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: } o=g)
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CountBean.java YlYTH_L>E
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/* TN0dfba[
* CountData.java avT>0b:
* U_!6pqFc
* Created on 2007年1月1日, 下午4:44 {:? -)Xq
* =A,i9Z&
* To change this template, choose Tools | Options and locate the template under _E1:3N|
* the Source Creation and Management node. Right-click the template and choose ul:jn]S*
* Open. You can then make changes to the template in the Source Editor. .qHgQ_%
*/ Bkcs4 x
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package com.tot.count; X2EC+<
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/** OW6i2 >Or
* bclA+!1
* @author z7GLpTa
*/ PB`94W
public class CountBean { 6.k2,C4dT<
private String countType; f-3lJ?6
int countId; }?H |9OS
/** Creates a new instance of CountData */ d-c+KV
public CountBean() {} 1c\$ziB
public void setCountType(String countTypes){ khyVuWN
this.countType=countTypes; "d{ |_Cf
} ;8ugI
public void setCountId(int countIds){ h>fY'r)DAx
this.countId=countIds; `"
} "EA%!P:d,
public String getCountType(){ aiz_6@Qfz*
return countType; eO*FoN
} "zYlddh
public int getCountId(){ Of-l<Ks\
return countId; L-q.Q
} -[G+*3Y{7
} eM{+R^8
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CountCache.java /5SBLp}Sy
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/* 0*+i~g,Kl@
* CountCache.java g_-Y-.M
* sv
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* Created on 2007年1月1日, 下午5:01 QKe=/;
* h19c*,0z!
* To change this template, choose Tools | Options and locate the template under >NK*$r8
* the Source Creation and Management node. Right-click the template and choose 1_f( ;WOg
* Open. You can then make changes to the template in the Source Editor. "*<9)vQ6|
*/ s<aJ pi{n4
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package com.tot.count; }ob#LC,
import java.util.*; EW|bs#l
/** QYDSE
* fyh9U_M);w
* @author |&3[YZY
*/ y&UcTE2;%(
public class CountCache { N<9CV!_
public static LinkedList list=new LinkedList(); 8|HuxE
/** Creates a new instance of CountCache */ #T&''a
public CountCache() {} 6gNsh
public static void add(CountBean cb){ HW)> `
if(cb!=null){ 7$Jb"s
list.add(cb); + C aPF
} 3Oy?_a$
} ]*D=^kA0[
} COZ<^*=A#p
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CountControl.java P|l62!m<
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/* I&
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* CountThread.java "sdzm%
* Ho2#'lSKM
* Created on 2007年1月1日, 下午4:57 Il `35~a
* }CIH1q3P
* To change this template, choose Tools | Options and locate the template under !g'kWE[
* the Source Creation and Management node. Right-click the template and choose ]MKW5Kq
* Open. You can then make changes to the template in the Source Editor. $qV, z
*/ ~+
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package com.tot.count; \QGh@AQp"
import tot.db.DBUtils; Y{ijSOl3
import java.sql.*; 49W@?:b
/** yb\T<*
* s IJl9
* @author ~=67#&(R
*/ bnIl@0Y
public class CountControl{ &e0BL z
private static long lastExecuteTime=0;//上次更新时间 m&a.i
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private static long executeSep=60000;//定义更新间隔时间,单位毫秒 9J+p.N
/** Creates a new instance of CountThread */ TF R8
public CountControl() {} `tw[{Wb
public synchronized void executeUpdate(){ P;4Y%Dq~Qo
Connection conn=null; q!iSY
PreparedStatement ps=null; _3~/Z{z8
try{ C>wOoXjt
conn = DBUtils.getConnection(); 4z%::?
conn.setAutoCommit(false); l1HMH?0|
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); jlXzfDT
for(int i=0;i<CountCache.list.size();i++){ `ECY:3"$KA
CountBean cb=(CountBean)CountCache.list.getFirst(); X$BN&DD
CountCache.list.removeFirst(); VokIc&!Uz
ps.setInt(1, cb.getCountId()); B>C+qj@
ps.executeUpdate();⑴ 'o}v{f
//ps.addBatch();⑵ xP/?E
} Is&0h|
//int [] counts = ps.executeBatch();⑶ .Q!_.LX
conn.commit(); Z uFk}R"x
}catch(Exception e){ C-)mP- |8
e.printStackTrace(); ad)jw:n
} finally{ )SU\s+"M
try{ hQ7-m.UZw
if(ps!=null) { 4*Uzomb?q
ps.clearParameters(); fab.%$
ps.close(); w}|XSJ!
ps=null; HKp|I%b]J
} x%_VzqR`
}catch(SQLException e){} =
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DBUtils.closeConnection(conn); RG&t0%yj}
} G.")Bg
} |#(KP
public long getLast(){ (;!92ct[?
return lastExecuteTime; $;iMo/
} :Oiz|b(
public void run(){ 2JdzeJb
long now = System.currentTimeMillis(); `^v=* &
if ((now - lastExecuteTime) > executeSep) { |qs8(
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//System.out.print("lastExecuteTime:"+lastExecuteTime); *jR4OY|DXH
//System.out.print(" now:"+now+"\n"); [g<Y,0,J
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); I|n?32F
lastExecuteTime=now; =y^`yv 3
executeUpdate(); \qf0=CPw8
} kz_gR;"(Z
else{ z( \4{Y
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); r=Tz++!
} ;NMv>1fI
} 5bB\i79$
} |` |#-xu
//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 ObPXVqG"?
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类写好了,下面是在JSP中如下调用。 \OJam<hZ
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<% 8$F"!dc _
CountBean cb=new CountBean(); I1pnF61U
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ,B~5;/|
CountCache.add(cb); 9r.h^
out.print(CountCache.list.size()+"<br>"); PZ>(cvX&
CountControl c=new CountControl(); `5Bv2wlIV
c.run(); X L3m#zW&
out.print(CountCache.list.size()+"<br>"); J Bgq2
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