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: qRTy}FU1
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CountBean.java y6;A4p>
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/* BsRxD9r
* CountData.java 'r3I/qg*m
* {G_ZEo#x8,
* Created on 2007年1月1日, 下午4:44 )
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* \
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* To change this template, choose Tools | Options and locate the template under XD9lox
* the Source Creation and Management node. Right-click the template and choose )fv0H&g
* Open. You can then make changes to the template in the Source Editor. l,L#y4#
*/ *V5R[
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package com.tot.count; xoPpu
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/** qY0p)`3!%
* tZwZZ0]Z
* @author Hcuvu[)T"
*/ `}"*i_0-5'
public class CountBean { ;ZB[g78%R%
private String countType; Q
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int countId;
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/** Creates a new instance of CountData */ lkOugjI
public CountBean() {} `9%@{Ryo
public void setCountType(String countTypes){ Kh}#At^C8e
this.countType=countTypes; 5^*I]5t8
} ,SH))%Cyt
public void setCountId(int countIds){ c:M~!CXO
this.countId=countIds; L3,p8-d9Z
} Beqzw0
public String getCountType(){ eNpGa0 eG
return countType; Y0
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} ~[t%g9
public int getCountId(){ b v~"_)C
return countId; K'Wg_ihA
} p8frSrcU
} ]^p6dbzWe
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CountCache.java hgL wxJu
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/* <Zl}u:(w
* CountCache.java >d&B:
* N!{('po
* Created on 2007年1月1日, 下午5:01 gYw4YP0Gz
* z`y!C3w<
* To change this template, choose Tools | Options and locate the template under ilHZx2k
* the Source Creation and Management node. Right-click the template and choose EE=!Y NP]
* Open. You can then make changes to the template in the Source Editor. d@JjqE[
*/ { owK~
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package com.tot.count; &82Za%
import java.util.*; \x5b=~/
/** ^giseWR(
* '1_CMr
* @author $OldHe[p
*/ 6=0"3%jn@
public class CountCache { .Ce30VE-
public static LinkedList list=new LinkedList(); mfc\w'
/** Creates a new instance of CountCache */ pqmtN*zV
public CountCache() {} |VQ17*4ff1
public static void add(CountBean cb){ 8m\*~IX=
if(cb!=null){ Bq3" l%hI
list.add(cb); jhOQ)QE|
} 5ro^<P0f**
} |
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} #(=8
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CountControl.java qwM71B!r
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/* %F_)!M;x
* CountThread.java F<39eDNpz
* "N>~]
* Created on 2007年1月1日, 下午4:57 D,b'1=
* FL*qV"r^n
* To change this template, choose Tools | Options and locate the template under XEl-5-M"
* the Source Creation and Management node. Right-click the template and choose )O*\}6:S
* Open. You can then make changes to the template in the Source Editor. 3|x*lmit
*/ e:D8.h+&}
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package com.tot.count; eg!s[1[_
import tot.db.DBUtils; WdI9))J2S
import java.sql.*; yyB;'4Af
/** jfF
* G<:_O-cPSv
* @author 7uQiP&v
*/ %? -E)n[
public class CountControl{ BJC$KmGk
private static long lastExecuteTime=0;//上次更新时间 0}H7Xdkp
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 c&me=WD
/** Creates a new instance of CountThread */ d5jZ?
public CountControl() {} *oZ]k`-!8
public synchronized void executeUpdate(){ (dmLEt
Connection conn=null; ?gD^K,A Hd
PreparedStatement ps=null; 3Z/_}5%"
try{ Pfi|RTX$'*
conn = DBUtils.getConnection(); `Y]t*`
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conn.setAutoCommit(false); $FXlH;_7
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); W>W b|W
for(int i=0;i<CountCache.list.size();i++){ HueGARS
CountBean cb=(CountBean)CountCache.list.getFirst(); )}w2'(!X8
CountCache.list.removeFirst(); PgHe;^?j
ps.setInt(1, cb.getCountId()); In13crr4!
ps.executeUpdate();⑴ x#
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//ps.addBatch();⑵ W'lejOiw
} ~j3O0s<gK
//int [] counts = ps.executeBatch();⑶ c[VVCN8dA
conn.commit(); ;\a?xtIy
}catch(Exception e){ ,Y9bXC8+dU
e.printStackTrace(); ~P!\;S
} finally{ w]1hoYuV
try{ eLF xGZ Z
if(ps!=null) { u|(;SY
ps.clearParameters(); hvW FzT5
ps.close(); lEAf\T7
ps=null; # `L?24%
} Ck1{\=t
}catch(SQLException e){} iepolO=
DBUtils.closeConnection(conn); t?1b(oJ
} u-</G-y
} wH]5VltUT1
public long getLast(){ ,i RUR8
return lastExecuteTime; "qh~wK J
} {0L.,T~g+[
public void run(){ =1#obB
long now = System.currentTimeMillis(); m4\e`nl
if ((now - lastExecuteTime) > executeSep) { D*=.;Rq
//System.out.print("lastExecuteTime:"+lastExecuteTime); {:;6 *W
//System.out.print(" now:"+now+"\n"); c o 8bnH
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ( fNG51h!
lastExecuteTime=now; qkXnpv
executeUpdate(); ~dXiyU,y2
} ;*(i}'
else{ (>49SOu;$\
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ~}"5KX\=#
} C*X=nezq
} ibP IT!5c
} l6_dVK;s
//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 iHa:6
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类写好了,下面是在JSP中如下调用。 R1C}S
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<% >;Ag7Ex
CountBean cb=new CountBean(); \^o I3K0`
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); <#nt?Xn
CountCache.add(cb); s,CN<`/>x
out.print(CountCache.list.size()+"<br>"); x`:c0y9uG
CountControl c=new CountControl(); PQj 'D<G
c.run(); XgI;2Be+&a
out.print(CountCache.list.size()+"<br>"); 0ZM#..3sI
%>