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: FH21m wV
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CountBean.java (a!,)
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/* *AQbXw]w
* CountData.java E
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* HbSx}bM_9
* Created on 2007年1月1日, 下午4:44 fDHISJv
* wSyu^KDz
* To change this template, choose Tools | Options and locate the template under >qvD39w
* the Source Creation and Management node. Right-click the template and choose jeFl+K'1
* Open. You can then make changes to the template in the Source Editor. SW'KYzn
*/ BmF>IQ`M?
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package com.tot.count; _-\{kJ
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/** >t}D5ah
* 4:PP[2?
* @author qAik$.
*/ =F[,-B~
public class CountBean { ^ 6|"=+cO\
private String countType; w|o@r%Q#l
int countId; z))[Lg
/** Creates a new instance of CountData */ 6lAo`S\)eX
public CountBean() {} )9Ojvp=#r:
public void setCountType(String countTypes){ ~(]DNXB8I`
this.countType=countTypes; }B/xQsTx-
} {*$J&{6V
public void setCountId(int countIds){ \^LR5S&
this.countId=countIds; {/!Gh\i
} deY<+!
public String getCountType(){ |?=1tS{iT
return countType;
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} PW4Wn`u
public int getCountId(){ 2U{RA's
return countId; }PL
} Tic9ri
} CW YJ<27v{
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CountCache.java v[3sg2.
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/* Hv*O9!cC
* CountCache.java 'Pu;]sC
* Bys|i 0tb-
* Created on 2007年1月1日, 下午5:01 p'} %pAY
* ScKfr
* To change this template, choose Tools | Options and locate the template under C8q-gP[
* the Source Creation and Management node. Right-click the template and choose :+!b8[?Z
* Open. You can then make changes to the template in the Source Editor. dS=,. }
*/ |c/rHEZ
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package com.tot.count; !P3|T\|]+
import java.util.*; /U]5#'i
/** dD<kNa}2
* Ec
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* @author )yZE>>3-
*/ hDMp^^$
public class CountCache { =oDrN7`,B
public static LinkedList list=new LinkedList(); 59 Y=VS
/** Creates a new instance of CountCache */ ;gV8f{X{Z
public CountCache() {} )^sfEYoA
public static void add(CountBean cb){ u;g}N'"
if(cb!=null){ vy?YA-
list.add(cb); e5KF ~0`
} Sn&%epi
} ':$a6f &T
} X5[sw;rk
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CountControl.java >WX'oP(<
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/* ~vFo 0k(
* CountThread.java _Y {g5t
* rID]!7~
* Created on 2007年1月1日, 下午4:57 gHshG;z*
* _4Pi>
* To change this template, choose Tools | Options and locate the template under Hefqzu
* the Source Creation and Management node. Right-click the template and choose
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* Open. You can then make changes to the template in the Source Editor. >.4Sx~VH2
*/ )wd~639U
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package com.tot.count; 7yl'!uz)9
import tot.db.DBUtils; 92Iv'(1ba
import java.sql.*; `,[c??h
/** 0in6z
* ApB0)N
* @author Cx~z^YP'
*/ 8t!"K_Mkx
public class CountControl{ kw'D2692
private static long lastExecuteTime=0;//上次更新时间 ]S ,GHPEN
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 (tN$G:+")F
/** Creates a new instance of CountThread */ UxtZBNn8
public CountControl() {}
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public synchronized void executeUpdate(){ t+ ]+Gn
Connection conn=null; Q2JjBV<
PreparedStatement ps=null; a mgex$
try{ hd-ds~ve
conn = DBUtils.getConnection(); "(qO}&b>
conn.setAutoCommit(false); O~VUViS6$
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); $h9!"f[|j
for(int i=0;i<CountCache.list.size();i++){ N0PX<$y
CountBean cb=(CountBean)CountCache.list.getFirst(); ta(x4fP_
CountCache.list.removeFirst(); gEu\X|7'
ps.setInt(1, cb.getCountId()); ZT#G:a
ps.executeUpdate();⑴ ><qE5D[
//ps.addBatch();⑵ Xy+|D#b
} Fu$sfq
//int [] counts = ps.executeBatch();⑶ 'P#I<?vB
conn.commit(); W+X
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}catch(Exception e){ NQ!F`
e.printStackTrace(); u 36;;z
} finally{ n>UvRn.7kz
try{ 7Wu2gky3
if(ps!=null) { XjbK!.
ps.clearParameters(); _guY%2%yR
ps.close(); (k~c]N)v
ps=null; R?Qou!*]
} ):@B1 yR
}catch(SQLException e){} 4r*6fJ*bJ
DBUtils.closeConnection(conn); cS"6%:hQ
} \Wk$>?+#@
} JV>OmUAk
public long getLast(){ CiSG=obw
return lastExecuteTime; xj<SnrrC]u
} Zj;!7ZuT1
public void run(){ vI@8DWs
long now = System.currentTimeMillis(); we9AB_y
if ((now - lastExecuteTime) > executeSep) { Jo@9f(hq
//System.out.print("lastExecuteTime:"+lastExecuteTime); 9^tyjX2
//System.out.print(" now:"+now+"\n"); {PKER$C
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); y(A"g3^=
lastExecuteTime=now; -E1}mL}I`
executeUpdate(); \q>,c49a{
} sBwgl9
else{ Ih0GzyU*4
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); $B2@mC([S
} ZSNg^)cN
} Z"jo
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} $&!U&uMt
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 Tp7?:YY|
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类写好了,下面是在JSP中如下调用。 ilP&ctn6+c
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<% 8
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CountBean cb=new CountBean(); XN@5TZoaW
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); >+r2I%
CountCache.add(cb); vhC"f*
out.print(CountCache.list.size()+"<br>"); 'zaB5d~l
CountControl c=new CountControl(); R)=<q]Ms
c.run(); ?:E;C<Ar
out.print(CountCache.list.size()+"<br>"); K5$ y
%>