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: wk2Ff*&
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CountBean.java s +0S,?{$
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/* ! ^aJS'aq
* CountData.java cmp@Ow"c
* Vzh\1cF
* Created on 2007年1月1日, 下午4:44 g]?QV2bX6
* Ki[&DvW:
* To change this template, choose Tools | Options and locate the template under EiPOY'
* the Source Creation and Management node. Right-click the template and choose C jz(-018
* Open. You can then make changes to the template in the Source Editor. nKch:g
*/ ?0d#O_la3
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package com.tot.count; $F@ ,,*
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/** s[t?At->
* rL/H{.@$`
* @author `Js"*[z
*/ b}ODc]3
public class CountBean { (I#3![q
private String countType; I7;|`jN5K
int countId; fHgvh&FU
/** Creates a new instance of CountData */ CeUC[cUQU
public CountBean() {} |Syulus
public void setCountType(String countTypes){ WFfn:WSWU
this.countType=countTypes;
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} <SSkCw
public void setCountId(int countIds){ Md*.q^:
this.countId=countIds; 1(WBvAPS
} 5?>ES*
public String getCountType(){
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return countType; CH0Nkf
} j
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public int getCountId(){ nx5I
return countId; q]Af I(
} 6&"GTK
} pE{Ecrc3|
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CountCache.java R-Gg= l5
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/* =DXN`]uN
* CountCache.java 4mm>6w8NT
* ufocj1IU
* Created on 2007年1月1日, 下午5:01 4V'HPD>=V
* Bh65qHQO
* To change this template, choose Tools | Options and locate the template under E_#?;l>
* the Source Creation and Management node. Right-click the template and choose ]}9[ys
* Open. You can then make changes to the template in the Source Editor. ^K:-r !v^
*/ ,-SWrp`f
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package com.tot.count; ?:i,%]zxC
import java.util.*; CTQJ=R"
/** ~L"?C
* kK.[v'[>&
* @author ZDm Y${J
*/ 3qy4nPg
public class CountCache { ;eW\41 w
public static LinkedList list=new LinkedList(); sV]I]DR
/** Creates a new instance of CountCache */ e_IRF+>
public CountCache() {} 2~%^y6lR
public static void add(CountBean cb){ *_K*GCy
if(cb!=null){ /1b7f'
list.add(cb); sY&Z/Y
} 7Q?^wx
} 1YtK+,mz
} &W*^&0AV
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CountControl.java 4-oaq'//BT
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/* k\-h-0[|
* CountThread.java ur[^/lxx0
* kG`&Z9P
* Created on 2007年1月1日, 下午4:57 dEZlJo@J
* XmN8S_M>v
* To change this template, choose Tools | Options and locate the template under _P*QX
* the Source Creation and Management node. Right-click the template and choose wv^n#
* Open. You can then make changes to the template in the Source Editor. M<P8u`)>4H
*/ :a9
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package com.tot.count; VPb8dv(a3
import tot.db.DBUtils; _IWLC{%V
import java.sql.*; xcH&B%;f
/** 9A *gW j
* ]D,\(|
* @author 4B)%I`
*/ #Sg"/Cc
public class CountControl{ Yh;A)Np
private static long lastExecuteTime=0;//上次更新时间 \t)`Cp6,[b
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 kq@~QI?9
/** Creates a new instance of CountThread */ uc/W/c u,
public CountControl() {} <T]ey
public synchronized void executeUpdate(){ "egpc*|]
Connection conn=null; 0e1-ZP CDj
PreparedStatement ps=null; ~EU\\;1Rmq
try{ Gr#WD=I-}
conn = DBUtils.getConnection(); ;3o7>yEv
conn.setAutoCommit(false); <6X*k{
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); <(i5hmuVd
for(int i=0;i<CountCache.list.size();i++){ ^,aI2vC
CountBean cb=(CountBean)CountCache.list.getFirst(); ER0B{b
CountCache.list.removeFirst(); B:Hr{%O
ps.setInt(1, cb.getCountId()); c:""&>Z
ps.executeUpdate();⑴ <
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//ps.addBatch();⑵ s;-AZr)
} lX"6m}~D
//int [] counts = ps.executeBatch();⑶ 6"R'z#{OF
conn.commit(); >T-4!ZvS\j
}catch(Exception e){ _PSOT5{
e.printStackTrace(); 8{_lB#<[E
} finally{ bAwKmk9C
try{ egVKAR-
if(ps!=null) { 8 [D"
ps.clearParameters(); KD?b|y@
ps.close(); bP> Kx-%q
ps=null; [2E(3`-u
} /Q_Dd
}catch(SQLException e){} Hz)i.AA 4
DBUtils.closeConnection(conn); u08QE,
} h J0U-m
} (e0(GOqf4
public long getLast(){ KC)}Mzt6_
return lastExecuteTime; ZB`d&!W>
} 6@eF|GoP
public void run(){ iu3L9UfL[
long now = System.currentTimeMillis(); {8h[Bd
if ((now - lastExecuteTime) > executeSep) { 5lM2nhlf'b
//System.out.print("lastExecuteTime:"+lastExecuteTime); I&31jn_o
/
//System.out.print(" now:"+now+"\n"); # 1dg%
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ;#:AM;
lastExecuteTime=now; -&=dl_m
executeUpdate(); X0R EC%
} e5
}amrz
else{ -:E~Z_J`
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 3R0ioi 7
} $sS~hy*
} w 5?D]u
} W/AF
//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 ~]q>}/&YLo
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类写好了,下面是在JSP中如下调用。 fP\q?X@]E
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<% 8QoxU"
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CountBean cb=new CountBean(); 52zE -SY
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); i1!1'T8
CountCache.add(cb); [:cvy[}v@
out.print(CountCache.list.size()+"<br>"); =E<H_cUS
CountControl c=new CountControl(); 2TNK
c.run(); kDI?v6y5
out.print(CountCache.list.size()+"<br>"); 6|~^P!&
%>