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: R,dbq4xkl
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CountBean.java ,8G6q_ud
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/* @L?KcGD
* CountData.java 7BkY0_KK
* RG_.0'5=hc
* Created on 2007年1月1日, 下午4:44 B-UsMO
* .C,D;T{
* To change this template, choose Tools | Options and locate the template under `Vl9/IEk
* the Source Creation and Management node. Right-click the template and choose YJu~iQ`i
* Open. You can then make changes to the template in the Source Editor. {;vLM*
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*/ 03H0(ku=
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package com.tot.count; M>[e1y>7
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/** +h08uo5c
* nM|Cv
* @author oju,2kpH7#
*/ #f<3[BLx
public class CountBean { TyhO+;
private String countType; GRh430V[
int countId; 50""n7I<%
/** Creates a new instance of CountData */ H)+QkQb}
public CountBean() {} w)C5XX30;
public void setCountType(String countTypes){ S#:l17e3
this.countType=countTypes; N@0cn
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} s@IgaF {
public void setCountId(int countIds){ 4-m6e$p;
this.countId=countIds; /mXxj93UA
} ,&.$r/x|?
public String getCountType(){ lhC hk7l
return countType; QQJf;p7
} s }Ql9
public int getCountId(){ rCUGaf~
return countId; 5]xSK'6W
} R.!.7dO
} |j~l%d*<w
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CountCache.java X|-[i hp;
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/* .cm2L,1h
* CountCache.java 5th?m>
* [5!dO\-[
* Created on 2007年1月1日, 下午5:01 1yVhO2`7]
* te4=
* To change this template, choose Tools | Options and locate the template under ,l Y4WO
* the Source Creation and Management node. Right-click the template and choose Q(36RX%@
* Open. You can then make changes to the template in the Source Editor. =*1NVi $n
*/ tzthc*-<
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package com.tot.count; 4jt(tZS
import java.util.*; VD<z]@
/** cPv(VjS1;
* HItNd
* @author C~R
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*/ yM~bUmSg
public class CountCache { UWidT+'Sa
public static LinkedList list=new LinkedList();
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/** Creates a new instance of CountCache */ }Ba_epM
public CountCache() {} -Caj>K
public static void add(CountBean cb){ K{{_qFj@<y
if(cb!=null){ *~>p;*
list.add(cb); G bclR:G
} ^H&U_
} yOt#6Vw
} 1)MDnODJ
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CountControl.java r0 )ne|&Hp
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/* .p, VZ9
* CountThread.java 9 @xl{S-
* vaGF(hfTA
* Created on 2007年1月1日, 下午4:57 !~yBzH;K
* ykx^RmD`~
* To change this template, choose Tools | Options and locate the template under naW!b&:
* the Source Creation and Management node. Right-click the template and choose t:5-Ro
* Open. You can then make changes to the template in the Source Editor. S
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*/ tKeTHj;jO
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package com.tot.count; ? ep#s$i
import tot.db.DBUtils; kJp~'\b
import java.sql.*; >a,D8M?
/** YT
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* ,_fz)@)
* @author +)iMJ]>
*/ a9z#l}IQ
public class CountControl{ `}$o<CJ
private static long lastExecuteTime=0;//上次更新时间 Ph1XI&us9
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 acR|X@\3
/** Creates a new instance of CountThread */ S k~"-HL|
public CountControl() {} `X}:(O^GO
public synchronized void executeUpdate(){ %^pi
Connection conn=null; <"J]u@|
PreparedStatement ps=null; jk{(o09
try{ k=hWYe$iAz
conn = DBUtils.getConnection(); jb-kg</A
conn.setAutoCommit(false); ||_hET
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); `;E/\eG"
for(int i=0;i<CountCache.list.size();i++){ u]};QR
CountBean cb=(CountBean)CountCache.list.getFirst(); ba);f[>
CountCache.list.removeFirst(); BzP,Tu{,
ps.setInt(1, cb.getCountId()); NEIkG>\7q
ps.executeUpdate();⑴ 6(Pan%
//ps.addBatch();⑵ `X6JZxGyd
} &$F<]]&
//int [] counts = ps.executeBatch();⑶ Jpj=d@Of70
conn.commit(); vRmn61
}catch(Exception e){ jdP)y]c
e.printStackTrace(); LdV&G/G-#D
} finally{ S{rltT-
try{ rP3HR5
if(ps!=null) { &0Yg:{k$
ps.clearParameters(); .p&@;fZ
ps.close(); *h!fqT%9
ps=null; DH-M|~.sf^
} /|1p7{km
}catch(SQLException e){} /Vn>(;lo
DBUtils.closeConnection(conn); !Qe;oMqy}
} aa`(2%(:
} ej`%}e%2
public long getLast(){ a>'ez0C
return lastExecuteTime; @1JwjtNk
} a /sj W
public void run(){ G^~[|a4`
long now = System.currentTimeMillis(); EiL#Dwx
if ((now - lastExecuteTime) > executeSep) { xc:E>-
//System.out.print("lastExecuteTime:"+lastExecuteTime); 2J ZR"P
//System.out.print(" now:"+now+"\n"); &X$T "Dp
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); =_7wd*,
lastExecuteTime=now; $*fJKR_N
executeUpdate(); <W80A J
} pk/#RUfT+
else{ H\67Pd(Z6
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); Az`Aa0h]7
} <(L@@.87R
} Y%s:oHt
} 1i y$ 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 HTJ2D@h
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类写好了,下面是在JSP中如下调用。 mL{P4a 1xf
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<%
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CountBean cb=new CountBean(); z8Q!~NN-K
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); C82_)@96
CountCache.add(cb); `@~e<s`j
out.print(CountCache.list.size()+"<br>"); Y'iX
CountControl c=new CountControl(); ,,'jyqD
c.run(); H}^ '
out.print(CountCache.list.size()+"<br>"); <v_=k],W
%>