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: N#&/d nV
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CountBean.java 2 e9lk$
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/* ~ \o
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* CountData.java O!ngQrI
* @w
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* Created on 2007年1月1日, 下午4:44 1<E:`,Mn?
* kNC]q,ljt5
* To change this template, choose Tools | Options and locate the template under PCX X[N
* the Source Creation and Management node. Right-click the template and choose oeA}b-Ct0
* Open. You can then make changes to the template in the Source Editor. X775j"<d
*/ U6Xi-@XP
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package com.tot.count; TYu(;~
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/** BWev(SF{Ny
* k3VRa|Y")
* @author z$b'y;k
*/ T(q/$p&q
public class CountBean { <F&53N&Zc
private String countType; 3x3 =ke!
int countId; ~0T,_N
/** Creates a new instance of CountData */ lCxPR'C|
public CountBean() {} 2E_d$nsJ
public void setCountType(String countTypes){ -esq]c%3
this.countType=countTypes; "Cn<x\E b
} <:!;79T\
public void setCountId(int countIds){ h$_5)d~
this.countId=countIds; pUm|e5
} ^hyp}WN
public String getCountType(){ T@gm0igW/;
return countType; K;P<c,9X/
} ^/:G`'
public int getCountId(){ WX}pBmU
return countId; /PTk296@
} Ojs^-R_
} bX'.hHR
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CountCache.java !UF(R^
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/* w)Wg 8
* CountCache.java ^M7pCetjdW
* WOR H4h9
* Created on 2007年1月1日, 下午5:01 c7f11N!v>b
* QvvH/u
* To change this template, choose Tools | Options and locate the template under .e1Yd8
* the Source Creation and Management node. Right-click the template and choose `HV~.C
* Open. You can then make changes to the template in the Source Editor. D?`|`Mu
*/ bO6LBSZx]
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package com.tot.count; L)-1( e<x
import java.util.*; &eY&6I
/** atYe$Db
* ;)ji3 M
* @author Eq/oq\(/6
*/ hVf;{p
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public class CountCache { ~=i<O&nai
public static LinkedList list=new LinkedList(); {L.=)zt>
/** Creates a new instance of CountCache */ 2x<4&^
public CountCache() {} M#o'h c
public static void add(CountBean cb){ 7J [s5'~|
if(cb!=null){ j5~nLo2
list.add(cb); fUa[3)I
} "c*&~GSE4
} y6`zdB
} MVXy)9q
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CountControl.java KreF\M%Ke
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/* NhF<2[mt
* CountThread.java iZn<j'u
* Q@5v> `
* Created on 2007年1月1日, 下午4:57 ZxU3)`O
* 94b*
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* To change this template, choose Tools | Options and locate the template under P)rz%,VF+
* the Source Creation and Management node. Right-click the template and choose !bQqzny$R
* Open. You can then make changes to the template in the Source Editor. 6:3F,!J!
*/ j*#k%;c
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package com.tot.count; 'RzzLk|$
import tot.db.DBUtils; }/g1s71
import java.sql.*; _(0GAz%9
/** !lk9U^wnd
* 7?a!x$-U(
* @author q~G@S2=}0}
*/ \z[L=
public class CountControl{ k.Q4oyei
private static long lastExecuteTime=0;//上次更新时间 .j^=]3
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 xn,I<dL39
/** Creates a new instance of CountThread */ `~+[pY1r
public CountControl() {} R~H +.Vh
public synchronized void executeUpdate(){ {bMOT*X=A
Connection conn=null; yR4++yk
PreparedStatement ps=null; &LDA=B
try{ &l
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conn = DBUtils.getConnection(); yYn7y1B
conn.setAutoCommit(false); z%~rQa./$
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); A_}6J,*u
for(int i=0;i<CountCache.list.size();i++){ E0aJ~A(Hv
CountBean cb=(CountBean)CountCache.list.getFirst(); #S') i1;
CountCache.list.removeFirst(); x}X
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ps.setInt(1, cb.getCountId()); 3iBUIv
ps.executeUpdate();⑴ DhzmC
//ps.addBatch();⑵ i f !
} Rs;Y|W4'
//int [] counts = ps.executeBatch();⑶ QrRnXlEM8
conn.commit(); =}m'qy
}catch(Exception e){ uL9O_a;!
e.printStackTrace(); `&5_~4T7
} finally{ gib'f@i ;
try{ bPUldkB:
if(ps!=null) { {^_K
ps.clearParameters(); Be~In~~
ps.close(); RAAu3QKu
ps=null; -i*]Sgese
} 8 GW0w
}catch(SQLException e){} [kL`'yi
DBUtils.closeConnection(conn); _8&a%?R@W
} (;cvLop
} zx`(ojfu
public long getLast(){ JE ''Th}
return lastExecuteTime; rhj_cw
} )POU58$
public void run(){ `C>De4nT@
long now = System.currentTimeMillis(); !]2`dp\!
if ((now - lastExecuteTime) > executeSep) { R-OQ(]<*
//System.out.print("lastExecuteTime:"+lastExecuteTime); f=T&$tZ<
//System.out.print(" now:"+now+"\n"); 0q_?<v_1
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); {I]>!V0j!
lastExecuteTime=now; 0^mCj<g
executeUpdate(); NXSjN~aG2
} v9XevLs
else{ /f]'_t0\.
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ZfnJ&H'
} ;(Kj-,>
} l?:S)[:
} gX;)A|9e
//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 ]@
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类写好了,下面是在JSP中如下调用。 qX:YI3:,@
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<% nZ8jBCh
CountBean cb=new CountBean(); K?eY<L
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); |^C35 6M>
CountCache.add(cb); A&L2&ofV&q
out.print(CountCache.list.size()+"<br>"); ,| ~Pa
CountControl c=new CountControl(); A1F!I4p5
c.run(); . 9@y*_9
out.print(CountCache.list.size()+"<br>"); #y*p7~|@
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