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: l $\2|D
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CountBean.java AJEbiP
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/* 8bdO-LJ9
* CountData.java R&.&x'<
* 0}NDi|o
* Created on 2007年1月1日, 下午4:44 hxMRmH[f:
* Y,0Z&6 <
* To change this template, choose Tools | Options and locate the template under 2H.g!( Oza
* the Source Creation and Management node. Right-click the template and choose /}~=)QHH
* Open. You can then make changes to the template in the Source Editor. 7yyX8p>
*/ Rkg8
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package com.tot.count; U&BCd$
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/** T(x@gwc
* L5x;#\#p
* @author WyatHC
*/ ?K7uy5Y
public class CountBean { K0j%\]\Tp
private String countType; G4SA
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int countId; W..*!UGl
/** Creates a new instance of CountData */ LEPLoF3,
public CountBean() {} *4%pXm;
public void setCountType(String countTypes){ EOu[X'gLr
this.countType=countTypes; ) dk|S\
} 9!X3Cv|+L
public void setCountId(int countIds){ uOzoE_i
this.countId=countIds; G8+&fn6
} rN|=cn
public String getCountType(){ ?{"r(
return countType; <{k{Coy
} 2YZ>nqy
public int getCountId(){ 6ScB:8M
return countId; q-;Y }q
} ;]grbqXVE
} M;y*`<x
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CountCache.java :<zIWje
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/* ^4$4x
* CountCache.java .o`Io[io
* o+=wQ$"tP
* Created on 2007年1月1日, 下午5:01 2mzn{S)nV
* P05`DX}r,
* To change this template, choose Tools | Options and locate the template under /J-'[Mc'D[
* the Source Creation and Management node. Right-click the template and choose xkRMg2X.>9
* Open. You can then make changes to the template in the Source Editor. kqih`E9P7B
*/ Skci;4T(
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package com.tot.count; k^;n$r"i5
import java.util.*; wO%lM
/** +U<YM94?
* M;<!C%K>
* @author g=nb-A{#
*/ _:Xmq&<W
public class CountCache { Nf!N;Cy?
public static LinkedList list=new LinkedList(); iS+"Jsz
/** Creates a new instance of CountCache */ .kFO@:
public CountCache() {} 7s6+I_n
public static void add(CountBean cb){ Ed u(dZbKg
if(cb!=null){ {DP9^hg
list.add(cb); WlQCP C
} @;OsHudd
} o]&q'>Rf
} /jJD
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CountControl.java `$JvWN,kB
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/* Qb?a[[3
* CountThread.java !gW`xVGv
* \;N+PE
* Created on 2007年1月1日, 下午4:57 o+{,>t
* AA[1[
* To change this template, choose Tools | Options and locate the template under Jfr'OD2$ %
* the Source Creation and Management node. Right-click the template and choose WT,I~'r=S
* Open. You can then make changes to the template in the Source Editor. bT 42G[x
*/ n',X,P0
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package com.tot.count; )M0(vog
import tot.db.DBUtils; Q/?`);
import java.sql.*; &v .S_Ym
/** C5 ILVQ
* 1z7+:~;l
* @author *:TwO=)
*/ dlfjx
public class CountControl{ r2\%/9uO
private static long lastExecuteTime=0;//上次更新时间 sc+%v1Y#}
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 69r%b7#
/** Creates a new instance of CountThread */ ~*1>)P8]#
public CountControl() {} Vv+nq_
public synchronized void executeUpdate(){ 7<]&pSt=
Connection conn=null; %OgK{h
PreparedStatement ps=null; i
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try{ K_L7a>Fr
conn = DBUtils.getConnection(); &T, ,fz$
conn.setAutoCommit(false); I1>f2/$z*
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); Cydo~/
for(int i=0;i<CountCache.list.size();i++){ u|}\Af
CountBean cb=(CountBean)CountCache.list.getFirst(); u~uz=Yse
CountCache.list.removeFirst(); m
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ps.setInt(1, cb.getCountId()); 79>x/jZka
ps.executeUpdate();⑴ .Xp,|T
//ps.addBatch();⑵ ZPw4S2yw3.
} c\o_U9=n
//int [] counts = ps.executeBatch();⑶ w~Q\:<x&~Z
conn.commit(); Sc{&h8KMTb
}catch(Exception e){ DDkN3\w
e.printStackTrace(); h?dSn:Y\?
} finally{ heIys.p
try{ D+uo gRS61
if(ps!=null) { v[uVAbfQ
ps.clearParameters(); V.`hk^V,
ps.close(); J&\Q3_vro9
ps=null; \wz^Z{U
} IQ\!wWKmY
}catch(SQLException e){} &_Cc
DBUtils.closeConnection(conn); ib(|}7Je
} bgE]Wk0
} 0o$RvxJ
public long getLast(){ 0(+<uo~6p1
return lastExecuteTime; m33&obSP
} i5le0lM
public void run(){ Awfd0L;9
long now = System.currentTimeMillis(); =Ks&m4
if ((now - lastExecuteTime) > executeSep) { UNb7WN
//System.out.print("lastExecuteTime:"+lastExecuteTime); T U_'1
//System.out.print(" now:"+now+"\n"); 0cB]:*W
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); .?NfV%vv
lastExecuteTime=now; vT{(7m!Ra
executeUpdate(); p9i7<X2&
} no-";{c
else{ 6
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//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); [7.Num_L
} ek5j;%~g1
} _$T
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} qfT9g>EF
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 c}OveR$'&
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类写好了,下面是在JSP中如下调用。 ^n~Kr1}nj
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<% BKTTta1mY
CountBean cb=new CountBean(); xS@jV6E~
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); (^B1Kt!<
CountCache.add(cb); prS%lg>
out.print(CountCache.list.size()+"<br>"); /Hk})o_
CountControl c=new CountControl(); Y{j~;G@Wl
c.run(); `/m]K~~
out.print(CountCache.list.size()+"<br>"); hb8oq3*x
%>