bi
if ((now - lastExecuteTime) > executeSep) { ECmW`#Otb)
//System.out.print("lastExecuteTime:"+lastExecuteTime); Z%UP6%
//System.out.print(" now:"+now+"\n"); ,ig/s2ZG6X
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 8}:nGK|kx
lastExecuteTime=now; FS.L\MjV]U
executeUpdate(); 5b7RYV
} ]`WJOx4
else{ $6IJP\
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); Nh+ H 9
} 5z)~\;[ -
} } Q+|W=2t
} JBZ@'8eqi]
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 WcGS9`m/
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类写好了,下面是在JSP中如下调用。 ns4,@C$
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<% OY({.uV dX
CountBean cb=new CountBean(); hDGF7
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); >H,*H;6
CountCache.add(cb); owv[M6lbD
out.print(CountCache.list.size()+"<br>"); ^-'fW7[m
CountControl c=new CountControl(); _yR^*}xJb
c.run(); 1$ {SRU7l
out.print(CountCache.list.size()+"<br>"); u*9V&>o
%>