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:
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CountBean.java :vm*miOF
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/* B`
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* CountData.java xr o
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* Created on 2007年1月1日, 下午4:44 k%.IIVRx
* fRq2sK;+
* To change this template, choose Tools | Options and locate the template under k ELV]iWb
* the Source Creation and Management node. Right-click the template and choose ?z?IEj}
* Open. You can then make changes to the template in the Source Editor. OI1&Z4Lx
*/ A]W`r}
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package com.tot.count; 2pZ|+!xc+
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/** ]"F0"UH,
* v k<By R
* @author ;ML21OjgN
*/ O.!|;)HQ
public class CountBean { 2#p6.4h=
private String countType; <@JK;qm>S
int countId; RW%e%
/** Creates a new instance of CountData */ 3d
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public CountBean() {} |r6<DEg
public void setCountType(String countTypes){ X}_kLfP/9
this.countType=countTypes; R5|c4v{B
} eB5;wH
public void setCountId(int countIds){ |wWBV{^
this.countId=countIds; `a
} :+en8^r%
public String getCountType(){ f%d7?<rw
return countType; U%"v7G-
} 3>c<E1
public int getCountId(){ +Z/Pj_.o
return countId; >^kRIoBkg
}
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} ^!?W!k!:V
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CountCache.java ? !cUAa>iH
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/* P**h\+M>{
* CountCache.java I6zKvP8pb
* ':6`M
* Created on 2007年1月1日, 下午5:01 &*A7{76x
* 5Z1b9.;.,
* To change this template, choose Tools | Options and locate the template under Y!"LrkC
* the Source Creation and Management node. Right-click the template and choose 0c
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* Open. You can then make changes to the template in the Source Editor. \"|E8A6/
*/ 6f{Kj)
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package com.tot.count; l/#;GYB]
import java.util.*; 48W$,
/** p^MV<}kk
* 8<{)|GoqB
* @author ]uG9WT6l
*/ L;wzvz\+
public class CountCache { Jvgx+{Xu
public static LinkedList list=new LinkedList(); Q6]SsV?x
/** Creates a new instance of CountCache */ o@XhL9
public CountCache() {} hCuUX)>Bt
public static void add(CountBean cb){ *FmY4w
if(cb!=null){ v[A)r]"j"M
list.add(cb); ^FIpkhw
} #2^eGhwnI
} .T#h5[S2x
} bM+}j+0
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CountControl.java 1-.6psE
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/* *@^9]$*$
* CountThread.java L9W'TvTwo
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* Created on 2007年1月1日, 下午4:57 o]u,<bM$
* tHgu#k0
* To change this template, choose Tools | Options and locate the template under *S%~0=
* the Source Creation and Management node. Right-click the template and choose WzDL(~m+Z
* Open. You can then make changes to the template in the Source Editor. =c8xg/
*/ }(FF^Mh
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package com.tot.count; DI"KH)XD
import tot.db.DBUtils; ckykRqk}
import java.sql.*; $3psSQQo
/** `bY>f_5+
* Utd`T+AF*
* @author r01Z
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*/ !Z]#1"A8
public class CountControl{ lkl+o&D9
private static long lastExecuteTime=0;//上次更新时间 NGIt~"e7R4
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 `n)e]
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/** Creates a new instance of CountThread */ d< j+a1&
public CountControl() {} }Vjg>"
public synchronized void executeUpdate(){ @{n"/6t
Connection conn=null; @komb IK
PreparedStatement ps=null; RrA9@95+
try{ .z0NMmz0z
conn = DBUtils.getConnection(); +&bJhX
conn.setAutoCommit(false); m~c6b{F3Z-
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); L6<.>\^Z"
for(int i=0;i<CountCache.list.size();i++){ 40h
CountBean cb=(CountBean)CountCache.list.getFirst(); FabgJu
CountCache.list.removeFirst(); {8p<iY- %
ps.setInt(1, cb.getCountId()); @$mh0K>
ps.executeUpdate();⑴ ^__';! e
//ps.addBatch();⑵ N)CM^$(T|
} 2 8>
//int [] counts = ps.executeBatch();⑶ uC$!|I
conn.commit(); lZ gX{
}catch(Exception e){ r`-=<@[
e.printStackTrace(); 5!-+5TJI
} finally{ ZP-^10
try{ >L4q>S^v
if(ps!=null) { n4Xh}KtH
ps.clearParameters(); $y{rM%6JU
ps.close(); =^ZDP1h/}
ps=null; kZ5;Fe\*
} <<WqL?8W
}catch(SQLException e){} uE E;~`G
DBUtils.closeConnection(conn); c`,'[Q5(O
} 7C / ^Gw
} yrvV<}
public long getLast(){ AcHr X=O
return lastExecuteTime; aoqG*qh}b
} =Vie0TV&h
public void run(){ \0j-p
long now = System.currentTimeMillis(); 2Sgv
if ((now - lastExecuteTime) > executeSep) { Oz{FM6
//System.out.print("lastExecuteTime:"+lastExecuteTime); kLE("I:7
//System.out.print(" now:"+now+"\n"); 9u?[{h.`B
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ;}B6`v
lastExecuteTime=now; S/,)X
executeUpdate(); ?*AhGza/
} 6K7DZ96L
else{ unvS `>)Np
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); >p*7)
} Wr+/9
} V
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} z"%{SI^
//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 zu_bno!
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类写好了,下面是在JSP中如下调用。 R,8 W7 3
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<% 3-Bz5sj9
CountBean cb=new CountBean(); 0?,<7}"<X
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); S\M+*:7
CountCache.add(cb); >BWe"{ ;
out.print(CountCache.list.size()+"<br>"); #W9{3JGUY
CountControl c=new CountControl(); L_`D
c.run(); `;Od0uh
out.print(CountCache.list.size()+"<br>"); 3D}Pa
%>