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: e M}Xn^}
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CountBean.java he,T\};
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/* wC19
* CountData.java 3c)LBM
* _z;N|Xe
* Created on 2007年1月1日, 下午4:44 P;GUGG*W
* .Kx5Kh{
* To change this template, choose Tools | Options and locate the template under 0(n/hJ
* the Source Creation and Management node. Right-click the template and choose Xs`/q}R
* Open. You can then make changes to the template in the Source Editor. dFlx6H+R!0
*/ YeQX13C"Z
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package com.tot.count; Q["}U7j
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/** {,m!%FDL
* +q1@,LxN
* @author J<2N~$
*/ ]du pU"VV
public class CountBean { "-9YvB#
private String countType; ^>>Naid
int countId; ?Gb
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/** Creates a new instance of CountData */ <H.Ml>q:r
public CountBean() {} Z1&8U=pax
public void setCountType(String countTypes){ \6o
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this.countType=countTypes; M:A7=rO~
} 8p5u1 ;2
public void setCountId(int countIds){ <B)lV'!Bd
this.countId=countIds; I$YF55uB
} n%Fa;!S
public String getCountType(){ ,,?t>|3
return countType; a}yJ$6xi
} 'uh6?2)wG
public int getCountId(){ %!@Dop/<
return countId; hod|o1C&
} GB0] |z5
} [mhY_Hmz]
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CountCache.java Fw|5A"9'a'
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/* x`$4
* CountCache.java U7OW)tUf
* :)+cI?\#
* Created on 2007年1月1日, 下午5:01 +m"iJW0
* QDU^yVa_
* To change this template, choose Tools | Options and locate the template under 7%X$6N-X
* the Source Creation and Management node. Right-click the template and choose -" DI,o
* Open. You can then make changes to the template in the Source Editor. #JVcl $0Y
*/ j0Q;OKu
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package com.tot.count; +s`n]1HC
import java.util.*; [hs{{II
/** rVkHo*Q
* "UE'dWz
* @author UXd\Q''
*/ WHU&9N
public class CountCache { .; :[sv)
public static LinkedList list=new LinkedList(); )%*uMuF
/** Creates a new instance of CountCache */ IE3GM^7\
public CountCache() {} ^CX~>j\(
public static void add(CountBean cb){ J=()
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if(cb!=null){ &AW?!rH
list.add(cb); $v+g3+7
} X/?3ifP6I
} 3o6N&bQ b
} Qq5)|m
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CountControl.java Q?vGg{>
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/* 7-)Y\D
* CountThread.java )=~1m85+5B
* mWtwp-
* Created on 2007年1月1日, 下午4:57 <.Pr+g
* /7*u!CNm
* To change this template, choose Tools | Options and locate the template under Tmq:,.^}
* the Source Creation and Management node. Right-click the template and choose BONM:(1
* Open. You can then make changes to the template in the Source Editor. &0M^UvO
*/ 98x(2fCvF(
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package com.tot.count; $AoN,B>
import tot.db.DBUtils; =\tg$
import java.sql.*; pmfyvkLS
/** C0'Tua'
* GMFp,Df
* @author c" yf>0
*/ >zXw4=J
public class CountControl{ V]IS(U(
private static long lastExecuteTime=0;//上次更新时间 ndN8eh:OR
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 P\SE_*&
/** Creates a new instance of CountThread */ `6UW?1_Z5
public CountControl() {} 9hcZbM]
public synchronized void executeUpdate(){ \s[Uq
Connection conn=null; F`f#gpQ
PreparedStatement ps=null; qW),)i
try{ UAa2oY&
conn = DBUtils.getConnection(); g!4"3Dtdg
conn.setAutoCommit(false); \ B<(9
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); lepgmQ|oY
for(int i=0;i<CountCache.list.size();i++){ R(3V !ph
CountBean cb=(CountBean)CountCache.list.getFirst(); U1B5gjN
CountCache.list.removeFirst(); %T!UEl`v
ps.setInt(1, cb.getCountId()); je.mX /Lpj
ps.executeUpdate();⑴ JIDE]f
//ps.addBatch();⑵ Q9{%
} Z|E( !"zE9
//int [] counts = ps.executeBatch();⑶ f:e~ystm
conn.commit(); !qT.D:!@zF
}catch(Exception e){ wOINcEdx
e.printStackTrace(); haS`V
} finally{ v]c1|?9p'
try{ $$`}b^, /
if(ps!=null) { A-uEZj_RD=
ps.clearParameters(); r'-)@|
ps.close(); LDO@$jg
ps=null; ?:~ `?
} wC;N*0Th
}catch(SQLException e){} ]e 81O#t3
DBUtils.closeConnection(conn); W +C\/
} R/U"]Rc
} PoQ@9
A
public long getLast(){ u.R:/H<>~
return lastExecuteTime; v$lP?\P;}X
} (V}DPA
public void run(){ )N<>L/R
long now = System.currentTimeMillis(); sJ25<2/
if ((now - lastExecuteTime) > executeSep) { &H<-joZ)Z\
//System.out.print("lastExecuteTime:"+lastExecuteTime); !ZHPR:k|
//System.out.print(" now:"+now+"\n"); o^2.&e+dQ
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); %/jmQ6z^
lastExecuteTime=now; Fod2KS;g
executeUpdate(); L3'o2@$
} 5YJLR;
else{ Lr_+)l
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); @zW'!Ol
} d2Bn`VI
} 1P@&xcvS\
} J8~3LE
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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 WADNr8.
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类写好了,下面是在JSP中如下调用。 eLM_?9AZ!R
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<% "EDn;l-Q
CountBean cb=new CountBean(); p~En~?<
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 3T%WfS+
CountCache.add(cb); 8 }nA8 J
out.print(CountCache.list.size()+"<br>"); }r9f}yX9Q
CountControl c=new CountControl(); fo^M`a!va0
c.run(); _z#zF[%
out.print(CountCache.list.size()+"<br>"); ;VNwx(1l`
%>