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\as@pqo\p
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CountBean.java cx&>#8s&
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/* MvK !u
* CountData.java PIu1+k.r?
* !g5xq
* Created on 2007年1月1日, 下午4:44 bpH^:fyLU`
* 62k^KO6Y
* To change this template, choose Tools | Options and locate the template under x4;"!Kq\
* the Source Creation and Management node. Right-click the template and choose ?[g=F <r
* Open. You can then make changes to the template in the Source Editor. "Zl5<
*/ {khqu:HUn`
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package com.tot.count; YQHw1
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/** YKH\rN6X
* QdL`|
* @author /&
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*/ HCyv ]LR
public class CountBean { bwD,YC
private String countType; S ?{#r
int countId; pA9+Cr!0Q
/** Creates a new instance of CountData */ &7PG.Ff!r
public CountBean() {} eJxw)zd7
public void setCountType(String countTypes){ qf!p 9@4F[
this.countType=countTypes; gQ'zW
} oU056
public void setCountId(int countIds){ g!lWu[d
this.countId=countIds; :S<f?*
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} gl\\+VyU
public String getCountType(){ V@zg}C|e
return countType; iBF|&h(\
} %?}33yV
public int getCountId(){ sz:g,}~h
return countId; fVF2-Rh=
} ]s'Q_wh_-v
} yeXx',]a
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CountCache.java -I8=T]_D
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/* `o=q%$f#k~
* CountCache.java g)#W>.Asd
* (7*%K&x
* Created on 2007年1月1日, 下午5:01 iII=;:p
* )wC?T
* To change this template, choose Tools | Options and locate the template under }& cu/o4
* the Source Creation and Management node. Right-click the template and choose uJzG|$;
* Open. You can then make changes to the template in the Source Editor. @ ;*Ksy@1O
*/ (s.0PO`
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package com.tot.count; ,K9*%rW)
import java.util.*; WI-&x
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/** lAb*fafQy
* 2oVSn"
* @author '[AlhBX
*/ w>pq+og&
public class CountCache { \-h%O
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public static LinkedList list=new LinkedList(); XGYbnZ~
/** Creates a new instance of CountCache */ RL!Oi|8
public CountCache() {} )J2mM
public static void add(CountBean cb){
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if(cb!=null){ ?}wk.gt>
list.add(cb); #M9~L[nFS
} G<}()+L
} ?zh9d%R
} A\4D79>x
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CountControl.java #.rdQ,)<
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/* >_[9t
* CountThread.java t^+ik1.
* \pPY37l
* Created on 2007年1月1日, 下午4:57 X <f8,n
* mk.9OhYY
* To change this template, choose Tools | Options and locate the template under uatm/o^~,
* the Source Creation and Management node. Right-click the template and choose l4F%VR4KT
* Open. You can then make changes to the template in the Source Editor. 2BQ
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*/ q]T1dz?
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package com.tot.count; SIBtmm1W
import tot.db.DBUtils; BmbyH{4
import java.sql.*; W0dSsjNio
/** uaT!(Y6
* k.uH~S _
* @author SF7\<'4\N
*/ 3O,+=?VK
public class CountControl{ my(2;IJ#{
private static long lastExecuteTime=0;//上次更新时间 Ro\8ZXUQa
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 0(eBZdRO
/** Creates a new instance of CountThread */ a L} %2
public CountControl() {} 2;k*@k-t
public synchronized void executeUpdate(){ <c2E'U)X
Connection conn=null; MI/MhkS
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PreparedStatement ps=null; %RTBV9LIXr
try{ <^&ehy:7y
conn = DBUtils.getConnection();
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conn.setAutoCommit(false); ,)0H3t
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 95ZyP!
for(int i=0;i<CountCache.list.size();i++){ ni.cTOSx
CountBean cb=(CountBean)CountCache.list.getFirst(); 9]k @Q_
CountCache.list.removeFirst(); h}[-'>{
ps.setInt(1, cb.getCountId()); 3
}duG/
ps.executeUpdate();⑴ \nXtH}9ZF
//ps.addBatch();⑵ /KFfU1
}
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//int [] counts = ps.executeBatch();⑶ j_K4;k#r
conn.commit(); 2GP=&K/A
}catch(Exception e){ PC~Y8,A|.t
e.printStackTrace(); ,|3MG",@@h
} finally{ ^X=arTE
try{ N4v~;;@(
if(ps!=null) { NSxoF3
ps.clearParameters(); n`#tKwWHYx
ps.close(); H=<S 9M
ps=null; ND'E8Ke pq
} BL0 {HV!
}catch(SQLException e){} t_o['F
DBUtils.closeConnection(conn); m4**~xfC
} bp*
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} Zq^At+8+
public long getLast(){ +[M6X}
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return lastExecuteTime; .!Oo|m`V@
} R cAwrsd
public void run(){ h?AS{`.1
long now = System.currentTimeMillis(); dzARI`
if ((now - lastExecuteTime) > executeSep) { =b%MXT
//System.out.print("lastExecuteTime:"+lastExecuteTime); o2nv+fyW
//System.out.print(" now:"+now+"\n"); o*b] p-
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); *QpMF/<?
lastExecuteTime=now; xe]y]
executeUpdate(); B;M?,<%FRU
} (uXL^oja
else{ vq0Vq(V=
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 3-[q4R
} 7r7YNn/?
} 0pK=o"^?@
} T5R-B=YWu
//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 MDnKX?Y
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类写好了,下面是在JSP中如下调用。 vleS2-]|
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<% !<j'Ea
CountBean cb=new CountBean(); S'k_olx7
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); I&2c&yO
CountCache.add(cb); H['N
out.print(CountCache.list.size()+"<br>"); Vy6qbC-Kt
CountControl c=new CountControl(); VyXKZ%\dQ/
c.run(); _G[g;$<
out.print(CountCache.list.size()+"<br>"); i5en*)O8
%>