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: 5\\#kjjx
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CountBean.java <//82j+px
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/* v[$-)vs*ag
* CountData.java (<M^C>pldf
* nP]tc
* Created on 2007年1月1日, 下午4:44 s*'L^>iZ
* 6yDj1PI
* To change this template, choose Tools | Options and locate the template under E`E$ }iLs
* the Source Creation and Management node. Right-click the template and choose Q1ox<-
* Open. You can then make changes to the template in the Source Editor. '5^$v{
*/ TFZvZi$u&
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package com.tot.count; l>(w]
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/** }s*H|z
* euxkw]`h6
* @author '*4>&V.yX
*/
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public class CountBean { Tbf@qid e
private String countType; A%Ov.~&\G
int countId; 1yFVF
/** Creates a new instance of CountData */ ^{ Kj{M22
public CountBean() {} ioIOyj
public void setCountType(String countTypes){ B: '}SA{
this.countType=countTypes; N3M:|D
}
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public void setCountId(int countIds){ ;HKb
this.countId=countIds; @ve4rc/LI
} <V> [H7
public String getCountType(){ rwZI;t$hf
return countType; tQ:g#EqL9B
} tVAWc$3T
public int getCountId(){
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return countId; ^A&i$RRO
} jwP}{mi*
} ;q=0NtCS=4
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CountCache.java g]fds Zv
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/* AD$$S.zoD<
* CountCache.java |3Fo4K%+
* Mz?xvP?z
* Created on 2007年1月1日, 下午5:01 fG *1A\t]
* P4\{be>e
* To change this template, choose Tools | Options and locate the template under "PFczoRZ
* the Source Creation and Management node. Right-click the template and choose E?VPCx
* Open. You can then make changes to the template in the Source Editor. 0r4,27w
*/ &1=Je$,
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package com.tot.count; 9EPE.+ns
import java.util.*; v jTs[eq>
/** YsX&]4vzm
* 2yB@)?V/
* @author n;Nr[hI
*/ *qX!
public class CountCache { p"xti+2,
public static LinkedList list=new LinkedList(); o{W4@:Ib
/** Creates a new instance of CountCache */ R*"31&3le4
public CountCache() {} Qkk3>{I
public static void add(CountBean cb){ +*W9*gl
if(cb!=null){ 3 s @6pI
list.add(cb); ^)JUl!5j]C
} |8QXjzH
} 2H,^i,
} sIVVF#0}]
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CountControl.java Sckt gp8
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/* ]+U:8*
* CountThread.java U-U^N7
* NmH1*w<A
* Created on 2007年1月1日, 下午4:57 g6s&nH`Z2
* @Cnn8Y&'
* To change this template, choose Tools | Options and locate the template under {OH
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* the Source Creation and Management node. Right-click the template and choose b I%Sq+"}
* Open. You can then make changes to the template in the Source Editor. pBZf=!+E
*/ 2qA"emUM
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package com.tot.count; Czl4^STiC
import tot.db.DBUtils; z<3{.e\e
import java.sql.*; #5Q?Q~E@
/** "M-zBBY ]
* Hm>7|!
* @author yLC5S3^1\"
*/ &J]|pf3m
public class CountControl{ 1WTDF
private static long lastExecuteTime=0;//上次更新时间 eX{:&Do
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 B4&K2;fg_
/** Creates a new instance of CountThread */ \zdY$3z
public CountControl() {} _`oP*g =
public synchronized void executeUpdate(){ rXIFCt8J
Connection conn=null; k=nN#SMn
PreparedStatement ps=null; @Sik~Mm_h
try{ y ~PW_,
conn = DBUtils.getConnection(); 3d1$w
conn.setAutoCommit(false); =do*(
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); HsF8$C$z
for(int i=0;i<CountCache.list.size();i++){ lc:dKGF6
CountBean cb=(CountBean)CountCache.list.getFirst(); (plsL
CountCache.list.removeFirst();
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ps.setInt(1, cb.getCountId()); \*wQ%_N5
ps.executeUpdate();⑴ ~ z< &vQ=
//ps.addBatch();⑵ #`g..3ey
} u|.c?fW'3
//int [] counts = ps.executeBatch();⑶ EgYM][:UU
conn.commit(); M0B6v}^H
}catch(Exception e){ ^(Y}j8sj
e.printStackTrace(); \68x]q[
} finally{ @nh*H{
try{ O BCH%\;g
if(ps!=null) { 7_=7 ;PQ<
ps.clearParameters(); nfldj33*
ps.close(); 9=l6NNe)|
ps=null; i"B q*b@
} 9s.x%m,
}catch(SQLException e){} 1"hd5a
DBUtils.closeConnection(conn); hoj('P2a#n
} FFG/v`NM
} L[j73z'
public long getLast(){ 9 rMP"td
return lastExecuteTime; A>bpP
} ycD}7
public void run(){ ~xp(k
long now = System.currentTimeMillis(); SU`RHAo
if ((now - lastExecuteTime) > executeSep) { $-=QT X
//System.out.print("lastExecuteTime:"+lastExecuteTime); K> rZJ[a
//System.out.print(" now:"+now+"\n"); P3W<a4 ==
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ^zfO=XN
lastExecuteTime=now; hx5oTJR
executeUpdate(); G\;a_]Q
} ytDp
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else{ 76} a
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); %k"qpu
} z5>
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} +=N!37+G
}
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//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 5PRS|R7
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类写好了,下面是在JSP中如下调用。 7GFE5>H
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<% hoDE*>i
CountBean cb=new CountBean(); +H4H$H
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); N Dqvt$
CountCache.add(cb); j "^V?e5
out.print(CountCache.list.size()+"<br>"); 2!Gb4V
CountControl c=new CountControl(); O^2@9
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c.run(); /uNgftj
out.print(CountCache.list.size()+"<br>"); W5f|#{&L:
%>