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: P$)9osr
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CountBean.java 'B"kUh%3$5
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/* =ot`V; Q>
* CountData.java U3^T.i"R
* KW.S)+<H&
* Created on 2007年1月1日, 下午4:44 O;:8mm%(
* T"Wq:
* To change this template, choose Tools | Options and locate the template under 2D
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* the Source Creation and Management node. Right-click the template and choose /s=TLPm
* Open. You can then make changes to the template in the Source Editor. #4''Cs
*/ E<a~
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package com.tot.count; "_C^Bc
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/** [6
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* 9h$-:y3
* @author ''wWw(2O
*/ lE[LdmwDrb
public class CountBean { 6[c
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private String countType; '&3Sl?E
int countId; ;'pEzz?k"
/** Creates a new instance of CountData */ wLU w'Ai
public CountBean() {} d <qbUk3;
public void setCountType(String countTypes){ d?&?$qf[
this.countType=countTypes; @}x)>tqD
} $RKd@5XP
public void setCountId(int countIds){ KL0u:I(lWU
this.countId=countIds; OR( )D~:n
} 89@89-_mC
public String getCountType(){ 0c7&J?"wE
return countType; DZ ~|yH
} 0tn5>Dsk
public int getCountId(){ @OFl^U0/
return countId; F!`.y7hY@
}
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} G+b $WQn2t
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CountCache.java b\gl9"X
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/* p`Omcl~Q
* CountCache.java Fdu0?H2TL
* MY9?957F
* Created on 2007年1月1日, 下午5:01 +VDl"Hx
* LD_aJ^(d
* To change this template, choose Tools | Options and locate the template under Ax0u \(p<^
* the Source Creation and Management node. Right-click the template and choose L\ _8}\
* Open. You can then make changes to the template in the Source Editor. vxr3|2`
*/ ~LO MwMHl
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package com.tot.count; '4dnC2a]
import java.util.*; 8DLR
/** <B$Lu4b@c
* bU2)pD!N
* @author Gk799SDL
*/ IH[/fd0
public class CountCache { z~o%U&DO}
public static LinkedList list=new LinkedList(); ;c:vzF~Q
/** Creates a new instance of CountCache */ V}pw ,2s
public CountCache() {} XuR!9x^5
public static void add(CountBean cb){ B{s[SZ
if(cb!=null){ JZu7Fb]L9
list.add(cb); $3Wl~
G}
} tPC8/ntP8
} 39"8Nq|e
} ] =>vv;L
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CountControl.java W1r- uR
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/* RU_=VB %
* CountThread.java %tUJ >qYU
* X?4tOsd
* Created on 2007年1月1日, 下午4:57 ,D
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* RG:ct{i
* To change this template, choose Tools | Options and locate the template under *tz"T-6O
* the Source Creation and Management node. Right-click the template and choose uZmfvMr3
* Open. You can then make changes to the template in the Source Editor. Om>6<3n
*/ ~+3f8%
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package com.tot.count; I+`~6
import tot.db.DBUtils; ! ~&X1,l1*
import java.sql.*; z?j~ 2K<4
/** b LL!iz?
* cQ3Dk<GZ
* @author #ye++.7WK
*/ v`y{l>r,
public class CountControl{ {v;Y}o-p
private static long lastExecuteTime=0;//上次更新时间 C/!2q$
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 <0R?#^XBZB
/** Creates a new instance of CountThread */ mqq~&nI
public CountControl() {} {r'#(\
public synchronized void executeUpdate(){ bG.aV#$FIg
Connection conn=null; J&8l1{gd
PreparedStatement ps=null; wQM(Lm#Q
try{ gyI5;il~
conn = DBUtils.getConnection(); apGf@b
conn.setAutoCommit(false); P-^Z7^o-bX
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); G_42ckLq
for(int i=0;i<CountCache.list.size();i++){ &h4(lM
CountBean cb=(CountBean)CountCache.list.getFirst(); @zd)]O]xH?
CountCache.list.removeFirst(); S'6(&"XCH
ps.setInt(1, cb.getCountId()); V-7!)&q
ps.executeUpdate();⑴ ;"joebZ/
//ps.addBatch();⑵ 4!/{CGP
} wk8XD(&
//int [] counts = ps.executeBatch();⑶ '^7Sa
conn.commit(); 1C .<@IZ
}catch(Exception e){ 5Z`f)qE
e.printStackTrace(); *(o~pxFTR
} finally{ x]y~KbdeB
try{ dLQ!hKD~
if(ps!=null) { -fG;`N5U
ps.clearParameters(); l)XzU&Sc~
ps.close(); F5+f?B~?R?
ps=null; x8zUGvtQ
} 8#7z5:_
}catch(SQLException e){} ]<z>YyBA
DBUtils.closeConnection(conn); s)ZL`S?</
} 9O@eJ$
} sEhdkN}6
public long getLast(){ QabF(}61
return lastExecuteTime; 6AZ/whn#
} 6\b B#a
public void run(){ ;znIY&Z
long now = System.currentTimeMillis(); #W!@j"8eK
if ((now - lastExecuteTime) > executeSep) { ~poy`h'
//System.out.print("lastExecuteTime:"+lastExecuteTime); #p=/P{*
//System.out.print(" now:"+now+"\n"); M@s2T|bQw
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); @uT\.W:Q2
lastExecuteTime=now; _E&*JX
executeUpdate(); w(.k6:e
} }v@w(*)h:
else{ ;t"#7\
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 9{xP~0g
} R:i7Rb2C
}
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} \t^q@}~0Wz
//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 gZ/M0px
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类写好了,下面是在JSP中如下调用。 i(L;1 `
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<% Ngh9+b6[
CountBean cb=new CountBean(); vpOzF>O
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); -br/
CountCache.add(cb); ,$W7Q
out.print(CountCache.list.size()+"<br>"); k gWF@"_
CountControl c=new CountControl(); r-&4<=C/N
c.run(); S37Bl5W
out.print(CountCache.list.size()+"<br>"); ~~:i+-[
%>