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: m])!'Pa(=
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CountBean.java (,5oqU9s@
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/* w/8`]q
* CountData.java uHBEpqC%
* K[wOK
* Created on 2007年1月1日, 下午4:44 DCJmk6p%0
* z (N3oBW
* To change this template, choose Tools | Options and locate the template under E8TJ*ZU
* the Source Creation and Management node. Right-click the template and choose +`EF0sux
* Open. You can then make changes to the template in the Source Editor. !]%M
*/ IETdL{`~
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package com.tot.count; i+/:^tc;
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/** \9U4V>p
* .Z,3:3,]
* @author _(CuuP$`I
*/ ?'xTSAn
public class CountBean { @/S6P-4
private String countType; N30w^W&
int countId; p*11aaIbp~
/** Creates a new instance of CountData */ K!X>k
public CountBean() {} }E01B_T9z
public void setCountType(String countTypes){ '~dE0ohWb
this.countType=countTypes; ~c
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} R&z)
public void setCountId(int countIds){ /UJ@e
this.countId=countIds; <OKzb3e
} T&?0hSYt
public String getCountType(){ so* lV
return countType; kI|Vv90l
} OL,3Jh% x
public int getCountId(){ 5e!YYt>
return countId; .YvE
} -Jo8jE~>V
} jzuOs,:R
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CountCache.java V:M$-6jv
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/* 5z ebH
* CountCache.java +O<0q"E
* ]!>ThBMa
* Created on 2007年1月1日, 下午5:01 ZE#f{qF(
* S.;>:Dd[K
* To change this template, choose Tools | Options and locate the template under KFCL|9P
* the Source Creation and Management node. Right-click the template and choose -*[?E!F
* Open. You can then make changes to the template in the Source Editor. K^V*JH\G
*/ F{1;~Yg%
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package com.tot.count; m){.{Vn]
import java.util.*; uV]4C^k;`[
/** {VWUK`3
* PZ/ gD
* @author ,&S^R yc
*/ Tct[0B
public class CountCache { !/4f/g4Ze
public static LinkedList list=new LinkedList(); %21i#R`E
/** Creates a new instance of CountCache */ j @c
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public CountCache() {} ILt95l
public static void add(CountBean cb){
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if(cb!=null){ stnyJ9
list.add(cb); -.A8kJ
} ?^z!yD\
} 2 }QD>
} q% Eze
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CountControl.java o.tCw\M$g
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/* ,}M@Am0~
* CountThread.java )k F/"'o
* |>(@n{
* Created on 2007年1月1日, 下午4:57 =RR225
* S~1>q+<Q
* To change this template, choose Tools | Options and locate the template under S7-ka{S
* the Source Creation and Management node. Right-click the template and choose KlgPDV9mg
* Open. You can then make changes to the template in the Source Editor. :uZfdu
*/ 7s%DM6li 6
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package com.tot.count; sIuk
import tot.db.DBUtils; Q]_3 #_'
import java.sql.*; lAsDdxB`
/** 6KiI3%y?0
* &z;;Bx0s
* @author M.K-)r,
*/ !UE'
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public class CountControl{ %H:uE*WZ
private static long lastExecuteTime=0;//上次更新时间 U;n$
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 X{rw+!
/** Creates a new instance of CountThread */ daT[2M
public CountControl() {} ?45 kN=%*s
public synchronized void executeUpdate(){ _//)|.6c3
Connection conn=null; \F%5TRoC
PreparedStatement ps=null; <{7CS=)
try{ ZF
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conn = DBUtils.getConnection(); 8tWOVLquJ
conn.setAutoCommit(false); PMk3b3)Z
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); w]n20&
for(int i=0;i<CountCache.list.size();i++){ YmM+x=G:
CountBean cb=(CountBean)CountCache.list.getFirst(); .3Nd[+[
CountCache.list.removeFirst(); &6A'}9Ch
ps.setInt(1, cb.getCountId()); eR r.j
ps.executeUpdate();⑴ !|`G<WD
//ps.addBatch();⑵ :.['e`
} !RLg[_'
//int [] counts = ps.executeBatch();⑶ ;aBK4<-vl
conn.commit(); bkkhx,Oi[G
}catch(Exception e){ _Zya GDv
e.printStackTrace(); vS-k0g;
} finally{ d%?+q0j
try{ =>Y b~r71
if(ps!=null) { xwa5dtcng
ps.clearParameters(); &eV& +j
ps.close(); ryzz!0l
ps=null; ]gYnw;W$
} >N>WOLbb7(
}catch(SQLException e){} i(9=` A}
DBUtils.closeConnection(conn); W O W4c&
} H8~<;6W
} OaU-4
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public long getLast(){ Z~{0XG\Y
return lastExecuteTime; ZSq7>}
} [-!
public void run(){ x[7jm"Pz
long now = System.currentTimeMillis(); <}-[9fW
if ((now - lastExecuteTime) > executeSep) { !=@Lyt)_b
//System.out.print("lastExecuteTime:"+lastExecuteTime); *,hS-
//System.out.print(" now:"+now+"\n"); Ed9ynJ~)X
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); b:/ ;
lastExecuteTime=now; 0Vv6B2<
executeUpdate(); x\r7q
} Ddde,WJA
else{ 1g6AzUXg
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); Z^,C><Yt
} ^,')1r,
} jq#_*&Eg]
} tVd\ r"0k
//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 Tx?,]c,(u
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类写好了,下面是在JSP中如下调用。 \|nF55W [
*@=in7*c
<% mh]'/C_*<w
CountBean cb=new CountBean(); o^;$-O!/
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); g1VdP[Y#
CountCache.add(cb); S?n k9T+
out.print(CountCache.list.size()+"<br>"); K^`3Bg
CountControl c=new CountControl(); [Hz_x(t26
c.run(); w\k|^
out.print(CountCache.list.size()+"<br>"); t9SzZ2E
%>