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: 2SRmh!hr
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CountBean.java -& T.rsp
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/* tpj6AMO/`d
* CountData.java ltg\x8w?c
* z>A;|iL
* Created on 2007年1月1日, 下午4:44 WCL#3uYk"
* M}\p/r=
* To change this template, choose Tools | Options and locate the template under K]H [A,
* the Source Creation and Management node. Right-click the template and choose m;oCi}fL
* Open. You can then make changes to the template in the Source Editor. |rL#HG
*/ O3En+m~3n)
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package com.tot.count; rGgP9
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/** |576)
* ,UATT]>
* @author iNG =x
*/ V:h3F7
public class CountBean { g..&x]aS(
private String countType; qE@H~&
int countId; #``Alh8
/** Creates a new instance of CountData */ g=Bge)
public CountBean() {} y*vg9`$k
public void setCountType(String countTypes){ Y5R|)x
this.countType=countTypes; rvRIKc|}l
} {Z_?7J&z
public void setCountId(int countIds){ 9|x{z
this.countId=countIds; xv9G%
} w1:%P36H
public String getCountType(){ #m6W7_
return countType; }_,={<g
} L5n /eg:Q
public int getCountId(){ (yv)zg9
return countId; Jie=/:&
} *f
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} 5fuYva
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CountCache.java
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/* a(IZ2Zmr
* CountCache.java m.&"D>
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* 2bt).gGm
* Created on 2007年1月1日, 下午5:01 +O?`uV
* 4cZlQ3OE.
* To change this template, choose Tools | Options and locate the template under ,ek0)z.
* the Source Creation and Management node. Right-click the template and choose JXqwy^f
* Open. You can then make changes to the template in the Source Editor. -5u. Ix3
*/ PD`EtkUnv
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package com.tot.count; Ch7&9NW
import java.util.*; ds:&{~7L<T
/** .s`7n
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* 5O]eD84B
* @author 9RmdQ]1n4
*/ K/|qn)
public class CountCache { hO..j
public static LinkedList list=new LinkedList(); tvR|!N }
/** Creates a new instance of CountCache */ rPkPQn:
public CountCache() {} ^.u
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public static void add(CountBean cb){ 5@yBUwMSj
if(cb!=null){ >e^8fpgSo
list.add(cb); x>[f+Tc
} #)z7&nD
} l;vA"b=]
} GEZ!z5";BQ
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CountControl.java =0_((eXwf
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/* z18<rj
* CountThread.java sV-UY!
* !WNO!S0/j
* Created on 2007年1月1日, 下午4:57 |6T"T P
* A}MF>.!}C
* To change this template, choose Tools | Options and locate the template under 8
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* the Source Creation and Management node. Right-click the template and choose G^A }T3
* Open. You can then make changes to the template in the Source Editor. <59G
*/ ^#&PTq>
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package com.tot.count; 7da~+(yhr
import tot.db.DBUtils; T~)zgu%q_
import java.sql.*; +W#["%kw
/** gbu@&
* .(X!*J]G
* @author 2PQY+[jx
*/ =e|
public class CountControl{ %40+si3c
private static long lastExecuteTime=0;//上次更新时间 (&xIBF_6
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 "fWm{;
/** Creates a new instance of CountThread */ 0s%]%2ON
public CountControl() {} &D#B"XI
public synchronized void executeUpdate(){ ,Laz515
Connection conn=null; 2hFOwI
PreparedStatement ps=null; C0-,<X
try{ ;;<[_gp,E
conn = DBUtils.getConnection(); >IEc4
conn.setAutoCommit(false); zD):
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); \5R>+[n!
for(int i=0;i<CountCache.list.size();i++){ ^/"2s}+
CountBean cb=(CountBean)CountCache.list.getFirst(); 3TF'[(K=
CountCache.list.removeFirst(); KK41I8Mw
ps.setInt(1, cb.getCountId()); L]QBh\
ps.executeUpdate();⑴ -14~f)%NQ*
//ps.addBatch();⑵ mmBZ}V+&=
} L^{wxOf&6E
//int [] counts = ps.executeBatch();⑶ {!37w[s~
conn.commit(); Ct pc]lJ}
}catch(Exception e){ u#`'|ko\9
e.printStackTrace(); z[*Y%o8-r
} finally{ #}aBRKZf6
try{ ^_XV }&7Q
if(ps!=null) { QI{<q<
ps.clearParameters(); _[8sL^
ps.close(); $[g8j`or!
ps=null; <: I]0|[
} Fu"@)xw/-q
}catch(SQLException e){} ;1L7+.A
DBUtils.closeConnection(conn); AS]jJc^
} D}L4uz?
} \!!1o+#1j
public long getLast(){ 0=c:O
return lastExecuteTime; 2hFj+Ay
} /V
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public void run(){ }W$}blbp
long now = System.currentTimeMillis(); xT;j_'9U;
if ((now - lastExecuteTime) > executeSep) { T8\%+3e.
//System.out.print("lastExecuteTime:"+lastExecuteTime); #PZBh
//System.out.print(" now:"+now+"\n"); kYU!6t1
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); TTm
lastExecuteTime=now; uoe>T:
executeUpdate(); T[]kun
} m_,j)A%
else{ 9<6Hs3|.!
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); A:YWXcg
} <PTi>C8;r
} g].v
} .Af H>)E
//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 #Q$`3rr
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类写好了,下面是在JSP中如下调用。 QliP9-im3
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<% g@IYD
CountBean cb=new CountBean(); 9}Qrb@DT
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 7kH
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CountCache.add(cb); KSy.
out.print(CountCache.list.size()+"<br>"); Eumdv#Qg
CountControl c=new CountControl(); 5H
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c.run(); 9Li.B1j
out.print(CountCache.list.size()+"<br>"); _~_6qTv-d
%>