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: !~l%6Z5
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CountBean.java B~#@fIL
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/* ) :@%xoF5
* CountData.java :GYv9OG
* s-V$N
* Created on 2007年1月1日, 下午4:44 ,AM-cwwT:u
* eFI4(Y
* To change this template, choose Tools | Options and locate the template under \(FDR
* the Source Creation and Management node. Right-click the template and choose _64@zdL+
* Open. You can then make changes to the template in the Source Editor. -JENY|6
*/ @ 1A_eF
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package com.tot.count; i|^6s87"N2
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/** 1W[(+TZ&s
* Q9>]@DrAx
* @author Y%l3SB,5L
*/ ~Wm}M
public class CountBean { 5,ahKB8
private String countType; l7!)#^`2_
int countId; 6{X>9hD
/** Creates a new instance of CountData */ .A/H+.H;
public CountBean() {} Rk[ * p
public void setCountType(String countTypes){ ItPK
this.countType=countTypes; 3= zQ
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} *KH@u
public void setCountId(int countIds){ eBIR*TZ):
this.countId=countIds; "J{zfWr
} r_E)HL/A
public String getCountType(){ U.'@S8
return countType; n;`L5
} 5z ^UQq
public int getCountId(){ 9%14k
return countId; ~{G:,|`
} F5MPy[
} 9 lJj/
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CountCache.java ^(*O$N*#
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/* !cwVJe
* CountCache.java W?
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* a3O_#l-Z
* Created on 2007年1月1日, 下午5:01 u/'sdt
* _ng= 5
* To change this template, choose Tools | Options and locate the template under C}'="g^=sl
* the Source Creation and Management node. Right-click the template and choose Ef!p:HBJ
* Open. You can then make changes to the template in the Source Editor. gdE `UZ\
*/ ;S`-9}6
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package com.tot.count; /t)c fFM
import java.util.*; ~"2@A
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/** ~!9Px j*
* yGGB
* @author p3FnYz-V
*/ vcO`j<`
public class CountCache { \N , ' +
public static LinkedList list=new LinkedList(); T}Vpy`
/** Creates a new instance of CountCache */ }k0-?_Z=1
public CountCache() {} +JS/Z5dl+}
public static void add(CountBean cb){ 6n\z53Mk
if(cb!=null){ A'QGTT
list.add(cb); _I-VWDCk
} \nAHpF
} 2U`W[
} Y*cJ4hQ
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CountControl.java ]~S+nlyd<
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/* )z235}P
* CountThread.java {a8^6dm*E
* ]j2v"n
* Created on 2007年1月1日, 下午4:57 Pph8"`mv.m
* g)?g7{&?>?
* To change this template, choose Tools | Options and locate the template under zZ"U9!T
* the Source Creation and Management node. Right-click the template and choose )]c3bMVE-
* Open. You can then make changes to the template in the Source Editor. s[2ZxCrCw
*/
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package com.tot.count; 83ic@[
import tot.db.DBUtils; S50x0$%<W
import java.sql.*; I
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/** h`h>H
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* k7|z$=zY
* @author G h[`q7B
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*/ _OU.JrqC
public class CountControl{ ^h6$>n5
private static long lastExecuteTime=0;//上次更新时间 W({TC
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 j-`X_8W
/** Creates a new instance of CountThread */ ~J>gVg%66
public CountControl() {} =Cy>$/H64
public synchronized void executeUpdate(){ tK|9qs<%
Connection conn=null; t)gi.Ed1"L
PreparedStatement ps=null; yC 7Vb
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try{ QK!:q{
conn = DBUtils.getConnection(); 3E!<p
conn.setAutoCommit(false); "R2t&X[9
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); DxKfWb5 R
for(int i=0;i<CountCache.list.size();i++){ w-H%B`/
CountBean cb=(CountBean)CountCache.list.getFirst(); rH&r6Xv[
CountCache.list.removeFirst(); f UF;SqT
ps.setInt(1, cb.getCountId()); YP#AB]2\}
ps.executeUpdate();⑴ O(D5A?tv!
//ps.addBatch();⑵ mk%"G =w
} B(\r+" PB
//int [] counts = ps.executeBatch();⑶ H8-D'q>R
conn.commit(); *M&VqG4P9w
}catch(Exception e){ 3_\{[_W
e.printStackTrace(); 2@3.xG
} finally{ $TA6S+
try{ 1KYbL8c
if(ps!=null) { 8S1P&+iKs
ps.clearParameters(); RHx+HBZ
ps.close(); ~i }+P71
ps=null; !<=%;+
} nRXSW&V"m
}catch(SQLException e){} kUg+I_j6*
DBUtils.closeConnection(conn); `o_fUOe8a
} c/=y*2,zo
} Y0PGT5].@'
public long getLast(){ E +Ujpd
return lastExecuteTime; OS"{"P
} LGo2^Xx
public void run(){ 6i]Nr@1C
long now = System.currentTimeMillis(); Z[k#AgC)
if ((now - lastExecuteTime) > executeSep) { [EmOA.6
//System.out.print("lastExecuteTime:"+lastExecuteTime); 1J-Qh<Q
//System.out.print(" now:"+now+"\n"); C'-zh\a
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); OHHNWg_5
lastExecuteTime=now; ," C[Qg(
executeUpdate(); y^X\^Kq
} XJmFJafQD
else{ lHcZi
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 29Z!p2{hk
} &R'w-0k_
} ,l$NJt
} N4a`8dS|
//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 /i{tS`[F2a
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类写好了,下面是在JSP中如下调用。 8
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<% #ox9&
CountBean cb=new CountBean(); dU ,)TKQ
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 1iNsX\M
CountCache.add(cb); oNuPP5d[]
out.print(CountCache.list.size()+"<br>"); \6SMn6a4
CountControl c=new CountControl(); 6.U"_%
c.run(); )@Zc?Da
out.print(CountCache.list.size()+"<br>"); /`+Hwdk
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