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: w~b:9_reY
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CountBean.java _M%S
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/* "kyCY9)%
* CountData.java wS*r<zj
* #XDgvX >
* Created on 2007年1月1日, 下午4:44 =#V^t$
* &<BBPn@\
* To change this template, choose Tools | Options and locate the template under 4@
* the Source Creation and Management node. Right-click the template and choose (w hl1
* Open. You can then make changes to the template in the Source Editor. `|ie#L(:7/
*/ <#C,66k
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package com.tot.count; lLTqk\8g
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/** 4|`>}Nu
* +twoUn{#
* @author ?7aZU
*/ DO*U7V02
public class CountBean { sE% $]Jp
private String countType; Z
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int countId; o%t4WQ|bj
/** Creates a new instance of CountData */ 5CFNBb%Xy
public CountBean() {} Qu61$!
public void setCountType(String countTypes){ nnv|GnQST
this.countType=countTypes; q*3OWr
} ?uq`| 1`
public void setCountId(int countIds){ ApCU|*r)
this.countId=countIds; WPL@v+
} xak)YOLRV
public String getCountType(){ ^HC6v;K
return countType; Lb/GL\J)
} p@Y=6 Bw
public int getCountId(){ 'E_~|C
return countId;
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} QhZg{v[d
} vV}w>Ap[
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CountCache.java 8z#Qp(he
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/* >NKJ@4Y
* CountCache.java =8\.fp
* ?R)]D:`
* Created on 2007年1月1日, 下午5:01 Z>9@)wo
* ,dIev<
* To change this template, choose Tools | Options and locate the template under xqG<R5k>>
* the Source Creation and Management node. Right-click the template and choose h !^=
c
* Open. You can then make changes to the template in the Source Editor. qiNVaV\wr|
*/ g_Z
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package com.tot.count; puC91
import java.util.*; ;,&cWz
/** 3v8LzS3@
* vgwpuRL5b
* @author n3a.)tcC
*/ _%nz-I
public class CountCache { ^e.-Ji
public static LinkedList list=new LinkedList(); pE5v~~9Ikv
/** Creates a new instance of CountCache */ %2}fW\%'
public CountCache() {} X;I9\Cp]!
public static void add(CountBean cb){ RxP H[7oZ
if(cb!=null){ yix[zfQt0
list.add(cb); 6zi>Q?] 1
} <CyU9`ye
} ]q]xU,
} n=.P46|
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CountControl.java G*CPj^O
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/* 1$>+rW{a
* CountThread.java ax&?Z5%a
* OIcXelS:@k
* Created on 2007年1月1日, 下午4:57 /WuYg
OI
* 80=0S^gEZ
* To change this template, choose Tools | Options and locate the template under Ir9GgB
* the Source Creation and Management node. Right-click the template and choose QUrPV[JQ
* Open. You can then make changes to the template in the Source Editor. &$MC!iMh
*/ n>Ff tVZNJ
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package com.tot.count; ~aob@(
import tot.db.DBUtils; 8SGaS&
import java.sql.*; 9wvlR6z;u
/** QQ(}71U
* L+am-k:T~
* @author 3Ua?^2l
*/ NAR6q{c
public class CountControl{ :viW
private static long lastExecuteTime=0;//上次更新时间 (> al-vZ6A
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 lzEynMO+
/** Creates a new instance of CountThread */ qe0 D[L
public CountControl() {} M8/a laoT
public synchronized void executeUpdate(){ 76nH)^%l<
Connection conn=null; ~YYnn7)
PreparedStatement ps=null; Su#0F0
try{ !}&|a~U@`k
conn = DBUtils.getConnection(); `'YX>u /
conn.setAutoCommit(false); idI w7hi4
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); a1Fx|#!
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for(int i=0;i<CountCache.list.size();i++){ $V~@w.-Z#
CountBean cb=(CountBean)CountCache.list.getFirst(); Lljn\5!r<
CountCache.list.removeFirst(); B~]Kqp7yU
ps.setInt(1, cb.getCountId());
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ps.executeUpdate();⑴ s)^/3a
//ps.addBatch();⑵ aO' #!k*R
} )^j_O^T5
//int [] counts = ps.executeBatch();⑶ um2a#6uo
conn.commit(); p+d-7'?I
}catch(Exception e){ x?h/e;
e.printStackTrace(); Kj4/fB
} finally{ ]VI^ hhf
try{ ATs_d_Sz
if(ps!=null) { K`4lL5oH
ps.clearParameters(); lTx_E#^s
ps.close(); ^m>4<~/
ps=null; 4V+bE$Wu
} 1h,iWHC
}catch(SQLException e){} /5@YZ?|#2
DBUtils.closeConnection(conn); &.)=>2
} |2(q9j
} ;ArwEzo(
public long getLast(){ CFtQPTw
return lastExecuteTime; }%wd1`l7
} 3lP;=*m.
public void run(){ 'a~@q~!
long now = System.currentTimeMillis(); ~ ld.I4
if ((now - lastExecuteTime) > executeSep) { t>j_C{X1(
//System.out.print("lastExecuteTime:"+lastExecuteTime); 7({)ou x
//System.out.print(" now:"+now+"\n"); <kn2
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); +-izC%G
lastExecuteTime=now; LF dvz0
executeUpdate(); L:i&OCU2k
} >*-%:ub
else{ :j\7</uu
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); c./\sN@
} VvhfD2*T
} iU)I"#\l'k
} T ,lM(2S[
//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 }3Es&p$9
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类写好了,下面是在JSP中如下调用。 D!j/a!MaKk
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<% 1/DtF
CountBean cb=new CountBean(); j\y;~
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cb.setCountId(Integer.parseInt(request.getParameter("cid"))); Ymut]`dX
CountCache.add(cb); @C;1e7
out.print(CountCache.list.size()+"<br>"); +f3Rzx]
CountControl c=new CountControl(); B%F]K<
c.run(); bvox7V>
out.print(CountCache.list.size()+"<br>"); 0z8(9DlTc
%>