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: 1seWR"
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CountBean.java cH>@ZFTF
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/* :`Kv\w.
* CountData.java [~_)]"pU
* -J &y]'
* Created on 2007年1月1日, 下午4:44 jEh Px
* u-</G-y
* To change this template, choose Tools | Options and locate the template under Uzh#zeZ`<
* the Source Creation and Management node. Right-click the template and choose -So$f-y
* Open. You can then make changes to the template in the Source Editor. F-R5Ib-F*A
*/ "t0l)P*C}
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package com.tot.count; ~aBf.
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/** A_8Xhem${
* Dc@OrQu
* @author ,F%2'W
*/ mY=Q#nG
public class CountBean { NJ^Bv`
private String countType; f/PqkHF
int countId; v_|k:l
/** Creates a new instance of CountData */ NI
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public CountBean() {} x`:c0y9uG
public void setCountType(String countTypes){ %fuV]
this.countType=countTypes; v`r![QpYf
} jWL%*dJrN
public void setCountId(int countIds){ @ /.w%
this.countId=countIds; L}=DC =E
} :X*$U
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public String getCountType(){ NoOrQ m
return countType; YMn*i<m
} <EKTFHJ!
public int getCountId(){ u']}Z%A9`
return countId; C;3
} 1K#%mV_
} g@zhhBtQ
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CountCache.java "T@9#7Obu
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/* :\Q#W4~p
* CountCache.java ^ItL_4
* 6$)FQ
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* Created on 2007年1月1日, 下午5:01 V]Rt[l]
* s^> >]
* To change this template, choose Tools | Options and locate the template under {TXfi'\
* the Source Creation and Management node. Right-click the template and choose RkZyqt
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* Open. You can then make changes to the template in the Source Editor. Q h{P>}
*/ :85QwN]\
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package com.tot.count; L1#_
import java.util.*; .~C%:bDnX7
/** s<+;5, Q|
* J#gG*(
* @author d#HlO}
*/ Q?V+
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public class CountCache { GG`j9"t4
public static LinkedList list=new LinkedList(); v|MT^.
/** Creates a new instance of CountCache */ 7|xu)zYB
public CountCache() {} =9h!K:,k
public static void add(CountBean cb){ K$l@0r ~k
if(cb!=null){ iR"6VO
list.add(cb); h1H$3TpP
} F`La_]f?b\
} GExr] 2r
} vb|
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CountControl.java i;atYltEJ2
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/* p~NHf\
* CountThread.java =W&m{F96
* S['cX ~
* Created on 2007年1月1日, 下午4:57 t,n2N13
* xs&xcRR"
* To change this template, choose Tools | Options and locate the template under (xE |T f
* the Source Creation and Management node. Right-click the template and choose \H9:%Tlp~4
* Open. You can then make changes to the template in the Source Editor. a`8]TD
*/ artn _
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package com.tot.count; `kE7PXqa
import tot.db.DBUtils; N~0ihTG5
import java.sql.*; B&7NF}CF2
/** :T|9;2
* 6$0<&')Yb
* @author 5dhy80|g]
*/ 6#AEVRJKU@
public class CountControl{ _Hd|y
private static long lastExecuteTime=0;//上次更新时间 B;S'l|-?
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 4l{$dtKbI
/** Creates a new instance of CountThread */ lSBR(a<\y
public CountControl() {} [Y~~C J
public synchronized void executeUpdate(){ V1,/qd_
Connection conn=null; '9=b@SaAj
PreparedStatement ps=null; m)LI|
v
try{ fL#r@TB-s
conn = DBUtils.getConnection(); yj@k0TWT$
conn.setAutoCommit(false); 6)p8BUft
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); S>>wf:\ c
for(int i=0;i<CountCache.list.size();i++){ wdAKU+tM
CountBean cb=(CountBean)CountCache.list.getFirst(); }O>4XFj
CountCache.list.removeFirst(); hv?T}E
ps.setInt(1, cb.getCountId()); "M@&*<S
ps.executeUpdate();⑴ ,Tu.cg
//ps.addBatch();⑵ 8{QCW{K
} #0vda'q=j
//int [] counts = ps.executeBatch();⑶ i]N<xcF9N*
conn.commit(); w@&z0ODJ
}catch(Exception e){ I`*5z;Q!%@
e.printStackTrace(); S0Io$\ha
} finally{ wP*3Hx;S
try{ o&&`_"18
if(ps!=null) { Kc95yt
ps.clearParameters(); qH5nw}]
ps.close(); Jfk#E^1
ps=null; NJ+$3n om
} vy}_aD{B
}catch(SQLException e){} 4I$Y"|_e
DBUtils.closeConnection(conn); ;[UI]?A%
} KS<@;Tt
} :V5 Co!/+
public long getLast(){ BWQ`8
return lastExecuteTime; SMIDW}U2S
} <F(S_w62
public void run(){ .d}yQ#5z
long now = System.currentTimeMillis(); 4sntSlz)~k
if ((now - lastExecuteTime) > executeSep) { 2$kB^g!:o
//System.out.print("lastExecuteTime:"+lastExecuteTime); bhGRD{=
//System.out.print(" now:"+now+"\n"); _/z_
X
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); tk R~(h
lastExecuteTime=now; jL8A_'3B
executeUpdate(); Z5n-3h!+ED
} w|]Tt="
else{ *;9H \%
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); -3i(N.)<;
} AWi>(wk<
} u<uc"KY=
} !L8q]]'XM
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 MH#"dGGu
QNINn>2
类写好了,下面是在JSP中如下调用。 z,$uIv}'@
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<% .B-b51Uz
CountBean cb=new CountBean(); ,*U-o}{8C?
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ?4U4o<
CountCache.add(cb); Ahl&2f\
out.print(CountCache.list.size()+"<br>"); ?8{Os;!je
CountControl c=new CountControl(); l[IL~
c.run(); v0dzM/?*
out.print(CountCache.list.size()+"<br>"); zN!yOlp5
%>