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: pD"YNlB^
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CountBean.java 1%%'6cWWu
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/* yQ9ZhdQS
* CountData.java
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* ^$!987"
* Created on 2007年1月1日, 下午4:44 W4(v6>5l
* sONBQ9
* To change this template, choose Tools | Options and locate the template under Bs[nV}c>>
* the Source Creation and Management node. Right-click the template and choose wu A^'T
* Open. You can then make changes to the template in the Source Editor. P''X_1oMC
*/ +noZ<KFW
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package com.tot.count; MU'@2c
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/** %%>_B2vc
* D3`}4 A
* @author baee?6
*/ +iy7e6P
public class CountBean { ` @8`qXg
private String countType; XAPYpBgm
int countId; Ur^j$B}
/** Creates a new instance of CountData */ @9Q2$
public CountBean() {} 'B_\TU0
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public void setCountType(String countTypes){ <\" .L
this.countType=countTypes; (zG.aaz*C
} SVagT'BB
public void setCountId(int countIds){ H6gU?9%
this.countId=countIds; '_dzcN,z
} ~]BMrgn
public String getCountType(){ ZsZcQj6G,
return countType; YzAFC11,
} Po(]rQbE
public int getCountId(){ ?vgH"W~3>
return countId; NBjeHtT
} m#f{]+6U
} z%1{
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CountCache.java C9qJP^F
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/* |ETiLR=&
* CountCache.java 1DE@N1l
* @m~RtC-Q
* Created on 2007年1月1日, 下午5:01 QV qK
* '7*=`q{
* To change this template, choose Tools | Options and locate the template under ;;Ds
* the Source Creation and Management node. Right-click the template and choose {fV}gR2
* Open. You can then make changes to the template in the Source Editor. :m'+tGs
*/ vMla'5|l
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package com.tot.count; iWE)<h
import java.util.*; -Xz&}QA
/** 5l DFp9
* ]XeO0Y
* @author W2Luz;(U
*/ :B|Dr
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public class CountCache { Lq (ZcEKo
public static LinkedList list=new LinkedList(); LZ U$
/** Creates a new instance of CountCache */ |E@djosyC
public CountCache() {} Xl_Uz8Hp
public static void add(CountBean cb){ rR,2UZR
if(cb!=null){ TeQNFo^_8
list.add(cb); 6Pn8f
} F7MzCZvu
} nmFC%p)4
}
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CountControl.java (\a6H2z8l
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/* s%pfkoOY%
* CountThread.java ] asBd"
* dQb.BOI)h
* Created on 2007年1月1日, 下午4:57 1tMQqI`N
* !k&Q 5s:
* To change this template, choose Tools | Options and locate the template under @}s$]i$|-
* the Source Creation and Management node. Right-click the template and choose 6rN(_Oi-
* Open. You can then make changes to the template in the Source Editor. B[5r|d'
*/ xJZ@DR,#
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package com.tot.count; fNu'((J-
import tot.db.DBUtils; rw7_5l
import java.sql.*; O
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/** }(XdB:C8
* kJQ#Wz|z]
* @author j'0r'
*/ ?7MqeR4/E
public class CountControl{ =Gk/k}1
private static long lastExecuteTime=0;//上次更新时间 &~e$:8+
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 27F~(!n
/** Creates a new instance of CountThread */ Yw;D:Y(
public CountControl() {} 5 BtX63
public synchronized void executeUpdate(){ [5$w=u"j
Connection conn=null; S8,Z;y
PreparedStatement ps=null; sJ
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try{ wJ<Oo@snm
conn = DBUtils.getConnection(); h*B|fy4K9U
conn.setAutoCommit(false); !ZRs;UZ>o
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); o>/O++7R a
for(int i=0;i<CountCache.list.size();i++){ c`*TPqw(B[
CountBean cb=(CountBean)CountCache.list.getFirst(); f~{}zGTM:
CountCache.list.removeFirst(); 76cG90!Z
ps.setInt(1, cb.getCountId()); RW$:9~
ps.executeUpdate();⑴ q my%J
//ps.addBatch();⑵ 1xE]6he4{T
} Mg,:UC:
//int [] counts = ps.executeBatch();⑶ +;}#B~:
conn.commit(); L I >(RMv
}catch(Exception e){ JPn$FQD
e.printStackTrace(); k>jbcSY(z<
} finally{ _ee
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try{ 7Q w|!
if(ps!=null) { 6x)$Dl
ps.clearParameters();
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ps.close(); s@hRqGd:
ps=null; YC_5YY(k
} '_k+WH&
}catch(SQLException e){} :!a2]-D}
DBUtils.closeConnection(conn); '})0!g<Y
} P|tNL}2`;
} `+:.L>5([
public long getLast(){ !HeSOzN
return lastExecuteTime; ^u}L;`L
} 7R#+Le)
public void run(){ _p-t<ytnh
long now = System.currentTimeMillis(); vsWHk7 9
if ((now - lastExecuteTime) > executeSep) { hN2:d1f0
//System.out.print("lastExecuteTime:"+lastExecuteTime); @+F4YJmB?l
//System.out.print(" now:"+now+"\n"); S [h];eM
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); %?^6).aEK
lastExecuteTime=now; W!!S!JF
executeUpdate(); obrl#(\P
} vDl- "!G1
else{ \#-W
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//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); :0)3K7Q
} ]u l$*
} U7uKRv9
} vx_o(wof
//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 +YLejjQ
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类写好了,下面是在JSP中如下调用。 )*; zW!H
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<% Z[\O=1E,
CountBean cb=new CountBean(); pD]0`L-HJU
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 0;4t&v7
CountCache.add(cb); @_:]J1jw7
out.print(CountCache.list.size()+"<br>"); ~_s?k3cd
CountControl c=new CountControl(); 'TH15r@
c.run(); 6hZ@;Q=b
out.print(CountCache.list.size()+"<br>"); G7--v,R1x
%>