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: jA<(#lm;
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CountBean.java R/!lDv!
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/* <x&0a$I
* CountData.java --S1p0
* @#HB6B
* Created on 2007年1月1日, 下午4:44 zL8Z8eh">
* TA2HAMx)
* To change this template, choose Tools | Options and locate the template under Y-Iu&H+\
* the Source Creation and Management node. Right-click the template and choose ALcin))+B
* Open. You can then make changes to the template in the Source Editor. 7rIz
*/ SB1j$6]OR7
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package com.tot.count; =sm<B^yj
@`Fv}RY{
/** DIqM\ ><
* RIC\f_Dv
* @author ar&j1""
*/ QR+xPY~
public class CountBean { s<z`<^hRe
private String countType; BE0Ov{'
int countId; ye<b`bL2.
/** Creates a new instance of CountData */ s=S9y7i(R
public CountBean() {} P}`|8b1W
public void setCountType(String countTypes){ lw\+!}8(
this.countType=countTypes; X| !VjUH
} 8k( zU>^
public void setCountId(int countIds){ 5taR[ukM
this.countId=countIds; Sb4^*
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} y ;/T.W9!
public String getCountType(){ HbI'n,+
return countType; J#>)+
} r|MBkpcvp
public int getCountId(){ Fe[)-_%G
return countId; V),wDyi
} T}}T`Ce
} R\a6#u3
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CountCache.java >^=;b5I2K
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/* H]P*!q`Ko
* CountCache.java @Ojbu@A
* Ao )\/AR'
* Created on 2007年1月1日, 下午5:01 aZ,j1j0p
* c$.Zg=
* To change this template, choose Tools | Options and locate the template under H|Y*TI2vf8
* the Source Creation and Management node. Right-click the template and choose /Hs\`Kg"!
* Open. You can then make changes to the template in the Source Editor. !V'~<&
*/ :[:*kbWN-
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package com.tot.count; 9bQD"%ha=d
import java.util.*; :hBLi99
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/** S.zY0
* .GSK!1{@
* @author ]Sey|/@D
*/ !b"2]Qv
public class CountCache { E5$Fhc
public static LinkedList list=new LinkedList(); Q\nIU7:bZ
/** Creates a new instance of CountCache */ ,/YTW@N
public CountCache() {} c(kYCVc
public static void add(CountBean cb){ [$DI!%e|
if(cb!=null){ dEI]|i
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list.add(cb); dHkI9;
} *`_2uBz
} vn+~P9SHQ
} FvJkb!5*e_
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CountControl.java to{7B7t>q
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/* dC/@OV)0#
* CountThread.java aH&Efz^
* K]'t>:G@
* Created on 2007年1月1日, 下午4:57 Zet80|q
* Lng@'Yr
* To change this template, choose Tools | Options and locate the template under \>tx:;D3
* the Source Creation and Management node. Right-click the template and choose <c&Nm_)
* Open. You can then make changes to the template in the Source Editor. $!vK#8-&{
*/ {pXqw'"1.
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package com.tot.count; aM4-quaG]
import tot.db.DBUtils; 489xoP
import java.sql.*; [7\x(W-:@>
/** /?1^&a
* Yw6uh4
* @author n}dLfg*
*/ #]h&GX
public class CountControl{ cR=o!2O
private static long lastExecuteTime=0;//上次更新时间 wg4Ol*y'
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 Ki>XLX,er=
/** Creates a new instance of CountThread */ *mz-g7
public CountControl() {} 61}eB/;7
public synchronized void executeUpdate(){ mgTzwE_\
Connection conn=null; Ri>ZupQ6
PreparedStatement ps=null; 9/=+2SZ
try{ RgVnx] IF
conn = DBUtils.getConnection(); ><qA+/4]_
conn.setAutoCommit(false); c=D~hz N
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); BZ,{gy7g7X
for(int i=0;i<CountCache.list.size();i++){ (K('@W%\?
CountBean cb=(CountBean)CountCache.list.getFirst(); hOYP~OR
CountCache.list.removeFirst(); P9x':I$
ps.setInt(1, cb.getCountId()); (3 Z;c_N
ps.executeUpdate();⑴ p/HGI)'
//ps.addBatch();⑵ vwzElZ{C:v
} + (Jh$b_
//int [] counts = ps.executeBatch();⑶ kz G W/
conn.commit(); buDz]ec
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}catch(Exception e){ iZ4"@G:,
e.printStackTrace(); [@2$W?0i
} finally{ \zeu vD
try{ !gcea?I
if(ps!=null) { "8Lv
ps.clearParameters(); =y=MljEX
ps.close(); VI-6t"l
ps=null; 5n[''#D
} 6),!sO?
}catch(SQLException e){} o+Mc%O Z
DBUtils.closeConnection(conn); fX2OH)6U
} I]%Kd('
} uDLj*U6L
public long getLast(){ !;K zR&
return lastExecuteTime; :sttGXQX
} <*9(m
public void run(){ W\<HUd
long now = System.currentTimeMillis(); )iJv?Y\]
if ((now - lastExecuteTime) > executeSep) { _M^^0kf
//System.out.print("lastExecuteTime:"+lastExecuteTime); MY^o0N
//System.out.print(" now:"+now+"\n"); DG}s`'
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); :?
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lastExecuteTime=now; &Mz]y?k'
executeUpdate(); q7I!wD9Cff
} bn7g!2
else{ !L<z(dV|(
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); p=\Q7<Z6d,
} (/E@.z[1
} %j2$ ezud
} )i_:[ l6
//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 s5V|.R
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类写好了,下面是在JSP中如下调用。 li{!Jp5]1b
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<% <AK9HPxP
CountBean cb=new CountBean(); [7 NO !^
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ou{V/?rb
CountCache.add(cb); yE~D0%Umq
out.print(CountCache.list.size()+"<br>"); { `xC~B h
CountControl c=new CountControl(); p 16+(m
c.run(); R&$fWV;'
out.print(CountCache.list.size()+"<br>"); C XNYWx
%>