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(F}[bP
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CountBean.java (,gpR4O[
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/* \+cU}
* CountData.java x)SW1U3TVx
* b$f@.L
* Created on 2007年1月1日, 下午4:44 Qw{LD+r(
* bnz2\C9^
* To change this template, choose Tools | Options and locate the template under ]S6`",+)<f
* the Source Creation and Management node. Right-click the template and choose %U&O
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* Open. You can then make changes to the template in the Source Editor. {/C
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*/ 5xm^[o2#y
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package com.tot.count; wW~y?A"{2
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/** H?~|Uj 6
* zw`T^N#
* @author c7[<X<yk
*/ <#s=78
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public class CountBean { L*Mt/
private String countType; p`)GO.pz
int countId; .X;zEyd
/** Creates a new instance of CountData */ mZ^z%+Ca|
public CountBean() {} \G?GX
public void setCountType(String countTypes){ 7|IOn5
this.countType=countTypes; E*ug.nxy
} K 9ytot
public void setCountId(int countIds){ 'E{n1[b
this.countId=countIds; nVF?.c
} Dk!;s8}*c
public String getCountType(){ +mQMzZZTZ
return countType; 9y(75Bn9
} R&cOhUj22J
public int getCountId(){ 37hs/=x
return countId; R#ABda9
} JC~L!)f
} j9@7\N<
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CountCache.java 0^41dfdE
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/* +rw?k/
* CountCache.java HJVi:;o
* H uPw?8w=
* Created on 2007年1月1日, 下午5:01 .Vm!Ng )j
* sw.cw}1
* To change this template, choose Tools | Options and locate the template under |F
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* the Source Creation and Management node. Right-click the template and choose P8N`t&r"7
* Open. You can then make changes to the template in the Source Editor. *OOi
*/ +/tNd2
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package com.tot.count; $^Is|]^
import java.util.*; j@xerY
/** ]Q Y:t:-
* IJxBPwh
* @author nyyKA_#:5
*/ ~C1lbn b
public class CountCache { i`3h\ku
public static LinkedList list=new LinkedList(); `ZCeuOH
/** Creates a new instance of CountCache */ ^ lrq`1k
public CountCache() {} (!72Eaw:]
public static void add(CountBean cb){ .E'Tfa
if(cb!=null){ CdCo+U5z{
list.add(cb); B{UL(6\B
} sb Wn1 T
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} 9`P<|(
} >h^CC*&'pw
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CountControl.java H ?Vo#/
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/* I}djDtJ
* CountThread.java S V2DvrIR
* ,(H`E?m1w4
* Created on 2007年1月1日, 下午4:57 {tUjUwhz(
* 8$k `bZ
* To change this template, choose Tools | Options and locate the template under _l`d+
\#
* the Source Creation and Management node. Right-click the template and choose
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* Open. You can then make changes to the template in the Source Editor. ~=$0=)c
*/ J9!}8uD
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package com.tot.count; _4eSDO[h
import tot.db.DBUtils; ;B4x>
import java.sql.*; ldd|"[Ds
/** ]ZV.@%+
* v6Vie o=
* @author J!O{.v
*/ ,/?7sHK-0
public class CountControl{ h<)YZ[;x
private static long lastExecuteTime=0;//上次更新时间 nQe^Bn
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 o~Jce$X
/** Creates a new instance of CountThread */ b-Q*!Ut
public CountControl() {} bXSsN\:Y@[
public synchronized void executeUpdate(){ x*]&Ca0+
Connection conn=null; >o=O^:/L
PreparedStatement ps=null; H =Y7#{}
try{ #2`ST=#
conn = DBUtils.getConnection(); vL>cYbJ<
conn.setAutoCommit(false); _[D6WY+
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); *C/bf)w
for(int i=0;i<CountCache.list.size();i++){ ,t"?~Hl".
CountBean cb=(CountBean)CountCache.list.getFirst(); =<,>dBs}\
CountCache.list.removeFirst(); ^HJvT)e4
ps.setInt(1, cb.getCountId()); p:*)rE
ps.executeUpdate();⑴ v:2*<;
//ps.addBatch();⑵ DhN{Y8'~
} s(~tL-_ K
//int [] counts = ps.executeBatch();⑶ m2%OX"# e
conn.commit(); B|\pzWD%
}catch(Exception e){ 1r!o,0!d-'
e.printStackTrace(); M]FA
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} finally{ 6Z09)}tZb
try{ :%_*C09
if(ps!=null) { (u/-ud1p
ps.clearParameters(); :Ma=P\J
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ps.close(); ORVFp]gG
ps=null; c[p>*FnP
} =t[hs l
}catch(SQLException e){} nK95v}p}Y
DBUtils.closeConnection(conn); Gi=sJV
} Ue:LKK1Gsr
} vBFMne1h
public long getLast(){ Pu|PIdu!08
return lastExecuteTime; (R'GrN>
} mEL<d,XhI
public void run(){ .<#oLM^
long now = System.currentTimeMillis(); yf >
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if ((now - lastExecuteTime) > executeSep) { d-GU164
//System.out.print("lastExecuteTime:"+lastExecuteTime); ,iUWLcOM
//System.out.print(" now:"+now+"\n"); ;rp("<g:>
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); Z2Q'9C},m
lastExecuteTime=now; Alo;kt@x
executeUpdate(); w'[^RZW:j
} c@eQSy
else{ j ^Tb=
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n");
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} uPe&i5YR
} p(B^](?
} ,, 8hU7P
//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 SRU}-
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类写好了,下面是在JSP中如下调用。 35q4](o9"
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<% [h5~1N
CountBean cb=new CountBean(); fGZZ['E
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); x9DG87P~+
CountCache.add(cb); rI'kGqU
out.print(CountCache.list.size()+"<br>"); ^bD)Tg5K
CountControl c=new CountControl(); *Z9Rl>
c.run(); DGc5Lol~
out.print(CountCache.list.size()+"<br>"); hSl6X3W
%>