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: (}"r 5
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CountBean.java u=jF\W9
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/* DL|,:2`
* CountData.java xqO'FQO%
* ;)5d
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* Created on 2007年1月1日, 下午4:44 #DwTm~V0"
* yVUA7IY
* To change this template, choose Tools | Options and locate the template under ,JN2q]QPP
* the Source Creation and Management node. Right-click the template and choose {~k/xM.-
* Open. You can then make changes to the template in the Source Editor. IBf&'/ 8\
*/ B1JdkL 3h
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package com.tot.count; A0cC)bd&
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/** #c'yAa
* 1@P/h#_Vr
* @author *.ri8
*/ 9loWh5_1Z
public class CountBean { 8*H-</ =
private String countType; J i :2P*
int countId; "L|Ew#
/** Creates a new instance of CountData */ MmI4J$F
public CountBean() {} n%"q>
public void setCountType(String countTypes){ Y]P';C_eP
this.countType=countTypes; ?5Wj y
} sk\U[#ohH
public void setCountId(int countIds){ Q`4=
this.countId=countIds; !Sy._NE`z
} xpxUn8.
public String getCountType(){ m beM/
return countType; =zDU!< U
} r )ZUeHt}w
public int getCountId(){ ~.u}v~
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return countId; D!h8NZ;El
} C~ t?<
} N#Y%+1
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CountCache.java gD3s,<>o
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/* {UX?z?0T
* CountCache.java %I9{)'+@x
* rIH/<@+
* Created on 2007年1月1日, 下午5:01 U":hJ*F)
* t
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* To change this template, choose Tools | Options and locate the template under E0'+]"B
* the Source Creation and Management node. Right-click the template and choose mcy\nAf5%
* Open. You can then make changes to the template in the Source Editor. "CLoM\M)
*/ =dx!R ,Bw
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package com.tot.count; n$
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import java.util.*; QO0}-wZR
/** |iKk'Rta4
* _ui03veA1
* @author M$~3`n*^
*/ ^q5~;_z|
public class CountCache { !O6e,l
public static LinkedList list=new LinkedList(); k!3X4;F!_
/** Creates a new instance of CountCache */ 3sIW4Cs7)U
public CountCache() {} ig<Eyr
public static void add(CountBean cb){ ,yus44w[
if(cb!=null){ g@wF2=
list.add(cb); [Oen{c9A
} dU1w)Y
} 0D/u`-
} 6w(Mb~[n
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CountControl.java uPKq<hBI
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/* &IsQgS7R
* CountThread.java nwswy]e8/
* 9pUvw_9MY
* Created on 2007年1月1日, 下午4:57 JTK>[|c9oE
* !>fYD8Ft,
* To change this template, choose Tools | Options and locate the template under b~fX=!M
* the Source Creation and Management node. Right-click the template and choose bwo-9B
* Open. You can then make changes to the template in the Source Editor. 1c_gh12
*/ 6(awO2{BP
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package com.tot.count; 1{+x >Pv:
import tot.db.DBUtils; i)9}+M5
import java.sql.*; $*
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/** U<,@u,_Ja
* ALvj)I`Al
* @author d]1%/$v^
*/ *z[G+JX
public class CountControl{ X8~dFjhX
private static long lastExecuteTime=0;//上次更新时间 dv=y,q@W
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 0^'A^
/** Creates a new instance of CountThread */ !wiW#PR
public CountControl() {} M
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public synchronized void executeUpdate(){ hY
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Connection conn=null; J-*&&
PreparedStatement ps=null; q/y4HT,x
try{ uC\FW6K=m
conn = DBUtils.getConnection(); +. /c=o/v
conn.setAutoCommit(false); GT\,
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?");
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for(int i=0;i<CountCache.list.size();i++){ .5Y%I;~v
CountBean cb=(CountBean)CountCache.list.getFirst(); &v!=\Fig4
CountCache.list.removeFirst(); )aoB-Lu
ps.setInt(1, cb.getCountId()); nQ|4.e;
ps.executeUpdate();⑴ %Q]u_0P*
//ps.addBatch();⑵ !iKR~&UpAL
} eXJt9olI
//int [] counts = ps.executeBatch();⑶ GwiG..Y]&
conn.commit(); 9pPb]v,6
}catch(Exception e){ JA W}]:jC
e.printStackTrace(); \s<7!NAE4
} finally{ =Y`P}vI]w%
try{ Gvo(iOU
if(ps!=null) { w0QN5?
ps.clearParameters(); i`o}*`//
ps.close(); 8
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ps=null; P.*J'q 28
} }.Eq_wP<
}catch(SQLException e){} *S_e:^
DBUtils.closeConnection(conn); hW*2Le!I
} M=[ /v/M=
} vQrce&
public long getLast(){ N;,?k.vU
return lastExecuteTime; \8\)5#?
} MWf ]U
public void run(){ M0!;{1
long now = System.currentTimeMillis(); g-'y_'%0G
if ((now - lastExecuteTime) > executeSep) { h}xUZ:
//System.out.print("lastExecuteTime:"+lastExecuteTime); OJE<2:K
//System.out.print(" now:"+now+"\n"); AoHA+>&U
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); VlW#_.
lastExecuteTime=now; N/)mw/?i
executeUpdate(); Wd4fIegk
} 2&91C[da0
else{ PpMZ-f@
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); P# 2&?.d\
} `;fh<kv
} >4TJH
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} GkMNV7"m
//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 8o8FL~&]
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类写好了,下面是在JSP中如下调用。 O{8"f\*
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<% bGRI^
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CountBean cb=new CountBean(); 2>Kq)Ii
cb.setCountId(Integer.parseInt(request.getParameter("cid")));
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CountCache.add(cb); FW7+!A&F
out.print(CountCache.list.size()+"<br>"); *lv)9L+0
CountControl c=new CountControl(); jIE>t5 fy
c.run(); ~l!(I-'?g
out.print(CountCache.list.size()+"<br>"); X[k-J\
%>