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: EKoCm)}d
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CountBean.java ?=4J
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/* +Tu:zCv.
* CountData.java -@#AQ\
* 9U;) [R Mb
* Created on 2007年1月1日, 下午4:44 )(!vd!p5
* hR{Fn L
* To change this template, choose Tools | Options and locate the template under }:hdAZ+z
* the Source Creation and Management node. Right-click the template and choose u-k*[!JU
* Open. You can then make changes to the template in the Source Editor. 45-pJf8F
*/ /-4%ug tD$
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package com.tot.count; @ObsW!g
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/** fwl
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* Pel3e ~?t
* @author %HSoQ?qA
*/ aMj3ov8p
public class CountBean { &'|bZms g
private String countType; Bq$bxuhV
int countId; cc^V~-ph
/** Creates a new instance of CountData */ t~bjD V^`
public CountBean() {} \{~x<<qFd
public void setCountType(String countTypes){ v1)jZ.:
this.countType=countTypes; :W'1Q2
} ^rxXAc[
public void setCountId(int countIds){ DsFrA]
this.countId=countIds; =n#xnZ3
} mY%PG
public String getCountType(){ a!>AhOk.
return countType; 8\ :T*u3
} "kN5AeRg
public int getCountId(){ q+m&V#FT%
return countId; -i;#4@^ t
} )T2Sw z/
} khEHMvVH
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CountCache.java W~7q&||;C
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/* dch(HB}[
* CountCache.java cPtP?)38.
* hy6px
* Created on 2007年1月1日, 下午5:01 &i!.6M2
* Mv;7kC7]
* To change this template, choose Tools | Options and locate the template under [(dAv7YbN
* the Source Creation and Management node. Right-click the template and choose .UJDn^@
* Open. You can then make changes to the template in the Source Editor. |:EUh
*/ 2=U4'C4#
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package com.tot.count; n7Re@'N<
import java.util.*; &Wn!W
/** @h$7C<
* US
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* @author k-w._E
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*/ fM8 :Nt$
public class CountCache { q|Ga
public static LinkedList list=new LinkedList(); >B3_P4pW9
/** Creates a new instance of CountCache */ xEZvCwsb
public CountCache() {} Wk$%0xZ7
public static void add(CountBean cb){ jI y'mGaG
if(cb!=null){ Q4Cw{2r
list.add(cb); `VS/Xyp
} 30B!hj$C
} =k &'ft
} ;H}?8L
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CountControl.java :@n e29,}
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/* \bfNki
* CountThread.java XV!P8n
* :]?I| .a
* Created on 2007年1月1日, 下午4:57 )C <sj
* :x16N|z
* To change this template, choose Tools | Options and locate the template under |*8 J.H*r
* the Source Creation and Management node. Right-click the template and choose @mw1(J
* Open. You can then make changes to the template in the Source Editor. 1tfm\/V}ho
*/ FVHEb\Z
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package com.tot.count; k2O==IG]6
import tot.db.DBUtils; h( Iti&
import java.sql.*; _%.atW7
/** gl HHr
* HQ4o^ WC
* @author cp]\<p('A
*/ ?HU(0Vgn'
public class CountControl{ ?n[+0a:8E
private static long lastExecuteTime=0;//上次更新时间 UXe @c@3
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 %/~Sq?f-9@
/** Creates a new instance of CountThread */ &Tl3\T0D
public CountControl() {} ;B!&( 50e
public synchronized void executeUpdate(){ [{'` |
Connection conn=null;
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PreparedStatement ps=null; %m{h1UQQ+
try{ WG1x:,-
conn = DBUtils.getConnection(); l? 7D0
conn.setAutoCommit(false); d)9=hp;,V
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); o2&mhT
for(int i=0;i<CountCache.list.size();i++){ ,@(lYeD"
CountBean cb=(CountBean)CountCache.list.getFirst(); z!?xz
CountCache.list.removeFirst(); $1/yc#w
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ps.setInt(1, cb.getCountId()); |"\A5v|1
ps.executeUpdate();⑴ 4fp}`U
//ps.addBatch();⑵ @7.Ews5Mke
} y1@{(CDp"
//int [] counts = ps.executeBatch();⑶ I+ydVj(Op
conn.commit(); wR\%tumk
}catch(Exception e){ Z+FJ cvYx
e.printStackTrace(); [N.4i"
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} finally{ FzW7MW>\x
try{ 8) 'OXR0/
if(ps!=null) { 1;S@XC>
ps.clearParameters(); ;5dJ5_ }
ps.close(); s}X2*o`,
ps=null; <08)G7
} zGA1
}catch(SQLException e){} Np+<)q2
DBUtils.closeConnection(conn); {0QNqjue
}
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} =5',obYN>c
public long getLast(){ :[,-wZiT~6
return lastExecuteTime; D8G5,s-.
} ;MR8E9
public void run(){ f{G
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long now = System.currentTimeMillis(); AwUc U;"9>
if ((now - lastExecuteTime) > executeSep) { h 5<46!P
//System.out.print("lastExecuteTime:"+lastExecuteTime); RMDzPda.
//System.out.print(" now:"+now+"\n"); !CY:XQm
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ~"#qG6dP
lastExecuteTime=now; ?7*.S Lt
executeUpdate(); Qw}uB$S>
} Y'mtMLfMc
else{ =g
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//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); RGf&KV/
} Z<@0~t_:?p
} -LhO
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} J<yt/V]
//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 o7;lR?
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类写好了,下面是在JSP中如下调用。 W 2&o'(P\
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<% +<a-;e{
CountBean cb=new CountBean(); `1{Y9JdQ
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); gE\&[;)DB
CountCache.add(cb); `-/-(v+ i
out.print(CountCache.list.size()+"<br>"); of659~EIW
CountControl c=new CountControl(); m%]1~b}"
c.run(); o#fr5>h-w
out.print(CountCache.list.size()+"<br>"); TkBHlTa"=
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