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: a[v0%W ]u
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CountBean.java \K_ET> !
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/* O ~(pg
* CountData.java !ds"9w
* 1;d$#j
* Created on 2007年1月1日, 下午4:44 8a&:6Zuo
* t![7uU.W
* To change this template, choose Tools | Options and locate the template under fs|)l$Rd
* the Source Creation and Management node. Right-click the template and choose 2{M^,=^>
* Open. You can then make changes to the template in the Source Editor. VGLaN%|
*/ t$+?6E
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package com.tot.count; yTyj'-4
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/** ".f ;+wH
* [N FFB96
* @author iF*:d
*/ LO'**}vm
public class CountBean { -Q2, "
private String countType; Bm.afsM;
int countId; F^l[GdUosK
/** Creates a new instance of CountData */ Y4%:7mw~=
public CountBean() {} DDvh4<Hk
public void setCountType(String countTypes){ sJ\BF
this.countType=countTypes; ke{8 ^X~#
} 7t3X)Ah
public void setCountId(int countIds){ 4)E_0.C
this.countId=countIds; #w;v0&p
} 9*$t!r{B@
public String getCountType(){ +U:$(UV'A
return countType; tWo{7) Eb
} _my"%@n
public int getCountId(){ 3sc+3-TF
return countId; *RT>`,t/
} T}
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} y@]_+2Vo
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CountCache.java }L
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/* \:R%4w#Jv
* CountCache.java $v,dz_O*\
* ai}mOyJs
* Created on 2007年1月1日, 下午5:01 8][nmjk0
* <CRP^_c
* To change this template, choose Tools | Options and locate the template under QU#w%|
* the Source Creation and Management node. Right-click the template and choose d^/3('H6
* Open. You can then make changes to the template in the Source Editor. #1J &7F1
*/ Yi
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package com.tot.count; BMhy=+\
import java.util.*; [vge56h
/** 832v"kCD
* ,/[6e\0~
* @author k")R[)92b?
*/ Z/Eb:
public class CountCache { L9-h;] x!
public static LinkedList list=new LinkedList(); BNz 5lrfq
/** Creates a new instance of CountCache */ +nUy,S?43
public CountCache() {} P
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public static void add(CountBean cb){ NIh:DbE
if(cb!=null){ hZ[E7=NTQ^
list.add(cb); -7m:91x
} _AYXc] 4%
} OtSL*'7>
} .#wqXRd
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CountControl.java
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/* qd+h$ "p
* CountThread.java W>!_|[a
* ekI2icD
* Created on 2007年1月1日, 下午4:57 A2^\q>_#
* Kqun^"Df
* To change this template, choose Tools | Options and locate the template under R=.4
* the Source Creation and Management node. Right-click the template and choose S2n39 3
* Open. You can then make changes to the template in the Source Editor. 4!$s}V=6
*/ za#s/b$[
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package com.tot.count; vQ<90ZxqB
import tot.db.DBUtils; %509\;el
import java.sql.*; zs%Hb48V
/** vesJEaw7
* &-s'BT[PGq
* @author ?P4w]a
*/ Pa(^}n|
public class CountControl{ .tkT<o-u<J
private static long lastExecuteTime=0;//上次更新时间
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private static long executeSep=60000;//定义更新间隔时间,单位毫秒 MzPzqm<
/** Creates a new instance of CountThread */ hbU+Usx
public CountControl() {} r~+\
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public synchronized void executeUpdate(){ |\_^B
Connection conn=null; rX*H)3F
PreparedStatement ps=null; ;g6M%;1-
try{ wg ^sGKN
conn = DBUtils.getConnection(); b'P eH\h{
conn.setAutoCommit(false); w0|gG+x jS
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); jlp:lX
for(int i=0;i<CountCache.list.size();i++){ u4m,'XR
CountBean cb=(CountBean)CountCache.list.getFirst(); V I,ACj
CountCache.list.removeFirst(); ";BlIovT=R
ps.setInt(1, cb.getCountId()); 9V,!R{kO!
ps.executeUpdate();⑴ $=5=NuX
//ps.addBatch();⑵ BQBeo&n6
} R E}?5XHb
//int [] counts = ps.executeBatch();⑶ :
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conn.commit(); Ib|Rf;J~-
}catch(Exception e){ CL)lq)1(
e.printStackTrace(); >:zK?(qu,N
} finally{ :}r.
try{ uqM yoIc
if(ps!=null) { YWMGB#=
ps.clearParameters(); |_}2f
ps.close(); Bt1p'g(V|
ps=null; D6CS8
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} G+F#n6Vx
}catch(SQLException e){} J~B<7O<?!1
DBUtils.closeConnection(conn); 7Q7-vx
} e2z h&j
} m.px>v-
public long getLast(){ 9m|kgY# 4
return lastExecuteTime; p`nPhk,:b
} ;2@BO-3K
public void run(){ +zu(
long now = System.currentTimeMillis(); qzI&<4
if ((now - lastExecuteTime) > executeSep) { $KUos+%
//System.out.print("lastExecuteTime:"+lastExecuteTime); ?I/qE='*
//System.out.print(" now:"+now+"\n"); z>jUR,!GT
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); }K1JU`Lz
lastExecuteTime=now; T|6jGZS^|W
executeUpdate(); $BkubWM
} WJNl5^
else{ N;Dni#tQ`
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); z ^_*&
} zS\E/.X2
} n8uv#DsdK
} \ {qI4=
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 xfy1pS.[:
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类写好了,下面是在JSP中如下调用。 [vMvV4,
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<% pAb.c
CountBean cb=new CountBean(); SfJA(v@E
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); @Ukr
CountCache.add(cb); '; = f
out.print(CountCache.list.size()+"<br>"); XO-Prs
CountControl c=new CountControl(); {~h*2n
c.run(); BYO"u6
out.print(CountCache.list.size()+"<br>"); j=*l$RG
%>