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: V<-htV
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CountBean.java qz:]-A
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/* a;&}zcc*
* CountData.java vXubY@k2
* 1l]C5P}E
* Created on 2007年1月1日, 下午4:44 A9n41,h
* Ygx,t|?7
* To change this template, choose Tools | Options and locate the template under 4$i} Xk#3
* the Source Creation and Management node. Right-click the template and choose 6F ;Or
* Open. You can then make changes to the template in the Source Editor. ,I39&;Iq
*/ *aG"+c6|
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package com.tot.count; h2&y<Eg >
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/** "UpOY
* ,eK2I Ao
* @author (fd[P|G_]
*/ QT_^M1%
public class CountBean { )d_U)b7i
private String countType; .D3`'K3t{[
int countId; ^N{X "
/** Creates a new instance of CountData */ ++k J\N{
public CountBean() {} ]-EN/V
public void setCountType(String countTypes){ ]+lF=kkc%
this.countType=countTypes; \4@a
} 'RQiLUF
public void setCountId(int countIds){ V g6S/-
this.countId=countIds; !=knppY
} @SQceQfB
public String getCountType(){ u7 u~
return countType; p|s2G~0<
} LT&/0
public int getCountId(){ <)J55++
return countId; Re\o
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} P,`=]Y*
} hG~ Uz
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CountCache.java (-'PD_|
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/* D9G0k[D,
* CountCache.java 85Dm8~
* /gX%ABmS
* Created on 2007年1月1日, 下午5:01 ebD{ pc`&
* %\l0-RA@<
* To change this template, choose Tools | Options and locate the template under U5clQiow
* the Source Creation and Management node. Right-click the template and choose iW-t}}Z>B
* Open. You can then make changes to the template in the Source Editor. Y)v%
*/ K]MzP|T,
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package com.tot.count; I2W{tl
import java.util.*; :^.u-bHI
/** O E]~@eU
* CL )%p"[x
* @author 8ur_/h7
*/ r.Lx%LZ\^
public class CountCache { 3m~U(yho
public static LinkedList list=new LinkedList(); (Y>U6
/** Creates a new instance of CountCache */ ) _#T c
public CountCache() {} vS2(Q0+TZi
public static void add(CountBean cb){ rSbQ}O4V
if(cb!=null){ lkyJ;}_**
list.add(cb); Y& m<lnB
} fW[_+r]
} ?Cc$]
} .;j"+Ef
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CountControl.java }Uq/kei^P
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/* ;wpW2%&
* CountThread.java R<t&F\>
* {6DpPw^ "
* Created on 2007年1月1日, 下午4:57 HK?Foo?
* |B,dEx/uU
* To change this template, choose Tools | Options and locate the template under WE7>?H*Ro
* the Source Creation and Management node. Right-click the template and choose R,XD6' Q
* Open. You can then make changes to the template in the Source Editor. Zq9>VqGe
*/ 9/^d~ZO
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package com.tot.count; [!5l0{0
import tot.db.DBUtils; 3 k`NNA
import java.sql.*; "^!j5fZ
/** % ghJ*iHR
* J511AoQ{R
* @author x[Hhj'
*/ "NlRSc#
public class CountControl{ $F<%Jl7_Z
private static long lastExecuteTime=0;//上次更新时间 f)qPFM]%z
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 zabw!@]
/** Creates a new instance of CountThread */ @i\7k(9:A
public CountControl() {} P%ye$SASd
public synchronized void executeUpdate(){ yM W'-\
Connection conn=null; La@\q[U{@
PreparedStatement ps=null; eO~eu]r
try{ z)r8?9u
conn = DBUtils.getConnection(); \gjl^#;
conn.setAutoCommit(false); /Lj%A
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ^9n}-Cqeq
for(int i=0;i<CountCache.list.size();i++){ ?#x'_2
CountBean cb=(CountBean)CountCache.list.getFirst(); N" 8*FiZ|
CountCache.list.removeFirst(); 9{T 8M
ps.setInt(1, cb.getCountId()); .`b4h"g:
ps.executeUpdate();⑴ rGGS]^
//ps.addBatch();⑵
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} oXvdR(Sb^
//int [] counts = ps.executeBatch();⑶ T<!\B]
conn.commit(); 3{6ps : w
}catch(Exception e){ o$*bm6o
e.printStackTrace(); Q=dw 6
} finally{ oA5<[&~<
try{ -wJ
if(ps!=null) { ccIDMJ=2
ps.clearParameters(); 6hR^qdHg
ps.close(); '3IkPy1Uz
ps=null; *1%e%G
} jt0H5-x
}catch(SQLException e){} W`
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DBUtils.closeConnection(conn); &E} I
} >|y>e{P
} F0X5dv
public long getLast(){ 7g {g}
return lastExecuteTime; Cij$GYkv
} MH C.k=
public void run(){ |k/`WC6As.
long now = System.currentTimeMillis(); "TEBByO'
if ((now - lastExecuteTime) > executeSep) { d<e+__2
//System.out.print("lastExecuteTime:"+lastExecuteTime); ly9x1`?$
//System.out.print(" now:"+now+"\n"); #JHy[!4
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 3U :YA&K(
lastExecuteTime=now; cg>!<T*
executeUpdate(); k8!hvJ)?
} UUt~W
else{ ay!6T`U`
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); <L[T'ZE+
} yBUZVqqDa
} r@N39O*Wq
} Q"x`+?!
//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 L{+&z7M
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类写好了,下面是在JSP中如下调用。 oAIY=z
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<% &<\4q
CountBean cb=new CountBean(); IBn'iE[>
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); TyxU6<>4J4
CountCache.add(cb); !Qj)tS#Az
out.print(CountCache.list.size()+"<br>"); &;SwLDF"1
CountControl c=new CountControl(); ]<&B
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c.run(); @]?? +f}#
out.print(CountCache.list.size()+"<br>"); :mCw.Jz<h
%>