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: gtH^'vFZ
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CountBean.java eHUyV@
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/* EB&hgz&_
* CountData.java Ijiw`\;
* 1^o})9
* Created on 2007年1月1日, 下午4:44 qWK}
* }2LG9B%
* To change this template, choose Tools | Options and locate the template under !Dc?9W!b
* the Source Creation and Management node. Right-click the template and choose vULDKJNHX
* Open. You can then make changes to the template in the Source Editor. GjEV]hqR
*/ C4E}.``Hm
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package com.tot.count; NUnwf
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/** NblPVxS
* uD{-a$6z
* @author 4?@5JpC9VA
*/ H8"RdKwg?
public class CountBean { g&/lyQ+G
private String countType; *8qRdI9
int countId; RQ|K?^k
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/** Creates a new instance of CountData */ Vfd_nD^8oZ
public CountBean() {} 1y[~xxgE
public void setCountType(String countTypes){ R|Bi%q|4P
this.countType=countTypes; t@lTA>;U@
} c%G~HOE=B
public void setCountId(int countIds){ Kc]
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this.countId=countIds; YH^U"\}i
} :Hitx
public String getCountType(){ xs6!NY
return countType; -d!84_d9
} S~ckIN]
public int getCountId(){ N*m;A6?
return countId; SgQmR#5
} n=rmf*,?
} -"Kjn`8
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CountCache.java CA|W4f}
/!&eP3^
/* ?a+J4Zr3
* CountCache.java [EPRBK`=
* _Hq)@AI
* Created on 2007年1月1日, 下午5:01 M| }?5NS
* 7KC2%s#7
* To change this template, choose Tools | Options and locate the template under CiU^U|~ 'L
* the Source Creation and Management node. Right-click the template and choose qu1! KS
* Open. You can then make changes to the template in the Source Editor. 4%v-)HGh
*/ P<1&kUZL
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package com.tot.count; NB3+kf ,
import java.util.*; \K2S.j
/** 'yOx&~H]
* }rVLWt
* @author C]ho7qC
*/ l}S96B
public class CountCache { s Fk{Tv@Yz
public static LinkedList list=new LinkedList(); "OP$n-*@%
/** Creates a new instance of CountCache */ uG.`
public CountCache() {} Tpnwwx[]:|
public static void add(CountBean cb){ |&S^L}V.C
if(cb!=null){ Ei,dO;&
list.add(cb); =*(_sW6;
} N^`S'FVA
}
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} V?MaI.gj
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CountControl.java A@.ruG$
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/* t P'._0n0
* CountThread.java *Q-uE
* H5FWk
* Created on 2007年1月1日, 下午4:57 S2I{?y&K
* V-%jSe<
* To change this template, choose Tools | Options and locate the template under o9D#d\G
* the Source Creation and Management node. Right-click the template and choose nm|"9|/
* Open. You can then make changes to the template in the Source Editor. OlW5k`B
*/ 5?#AS#TD'
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package com.tot.count; `sdbo](76
import tot.db.DBUtils; w&^Dbme
import java.sql.*; U&+lw=
/** )1 0aDTlr
* QSYKYgxC
* @author a$11u.\q+
*/ p|>/Hz1v
public class CountControl{ pkIJbI{aS
private static long lastExecuteTime=0;//上次更新时间 (:#4{C
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 &fxyY(
/** Creates a new instance of CountThread */ sBN4:8
public CountControl() {} ]x_14$rk
public synchronized void executeUpdate(){ oe_,q&e
Connection conn=null; Q`h@-6N
PreparedStatement ps=null; 5zJ#d}%}S"
try{ [HRP&jr
conn = DBUtils.getConnection(); Xs4G#QsAJ
conn.setAutoCommit(false); 2c9]Ja3:6
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); L~M6ca"
for(int i=0;i<CountCache.list.size();i++){ Gnqun%
CountBean cb=(CountBean)CountCache.list.getFirst(); ]waCYrG<sY
CountCache.list.removeFirst(); <ot%>\C
ps.setInt(1, cb.getCountId()); :; 3y^!
ps.executeUpdate();⑴ rYyEs
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//ps.addBatch();⑵ g3w-Le&T
} nza^<DlS
//int [] counts = ps.executeBatch();⑶ SP|Dz,o
conn.commit(); Wf
*b"#
}catch(Exception e){ wqn}t]
e.printStackTrace(); `t#Ie*
} finally{ 4y9n,~Qgw
try{ @aoHz8K
if(ps!=null) { Q0_|?]v
ps.clearParameters(); {<^PYN>`
ps.close(); '6>nXp?)r
ps=null; ;fY)7
'
} ])T_&%
}catch(SQLException e){} rI1;>/Ir
DBUtils.closeConnection(conn); }~Y#N
}
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} WB|SXto%4D
public long getLast(){ #w]:<R^
return lastExecuteTime; ZsDn`8
} w W;!L=j
public void run(){ )Chx,pcx<
long now = System.currentTimeMillis(); /aMeKM[L`
if ((now - lastExecuteTime) > executeSep) { 8!dA1]2;
//System.out.print("lastExecuteTime:"+lastExecuteTime); !P* z=
//System.out.print(" now:"+now+"\n"); "(y| iS$^T
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); dzc.s8T(0
lastExecuteTime=now; 5zII4ukn*
executeUpdate(); b"#|0d0
} L}U fd >*
else{ e0u*\b
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); $30lNZK1m8
} Y]1b39O
} )e:u 6]
} sJ/?R:
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 YR/rN,
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类写好了,下面是在JSP中如下调用。 ZTSNM)f
\c$!C8z
<% 8|p*T&Cn&
CountBean cb=new CountBean(); (/l9@0Y.t
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); =C2,?6!
CountCache.add(cb); TL_8c][.4$
out.print(CountCache.list.size()+"<br>"); ijWn,bj
CountControl c=new CountControl(); ,U/ZG|=v
c.run(); j'JNQo;q
out.print(CountCache.list.size()+"<br>"); ul3._Q
%>