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: pON#r
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CountBean.java g%^/^<ei
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/* ,SdxIhL
* CountData.java *'M+oi
* z,dFDl$
* Created on 2007年1月1日, 下午4:44 ZRwN #?x
* G i(
* To change this template, choose Tools | Options and locate the template under Cl&)#
* the Source Creation and Management node. Right-click the template and choose
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* Open. You can then make changes to the template in the Source Editor. 'ju_l)(R
*/ H0lW gJmi|
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package com.tot.count; >bhF{*t#;y
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/** l$HBYA\Qh
* /']`}*d
* @author C~.\2D`zy
*/ cR55,DR,#W
public class CountBean { ih75C"
private String countType; 5BLBcw\;
int countId; ?l
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/** Creates a new instance of CountData */ f`-vnh^+
public CountBean() {} e iH&<AH
public void setCountType(String countTypes){ l`X?C~JhJ
this.countType=countTypes; r~,3
} wXdt\@Qr
public void setCountId(int countIds){ D]'8BS3
this.countId=countIds; vt(}8C+
} *N{k#d/
public String getCountType(){ mdmJne.
return countType; Sc}Rs
} x|^p9m"=%
public int getCountId(){ `8\"3S
return countId; &h6 `hP_
} z([HGq5
} rt)[}+ox
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CountCache.java +>u 8r&Jw.
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/* C\{hN
* CountCache.java ^
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* E2.!|u2
* Created on 2007年1月1日, 下午5:01 $kR%G{j 4
* CL(D&8v8~
* To change this template, choose Tools | Options and locate the template under ||7x51-yj
* the Source Creation and Management node. Right-click the template and choose mB
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* Open. You can then make changes to the template in the Source Editor. mL;oR4{
*/ -Fop<q\b
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package com.tot.count; g86^Z%c(k
import java.util.*; -J]N
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/** hS%oQ)zvE
* lPA}06hU
* @author q!5`9u6
*/ @K#}nKN'
public class CountCache { K^b'<} $|p
public static LinkedList list=new LinkedList(); {Rxb_9
/** Creates a new instance of CountCache */ v`7~#Avhz
public CountCache() {} A&-2f]L
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public static void add(CountBean cb){ "1DlusmCCB
if(cb!=null){ n{m[
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list.add(cb); =gd~rk9
} k%N$eO$
} Vm I
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} ?4W6TSW-'
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CountControl.java :F"NF
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/* Z)u_2e
* CountThread.java +& M>J|
* ] J|#WtS
* Created on 2007年1月1日, 下午4:57 !\Xrl) $j{
* /kO%aN
* To change this template, choose Tools | Options and locate the template under RWJyd=
* the Source Creation and Management node. Right-click the template and choose 9:E.Iy
* Open. You can then make changes to the template in the Source Editor. 4a.8n!sys
*/ LTb#1JC
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package com.tot.count; Jep/%cT$w
import tot.db.DBUtils; Gch3|e
import java.sql.*; DsHm,dZ
/** x IL]Y7HWM
* Qk.[#
* @author 2,h]Y=.s
*/ u+pZ<Bb
public class CountControl{ ,x[~|J!
private static long lastExecuteTime=0;//上次更新时间 ob[G3rfd@Z
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 5'wFZ=>vMt
/** Creates a new instance of CountThread */ 2ryg3%+O
public CountControl() {} 9wC='
public synchronized void executeUpdate(){ NZXCaciG
Connection conn=null; -Ji uq
PreparedStatement ps=null; 7Mh!@Rd_V
try{ ]0}NF
conn = DBUtils.getConnection(); PnI_W84z
conn.setAutoCommit(false); ExOSHKU,e
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); %=vU
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for(int i=0;i<CountCache.list.size();i++){ iVM% ]\
CountBean cb=(CountBean)CountCache.list.getFirst(); )Tn(!.
CountCache.list.removeFirst(); M=5hp&=
ps.setInt(1, cb.getCountId()); \@
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ps.executeUpdate();⑴ 3X`N~_+
//ps.addBatch();⑵ 2P|j<~JS
} t6%zfm
//int [] counts = ps.executeBatch();⑶ 3#`Sk`z<
conn.commit(); ~>3#c#[
}catch(Exception e){ "@jYZm8
e.printStackTrace(); ~yRKNH*M
} finally{ _G^ 4KwYp
try{
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if(ps!=null) { CL!s #w1I\
ps.clearParameters(); 0(A&m ,
ps.close(); S\2@~*{-8
ps=null; Dv=pX.Z+
} 7wbpQ&1_
}catch(SQLException e){} _=I&zUF
DBUtils.closeConnection(conn); ]L\]Ll;
} #BI Z|
} >H]|R }h
public long getLast(){ ;![rwra
return lastExecuteTime; iis}=i7|
} 94[8~_{fG
public void run(){ OI^qX;#Kd
long now = System.currentTimeMillis(); u$(XZ;Jg
if ((now - lastExecuteTime) > executeSep) { <EuS6Pg
//System.out.print("lastExecuteTime:"+lastExecuteTime); 8;(3fSNC
//System.out.print(" now:"+now+"\n"); ]_! .xx>
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); hx}X=7w
lastExecuteTime=now; ,#(k|Zztc
executeUpdate(); Tnnj8I1v
} ,Q+.kAh !G
else{ s`dUie}y<
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 2)|G%f_lS
} Okd7ua-f
} *UdP1?Y
} ^
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//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 .fNLhyd
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类写好了,下面是在JSP中如下调用。 %? O$xQ.<
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<% $< .wQ8:Q
CountBean cb=new CountBean(); Mg\8m-L^
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); rJCu6
CountCache.add(cb); F<2qwP
out.print(CountCache.list.size()+"<br>"); >ti)m >f
CountControl c=new CountControl(); (U|WP%IM'
c.run(); Ap<j;s4`
out.print(CountCache.list.size()+"<br>"); Ce@"+k+w
%>