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: )s,L:{<
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CountBean.java *rSMD_>
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/* 6/hY[a!
* CountData.java i&-g 0
* n*CH,fih:
* Created on 2007年1月1日, 下午4:44 ylLQKdcL
* upQ:C>S
* To change this template, choose Tools | Options and locate the template under T.d+@ZV<#
* the Source Creation and Management node. Right-click the template and choose Q7&Yy25
* Open. You can then make changes to the template in the Source Editor. #R"9(Q&
*/ {\ P$5O{%
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package com.tot.count; WfBA5
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/** l^:m!SA_
* LVq3R 8A
* @author 49nZWv48"_
*/ gZ%B9i:
public class CountBean { kwMuL>5
private String countType; yTz@q>6s-
int countId; { r`l
/** Creates a new instance of CountData */ zwN;CD1
public CountBean() {} \U4O*lq
public void setCountType(String countTypes){ VmF?8Vi4
this.countType=countTypes; ?Vb=W)Es
} JHwkLAuz
public void setCountId(int countIds){ yAU[A
this.countId=countIds; |rH;}t|un
} dD1`[%
public String getCountType(){ %Xh/16X${
return countType; O4$ra;UM`
} Kw3fpNd
public int getCountId(){ ^-w:D
return countId; El Z'/l*\
} /v:g' #n
} DOaEz?2)
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CountCache.java X |.'_6l.
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/* 4
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* CountCache.java pB@8b$8(Z
* }.3F|H
* Created on 2007年1月1日, 下午5:01 _J }ce
* '(5 &Sj/C
* To change this template, choose Tools | Options and locate the template under z) yUBcq
* the Source Creation and Management node. Right-click the template and choose @%IZKYfc~
* Open. You can then make changes to the template in the Source Editor. p \; * :
*/ SGZOfTcY
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package com.tot.count; Z=sy~6m+v
import java.util.*; $R2T)
/** im>Sxu@
* ;tf1#6{
* @author J|sX{/WT
*/ qo}-m7
public class CountCache { m( C7Fa
public static LinkedList list=new LinkedList(); S]KcAz( fX
/** Creates a new instance of CountCache */ Cmm"K[>Rx
public CountCache() {} d;Z<")
public static void add(CountBean cb){ >T%Jlj3ZG
if(cb!=null){ KM g`O3_16
list.add(cb); =%znY`0b56
} b3wE8Co
} 3%/]y=rA
} a^'1o9
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CountControl.java S6B(g_D|
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/* hqnJ@N$yY
* CountThread.java &32qv`
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* ;DL|%-%;$r
* Created on 2007年1月1日, 下午4:57 |VB}Kv
* }9R45h}{<
* To change this template, choose Tools | Options and locate the template under D%LqLLD
* the Source Creation and Management node. Right-click the template and choose 6dV@.(][a
* Open. You can then make changes to the template in the Source Editor. xrA(#\}f$
*/ .LEQ r)
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package com.tot.count; *qAF#
import tot.db.DBUtils; nSz Fs(]f
import java.sql.*; g(33h2"
/** D7X-|`kH
* `.
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* @author %/,PY>:|
*/ I--WS[
public class CountControl{ *;7&
private static long lastExecuteTime=0;//上次更新时间 r62x*?/
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ;Z-Cn.
/** Creates a new instance of CountThread */ NZe3
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public CountControl() {} xB68RQe)
public synchronized void executeUpdate(){ !3DWz6u
Connection conn=null; U;?%rM6
PreparedStatement ps=null; qDqIy+WR
try{ b+'G^!JR
conn = DBUtils.getConnection(); +e)So+.W
conn.setAutoCommit(false); qlIC{:E0
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); G&0&*mp
for(int i=0;i<CountCache.list.size();i++){ U)zd~ug?m
CountBean cb=(CountBean)CountCache.list.getFirst(); Yi{[llru
CountCache.list.removeFirst(); 7,!Mmu
ps.setInt(1, cb.getCountId()); 9;&2LT7z
ps.executeUpdate();⑴ aj20, w
//ps.addBatch();⑵ R)I 8 )
} ^8o'\V"m^
//int [] counts = ps.executeBatch();⑶ /1h`O@VA
conn.commit();
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}catch(Exception e){ R I:x`do
e.printStackTrace(); VD,F?L!
} finally{ 6.6~w\fR8
try{ yH|ucN~k5S
if(ps!=null) { T73oW/.0X?
ps.clearParameters(); ZF51|b
ps.close(); `-D6:- ,w
ps=null; ?#qA>:2,
} V3$!`T}g4
}catch(SQLException e){} G`R Ed-Z[
DBUtils.closeConnection(conn); Fh?;,Z
} $e+@9LNK
} s^^X.z ,
public long getLast(){ 5w gtc~
return lastExecuteTime; +#6WORH0S
} Eg3rbqM- 8
public void run(){ YZ7rs]A
long now = System.currentTimeMillis(); 5u:+hB
if ((now - lastExecuteTime) > executeSep) { r4gkSwy
//System.out.print("lastExecuteTime:"+lastExecuteTime); doFp53NhV
//System.out.print(" now:"+now+"\n"); %Wom]/&,'
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 3LG}x/l
lastExecuteTime=now; EX>> -D7L
executeUpdate(); N$/{f2iC
} A%"XN k
else{ Eof1sTpA
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); "]LNw=S
} #v:<\-MjN
} 90k|W>
} MEI]N0L3
//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 x1/Usupi
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类写好了,下面是在JSP中如下调用。 37ll8
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<% vPi\ vU{
CountBean cb=new CountBean(); +LQ2To
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); #"O9\X/B
CountCache.add(cb); ]RPv@z:V
out.print(CountCache.list.size()+"<br>"); +;C|5y
CountControl c=new CountControl(); E;$t|~#
c.run(); Ufq"_^4
out.print(CountCache.list.size()+"<br>"); !#rZeDmw
%>