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: j
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CountBean.java N2#Wyt8MC
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/* Y23- Im
* CountData.java oc7&iL
* AY<(`J{
* Created on 2007年1月1日, 下午4:44 HRn
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* hSr2<?yk
* To change this template, choose Tools | Options and locate the template under VKqIFM1b
* the Source Creation and Management node. Right-click the template and choose #ue WU
* Open. You can then make changes to the template in the Source Editor. oR}cE
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*/ C-u'Me)H
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package com.tot.count; LDc?/
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/** iI.pxo
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* G9 v'a&
* @author Td(eNe_4T
*/ zZp0g^;.?
public class CountBean { ]ie38tX$
private String countType; ua%@Ay1|
int countId; -Y>,\VEK
/** Creates a new instance of CountData */ QP>tu1B|
public CountBean() {} )cP&c=
public void setCountType(String countTypes){ }$%j} F{
this.countType=countTypes; 3u[m? Vw
}
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public void setCountId(int countIds){ e%[0
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this.countId=countIds; Q3"{v0
} 4*Uzomb?q
public String getCountType(){ RD6n1Wb(@
return countType; <$z6:4uN_
} 00SYNG!
public int getCountId(){ `)~]3zmG
return countId; u:]c
}
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} cV$an
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CountCache.java FP=up#zl
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/* Jn7T5$pJ
* CountCache.java >V%lA3
* 6;:z?Q
* Created on 2007年1月1日, 下午5:01 =e)t,YVm
* pq"Z,9,F%
* To change this template, choose Tools | Options and locate the template under *c<6 Er>s
* the Source Creation and Management node. Right-click the template and choose OI^??joQ
* Open. You can then make changes to the template in the Source Editor. ^ YOCHXg
*/ !),eEy
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package com.tot.count; ;NMv>1fI
import java.util.*; y`,;m#frT
/** jFDVd;#CS
* I=[Ir8};
* @author 9| g]M:{
*/ DHq#beN
public class CountCache { l*>,K2F
public static LinkedList list=new LinkedList(); @>fsg-|
/** Creates a new instance of CountCache */ *"nN To
public CountCache() {} u4#YZOiY)A
public static void add(CountBean cb){ hv0bs8h
if(cb!=null){ oyT`AYa
list.add(cb); dy>5LzqK3
} &t~NR$@
} S;0z%$y
} PZ>(cvX&
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CountControl.java n!dXjInV
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/* aPdEEqc\l
* CountThread.java {j6$'v)0
* 3Ofh#|qc&
* Created on 2007年1月1日, 下午4:57 5jq @ nq6
* {^D; ($lm
* To change this template, choose Tools | Options and locate the template under z+Guu8
* the Source Creation and Management node. Right-click the template and choose v,'k2H
* Open. You can then make changes to the template in the Source Editor. ;Rlf[](iL
*/ Z;O!KsJ
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package com.tot.count; pwH*&YU
import tot.db.DBUtils; EQWRfx?d
import java.sql.*; <z#.J]
/** a<0q%Ax
* a&Qr7tTY"
* @author " Tk,
*/ K0W X($z~;
public class CountControl{
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private static long lastExecuteTime=0;//上次更新时间 7W'&v+\
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 Ze!/b|`xI
/** Creates a new instance of CountThread */ O _C<h
public CountControl() {} ,\?s=D{
public synchronized void executeUpdate(){ -5oYGLS$y3
Connection conn=null; c,^W/:CQAB
PreparedStatement ps=null; *knN?`(x
try{ CNe(]HIOH
conn = DBUtils.getConnection(); 8J#x B
conn.setAutoCommit(false); 0&u=(;Dr\
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); j8oX9
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for(int i=0;i<CountCache.list.size();i++){ ;Fo7 -kK
CountBean cb=(CountBean)CountCache.list.getFirst(); ~:L5Ar<
CountCache.list.removeFirst();
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ps.setInt(1, cb.getCountId()); S{RRlR6Z
ps.executeUpdate();⑴ /mA\)TL|]
//ps.addBatch();⑵ -^)<FY\
} {)iiu
//int [] counts = ps.executeBatch();⑶ 3:O|p[2)L
conn.commit(); aGOS9
}catch(Exception e){ Sp6==(:.
e.printStackTrace(); R4X9g\KpAt
} finally{ &xt[w>/i
try{ w~_ycY.e
if(ps!=null) { g:O/~L0Xb
ps.clearParameters(); r$v\ \^?2
ps.close(); `YUeVz>q?
ps=null; *8Su:=*b
} &zd@cr1
}catch(SQLException e){} [p'A?-
DBUtils.closeConnection(conn); 7;c^*"Ud
} a"i(.(9$J
} <ne?;P1L
public long getLast(){ H<}|n1w<
return lastExecuteTime; cuC'
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} KWxTN|>
public void run(){ <"K2t
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long now = System.currentTimeMillis(); n=)LB&
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if ((now - lastExecuteTime) > executeSep) { zB`J+r;LU
//System.out.print("lastExecuteTime:"+lastExecuteTime); pP#D*hiP-g
//System.out.print(" now:"+now+"\n"); /Xj{]i3{
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); e_-7,5Co
lastExecuteTime=now; dWi<U4
executeUpdate(); *o5[P\'6
} 7O8 @T-f+2
else{ $}IG+,L
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 2
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}
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} .Tm.M7
} \03<dUA6
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 }Ml BmD
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类写好了,下面是在JSP中如下调用。 %y\5L#T!>
[MQ* =*
<% AFM+`{Cq
CountBean cb=new CountBean(); "uP*pR^
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); !VaC=I^{
CountCache.add(cb); !4!qHJISa
out.print(CountCache.list.size()+"<br>"); Q>$lf.)
CountControl c=new CountControl(); 1ni72iz\
c.run(); ur E7ZKdI
out.print(CountCache.list.size()+"<br>"); n&o"RE 0~0
%>