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: #- hYjE5
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CountBean.java }+1Y>W7q
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/* 1JI\e6]I
* CountData.java v2uyn
* Rg!Fu
* Created on 2007年1月1日, 下午4:44 ]c'12 g]h
* E1uyMh-dy
* To change this template, choose Tools | Options and locate the template under w[S!U<9/
* the Source Creation and Management node. Right-click the template and choose 8~>5k
* Open. You can then make changes to the template in the Source Editor. }t^N|I
*/ k[p7)ec
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package com.tot.count; r-];@
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/** 6cV -iDOH
* gI SP .
* @author >5Rcj(-&l
*/ NlS/PWc6(
public class CountBean { ]
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private String countType; <-1(G1v
int countId; 8;C_@
/** Creates a new instance of CountData */ x!08FL)
public CountBean() {} lnk`D(>W
public void setCountType(String countTypes){ Gz9w1[t
this.countType=countTypes; `N69xAiy
} Ikn)XZU^
public void setCountId(int countIds){ [?vn>
this.countId=countIds; 7z=zJ4C
} 3.
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public String getCountType(){ 9svn B@
return countType; y.l`NTT]<
} "#a_--"k9
public int getCountId(){ t)*MLg<C
return countId; R\B-cU[,
} c3>#.NP_
} B4 cm_YGE
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CountCache.java EN =oA P
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/* H~IN<3ko
* CountCache.java I-QaR
* _ZnVQ,zY
* Created on 2007年1月1日, 下午5:01 x!A.**
* >Bj+!)96q
* To change this template, choose Tools | Options and locate the template under _djr>C=H"
* the Source Creation and Management node. Right-click the template and choose vyt$
* Open. You can then make changes to the template in the Source Editor. *P#okwp
*/ 9bL`0L
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package com.tot.count; Z*}5M4
import java.util.*; rl0sN5n
/** ~e,D`Lv
* i9qn_/<c
* @author =-r[ s%t&
*/ &3SQVOW ~T
public class CountCache { 8e`'Ox_5a
public static LinkedList list=new LinkedList(); 2&f]v`|M|
/** Creates a new instance of CountCache */ l.#iMi(@p~
public CountCache() {} *<PQp
public static void add(CountBean cb){ yj6o533o
if(cb!=null){ 4+Sq[Rv0
list.add(cb); :+9KNyA
} y7;i4::A\
} bF#* cH
}
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CountControl.java XF`,mV4
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/* *vL2n>HH
* CountThread.java &vf%E@<
* +wAH?q8f
* Created on 2007年1月1日, 下午4:57 v[r5!,F
* 1 h.=c
* To change this template, choose Tools | Options and locate the template under )}-,4Iu%
* the Source Creation and Management node. Right-click the template and choose &B</^:
* Open. You can then make changes to the template in the Source Editor. Hqel1J
*/ ;^q@w
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package com.tot.count; 7gL N7_2
import tot.db.DBUtils; eVobs2s
import java.sql.*; 1e 8J-Nkj
/** _Ra$"j
* Vt {uG
* @author H8V${&!ho
*/ _%M5
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public class CountControl{ 9!u=q5+E
private static long lastExecuteTime=0;//上次更新时间 |a(%a43fC
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 wF +9Iu
/** Creates a new instance of CountThread */ tFY;q##z
public CountControl() {} Ag3[Nu1
public synchronized void executeUpdate(){ ,X[lC\1a
Connection conn=null; U4J9bp|
PreparedStatement ps=null; |mSF a8G@
try{ -'j_JJ
conn = DBUtils.getConnection(); q K sI}X~
conn.setAutoCommit(false); 7IrbwAGZ3
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); y#4f^J!V
for(int i=0;i<CountCache.list.size();i++){ 'l%b5:
CountBean cb=(CountBean)CountCache.list.getFirst(); qno8qF*
CountCache.list.removeFirst(); 1}moT#
ps.setInt(1, cb.getCountId()); 3fS+,>s\O
ps.executeUpdate();⑴ xQ[~ c1
//ps.addBatch();⑵ ZfPWH'P
} ionFPc].
//int [] counts = ps.executeBatch();⑶ Sn I-dXNF
conn.commit(); 1@&i
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}catch(Exception e){ ?onaJ=mT
e.printStackTrace(); He#5d!cf:M
} finally{ xz-z"
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try{ EJM6TI"
if(ps!=null) { gWxpGW^eZ~
ps.clearParameters(); jE
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ps.close(); "f/Su(6{0
ps=null; '[E|3K5d
} Qi
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}catch(SQLException e){} ^x Wu7q
DBUtils.closeConnection(conn); Vv"JN?dHi
} aZ[
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} Uxla,CCp-
public long getLast(){ ~
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return lastExecuteTime; 82S?@%}#J
} e)pQh&uD
public void run(){ ,_STt)
long now = System.currentTimeMillis(); 6qW/Td|g
if ((now - lastExecuteTime) > executeSep) { Md~%
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//System.out.print("lastExecuteTime:"+lastExecuteTime); K%Dksx7ow
//System.out.print(" now:"+now+"\n"); i+x$Y)=
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); F/MzrK\':m
lastExecuteTime=now; X@;o<2^
executeUpdate(); 4fK(<2i
} > 3<P^-9L
else{ Q}pnb3J>T
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ' }G!D
} W'3&\}
} _0~WT
} ]}KoW?M
//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 <r6e23
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类写好了,下面是在JSP中如下调用。 {s=n "*Qp)
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<% 2~:jg1
CountBean cb=new CountBean(); E5-f{Qc
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); v9<7= D&x
CountCache.add(cb); 8db J'
out.print(CountCache.list.size()+"<br>"); f L @rv
CountControl c=new CountControl(); K+9oV[DMs
c.run(); (7C&I-l
out.print(CountCache.list.size()+"<br>"); ZG=B'4W
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