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: pwo5Ij,~q
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CountBean.java a)J3=Z-
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/* EOJ k7
* CountData.java (O {5L(
* <Y~?G:v6+
* Created on 2007年1月1日, 下午4:44 4a3Xz,[(a
* 4/YEkD
* To change this template, choose Tools | Options and locate the template under / *3[9,
* the Source Creation and Management node. Right-click the template and choose G{$(t\>8
* Open. You can then make changes to the template in the Source Editor. :K&>
*/ 62lG,y_L
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package com.tot.count; uim4,Zm{
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/** \Y.&G,?
* %qA@)u53
* @author C"l_78
*/ "q@OMf
public class CountBean { lrSdFJ%
private String countType; {TT@Mkz_QC
int countId; !u~h.DrvZ
/** Creates a new instance of CountData */ G8xM]'y
public CountBean() {} sVP[7&vr~
public void setCountType(String countTypes){ lF-;h{
this.countType=countTypes; YT!QY@qw
} SN2X{Q|*
public void setCountId(int countIds){ Ar&]/X,WG
this.countId=countIds; mD }&X7
} iC-WQkQY
public String getCountType(){ XrR@cDNx{
return countType; ;#c|ZnX
} #N%ATV
public int getCountId(){ ]D|sQPi]F
return countId; J qWMO!1
} 0v6(A4Y
} !wH7;tU
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CountCache.java 4T#B7wVoM
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/* 3&Dln
* CountCache.java (I3:u-A
* ECHl9;
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* Created on 2007年1月1日, 下午5:01 |rJ1/T.9
* TAz#e
* To change this template, choose Tools | Options and locate the template under d>"t*>i]>
* the Source Creation and Management node. Right-click the template and choose Z9-HQ5>
* Open. You can then make changes to the template in the Source Editor. mq~rD)T
*/ 6GVj13Nr
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package com.tot.count; }'HJV B_
import java.util.*; :%GxU;<E{
/** oXw} K((|
* d"zbY\`
* @author uv*OiB"
*/ "0Xa?z8"
public class CountCache { Bi?.w5
public static LinkedList list=new LinkedList(); cU}j
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/** Creates a new instance of CountCache */ l!Q |]-.@
public CountCache() {} [s?H3yQ.
public static void add(CountBean cb){ A#9@OWV5f
if(cb!=null){ cJ9:XWW
list.add(cb); l:NEK`>i
} (WT0j
} }W&hPC
} S.o 9AUv9
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CountControl.java _%WJ7~>
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/* RB1c!h$u
* CountThread.java cVv>"oF;~*
* G=4Da~<ij
* Created on 2007年1月1日, 下午4:57 @}@`lv65}
* p"^^9'`=
* To change this template, choose Tools | Options and locate the template under "B`yk/GM]
* the Source Creation and Management node. Right-click the template and choose e6s-;
* Open. You can then make changes to the template in the Source Editor. :nki6Rkowt
*/ <p<jXwl
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package com.tot.count; $-""=O|"
import tot.db.DBUtils; ~7PPB|XY
import java.sql.*; ,=KJ7zIK?
/** 7aTo!T
* 9k.LV/Y
* @author @+A`n21,O
*/ 9:0JWW^so
public class CountControl{ Alh"G6
private static long lastExecuteTime=0;//上次更新时间 `X?l`H;#
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 %XGwQB$zk8
/** Creates a new instance of CountThread */ IQ$l!)
public CountControl() {} Nx4_Oc^hY
public synchronized void executeUpdate(){ PN0l#[{EN
Connection conn=null; }vBk,ED
PreparedStatement ps=null; .Ajs0 T2
try{ ^T\JFzV
conn = DBUtils.getConnection(); Ikiv+Fq(
conn.setAutoCommit(false); k>#,1GbNZy
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ,lm.~% }P*
for(int i=0;i<CountCache.list.size();i++){ e#`wshtN:
CountBean cb=(CountBean)CountCache.list.getFirst(); 4)Y=)#=
CountCache.list.removeFirst(); W2h^ShG
ps.setInt(1, cb.getCountId()); 061@N=p8
ps.executeUpdate();⑴ nIVPh99
//ps.addBatch();⑵ _$/(l4\T[
} k^gnOU ;
//int [] counts = ps.executeBatch();⑶ NC::;e
conn.commit(); MNip;S_j
}catch(Exception e){ i}Ea>bi{N
e.printStackTrace(); w2y{3O"p=
} finally{ KfJF9!U*?
try{ mMO:m8W
if(ps!=null) { _QCspPT' c
ps.clearParameters(); ,vP9oY[n
ps.close(); G`E%uyjG$j
ps=null; *g&[?y`UC
} N,|:=gD_
}catch(SQLException e){} @;x|+@r
DBUtils.closeConnection(conn); ,c_[`q\
} 5}gcJjz
} Bt|S!tEy
public long getLast(){ z<_{m4I;
return lastExecuteTime; EOhUr=5~
} b8)>:F
public void run(){ }S'+Ytea
long now = System.currentTimeMillis(); s9)
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if ((now - lastExecuteTime) > executeSep) { WQ4:='(
//System.out.print("lastExecuteTime:"+lastExecuteTime); 4A0R07"
//System.out.print(" now:"+now+"\n"); e#L/
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 7dI+aJ
lastExecuteTime=now; Sj{z
executeUpdate(); cF_`m
} <jU[&~p
else{ !I5_ln
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); UzFd@W u#
} AR'q2/cw
} [La=z7*
} +jzpB*@
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 \Oh9)X:I
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类写好了,下面是在JSP中如下调用。 -?<wvUbR{
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<% uc~PKU?tO
CountBean cb=new CountBean(); D8slSX`6j
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); O-:#Q(H!
CountCache.add(cb); yJ8WYQQMG
out.print(CountCache.list.size()+"<br>"); nab:y(]$/
CountControl c=new CountControl(); j y{T=Nb
c.run(); x,
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out.print(CountCache.list.size()+"<br>"); Y[Us"K`
%>