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: @e$EwCV,
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CountBean.java s'IB{lJ9
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/* eIN0T;1T
* CountData.java P7l3ZH( g
* t -fmA?\
* Created on 2007年1月1日, 下午4:44 Sl%6F!
* /;E=)(w
* To change this template, choose Tools | Options and locate the template under :_,3")-v
* the Source Creation and Management node. Right-click the template and choose :C,}DyZy
* Open. You can then make changes to the template in the Source Editor. -pQ?ybQ
*/ -C!m#"PDW
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package com.tot.count; 5N bq9YY
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/** Nei i$
* _g,_G
* @author o&$lik
*/ qG g2 9
public class CountBean { e+>$4Jq
private String countType; n1PvZ~^3
int countId; yw89*:A6
/** Creates a new instance of CountData */ bMv[.Z@v(
public CountBean() {} \%V !&
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public void setCountType(String countTypes){ Dqd2e&a\
this.countType=countTypes; \0 &$n
} %5@>
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public void setCountId(int countIds){ :1@jl2,
this.countId=countIds; kr!>rqN5
} N3oa!PE
public String getCountType(){ |)*!&\Ch
return countType; hFhC&2HN
} [kqO6U
public int getCountId(){ <i`s)L
return countId; X;#Ni}af
} 7-\wr^ll3
} y>d`cRy
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CountCache.java Xf
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/* ?@MWV
* CountCache.java &!HG.7AY
* 6q
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* Created on 2007年1月1日, 下午5:01 HsT6 #K
* %kgT=<E'
* To change this template, choose Tools | Options and locate the template under ;M\Cw.%![
* the Source Creation and Management node. Right-click the template and choose 5Kk}sxol
* Open. You can then make changes to the template in the Source Editor. L%- ENk
*/ +"~*L,ken0
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package com.tot.count; 1(%6X*z
import java.util.*; Ub4)x
/** 8H8Q
* \]\ h,Y8
* @author ?`6Mfpvj96
*/ &>K|F >7q
public class CountCache { 4\uq$.f-
public static LinkedList list=new LinkedList(); ~SsfkM"
/** Creates a new instance of CountCache */ |t;Ktl
public CountCache() {} T|
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public static void add(CountBean cb){ rL?{+S]&^)
if(cb!=null){ n0%S: (
list.add(cb); 3x
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} |It{L0=U
} */$] kE
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CountControl.java HW"5MZ8E
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/* _)4zm
* CountThread.java C]ax}P>BQ
* M*~X pT3
* Created on 2007年1月1日, 下午4:57 #]^M/y
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* s5MG#M 9
* To change this template, choose Tools | Options and locate the template under 'RNj5r
* the Source Creation and Management node. Right-click the template and choose &lxMVynL
* Open. You can then make changes to the template in the Source Editor. LJt5?zQKrW
*/ ,">CPl]
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package com.tot.count; 0G+qF96
import tot.db.DBUtils; qP=a:R-
import java.sql.*; T?`Ha\go
/** zn|O)"C
* vB5mOXGN q
* @author [?g}<fa
*/ pK/RkA1
public class CountControl{ yWr&G@>G
private static long lastExecuteTime=0;//上次更新时间 r "\<+$ 7
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 GW%!?mJ
/** Creates a new instance of CountThread */ *GdJ<B$
public CountControl() {} %0 U@k!lP
public synchronized void executeUpdate(){ 3jto$_3'w
Connection conn=null; Lu[Hz8
PreparedStatement ps=null; !9j6l0
try{ *0r!eD
conn = DBUtils.getConnection(); HPo><u
conn.setAutoCommit(false); /^WawH6)6
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); |>>^Mol
for(int i=0;i<CountCache.list.size();i++){ D (e,R9hPU
CountBean cb=(CountBean)CountCache.list.getFirst(); XZ3M~cDq
CountCache.list.removeFirst(); wGHVq
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ps.setInt(1, cb.getCountId()); ^a!oq~ZSy
ps.executeUpdate();⑴ W4h ]4X
//ps.addBatch();⑵ sp0_f;bC
} ?;w\CS^Qu
//int [] counts = ps.executeBatch();⑶ I^D*) z
conn.commit(); f&&Ao
}catch(Exception e){ C?6q]k]r
e.printStackTrace(); -:b<~S[
} finally{ 2t=&h|6EW
try{ 2{g&9
if(ps!=null) { {WeRFiQ?-
ps.clearParameters(); jX t5.9 t
ps.close(); \oP
ps=null; i9peQ61{
} +hlR
}catch(SQLException e){} 4(,X.GVY/
DBUtils.closeConnection(conn); >F/E,U ]
} hWX4 P
} gDX\ p>7
public long getLast(){ .l,NmF9
return lastExecuteTime; *_ajb:
} 1D~B\=LL}
public void run(){ 'w|N}
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long now = System.currentTimeMillis(); M?['HoRo
if ((now - lastExecuteTime) > executeSep) { s(MdjWw
//System.out.print("lastExecuteTime:"+lastExecuteTime); 90H/Txq
//System.out.print(" now:"+now+"\n"); ;BHIss7
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); \z.p [;'ir
lastExecuteTime=now; |I.5]r-EK
executeUpdate(); [[ }ukG4
} -,$:^4
else{ oiz]Bd
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); z34+1d
} Z_T~2t
} ^vOEG;TR<-
} 5?E;YyA
//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 ZCfd<NS?
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类写好了,下面是在JSP中如下调用。 KkR.p,/
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<% ;N
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CountBean cb=new CountBean(); 9HlM0qE5b
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); M IU B]
CountCache.add(cb); ;;EFiaA
out.print(CountCache.list.size()+"<br>"); owO&[D/
CountControl c=new CountControl(); p\]rxtm
c.run(); 1}CJ&
out.print(CountCache.list.size()+"<br>"); SNH AL F
%>