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: :{l_FY436
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CountBean.java p]+Pkxz]'
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/* J<h$
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* CountData.java `l[c_%Bm
* I-(zaqp@
* Created on 2007年1月1日, 下午4:44 SZ'R59Ee<
* flbd0NB
* To change this template, choose Tools | Options and locate the template under $G@5qxcV
* the Source Creation and Management node. Right-click the template and choose Wt-GjxGi
* Open. You can then make changes to the template in the Source Editor. bJTBjS-7
*/ iz PDd{[
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package com.tot.count; `dN@u@[\ks
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/** ?NsW|w_
* WP'!*[z
* @author kxhWq:[c
*/ 0~/_|?]`7
public class CountBean { 7[XRd9a5(
private String countType; +\
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int countId; >KhOz[Zg
/** Creates a new instance of CountData */ :':s@gqr
public CountBean() {} 9qzHS~l
public void setCountType(String countTypes){ WW~sNC\3`(
this.countType=countTypes; p}~JgEE
} ;[OH(!
public void setCountId(int countIds){ i<Zc"v;
this.countId=countIds; [ sjosV
} 4!no~ $b
public String getCountType(){ Q/0Tj]D
return countType; 7;wd(8
} `|&O*`
public int getCountId(){ B[?Ng}<g`
return countId; A$0fKko
} qu{&xjTH8
} ;85>xHK
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CountCache.java ]Q)OL
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/* uz
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* CountCache.java @`- 4G2IU}
* JP[K;/
* Created on 2007年1月1日, 下午5:01 R!gEwTk
* w_K1]<Q*
* To change this template, choose Tools | Options and locate the template under }Oq5tC@$G
* the Source Creation and Management node. Right-click the template and choose n9ej7oj
* Open. You can then make changes to the template in the Source Editor. \\;jw[P0
*/ ^8N}9a
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package com.tot.count; VTY 5]|;
import java.util.*; .Vvx,>>D
/** e=m42vIB-
* RQ"
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* @author d|Lj~x|
*/ 4O!ikmY:t
public class CountCache { ar+9\
public static LinkedList list=new LinkedList(); x7<K<k;s
/** Creates a new instance of CountCache */ 0)Wltw~`&
public CountCache() {} H8}oIA"b
public static void add(CountBean cb){ 7?w*]
if(cb!=null){ Si;H0uP O
list.add(cb); MeZf*'
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} i5@z< \
} u>a5GkG.
} `1IgzKL9
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CountControl.java $c(nF01
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/* B>P{A7Q
* CountThread.java )R1<N
* TJXT-\Vk
* Created on 2007年1月1日, 下午4:57 w@w(-F!%l
* 8P&:_T!
* To change this template, choose Tools | Options and locate the template under |z^^.d~a0
* the Source Creation and Management node. Right-click the template and choose .V8Lauz8
* Open. You can then make changes to the template in the Source Editor. z 1X` o
*/ <*cikXS
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package com.tot.count; D_zZXbNc
import tot.db.DBUtils; suDQ~\n
import java.sql.*; R.yvjPwJ
/** V+9 MoT?8
* JYHl,HH#z
* @author SSMHoJGm
*/ J)p
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public class CountControl{ -=\c_\ O
private static long lastExecuteTime=0;//上次更新时间 O)r4?<Q
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 WOL:IZX%
/** Creates a new instance of CountThread */ sdw(R#GE
public CountControl() {} =]0&i]z[.
public synchronized void executeUpdate(){ v0.#Sl-
Connection conn=null; BR;D@R``}
PreparedStatement ps=null; t'k$&l}+
try{ 3AN/
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conn = DBUtils.getConnection(); XUuN )i
conn.setAutoCommit(false); $*=<Yw4
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); bY~pc\V:`w
for(int i=0;i<CountCache.list.size();i++){ :,6\"y-
CountBean cb=(CountBean)CountCache.list.getFirst(); aO4?m+
CountCache.list.removeFirst(); {;6`_-As%
ps.setInt(1, cb.getCountId()); &6nWzF
ps.executeUpdate();⑴ ~oY^;/ j
//ps.addBatch();⑵ kc&U'&RgY
} \(2sW^fY
//int [] counts = ps.executeBatch();⑶ sD#.Oq4&]y
conn.commit(); oW6XF-yM
}catch(Exception e){ YS"=yye3e
e.printStackTrace(); P71Lqy)5}A
} finally{ -PR N:'T
try{ WNrk}LFof
if(ps!=null) { C!bUI8x
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ps.clearParameters(); E+;7>ja
ps.close(); </*6wpN
ps=null; h2fNuu"
} }:)&u|d_
}catch(SQLException e){} #?:l b1
DBUtils.closeConnection(conn); gc$l^`+M
} O3kA;[f;
} k~w*W X'
public long getLast(){ ]~3V}z,T*
return lastExecuteTime; -6B4sZpzD
} h(EhkCf
public void run(){ %._.~V
long now = System.currentTimeMillis(); H"WprHe
if ((now - lastExecuteTime) > executeSep) { c9h6C
//System.out.print("lastExecuteTime:"+lastExecuteTime); XlR@pr6tw
//System.out.print(" now:"+now+"\n"); o!A+&{
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); DN:EB@
lastExecuteTime=now; g]0_5?i
executeUpdate(); 3)ywX&4"L
} ^k9I(f^c-_
else{ wI/iuc
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); xU`p|(SS-
} H9e<v4c
} {R6ZKB
} $6SW;d+>n
//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 <7jW_R@
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类写好了,下面是在JSP中如下调用。 ~b8]H|<'Y
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<% 9 djk[ttA)
CountBean cb=new CountBean(); Er?&Y,o
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); %1+4_g9
CountCache.add(cb); vx5Zl&6r
out.print(CountCache.list.size()+"<br>"); TOQP'/
CountControl c=new CountControl(); c{w2Gt!
c.run(); qlPT Ll
out.print(CountCache.list.size()+"<br>"); 0LJv'
%>