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: Ui@Q&%b
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CountBean.java Jj*XnL*
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/* UMpC2)5
* CountData.java L qMH]W
* ;XSV}eLu
* Created on 2007年1月1日, 下午4:44 ox{)O/aj
* uNxR#S
* To change this template, choose Tools | Options and locate the template under {1'XS,2
* the Source Creation and Management node. Right-click the template and choose M-,vX15S
* Open. You can then make changes to the template in the Source Editor. 1&ZG6#16q
*/ :@KWp{ D7
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package com.tot.count; ;<Oe\X
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/** m!er"0
* ea3AcT6
* @author 320Wm)u>:
*/ *$Aneq0f
public class CountBean { j0>S)Q
private String countType; I5wf|wB-
int countId; _]E"hr6a
/** Creates a new instance of CountData */ Q 6{2@
public CountBean() {} fCJ:QK!
public void setCountType(String countTypes){ wWko9h=|mQ
this.countType=countTypes; U`ey7
} RvZi %)
public void setCountId(int countIds){ wr~# rfH
this.countId=countIds; BLgmFE2
} CtTG`)"|
public String getCountType(){ "S(m1L?
return countType; wz +
} &Y\Vh}
public int getCountId(){ 6 KP
return countId; c|X.&<lX
} w1KLQd:yq
} Se9I1~mX
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CountCache.java 9IIQon
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/* i*:lZ eU61
* CountCache.java w")VcAq
* DM/J,q
* Created on 2007年1月1日, 下午5:01 =O?<WJoK
* 9`f]Rf"
* To change this template, choose Tools | Options and locate the template under N8m|Y]^H#
* the Source Creation and Management node. Right-click the template and choose T)6p,l
* Open. You can then make changes to the template in the Source Editor. ^Jcs0c
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*/ HDvj{
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package com.tot.count; .n[!3X|d
import java.util.*; 3+u11'0=t
/** E)H:
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* @QV|<NeH
* @author +yiGZV/X
*/ EjV,&7o)
public class CountCache { mg[=~&J^
public static LinkedList list=new LinkedList(); !R-M:|
/** Creates a new instance of CountCache */ d^
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public CountCache() {} d&&^_0O
public static void add(CountBean cb){ wQgW9546
if(cb!=null){ N&K:Jp
list.add(cb); P6&@fwJ<
} *.K+"WS%
} 2>l4$G0
} p 2It/O
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CountControl.java c}kZx1
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/* R(@B4M2
* CountThread.java lZ.x@hDS
* Ac0C,*|^
* Created on 2007年1月1日, 下午4:57 1Y6<i8
* 5, R\tJCK
* To change this template, choose Tools | Options and locate the template under 'e^,#L_!o
* the Source Creation and Management node. Right-click the template and choose k(+EY%
* Open. You can then make changes to the template in the Source Editor. "toyfZq@
*/ v!27q*;8H
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package com.tot.count; 2~Z P[wr
import tot.db.DBUtils; Eqc&iS~
import java.sql.*; :CH "cbo
/** E;.<'t>
* N3
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* @author OJPxV~y
*/ Q*&>Ui[&
public class CountControl{ }&BE*U8_
private static long lastExecuteTime=0;//上次更新时间 )XV|D
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 O]>9\!0{
/** Creates a new instance of CountThread */ 28[hp[<
public CountControl() {} ;wwhW|A
public synchronized void executeUpdate(){ }R4%%)j(Vj
Connection conn=null; Pz7{dQqjk#
PreparedStatement ps=null; kW0|\
try{ .lAqD-
conn = DBUtils.getConnection(); `WQz_}TqB
conn.setAutoCommit(false); Cj"+` C)l
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); N7Vv"o
for(int i=0;i<CountCache.list.size();i++){ ,r~pf(nz
CountBean cb=(CountBean)CountCache.list.getFirst(); SxMmy
CountCache.list.removeFirst(); 4Xt.}S!
ps.setInt(1, cb.getCountId()); Wd#r-&!6j
ps.executeUpdate();⑴ H^z6.!$m
//ps.addBatch();⑵ iU"jV*P]
} <9z2:^
//int [] counts = ps.executeBatch();⑶ K>iM6Uv
conn.commit(); C"}CD{<H]M
}catch(Exception e){ aNLRUdc.
e.printStackTrace(); #$7d1bx
} finally{ rDFDrviW_
try{ _^K)>
if(ps!=null) { )d5Hv2/0
ps.clearParameters(); TbX#K:l
ps.close(); v zgR3r
ps=null; ]S;^QZ
} u`?MV2jU2
}catch(SQLException e){} QY2/mtI
DBUtils.closeConnection(conn); g}
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} Z Ear~
} [&12`!;j
public long getLast(){ 5-'jYp/
return lastExecuteTime; f$#--*
} F]o&m::/K
public void run(){ '-C%?*ku
long now = System.currentTimeMillis(); q)0?aL
if ((now - lastExecuteTime) > executeSep) { $>Md]/I8
//System.out.print("lastExecuteTime:"+lastExecuteTime); v0uDL7
//System.out.print(" now:"+now+"\n"); _+Tq&,_:o
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 4@ EY+p
lastExecuteTime=now; L3}n(KAJj
executeUpdate(); U8TH} 9Q
} vEQw`OC
else{ ^w]N#%k\H
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); c#o(y6
} r\nKJdh;ka
} C1w~z4Qp
} 7|$cM7_r
//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 Su"9`
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类写好了,下面是在JSP中如下调用。 I
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<% !J#oN+AR
CountBean cb=new CountBean(); MR4e.+#E
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 'Mp8!9=&
CountCache.add(cb); 2J7=
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out.print(CountCache.list.size()+"<br>"); Y2lBQp8'|
CountControl c=new CountControl(); 0_nY70B
c.run(); n1
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out.print(CountCache.list.size()+"<br>"); Kf=6l#J7
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