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: qS\#MMsTd
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CountBean.java =|-=4.b+|
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/* B,\VLX
* CountData.java t}eyfflZ
* %]Z4b;W[Y
* Created on 2007年1月1日, 下午4:44 K ~mUO
* aG]>{(~cL
* To change this template, choose Tools | Options and locate the template under pA*C|g
* the Source Creation and Management node. Right-click the template and choose w*6b%h%ww
* Open. You can then make changes to the template in the Source Editor. 74M 9z
*/ l$/pp
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package com.tot.count; v\,N"X(,
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/**
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* i3,.E]/wX@
* @author KZjh<sjX|
*/ ~bZ=]i
public class CountBean { 0cycnOd
private String countType; m}'_Poc
int countId; XX/gS=NE#.
/** Creates a new instance of CountData */ \Sd8PGl*'
public CountBean() {} H<Sf0>OA
public void setCountType(String countTypes){ (1'DZxJ&u
this.countType=countTypes; i"G'#n~e
} ?z1v_Jh
public void setCountId(int countIds){ {K.H09Y
this.countId=countIds; F(hPF6Zx(
} R `tJ7MB
public String getCountType(){ 3Cj)upc
return countType; I&+.I K_
} S[K5ofV
public int getCountId(){ FPY k`D
return countId; tkctwjD
} /Q3>w -h
} ~W21%T+
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CountCache.java =#u4^%i)
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/* `0NU
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* CountCache.java /u$'=!<b;
* ==[(Mn,%d
* Created on 2007年1月1日, 下午5:01 J|BElBY
* ^^V3nT2rR3
* To change this template, choose Tools | Options and locate the template under 4<-Kd~uL
* the Source Creation and Management node. Right-click the template and choose eS!]..%y
* Open. You can then make changes to the template in the Source Editor. 6o^>q&e}%
*/ -{0Pq.v
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package com.tot.count; ,4H? + |!
import java.util.*; WhW}ZS'r
/** bJ_rU35s>
* aLh(8 ;$
* @author iI<c
*/ .u)KP*_
public class CountCache { |Ml~Pmpp
public static LinkedList list=new LinkedList(); fv7VDo8vb
/** Creates a new instance of CountCache */ Y_Gd_+oJ
public CountCache() {} =v<w29P(g
public static void add(CountBean cb){ YcA. Bn|as
if(cb!=null){ %k#+nad
list.add(cb); b23A&1X
} n 0=]C%wr
} &|XgWZS5
} ATkd# k%S
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CountControl.java Gt&yz"?D
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/* 9Q1%+zjjMq
* CountThread.java sg,\!'
* ` &A`&-nc=
* Created on 2007年1月1日, 下午4:57 ,w~3K%B4
* 1x_EAHZ>7
* To change this template, choose Tools | Options and locate the template under U:*rlA@_.
* the Source Creation and Management node. Right-click the template and choose :Vxt2@p{
* Open. You can then make changes to the template in the Source Editor. xq;>||B
*/ >2s6Y
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package com.tot.count; E.*hY+kGZ
import tot.db.DBUtils; J920A^)j!
import java.sql.*; 0HWSdf|w
/** K F'fg
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* c$ /.Xp
* @author ^dpM2$J
*/ w<B
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public class CountControl{ 'aEK{#en
private static long lastExecuteTime=0;//上次更新时间 TIJH}Ri
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 1e[?}q]*
/** Creates a new instance of CountThread */ x~5,v5R^]
public CountControl() {} qA '^b~
public synchronized void executeUpdate(){ V<9L-7X 8
Connection conn=null; p-"C^=l
PreparedStatement ps=null; Qp<*or@
try{ "9xJ},:-
conn = DBUtils.getConnection(); ?>+uO0*S
conn.setAutoCommit(false); ={xRNNUj_
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); "#E
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for(int i=0;i<CountCache.list.size();i++){ #+o$Tg
CountBean cb=(CountBean)CountCache.list.getFirst(); LhAN( [
CountCache.list.removeFirst(); 1vq2`lWpx
ps.setInt(1, cb.getCountId()); 9C \}bT
ps.executeUpdate();⑴ ]lA}5
//ps.addBatch();⑵ 2@MpWj4
} B5 /8LEWw
//int [] counts = ps.executeBatch();⑶ "1gIR^S%9
conn.commit(); s#5#WNzP
}catch(Exception e){ 1?QVtfwY
e.printStackTrace();
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} finally{ <*J"6x
try{ @rT$}O1?`
if(ps!=null) { )s>|;K{
ps.clearParameters(); `mcb0
ps.close(); Ei:m@}g
ps=null; nN&dtjoF
} UhJS=YvT
}catch(SQLException e){} lai@,_<GV
DBUtils.closeConnection(conn); eM!Oc$C8[
} Ly(iq
} (^~a1@f,J
public long getLast(){ ^JxVs
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return lastExecuteTime; 6/cm TT$i
} w(bvs&`{uC
public void run(){ o%Q9]=%!
long now = System.currentTimeMillis(); R7IFlQH%
if ((now - lastExecuteTime) > executeSep) { s[7$%|~W
//System.out.print("lastExecuteTime:"+lastExecuteTime); h*^JFZb
//System.out.print(" now:"+now+"\n"); }*J04o$oI
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); dUB;ZB7
lastExecuteTime=now; =eY
executeUpdate(); +ase>'<N#
} 8o:h/F
else{ (;g/wb:
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); !QdX+y<re
} t~qSiHw
} 5xr2
} S'RRe84C
//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 Pjq9BK9p
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类写好了,下面是在JSP中如下调用。 V+y|C[A
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<% 9+(6/<
CountBean cb=new CountBean(); KOR*y(* 8
cb.setCountId(Integer.parseInt(request.getParameter("cid")));
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CountCache.add(cb); L"0dB.
out.print(CountCache.list.size()+"<br>"); KYkS^v
CountControl c=new CountControl(); rk%pA-P2
c.run(); %l%ad-V
out.print(CountCache.list.size()+"<br>"); ih("`//nP
%>