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: ~(]'ah,
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CountBean.java 9qm'qx
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/* $ZlzS`XF7
* CountData.java ?N]G;%3/
* W/.Wp|C}K3
* Created on 2007年1月1日, 下午4:44 2/ejU,S
* y=zs6HaS
* To change this template, choose Tools | Options and locate the template under C:z7R" yj
* the Source Creation and Management node. Right-click the template and choose IwR=@Ne8
* Open. You can then make changes to the template in the Source Editor. B$MHn?
*/ o.wXaS8
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package com.tot.count; I].ddR%
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/** &/?OP)N,}
* BiA^]h/|
* @author ~!6
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*/ r{wf;5d(
public class CountBean { B C R]K
private String countType; g ,yB^^%
int countId; GW2v&Ul7(
/** Creates a new instance of CountData */ %'eaW
public CountBean() {} /4$ c-k
public void setCountType(String countTypes){ 1w#vy1m J
this.countType=countTypes; Y4N)yMSl"
} M$e$%kPShE
public void setCountId(int countIds){ #M<u^$Jz
this.countId=countIds; !}q@O-}j
} ge#P(Itz
public String getCountType(){ 7-mo\jw<
return countType; {BZ0x2
} tR(L>ZG{
public int getCountId(){ !,{-q)'D
return countId; @B9#Hrc
} w:2yFC
} M $zt;7P|
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CountCache.java Mo\nY5
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/* vH@$?b3VP
* CountCache.java 5uU{!JuSa
* 06I(01M1
* Created on 2007年1月1日, 下午5:01 USH>`3
* *_"lXcG.
* To change this template, choose Tools | Options and locate the template under orhzeOi\
* the Source Creation and Management node. Right-click the template and choose i}@5<&J
* Open. You can then make changes to the template in the Source Editor. =Ds&ArG
*/ ~zDFL15w
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package com.tot.count; %:y"o_X_
import java.util.*; d.k'\1o
/** 'grb@+w(
*
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* @author Tx(=4ALY
*/ 7eG@)5Uy
public class CountCache { c+jnQM'
public static LinkedList list=new LinkedList(); i}>}%l|
/** Creates a new instance of CountCache */ @}{Fw;,(7n
public CountCache() {} ._<gc;G
public static void add(CountBean cb){ 9mEhZ"
if(cb!=null){ %3T:W\h
list.add(cb); c3Zwp%
} i|fkwV,5
} e r"gPW
} `3.bux~
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CountControl.java 29NP!W
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/* EC?U#!kv
* CountThread.java !={QL :
* EI@ep~
* Created on 2007年1月1日, 下午4:57 ~HXZ-*
* )T@+"Pw8t
* To change this template, choose Tools | Options and locate the template under BA_l*h%=Cc
* the Source Creation and Management node. Right-click the template and choose &sGLm~m#
* Open. You can then make changes to the template in the Source Editor. Zk0? =f?j
*/ 8TO5j
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package com.tot.count; b2YOnV
import tot.db.DBUtils; P>
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import java.sql.*; = %wBC;
/** cX5t x]
* E /V`NqC
* @author sJ|IW0Mr
*/ 7/BA!V(na
public class CountControl{ 4<U6jB5
private static long lastExecuteTime=0;//上次更新时间 @fd{5 >\
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 F=yE>[! LB
/** Creates a new instance of CountThread */ Ls NJ3oy
public CountControl() {} /7C%m:
public synchronized void executeUpdate(){ bc\?y2
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Connection conn=null; ~q{QquYV
PreparedStatement ps=null; }j,G)\g#
try{ n7d`J_%s
conn = DBUtils.getConnection(); Yq:TWeZD
conn.setAutoCommit(false); e{0O"Jd`
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); RueL~$*6.~
for(int i=0;i<CountCache.list.size();i++){ m\ /V 0V\
CountBean cb=(CountBean)CountCache.list.getFirst(); LY!.u?D`P
CountCache.list.removeFirst(); Fprhu;h
ps.setInt(1, cb.getCountId()); Y+"Gx;F>
ps.executeUpdate();⑴ qFjnuQ,w
//ps.addBatch();⑵ !Ly1!;<
} j,#R?Ig
//int [] counts = ps.executeBatch();⑶ m`8tHHF
conn.commit(); G)\6W#de4
}catch(Exception e){ x[2eA!NC
e.printStackTrace(); .?.Q[ic
} finally{ 9|//_4]
try{ Q3x.qz
if(ps!=null) { uB35CRd
ps.clearParameters(); i%9xt1c_
ps.close(); /f
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ps=null; BU;E6s>P
} }C&kzJBEF
}catch(SQLException e){} +K[H!fD
DBUtils.closeConnection(conn); j(\jYH>
} SL>0 _
} ^v@&
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public long getLast(){ U+g<lgH1J
return lastExecuteTime; vjD||!g'
} !,PoH
public void run(){ a5%IjgQ&z
long now = System.currentTimeMillis(); T8a!"lPP7
if ((now - lastExecuteTime) > executeSep) { PWs=0.Wj
//System.out.print("lastExecuteTime:"+lastExecuteTime); R~(_m#6`:
//System.out.print(" now:"+now+"\n"); uJ/&!q<3
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 5K?%Eo72!=
lastExecuteTime=now; 84maX'
executeUpdate(); k'+Mc%pg4E
} ]}dAm S/
else{ NeY,Of|
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); Q
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} (Y]G6>
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} xGymQ|y84
} )NS&1$
//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 =k22f`8ew
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类写好了,下面是在JSP中如下调用。 fHwr6"DJ
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<% \~'+TW
CountBean cb=new CountBean(); P[C03a!lXg
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); a]_eSU@
CountCache.add(cb); VcR(9~
out.print(CountCache.list.size()+"<br>"); M]OZS\9.B
CountControl c=new CountControl(); 4f>
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c.run(); %q
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out.print(CountCache.list.size()+"<br>"); n+uDg
%>