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: u\K`TWb%
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CountBean.java efyGjfoO
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/* M\08 7k
* CountData.java w\JTMS$
* &61h*s
* Created on 2007年1月1日, 下午4:44 -9 |)O:
* rB =c
* To change this template, choose Tools | Options and locate the template under :K*/
* the Source Creation and Management node. Right-click the template and choose ;A?86o'?
* Open. You can then make changes to the template in the Source Editor. AB.ZmR9|
*/ [xDn=)`{V
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package com.tot.count; 7%|HtBXv^
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/** $3Sm?
* @ +>>TGC
* @author nI`9|W
*/ hC!8-uBK5<
public class CountBean { m4 c2WY6k
private String countType; vf!lhV-UG+
int countId; -+Ox/>k
/** Creates a new instance of CountData */ ocj^mxh=O
public CountBean() {} 7MX5hZF"
public void setCountType(String countTypes){ :<6gP(
this.countType=countTypes; _nIt4l7
} wA";N=i=
public void setCountId(int countIds){ xqj@T^y
this.countId=countIds; |Mnc0Fgvy,
} _.GHtu/I
public String getCountType(){ *)T7DN8
return countType; p+F>+OQ*
} DPWnvd
public int getCountId(){ g0s*4E
return countId; NV18~5#</
} xf3/J{n3
} kI^Pu
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CountCache.java 9!Bz)dJ3
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/* B5qlU4km&
* CountCache.java Mgux(5`;
* z|m-nIM
* Created on 2007年1月1日, 下午5:01 %hA0
* 9d+z?J:
* To change this template, choose Tools | Options and locate the template under E>1%7"
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* the Source Creation and Management node. Right-click the template and choose hhJ>>G4R2
* Open. You can then make changes to the template in the Source Editor. :D
*/ -aM7>YR
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package com.tot.count; UmP\;
import java.util.*; -pN'r/$3V
/** f!}e*oX
* MJcWX|(y
* @author i)MJP *
*/
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public class CountCache { ^4
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public static LinkedList list=new LinkedList(); i=`@)E
/** Creates a new instance of CountCache */ )VkH':yCM
public CountCache() {} bx3kd+J7
public static void add(CountBean cb){ $_u)~O4$
if(cb!=null){ kXZG<?
list.add(cb); $G#)D^-5G
} +Y440Tz
} DP
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} wN$u^]
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CountControl.java M~djX} #\
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/* ,Y27uey{wa
* CountThread.java joJQ?lG
* =R||c
* Created on 2007年1月1日, 下午4:57 }b]z+4Ua(
* ~=c[?:
* To change this template, choose Tools | Options and locate the template under N'M+Z=!
* the Source Creation and Management node. Right-click the template and choose
+`~kt4W
* Open. You can then make changes to the template in the Source Editor. 6F?U:N#<
*/ j7=x&)qbx
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package com.tot.count; dJ=z'?|%g
import tot.db.DBUtils; b^&nr[DC
import java.sql.*; 2~!+EH
/** +#7)'c
* T']G:jkb
* @author 2PEA<{u
*/ pa6-3c
public class CountControl{ z5IdYF?
private static long lastExecuteTime=0;//上次更新时间 c~n:xblv
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ),U>AiF]
/** Creates a new instance of CountThread */ $w
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public CountControl() {} kSU]~x
public synchronized void executeUpdate(){ '>dx~v %
Connection conn=null; fqD1Ej
PreparedStatement ps=null; ??? ;H
try{ +IbQVU~/
conn = DBUtils.getConnection(); M>|R&v
conn.setAutoCommit(false); eW;0{P
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); p7]V1w :
for(int i=0;i<CountCache.list.size();i++){ @x/D8HK2
CountBean cb=(CountBean)CountCache.list.getFirst(); wT^Q O^.
CountCache.list.removeFirst(); S,^)\=v
ps.setInt(1, cb.getCountId()); hH=}<@z
ps.executeUpdate();⑴ qku!Mg
//ps.addBatch();⑵ {Nny.@P)H
} 7\ kixfEg
//int [] counts = ps.executeBatch();⑶ gw v
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conn.commit(); @LR :^>&*
}catch(Exception e){ ^ub@Jwe
e.printStackTrace(); K|sx"u|?
} finally{ sB%QqFRP
try{ 6%fF6
if(ps!=null) { tF~D!t@
ps.clearParameters(); H4IJLZ3G
ps.close(); U9:I"f,
ps=null; 4Y4QR[>IU3
} pJ3Yjm[l
}catch(SQLException e){} (z.eXo P@>
DBUtils.closeConnection(conn); [BKX$A:Y
} j#YPo
} E@92hB4D"
public long getLast(){ NVq3h\[X
return lastExecuteTime; 45$FcK
} I2<5#|CXpZ
public void run(){ >sm<$'vZ/
long now = System.currentTimeMillis(); -)$5[jM]
if ((now - lastExecuteTime) > executeSep) { ~)IiF.I b
//System.out.print("lastExecuteTime:"+lastExecuteTime); +:#UU;W
//System.out.print(" now:"+now+"\n"); nx'Yevi0$
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); xHi.N*~D
lastExecuteTime=now; m}o4Vr;"
executeUpdate(); `w#p8vR
} 31k2X81;a
else{ Tt\G y
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); y8CH=U[
} [X\~J &kD
} jP"l5
} LV!<vakCK
//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 @;ob 4sU
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类写好了,下面是在JSP中如下调用。 T~-OC0
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<% Vs@H>97,G
CountBean cb=new CountBean(); GR>kxYM%q
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); Hw
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CountCache.add(cb); Rr6}$]1
out.print(CountCache.list.size()+"<br>"); g]E>e v{`
CountControl c=new CountControl(); CH+mzy
c.run(); GLE"[!s]f
out.print(CountCache.list.size()+"<br>"); K *xca(6
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