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: t@HE.h
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CountBean.java pq&c]8H
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/* 7=AKQ7BB>b
* CountData.java vZDQ@\HrC
* ,`7GI*Vq
* Created on 2007年1月1日, 下午4:44 Cp* n2
* 8Z!ea3kAT
* To change this template, choose Tools | Options and locate the template under K/,lw~>
* the Source Creation and Management node. Right-click the template and choose mDmWTq\
* Open. You can then make changes to the template in the Source Editor. r4lG 5dV
*/ |5/[0V-vy
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package com.tot.count; mHMej@
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/** KE3v3g<
* o <'gM]$
* @author ]/']{*T1
*/ D_)vGvv3;.
public class CountBean { T:&+#0<
private String countType; N.`]D)57
int countId; @&W?e?O ~G
/** Creates a new instance of CountData */ C(P$,;6
public CountBean() {} ~<U3KB
public void setCountType(String countTypes){ t}FMBGo[
this.countType=countTypes; +J4t0x
} %dU}GYL_
public void setCountId(int countIds){ /YbL{G
)j}
this.countId=countIds; eBV{B70k
} 7| T:TbY>
public String getCountType(){ ^Bb_NcU
return countType; HW G~m:km
} S_CtEM
public int getCountId(){ vSA%A47G
return countId; FTfA\/tl(;
} /fq6-;co+
} PS22$_}
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CountCache.java 0R]CI
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/* A!kyga6F5
* CountCache.java Mt Z(\&~
* QBy*y $
* Created on 2007年1月1日, 下午5:01 D=>^m=?0
* +;Gl>$
* To change this template, choose Tools | Options and locate the template under ~e+w@ lK
* the Source Creation and Management node. Right-click the template and choose Q=8
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* Open. You can then make changes to the template in the Source Editor. u3:Q t2^S
*/ ,')bO*Ng
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package com.tot.count; b9N4Gr
import java.util.*; #0D.37R+k
/** |7$h@KF=S
* TH!8G,(w
* @author pQ Y>
*/ Q2NnpsA^6
public class CountCache { G~L?q~b
public static LinkedList list=new LinkedList(); `RcNqPY#S
/** Creates a new instance of CountCache */ RX1{?*r]Z
public CountCache() {} 4g9b[y~U
public static void add(CountBean cb){ \ c&)8.r
if(cb!=null){ <yPHdbF
list.add(cb); ,9qB}HG
} SEIu4
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} N0[I2'^.
} Ol9fwd
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CountControl.java PuJ{!S\T7
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/* { NJ>[mKg
* CountThread.java 9VE;I:NO3
* H@ms43v\
* Created on 2007年1月1日, 下午4:57 QP%Fz#u`
* ek)(pJ(+#
* To change this template, choose Tools | Options and locate the template under WtfOE@h
* the Source Creation and Management node. Right-click the template and choose jPNfLwVkl:
* Open. You can then make changes to the template in the Source Editor. N08n/u&cr,
*/ P{!:pxu[
*h:EE6|
package com.tot.count; +[/r^C
import tot.db.DBUtils; 8M9\<k6
import java.sql.*; ^&H=dYcV>/
/** A'1AU:d
* R?~h7 d
* @author Z3>xpw G
*/ ~+egu89'TU
public class CountControl{ jYX9;C;J
private static long lastExecuteTime=0;//上次更新时间 tC:,!4 P$
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 TrU@mYnE
/** Creates a new instance of CountThread */ \{zAX~k6
public CountControl() {} bV*zMoD#
public synchronized void executeUpdate(){ A9Wqz"[
Connection conn=null; vfUfrk@D~
PreparedStatement ps=null; Gc!8v}[7J
try{ s;7qNwYO
conn = DBUtils.getConnection(); %*c|[7Z~V
conn.setAutoCommit(false); (iOCzZ6S
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); /^3oq]
for(int i=0;i<CountCache.list.size();i++){ -QPWi2:k
CountBean cb=(CountBean)CountCache.list.getFirst(); BemkCj2
CountCache.list.removeFirst(); lp-Zx[#`}C
ps.setInt(1, cb.getCountId()); Cw&D}
ps.executeUpdate();⑴ G5#}Ed4
//ps.addBatch();⑵ )?&kQ^@v
} Y;F
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//int [] counts = ps.executeBatch();⑶ ?s)sPM?
conn.commit(); ,Kf8T9z`
}catch(Exception e){ -wQ^oOJ
e.printStackTrace(); J%:/<uCmZ
} finally{ 4)+IO;
try{ %Rep6=K*$
if(ps!=null) { p
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ps.clearParameters(); +c8AbEewg
ps.close(); ;c-
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ps=null; iEVA[xy=D
} xY'qm8V
}catch(SQLException e){} -^4bA<dCCE
DBUtils.closeConnection(conn); R:OU>HsdX
} ~]W[ {3 ;
} ZoON5P>
public long getLast(){ 9jR[:[
return lastExecuteTime; <cv2-?L{
} ~8xh0TSi
public void run(){ $7n#\h
long now = System.currentTimeMillis(); d&T6p&V$
if ((now - lastExecuteTime) > executeSep) { CLY6 YB' R
//System.out.print("lastExecuteTime:"+lastExecuteTime); XMEK5Z9Dd
//System.out.print(" now:"+now+"\n"); 3$N %iE6
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); c Z6p^
lastExecuteTime=now; Wda\a.bXT
executeUpdate(); 5`"*y iv
} x , Vh
else{ 4Wla&yy
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 1Y"35)CR)
} =Esbeb7P
} nl'J.dJe
} yMbcFDlBr
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 <Hh5u~
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类写好了,下面是在JSP中如下调用。 te;Ox!B&
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<% oB0 8
CountBean cb=new CountBean(); ] `B,L*m6
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); N$%61GiulT
CountCache.add(cb); >{ECyh;
out.print(CountCache.list.size()+"<br>"); &7($kj
CountControl c=new CountControl(); r2SJp@f
c.run(); uGa(_ut
out.print(CountCache.list.size()+"<br>"); 'l'
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%>