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: E[tEW0ub
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CountBean.java \"l/D?+Q
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/* Z'_EX7r
* CountData.java P|;=dX#-
* (z^987G
* Created on 2007年1月1日, 下午4:44 !N\i9w}
* 6Lz:J:Q)
* To change this template, choose Tools | Options and locate the template under B^BbA-I
* the Source Creation and Management node. Right-click the template and choose &u0on)E
* Open. You can then make changes to the template in the Source Editor. kx07Ium
*/ #RP7?yGM,
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package com.tot.count; T@j@IEGH
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/** 9`5qVM1O{
* WGI4DzKa
* @author CxJH)H$
*/ -](3iPy}
public class CountBean { NXdT"O=P
private String countType; N>',[4pJ|
int countId; $GX9-^og=T
/** Creates a new instance of CountData */ B2)SNhF2Y
public CountBean() {} GKf%dKL
public void setCountType(String countTypes){ HKYJgx
this.countType=countTypes; ,dSP%?vV
} ="s>lI-1a
public void setCountId(int countIds){ \-RVPa8k
this.countId=countIds; )}4xmf@gl
} cfUG)-]P~
public String getCountType(){ AHdh]pfH
return countType; U[c^xz&
} sU;aA0kz
public int getCountId(){ E(0 [/N~
return countId; j/w*2+&v
} Q#sLIZ8=
} u;=a=>05IR
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CountCache.java
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/*
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* CountCache.java +{@hD+
*
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* Created on 2007年1月1日, 下午5:01 >l(|c9OWM
* ~\[\S!"
* To change this template, choose Tools | Options and locate the template under Dt]*M_
* the Source Creation and Management node. Right-click the template and choose $qfNEAmDf\
* Open. You can then make changes to the template in the Source Editor. PVX23y;
*/ eC*-/$D
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package com.tot.count;
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import java.util.*; ^3w
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/** |f<-lB[k
* HbQ+:B]
* @author w$[ck=
*/ aDVBi: _
public class CountCache { p^?]xD(
public static LinkedList list=new LinkedList(); jt4c*0z
/** Creates a new instance of CountCache */ uI+^8-HZ;
public CountCache() {} D|X@aUp8}
public static void add(CountBean cb){ /|aD,JVN"
if(cb!=null){ %$}*y
list.add(cb); <#No t1R
} pXq5|,aC
} ,|Lf6k
} 0j(/ N
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CountControl.java B&4NdL/
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/* &l2C-(
* CountThread.java !;COFR
* Nk&$b
* Created on 2007年1月1日, 下午4:57 aW7)}"j4
* O`Ge|4
* To change this template, choose Tools | Options and locate the template under 0ZjinWkR[
* the Source Creation and Management node. Right-click the template and choose SKrkB~%z
* Open. You can then make changes to the template in the Source Editor. pTIE.:g(
*/ q5u"v
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package com.tot.count; @#KZ2^
import tot.db.DBUtils; <jHo2U8/"s
import java.sql.*; ~91) DNaE
/** 6xAR:
* A]q"+Z]
* @author 2]/[
*/ !i*bb~
public class CountControl{ OAd}#R\U
private static long lastExecuteTime=0;//上次更新时间 Uh8c!CA8:\
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 "[p-Iy1
/** Creates a new instance of CountThread */ <-K'9ut,
public CountControl() {} @G:aW\Z
public synchronized void executeUpdate(){ N!W2O>VS
Connection conn=null; 0ntf%#2{
PreparedStatement ps=null; $ru()/pI)z
try{ CiTjRJ-ZW)
conn = DBUtils.getConnection(); pv){R;f
conn.setAutoCommit(false); `w/`qG:dK
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 9|9Hk1
for(int i=0;i<CountCache.list.size();i++){ {8Uk]
CountBean cb=(CountBean)CountCache.list.getFirst(); D_)n\(3
CountCache.list.removeFirst(); zTQTmO
ps.setInt(1, cb.getCountId()); TE t+At`]
ps.executeUpdate();⑴ ~(/OB
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//ps.addBatch();⑵ F)^:WWVc#
} ?Z[`sm
//int [] counts = ps.executeBatch();⑶ wSd o7Lb
conn.commit(); #JIh-h@
}catch(Exception e){ Fi_JF;
e.printStackTrace(); ?5MOp
} finally{ mq*Efb)!
try{ FCMV1,
if(ps!=null) { +4*jO5EZ
ps.clearParameters(); :{ Q[kYj
ps.close(); y:+4-1
ps=null; s6| S#
} y?*4SLy
}catch(SQLException e){} MH=;[ | N
DBUtils.closeConnection(conn); ^i!6q9<{e
} BA t0YE`-,
} yPhTCr5pK
public long getLast(){ %`1p 8>n
return lastExecuteTime; m C&*K
} \C.s%m
public void run(){ )mF;^3
long now = System.currentTimeMillis(); =w <;tb
if ((now - lastExecuteTime) > executeSep) { {e'V^l.v
//System.out.print("lastExecuteTime:"+lastExecuteTime); X23#y7:
//System.out.print(" now:"+now+"\n"); -VVJf5/
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); CBvvvgI o
lastExecuteTime=now;
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executeUpdate(); LIZsDTU
} j`A 3N7;
else{ x\MzMQ#Bf
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); xgV(0H}Mf
} B6gn(w3
} pwG" _|h
} vRn"0Mzl8
//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 ,U^V]jC
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类写好了,下面是在JSP中如下调用。 m"y_@Jk
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<% 0k\BE\PQk
CountBean cb=new CountBean(); (viGL|Ogn
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); bw& U[|A0%
CountCache.add(cb); ^a+H`RD
out.print(CountCache.list.size()+"<br>"); s8
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CountControl c=new CountControl(); WY 'QhieH
c.run(); :kz"Wya.
out.print(CountCache.list.size()+"<br>"); ;+-M+9"?O
%>