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: BZ54*\t
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CountBean.java gKYfQ+
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/* E_e6^Sk5B(
* CountData.java .mLK`c6
* 4%nE*H%
* Created on 2007年1月1日, 下午4:44 q@t0NvNSu
* )G^
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* To change this template, choose Tools | Options and locate the template under ",7Q
* the Source Creation and Management node. Right-click the template and choose *!s;"U
* Open. You can then make changes to the template in the Source Editor. #|&Sc_#4)
*/ 1i[FY?6`dh
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package com.tot.count; #9-P%%kQ
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/** /='. 4v
* InXn%9]p]
* @author VXIP0p@
*/ 2EZb
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public class CountBean { Y2o?gug
private String countType; $6OkIP.
int countId; gL_Y,A~Q{
/** Creates a new instance of CountData */ 3 @ak<9&
public CountBean() {} 'u4<BQVV[
public void setCountType(String countTypes){ }by;F9&B
this.countType=countTypes;
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} u/cg|]x&T
public void setCountId(int countIds){ q\m2EURco
this.countId=countIds; $,+O9Et
} ),G= s Oo
public String getCountType(){ #wL
return countType; OQW#a[=WQ
} T}V!`0vKw
public int getCountId(){ M`rl!Ci#
return countId; 91=OF*w
} n2)q}_d
} ]o cWt3|
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CountCache.java QFYWA1<pDh
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/* d&ex5CU5
* CountCache.java J5^'HU3
* &|f@$ff
* Created on 2007年1月1日, 下午5:01 8GvJ0Jq}U
* Hemq+]6^
* To change this template, choose Tools | Options and locate the template under 5R(/Uiv3F
* the Source Creation and Management node. Right-click the template and choose WI?oSE w
* Open. You can then make changes to the template in the Source Editor. u%w`:v7Yo(
*/ nqInb:
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package com.tot.count; \"X!2
import java.util.*; tjupJ*Rt
/** C:PMewn
* J]nohICe
* @author uc;8 K,[t
*/ cWoPB
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public class CountCache { \v'p/G)g
public static LinkedList list=new LinkedList(); tmQH|'>>
/** Creates a new instance of CountCache */ 87D*-Gw
public CountCache() {} /YZr~|65
public static void add(CountBean cb){ E\Rhz]G(
if(cb!=null){ x>Zn?YR,"
list.add(cb); b )B?
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} {q"OM*L(
} {NHdyc$
} W[Ls|<Q
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CountControl.java &*+'>UEe5
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/* q@[QjGj@
* CountThread.java Y;?{|
* _lamn}(x0
* Created on 2007年1月1日, 下午4:57 D9
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* :]\([Q+a
* To change this template, choose Tools | Options and locate the template under eEuvl`&
* the Source Creation and Management node. Right-click the template and choose <StN%2WQ1
* Open. You can then make changes to the template in the Source Editor. .&DhN#EN0
*/ 9I}-[|`u
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package com.tot.count; gIjh:_ Pz
import tot.db.DBUtils; 7 @D@ucL
import java.sql.*; #"@|f
/** *MKO
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* \WxukYH
* @author L7dd(^
*/ o,_?^'@
public class CountControl{ n*2UnKaJ
private static long lastExecuteTime=0;//上次更新时间 a{L
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private static long executeSep=60000;//定义更新间隔时间,单位毫秒 wOU_*uY@6'
/** Creates a new instance of CountThread */ ML|FQ
public CountControl() {} &5yVxL:
public synchronized void executeUpdate(){ <g"{Wv: h
Connection conn=null; W"k"IvTW}
PreparedStatement ps=null; &litXIvT>
try{ y*qVc E
conn = DBUtils.getConnection(); #d6)#:uss
conn.setAutoCommit(false); {\81i8b]
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); <0Xf9a8>
for(int i=0;i<CountCache.list.size();i++){ \W~N
CountBean cb=(CountBean)CountCache.list.getFirst(); =vX/{C
CountCache.list.removeFirst(); gEy?s8_,
ps.setInt(1, cb.getCountId()); Zy`m!]G]80
ps.executeUpdate();⑴ h2G$@8t}I
//ps.addBatch();⑵ 16=sij%A
} Sc;BCl{=|
//int [] counts = ps.executeBatch();⑶ 4K\G16'$v
conn.commit(); 8Vr%n2M
}catch(Exception e){ [_k1jHr48N
e.printStackTrace(); pH9VTM.*
} finally{ \NPmym_6J
try{ .P8&5i)'P,
if(ps!=null) { fp`;U_-&0
ps.clearParameters(); ;ub;lh 3
ps.close(); V<GHpFi0
ps=null; X
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} ZOh`(})hy
}catch(SQLException e){} QIG$z?
DBUtils.closeConnection(conn); EJMM9(DQ7
} ,o86}6Ag
} B38]~'8
public long getLast(){ l9{hq/V
return lastExecuteTime; GeH#I5y
} g6j?,c|y
public void run(){ 9jM}~XvV
long now = System.currentTimeMillis(); H\ F:95
if ((now - lastExecuteTime) > executeSep) { Lt64JH^lz
//System.out.print("lastExecuteTime:"+lastExecuteTime); (A9Fhun
//System.out.print(" now:"+now+"\n"); 0X6YdW _2X
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ;U/&I3dzV
lastExecuteTime=now; ag [ZW
executeUpdate(); */`ki;\A
} +r2+X:#~T
else{ ]d$8f
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ^aItoJq
} j()7_
} (ZUHvvL
} oB(?_No7
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 ,Vc6Gwm
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类写好了,下面是在JSP中如下调用。 ]L5@,E4.
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<% J,'M4O\S
CountBean cb=new CountBean(); glO^yZ s
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); SW@$ci
CountCache.add(cb); , qMzWa
out.print(CountCache.list.size()+"<br>"); fK>L!=Q
CountControl c=new CountControl(); 1m4$ p2j
c.run(); } Y12
out.print(CountCache.list.size()+"<br>"); n(1l}TJy
%>