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: 5sG ]3z+1
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CountBean.java q$bHO
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/* Y"r3i]
* CountData.java 58qaA\iw
* o-L|"3P
* Created on 2007年1月1日, 下午4:44 ^ b=5 6~[
* EPQ&?[6
* To change this template, choose Tools | Options and locate the template under M4R%Gr,La
* the Source Creation and Management node. Right-click the template and choose e6Wl7&@6
* Open. You can then make changes to the template in the Source Editor. f S(^["*G
*/ 6'S5sRA
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package com.tot.count; Pw0{.W~r
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/** @\#'oIc|
* B.{8/.4
* @author l_UXrnm/N
*/ rOs)B 21/
public class CountBean { u?F7L8q]
private String countType; B.h0" vJ
int countId; mvUVy1-c
/** Creates a new instance of CountData */ @hE7r-}]
public CountBean() {} kxcgOjrmI
public void setCountType(String countTypes){ E!:.G+SEl
this.countType=countTypes; #-l!`\@
} `HE>%=]b
public void setCountId(int countIds){ T3=-UYx]
this.countId=countIds; .%-6&%1
} Tb>IHoil
public String getCountType(){ 8:;u
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return countType; k#{lt-a/
} 9\\@I
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public int getCountId(){ ~nLkn#Z
return countId; T2c_vY
} J"m%q\'
} qg) Af
}Bv30V2-(
CountCache.java nPQZI6>
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/* n_e}>1_
* CountCache.java ,U} 5
*
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* Created on 2007年1月1日, 下午5:01 oyi7YRvwd
* e<ism?WG
* To change this template, choose Tools | Options and locate the template under (h'$3~
* the Source Creation and Management node. Right-click the template and choose [wXwKr
* Open. You can then make changes to the template in the Source Editor. /6Jy'"+'0
*/ 3G:NZ) p
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package com.tot.count; #dxJ#
import java.util.*; !W+p<F1i
/** 6KBzlj0T+
* N,'[:{GOY
* @author r7]?g~zb
*/ mjkw&2
public class CountCache { 3Vb=6-|
public static LinkedList list=new LinkedList(); LOyCx/n
/** Creates a new instance of CountCache */ r1^m#!=B
public CountCache() {} 5bGjO&$l
public static void add(CountBean cb){ LZZ:P
if(cb!=null){ y~4SKv
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list.add(cb); ebl)6C
} q.u[g0h;
} YU ]G5\UU
} UIm[DYMS
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CountControl.java B6Wq/fl/
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/* hPEp0("
* CountThread.java <IHFD^3|j
* i+qLc6|S=2
* Created on 2007年1月1日, 下午4:57 GDNh?R
* <MWXew7b
* To change this template, choose Tools | Options and locate the template under ~|0F?~eR7
* the Source Creation and Management node. Right-click the template and choose T9U2j-lA?
* Open. You can then make changes to the template in the Source Editor. E9Qd>o
*/ D:RBq\8
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package com.tot.count; /w}B07.
import tot.db.DBUtils; [EW$7 se~
import java.sql.*; )$Dcrrj
/** GtAJ#[5w
* q|Pt>4c5?
* @author eD`
,
*/ f2SU5e2
public class CountControl{ %FR^[H]
private static long lastExecuteTime=0;//上次更新时间 XeIUdg4>R
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 h.}t${1ZC
/** Creates a new instance of CountThread */ !txELA~24
public CountControl() {} N.Wdi
public synchronized void executeUpdate(){ Ndug9j\2
Connection conn=null; a2klOX{
PreparedStatement ps=null; qk+{S[2j
try{ ?( dYW7S
conn = DBUtils.getConnection(); F`ZIc7(.{
conn.setAutoCommit(false); ]L%R[Z!3
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); &[2Ej|o
for(int i=0;i<CountCache.list.size();i++){ x(/@Pt2B
CountBean cb=(CountBean)CountCache.list.getFirst(); bN7 UO
CountCache.list.removeFirst(); 3A}nNHpN
ps.setInt(1, cb.getCountId()); j~,LoGuPh
ps.executeUpdate();⑴ EZwdx
//ps.addBatch();⑵ f2w=ln
} C^\*|=*\
//int [] counts = ps.executeBatch();⑶ X
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conn.commit(); ~y-vKCp|
}catch(Exception e){ y
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e.printStackTrace(); /i~^LITH
} finally{ lu@>?,<
try{ SJ WP8+
if(ps!=null) { 'Kso@St`o
ps.clearParameters(); E23 Yk?"
ps.close(); 4W//Oc@e
ps=null; \w0b"p
} " jQe\
}catch(SQLException e){} "<jEI /
DBUtils.closeConnection(conn); L/iVs`qF
} %Dr4~7=7a
} a@_Cx
public long getLast(){ :C:N]6_{SZ
return lastExecuteTime; >$S,>d_k`
} yzM+28}L<I
public void run(){ eE.5zXU3R
long now = System.currentTimeMillis(); KZ<RDXV T
if ((now - lastExecuteTime) > executeSep) { )T};Q:
//System.out.print("lastExecuteTime:"+lastExecuteTime); cLyuCaH>c
//System.out.print(" now:"+now+"\n"); ]htZ!; 8J
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); >%p
m"+h{
lastExecuteTime=now; 5c}9
executeUpdate(); :!iPn%
} >&TnTv?I
else{ 4xpWO6Q
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); z)Q^j>%
} kFIB lPV
} ng&EGM
} 8$<AxNR
//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 MkNURy>n&
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类写好了,下面是在JSP中如下调用。 Y1E>T-Ma
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<% 3Llj_lf
CountBean cb=new CountBean(); Zqs-I8y
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); a6k(O8Ank3
CountCache.add(cb); 2bn@:71`
out.print(CountCache.list.size()+"<br>"); =u3@ Dhw
CountControl c=new CountControl(); Z/05 wB
c.run(); hpz*jyh8
out.print(CountCache.list.size()+"<br>"); ^3)2]>pW
%>