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: cOX )+53
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CountBean.java ]B=*p0~j^n
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/* O& Sk}^
* CountData.java aq}hlA(w
* d4;$=P
* Created on 2007年1月1日, 下午4:44 PR:B6 F8
* A+* lV*@0
* To change this template, choose Tools | Options and locate the template under L,y
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* the Source Creation and Management node. Right-click the template and choose 8xgBNQdPT
* Open. You can then make changes to the template in the Source Editor. jc
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*/ }%/mPbd#
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package com.tot.count; _uMG?Sbx
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/** klT?h[I!
* `D~oY=
* @author f^B8!EY#:
*/
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public class CountBean { M=pQx$%a
private String countType; uhfK\.3
int countId; bXF8V
/** Creates a new instance of CountData */ c-XO}\?
public CountBean() {} >j hcSvM6
public void setCountType(String countTypes){ E4892B:`
this.countType=countTypes; ?96r7C|
} ~&D
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public void setCountId(int countIds){ `mz}D76~#
this.countId=countIds; K9%rr_ja!
} )2?]c
public String getCountType(){ zMbFh_dcq
return countType; w!6{{m
} E0+L?(;
public int getCountId(){ mB_?N $K
return countId; pxTtV g.
} ;QXg*GNAv$
} <$z[pw<
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CountCache.java Twa(RjB<
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/* '2lzMc>wvP
* CountCache.java 9m$"B*&6G
* V4V`0I
* Created on 2007年1月1日, 下午5:01 !?JZ^/u
* it\$Pih]
* To change this template, choose Tools | Options and locate the template under ~F'6k&A^q
* the Source Creation and Management node. Right-click the template and choose m_/Ut
* Open. You can then make changes to the template in the Source Editor. x;u#ec4
*/ r4SwvxhG
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package com.tot.count; L.'61ZU
import java.util.*; w gS'/
/** { im?tZ,
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* @author J\*uW|=F
*/ _F6<ba}o3
public class CountCache { 1!MJ+?Jl
public static LinkedList list=new LinkedList(); D=z~]a31!
/** Creates a new instance of CountCache */ -\f7qRW^U
public CountCache() {} #17 &rizl
public static void add(CountBean cb){ OXrm!'
if(cb!=null){ iRsB|7v[ ,
list.add(cb); !VWA4 e!+
} I~n4}}9M
} 3=uhy|f! /
} 7@<.~*Bl6
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CountControl.java G]rY1f0
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/* }[JB%
* CountThread.java D8L5t<^1R
* D2&d",%&f
* Created on 2007年1月1日, 下午4:57 Y
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* CjpGo}a/
* To change this template, choose Tools | Options and locate the template under Wf3BmkZzz
* the Source Creation and Management node. Right-click the template and choose GbQi3%
* Open. You can then make changes to the template in the Source Editor. !lNyoX/
*/ ;
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package com.tot.count; Ak@!F6~
import tot.db.DBUtils;
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import java.sql.*; C`;igg$t_
/** 2(DhKHrF
* &!/>B .
* @author )^o.H~Pv
*/ .|[{$&B
public class CountControl{ YgcW1}
private static long lastExecuteTime=0;//上次更新时间 )v;O2z
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 B=d<L^
/** Creates a new instance of CountThread */ `YqtI/-w
public CountControl() {} 6o#/[Tz
public synchronized void executeUpdate(){ c46-8z$
Connection conn=null; Qa=Y?=Za
PreparedStatement ps=null; 7zw0g~+
try{ %RV81H9B
conn = DBUtils.getConnection(); >b2!&dm
conn.setAutoCommit(false); ~_EDJp1J
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); y`n?f|nf
for(int i=0;i<CountCache.list.size();i++){ 6a,8t
CountBean cb=(CountBean)CountCache.list.getFirst(); n%F _3`
CountCache.list.removeFirst(); :%sBY0 yF
ps.setInt(1, cb.getCountId()); h}SZ+G/L
ps.executeUpdate();⑴ %evb.h)
//ps.addBatch();⑵ $XQgat@&]
} \09A"fs{
//int [] counts = ps.executeBatch();⑶ b69nj
conn.commit(); G"FO%3&|
}catch(Exception e){ O +o)z6(
e.printStackTrace(); nvrh7l9nX
} finally{ ^.LB(GZ,
try{ j<(E%KN3
if(ps!=null) { 0V<kpC,4
ps.clearParameters(); jOfG}:>e\
ps.close(); 6ncwa<q5
ps=null; P'8RaO&d
} _:9}RT?
}catch(SQLException e){} Py
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DBUtils.closeConnection(conn); v>`Fo[c
} 0`S{>G
} 6{.U7="
public long getLast(){ (y]Z *p:EW
return lastExecuteTime; L@H^?1*L?
} U_IGL
public void run(){ o.!o4&WH
long now = System.currentTimeMillis(); ;iiCay37F
if ((now - lastExecuteTime) > executeSep) { h_ 4*?w
//System.out.print("lastExecuteTime:"+lastExecuteTime); p48enH8CO
//System.out.print(" now:"+now+"\n"); _ VuWo
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 0V3dc+t)O
lastExecuteTime=now; yx|iZhK0:}
executeUpdate(); y-E'Y=j
} .@)vJtH)
else{ L/rf5||@
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ;:bp?(
} ];w}?LFb
} g PCf+>X{
} j2,sI4
//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 ZJ%NZAxy
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类写好了,下面是在JSP中如下调用。 C,+
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<% ;'{7wr|9
CountBean cb=new CountBean(); Zm0VaOT $I
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); q~> +x?30
CountCache.add(cb); Y!xPmL^]?
out.print(CountCache.list.size()+"<br>"); ~b]enG5xS4
CountControl c=new CountControl(); _R ]s1
c.run(); &7\}Sqp
out.print(CountCache.list.size()+"<br>"); m,\+RUW'
%>