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: KAj"p9hq+k
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CountBean.java a'
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/* KXoL,)Hl
* CountData.java b lRY7
* !p]T6_t]Q
* Created on 2007年1月1日, 下午4:44 9]]!8_0=r
* 7af?E)}v
* To change this template, choose Tools | Options and locate the template under Y=P9:unG
* the Source Creation and Management node. Right-click the template and choose t7jh?]
* Open. You can then make changes to the template in the Source Editor. @!z$Sp=
*/ 88 Fb1!a5Z
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package com.tot.count; e={k.y}x}
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/** wFK:Dp_^
* MuDFdbtR
* @author nwa\Lrh
*/ ;yk9(wea}"
public class CountBean { @wd!&%yzO
private String countType; V+qFT3?-
int countId; y;,=ajrF
/** Creates a new instance of CountData */ EzzTJ>
public CountBean() {} O{lIs_1.Z
public void setCountType(String countTypes){ 8yHq7=
this.countType=countTypes; qiG]nCq
} mV6#!_"
public void setCountId(int countIds){ a(PjcQ4dY
this.countId=countIds; ePV-yy
} .@y{)/
public String getCountType(){ bWGyLo,
return countType; 6@"Vqm|HD
} Si#"Wn?|
public int getCountId(){ o\_
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return countId; X4d Xm>*?=
} Pk$}%;@v
} W0VA'W
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CountCache.java fC=fJZU7$
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/* =}~NRmmF
* CountCache.java 3x04JE3!
* [:AB$l*
* Created on 2007年1月1日, 下午5:01 *e(:["v
* T&o,I
* To change this template, choose Tools | Options and locate the template under m(2G*}
* the Source Creation and Management node. Right-click the template and choose j`>?"1e@x
* Open. You can then make changes to the template in the Source Editor. fUb1/-}
*/ ,]0S4h67
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package com.tot.count; l_^T&xq8
import java.util.*; oUl=l}qnD
/** Kg4QT/0VA
* zt7_r`#z
* @author ]O6KKz
*/ x7vq?fP0n
public class CountCache { XxmJP5
public static LinkedList list=new LinkedList(); /yLzDCKn
/** Creates a new instance of CountCache */ aXRv}WO$>k
public CountCache() {} +n@f'a">
public static void add(CountBean cb){ /)sDnJ1r
if(cb!=null){ *
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list.add(cb); Gh2#-~|cB
} t[%x}0FP-F
} BmJkt3j."
} Bx+d3
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CountControl.java A ?#]s
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/* a`DWpc~
* CountThread.java L30>|g
* gdOe)il\
* Created on 2007年1月1日, 下午4:57 0LS-i% 0
* N2ni3M5v
* To change this template, choose Tools | Options and locate the template under MK omq
* the Source Creation and Management node. Right-click the template and choose BqQ] x'AF
* Open. You can then make changes to the template in the Source Editor. ||R0U@F,
*/ R78!x*U}
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package com.tot.count; 6hp{,8|D"m
import tot.db.DBUtils; |a%B|CX
import java.sql.*; 5i|s>pD4z1
/** <#zwKTmK1
* XFtOmY
* @author OWqrD@
*/ -UJ?L
public class CountControl{ Sbp
private static long lastExecuteTime=0;//上次更新时间 aD+0\I[x
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 k69kv9v@J
/** Creates a new instance of CountThread */ ~D*b3K8X
public CountControl() {} /j11,O?72
public synchronized void executeUpdate(){ I"B8_
Connection conn=null; f(!E!\&n^
PreparedStatement ps=null; ,g%o
try{ w-r_H!-
conn = DBUtils.getConnection(); <} &7 a s
conn.setAutoCommit(false); y7>iz6N
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 8Bj4_!g
for(int i=0;i<CountCache.list.size();i++){ nHnk#SAAu
CountBean cb=(CountBean)CountCache.list.getFirst(); xsYE=^uv
CountCache.list.removeFirst(); /CH(!\bQ
ps.setInt(1, cb.getCountId()); 7LG+$LEz
ps.executeUpdate();⑴ %Nl`~Kz9U
//ps.addBatch();⑵ AU/#b(mI
} +a #lofhv
//int [] counts = ps.executeBatch();⑶ Gv;;!sZ
conn.commit(); Jff 79)f
}catch(Exception e){ JwjI{,jY
e.printStackTrace(); Rl1$?l6Rf
} finally{ ` ovgWv
try{ &D]&UQf
if(ps!=null) { 5qC:yI
ps.clearParameters(); }X.>4\B5
ps.close(); L1rwIOgq^
ps=null; &&&9
} z*RSMfRW
}catch(SQLException e){} >jv\Qh
DBUtils.closeConnection(conn); =9^Q"t4
} p+RAtR f
} z/weit
public long getLast(){ _$8{;1$T?
return lastExecuteTime; *_PPrx5
} m#*h{U$
public void run(){ ("OAPr\2dw
long now = System.currentTimeMillis(); ln fm0
if ((now - lastExecuteTime) > executeSep) { -xz|ayn
//System.out.print("lastExecuteTime:"+lastExecuteTime); _r]nJEF5
//System.out.print(" now:"+now+"\n"); <>]1Y$^Y
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); pL! a
lastExecuteTime=now; IJ0#iA. T
executeUpdate(); C w%BZ
} RE 9nU%!
else{ MA$Xv`6I\
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n");
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} l~rb]6E
} oKRFd_r +
} Rnr#$C%
//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 +ZclGchw
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类写好了,下面是在JSP中如下调用。 L@nebT;\'
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<% zFywC-my@
CountBean cb=new CountBean(); , |l@j%
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); wYjQV?,
CountCache.add(cb); #sZIDn J#
out.print(CountCache.list.size()+"<br>"); 1+a@k
CountControl c=new CountControl(); &Xv1[nByU
c.run(); 7-X/>v
out.print(CountCache.list.size()+"<br>"); {\EOo-&A
%>