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 z
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CountBean.java i695P}J2
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/* X~VI} dJ
* CountData.java =:g\I6'a
* =t_+ajY%
* Created on 2007年1月1日, 下午4:44 *c4OhMU(
* QmSj6pB>
* To change this template, choose Tools | Options and locate the template under h*;c"/7
* the Source Creation and Management node. Right-click the template and choose 6
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* Open. You can then make changes to the template in the Source Editor. [7.Num_L
*/ 4qDO(YWf
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package com.tot.count; ~\-=q^/!
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/** <#BK(W~$
* [p'2#Et
* @author 51eZf JB
*/ A*0X~6W
public class CountBean { k8ILo)
private String countType; 4S4MQ
int countId; 3"Oipt+
/** Creates a new instance of CountData */ STu(I\9
public CountBean() {} R-pON4D"*
public void setCountType(String countTypes){ 1d49&-N
this.countType=countTypes; <FkaH8,7
} zZ-/S~l
public void setCountId(int countIds){ aO1.9!<v
this.countId=countIds; 8HLL3H0
} y'>9'/&
public String getCountType(){ OcF_x/#
return countType; bl!pKOY
} l5^Q
public int getCountId(){ j^#\km B
return countId; +/$&P3
} WVQHb3Pe0
} 7n .A QII
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CountCache.java Hvz;[!
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/* n,2 p)#?
* CountCache.java .sit5BX
* {@Lun6\
* Created on 2007年1月1日, 下午5:01 +~F>:v?Rh
* AiR#:r
* To change this template, choose Tools | Options and locate the template under ,~$sJ2
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* the Source Creation and Management node. Right-click the template and choose g,YF$:e
* Open. You can then make changes to the template in the Source Editor. BPW.&2?<
*/ V+sZ;$
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package com.tot.count; IG}yGGn
import java.util.*; S`[(y?OF?
/** 2IHS)kkT|
* aO |@w"p8
* @author FB?V<x
*/ uh9b!8
public class CountCache { V
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public static LinkedList list=new LinkedList(); y /8iEs
/** Creates a new instance of CountCache */ NlhC7
public CountCache() {} 2vUcSKG7
public static void add(CountBean cb){ D3g5#.$,}>
if(cb!=null){ G@D8[
list.add(cb);
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} &VU^d3gv~
} ok ,O/|E}?
} 0*P-/)o x
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CountControl.java ,^
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/* pT+OPOSR
* CountThread.java 4avkyFj!h
* e 0$m<5
* Created on 2007年1月1日, 下午4:57 B;Z _'.i,d
* 1HSt}
* To change this template, choose Tools | Options and locate the template under L1`^M
* the Source Creation and Management node. Right-click the template and choose \g]rOYW
* Open. You can then make changes to the template in the Source Editor. _{if"
*/ ffB<qf)?G
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package com.tot.count; 56c3tgVF
import tot.db.DBUtils; ]E:L
import java.sql.*; -
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/** }n^}%GB
* 6U|"d[
* @author @ajdO/?(Y
*/ #WDpiV7B
public class CountControl{ ;gaTSYVe
private static long lastExecuteTime=0;//上次更新时间 A0.xPru1p
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ={h^X0<s9
/** Creates a new instance of CountThread */ Ia9!ucN7DA
public CountControl() {} ?o]NV
public synchronized void executeUpdate(){ _^eA1}3
Connection conn=null; Wvd-be
PreparedStatement ps=null; nF3Sfw,
try{ OI/]Y7D[Oq
conn = DBUtils.getConnection(); IO?a.L:6U
conn.setAutoCommit(false); g~|x^d^;|
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ., thdqOO
for(int i=0;i<CountCache.list.size();i++){ vcy(!r
CountBean cb=(CountBean)CountCache.list.getFirst(); bjj
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CountCache.list.removeFirst(); =RWY0| f
ps.setInt(1, cb.getCountId()); DKlHXEt>
ps.executeUpdate();⑴ 01aw+o
//ps.addBatch();⑵ _wg~5'w8
} v7+|G'8M`
//int [] counts = ps.executeBatch();⑶ _Co
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conn.commit(); iRW5*-66f
}catch(Exception e){ Ak`?,*LM
e.printStackTrace(); \8{Tj54NA
} finally{ .Xxxz
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try{ "AWk
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if(ps!=null) { K;`*n7=IA
ps.clearParameters(); Iw$T'I+4W
ps.close(); w3fD6$
ps=null; Uq%|v
} NXOvC!<
}catch(SQLException e){} rTC| 8e
DBUtils.closeConnection(conn); P4MP`A
} g*9&3ov
} 8z&/{:Z@pH
public long getLast(){ f4X}F|!h
return lastExecuteTime; '/ueY#eG
} +~
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public void run(){ 4^6Oh#p0
long now = System.currentTimeMillis(); >Zf*u;/dW$
if ((now - lastExecuteTime) > executeSep) { FNl^ lj`Y
//System.out.print("lastExecuteTime:"+lastExecuteTime); rhQO#_`
//System.out.print(" now:"+now+"\n"); $Ixd;`l*
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); da8
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lastExecuteTime=now; ~Ty6]A
executeUpdate(); hg+;!|ha
} FFN.9[Ly
else{ k[1[Y{n.
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); s, #$o3
} <dk9n}y<,
} !C.{nOfyv
} cwUor}<|
//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 !VfVpi+-
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类写好了,下面是在JSP中如下调用。 jd+HIR
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<% {#{nU NW
CountBean cb=new CountBean(); %
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cb.setCountId(Integer.parseInt(request.getParameter("cid"))); giN(wPgYP
CountCache.add(cb); LR17ilaa'
out.print(CountCache.list.size()+"<br>"); +hWeN&A
CountControl c=new CountControl(); [9p@uRE
c.run(); mL,{ZL ^
out.print(CountCache.list.size()+"<br>"); l4^8$@;s
%>