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: r:WgjjA%
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CountBean.java iX>!ju'V
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/* zT4ulXN
* CountData.java 9znx1AsN
* |=^#d\?]j
* Created on 2007年1月1日, 下午4:44 *Sz{DE1U
* @
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* To change this template, choose Tools | Options and locate the template under },Y;
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* the Source Creation and Management node. Right-click the template and choose (IWix){
* Open. You can then make changes to the template in the Source Editor. FVC2 XxP
*/ <*r<+S
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package com.tot.count; aaqd:N)
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/** &JXHDpd$a^
* U>plv
* @author xvx\H'
*/ m`yn9(1Y[
public class CountBean { 5|~r{w)9
private String countType; lM|WOmD
int countId; @7HOL-i
/** Creates a new instance of CountData */ %.Tf u0M
public CountBean() {} {YKMQI^O/
public void setCountType(String countTypes){ \9|]
this.countType=countTypes; picP_1L
} $*v 20
public void setCountId(int countIds){ !6tC[W`
this.countId=countIds; ?CT^Zegmr
} PkCeV]`w
public String getCountType(){ ssr)f8R#,#
return countType; CI~;B
} 5%Fn^u:
public int getCountId(){ SX?$H~A
return countId; ^;k _
} Nh\8+v*+{
} DKVt8/vq
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CountCache.java H-cBXp5z
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/* >NOYa3
* CountCache.java hRy}G'0
* ]6VUqFO)
* Created on 2007年1月1日, 下午5:01 t0V_ c'm
* }DUDA%U
* To change this template, choose Tools | Options and locate the template under " ;R3260
* the Source Creation and Management node. Right-click the template and choose PRk%C0`
* Open. You can then make changes to the template in the Source Editor. ^; V>}08
*/ 4h_4jqf=pU
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package com.tot.count; +}-W.H%` 0
import java.util.*; zloaU
/** SJ[@fUxO)
* \(>$mtS:
* @author 0rm;)[SjF
*/ b
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public class CountCache { ;~@PYIp
public static LinkedList list=new LinkedList(); j3[OY
/** Creates a new instance of CountCache */ 9;v"bcQ
public CountCache() {} nog\,NT
public static void add(CountBean cb){ 2E;%=e
if(cb!=null){ ,^IZ[D>u)
list.add(cb); HlL@{<
} 2-E71-J
} {O&liU4
} dYqDL<se/I
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CountControl.java vK.4JOlRF
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/* -L 'K
* CountThread.java 4^NHf|UJH
* "0 PN
* Created on 2007年1月1日, 下午4:57 np\Q&
* 7}1Kafs
* To change this template, choose Tools | Options and locate the template under +heS\I_Mp
* the Source Creation and Management node. Right-click the template and choose ])wMUJWg2
* Open. You can then make changes to the template in the Source Editor. /qq&'}TZP
*/ wY
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package com.tot.count; yg[;
import tot.db.DBUtils; x>9EVa)
import java.sql.*; F.
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/** --%2=.X=
* OYtus7q<
* @author WZ6{(`;#m
*/ &'yV:g3H
public class CountControl{ o>A%}YU
private static long lastExecuteTime=0;//上次更新时间 !g&B)0u]*
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 KZ}4<{3
/** Creates a new instance of CountThread */ >)A
public CountControl() {} !6/IKh`J
public synchronized void executeUpdate(){ t02"v4_i
Connection conn=null; g+/U^JIc4l
PreparedStatement ps=null; 3N%Evo
try{ 6dy4{i
conn = DBUtils.getConnection(); UuqnL{
conn.setAutoCommit(false); 8kc'|F\
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); rH:X/i;D
for(int i=0;i<CountCache.list.size();i++){ /~rO2]rZ@
CountBean cb=(CountBean)CountCache.list.getFirst(); [pWDhY
CountCache.list.removeFirst(); l/UG+7
ps.setInt(1, cb.getCountId()); [<fLPa
ps.executeUpdate();⑴ 8'xnhV
//ps.addBatch();⑵ ,0~
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} 8Bt-
//int [] counts = ps.executeBatch();⑶ =XBXSW8)DJ
conn.commit(); x-#9i
}catch(Exception e){ Mh.eAM8 _
e.printStackTrace(); #DRtMrfat
} finally{ -*q2Y^A^l
try{ bfI -!,
if(ps!=null) { xAz4ZXj=q
ps.clearParameters(); J o(}#_y?
ps.close(); l(#Y8
ps=null; KC-aLq/
} nJ#@W b@
}catch(SQLException e){} E0Y/N?
DBUtils.closeConnection(conn); h_G7T1;L
} (dipKs?K
} #Ii.tTk
public long getLast(){ \q1%d.\X
return lastExecuteTime; zPkPC}f(O
} vhEs +j
public void run(){ }R5&[hxh4t
long now = System.currentTimeMillis(); Odtck9L
if ((now - lastExecuteTime) > executeSep) { ,k! f`
//System.out.print("lastExecuteTime:"+lastExecuteTime); %R"/`N9R,
//System.out.print(" now:"+now+"\n"); yaYt/?|
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); >`|uc
lastExecuteTime=now; &2]D+aL|h
executeUpdate(); HPdwx
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} y8S6ZtA}2
else{ q<uLBaL_]r
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); =pOY+S|
} +<WT$ddK=5
} [f(^vlK
} d>98 E9
//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 BF[?* b
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类写好了,下面是在JSP中如下调用。 ~%K(ou=2
% P)}(e6y
<% w&cyGd D5
CountBean cb=new CountBean(); uBkny;
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 7=*k@9
CountCache.add(cb); K$GXXE`
out.print(CountCache.list.size()+"<br>"); J+gsmP-_
CountControl c=new CountControl(); :{uUc
c.run(); $K fk=@
out.print(CountCache.list.size()+"<br>"); DmPsltpzQ
%>