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: 4 -dV%DgC
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CountBean.java Db5y";T
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/* 1MF0HiC
* CountData.java g12mSbf=9
* hV6=-QL*B
* Created on 2007年1月1日, 下午4:44 u3XQ<N{Gj
* Jjgy;*hM
* To change this template, choose Tools | Options and locate the template under x(UOt;
* the Source Creation and Management node. Right-click the template and choose J91O$szA
* Open. You can then make changes to the template in the Source Editor. 3"pl="[*
*/ TiF2c#Q*y
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package com.tot.count; *z{.9z`
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/** (H*d">`mz
* y,OwO4+y\
* @author g\n0v~T+
*/ B&Igm<72x
public class CountBean { my|UlZ(qg
private String countType; )U':NV2
int countId; 1sHaG
/** Creates a new instance of CountData */ =yZiBJ
public CountBean() {} 01-n_ $b
public void setCountType(String countTypes){ nnm9pnx
this.countType=countTypes; UJX=lh.o
} :.k)!
public void setCountId(int countIds){ oF(<}0Z
this.countId=countIds; 1D pRm(
} t'F_1P^*/
public String getCountType(){ Wxxnc#;lv
return countType; ?[ts<Ltp
} 1~x=bphS
public int getCountId(){ > 10pk
return countId; .vbUv3NI
} (6WSQqp
} S/XkxGZ2
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CountCache.java YVEin1]
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/* \~YyY'J
* CountCache.java o.Jq1$)~y
* 6a=Y_fma
* Created on 2007年1月1日, 下午5:01 I'NE>!=Q
* ;~ >E^0M
* To change this template, choose Tools | Options and locate the template under %j[DG_
* the Source Creation and Management node. Right-click the template and choose LT5rLdn
* Open. You can then make changes to the template in the Source Editor. Yom,{;Bv
*/ MDo4{7
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package com.tot.count; O+o4E?}
import java.util.*; bLHj<AX#>|
/** #{t?[JUn
* ;AwQpq>dy
* @author oo:(GfO}
*/ d/Z258
public class CountCache { ?xTh}Sky
public static LinkedList list=new LinkedList(); g7|$JevR0
/** Creates a new instance of CountCache */ r:&"#F
public CountCache() {} 77Fpb?0`
public static void add(CountBean cb){ iSZiJ4AUq
if(cb!=null){ l/JE}Eg(
list.add(cb); zMXlLRC0
} :IZ(9=hs
} ?rD`'B
} ^lP_{c
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CountControl.java SnhB$DG
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/* QqC4g]
* CountThread.java Eoj 2l&\
* 'Gw;@[
* Created on 2007年1月1日, 下午4:57 E/MNz}+
* ;,8bb(j
* To change this template, choose Tools | Options and locate the template under XQ{G)
* the Source Creation and Management node. Right-click the template and choose UI*^$7z1 +
* Open. You can then make changes to the template in the Source Editor.
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*/ ?`nF"u>
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package com.tot.count; qXGAlCq@
import tot.db.DBUtils; ::xH C4tw
import java.sql.*; D{](5?$`|
/** f|*vWHSM
* CTbz?Kn
* @author ^Fl6-|^~
*/ \qrSJ=}t
public class CountControl{ R7L:U+*V"
private static long lastExecuteTime=0;//上次更新时间 btfjmR<Tp
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ohdWEU,
/** Creates a new instance of CountThread */ 86^xq#+Uw
public CountControl() {} fC2
public synchronized void executeUpdate(){ \k=.w
Connection conn=null; &~u=vuX
PreparedStatement ps=null; [3s p
try{ vu%:0p`K
conn = DBUtils.getConnection(); Uf`lGGM
conn.setAutoCommit(false); *|f&a
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); wXc"Car)
for(int i=0;i<CountCache.list.size();i++){ ERW>G{+
CountBean cb=(CountBean)CountCache.list.getFirst(); 93Yo}6>
CountCache.list.removeFirst(); fwojFS.K
ps.setInt(1, cb.getCountId()); [I;5V= bKW
ps.executeUpdate();⑴ 1GnT^u y/
//ps.addBatch();⑵ 4DVkycM
} u#8J`%g
//int [] counts = ps.executeBatch();⑶ b"ypS7
_
conn.commit(); n.{+\M6k
}catch(Exception e){ )U`"3R
e.printStackTrace(); pr|P#mc"J
} finally{ S^GB\uJ
try{ 0x}8}
if(ps!=null) { !9!kb
ps.clearParameters(); -}lcMZY
ps.close(); /`3^?zlu"
ps=null; )p-B@5bb
} r@xMb,!H
}catch(SQLException e){} ob
DBUtils.closeConnection(conn); v5|X=B>&>
} y@;4F n/
} oh '\,zpL
public long getLast(){ LF'M!C9|
return lastExecuteTime; yJaQcGxE"
} wl{Fx+<^3
public void run(){ U}xQUFT|
long now = System.currentTimeMillis(); }57wE$9K
if ((now - lastExecuteTime) > executeSep) { .(Gq9m[~8H
//System.out.print("lastExecuteTime:"+lastExecuteTime); o0~+%&
//System.out.print(" now:"+now+"\n"); IED7v
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); !A"`jc~x:
lastExecuteTime=now; rSIb1zJ
executeUpdate(); 8@)/a
} Hp_3BulS<
else{ ,`/J1(\nd
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); O[3AI^2
} t6;Ln().Hw
} 1NO<K`
} ExDH@Lb
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 Jy'ge4]3
@L%9NqE`O
类写好了,下面是在JSP中如下调用。 R|T_9/#)
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<% '|0Dt|$
CountBean cb=new CountBean(); *M_.>".P
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); P-L<D!25
CountCache.add(cb); >Au]S`
out.print(CountCache.list.size()+"<br>"); p~h=]o'i
CountControl c=new CountControl(); 4-`C !q
c.run(); =|n NC
out.print(CountCache.list.size()+"<br>"); X6mY#T'fQ
%>