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: U@t"o3E
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CountBean.java ^RL#(O
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/* LV4\zd6
* CountData.java i4<&zj})
* 05sWN 0
* Created on 2007年1月1日, 下午4:44 &d,chb(
* (PVK|Q55y
* To change this template, choose Tools | Options and locate the template under eAqSY s!1
* the Source Creation and Management node. Right-click the template and choose lKVy{X3]*
* Open. You can then make changes to the template in the Source Editor. 8H2zMIB
*/ g%C!)UbT
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package com.tot.count; (CUrFZT$
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/** jM<=>P
* bx!uHL=
* @author )q.Z}_,)@
*/ X?6E0/r&9
public class CountBean { }s*H|z
private String countType; euxkw]`h6
int countId; GUX!kj
/** Creates a new instance of CountData */ Iw07P2
public CountBean() {} 0^%\! Xxq
public void setCountType(String countTypes){ .`I;qF
this.countType=countTypes; oAnNdo
} [_$r- FA
public void setCountId(int countIds){ \VL_
this.countId=countIds; Drn{ucIs
} ~Onj|w7
public String getCountType(){ m7~<z>5$
return countType; "hE/f~\
} #=}dv8
public int getCountId(){ gzHMZ/31
return countId; `zRE $O
} 1\'?.
} %_kXC~hH_
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CountCache.java ;q=0NtCS=4
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/* Lg;b17
* CountCache.java '7'*+sgi$
* 1q?b?.
* Created on 2007年1月1日, 下午5:01 sl5y1W/]]
* \tpJ
* To change this template, choose Tools | Options and locate the template under bCV3h3<
* the Source Creation and Management node. Right-click the template and choose TT85G
* Open. You can then make changes to the template in the Source Editor. {S9't;%]
*/ >e
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package com.tot.count; r>>4)<C7J
import java.util.*; #!A'6SgbkM
/** 9s#Q[\B!
* u~uR:E%'C
* @author 4qd =]i
*/ O^Y}fo'
public class CountCache { $0kuR!U.N
public static LinkedList list=new LinkedList(); +hUS
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/** Creates a new instance of CountCache */ gI~4A,
public CountCache() {} !=)R+g6b
public static void add(CountBean cb){ !Q/%N#
if(cb!=null){ aEO`` W
list.add(cb); ?{)s dJe
} @;6I94Bp
} iXF iFsb
} Mu1H*;_8
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CountControl.java @]{+9m8G@
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/* cC4 2b2+
* CountThread.java t PJW|wo
* ?k|}\l[X1
* Created on 2007年1月1日, 下午4:57 =DL
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* Q5ZZ4`K!
* To change this template, choose Tools | Options and locate the template under !R
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* the Source Creation and Management node. Right-click the template and choose !nm[ZrSP
* Open. You can then make changes to the template in the Source Editor. 5qe6/E@
*/ #`g..3ey
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package com.tot.count; '\,|B
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import tot.db.DBUtils; <FkoWN
import java.sql.*; (G E)
/** %8L>|QOX
* 6Mh;ld@
* @author
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*/ GKk>;X-
public class CountControl{ |}FK;@'I 6
private static long lastExecuteTime=0;//上次更新时间 RaT_5P H~g
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 7A@iu*t
/** Creates a new instance of CountThread */ ~Z{IdE
public CountControl() {} y8HwyU>
public synchronized void executeUpdate(){ tM%
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Connection conn=null; bV3az/U
PreparedStatement ps=null; ,A{'lu
try{ G\;a_]Q
conn = DBUtils.getConnection(); ^D}]7y|fm
conn.setAutoCommit(false); fr19C%{
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 0afDqvrC6
for(int i=0;i<CountCache.list.size();i++){ ycPGv.6
CountBean cb=(CountBean)CountCache.list.getFirst(); $:4*?8K2
CountCache.list.removeFirst(); l>kREfHq!{
ps.setInt(1, cb.getCountId()); hoDE*>i
ps.executeUpdate();⑴ fYt
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//ps.addBatch();⑵ C4].egVg
} gZg5On
//int [] counts = ps.executeBatch();⑶ Cj +{%^#
conn.commit(); d%EUr9~?
}catch(Exception e){ eM) I%
e.printStackTrace(); 6^Q/D7U;s
} finally{ 1Z$` }a
try{ ULJV
if(ps!=null) { k0/S&e,*
ps.clearParameters(); v0 3
ps.close(); G9|w o)N
ps=null; K8R}2K-Y
}
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}catch(SQLException e){} *}@zxFe+
DBUtils.closeConnection(conn); !#[=,'Y
} jMAZ4M
} yPmo@aw]1
public long getLast(){ G%q^8#
return lastExecuteTime; C@ns`Eh8w
} ElK7jWJ+
public void run(){ g2|qGfl{C
long now = System.currentTimeMillis(); en?J#fz
if ((now - lastExecuteTime) > executeSep) { "dItv#<:}
//System.out.print("lastExecuteTime:"+lastExecuteTime); Pc:5*H
//System.out.print(" now:"+now+"\n"); ,SQ`, C
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// System.out.print(" sep="+(now - lastExecuteTime)+"\n");
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lastExecuteTime=now; *pP&$!bH%
executeUpdate(); zF([{5r[!)
} Y48MCL
else{ ER'zjI>t@
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 6]D%|R,Q#}
} -V_iv/fmM
} tEbR/?,GI
} @L/p
//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 |}07tUq
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类写好了,下面是在JSP中如下调用。 ! !we4tWq
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<% /9 ^F_2'_
CountBean cb=new CountBean(); 0LW|5BVbIO
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); GLpl
CountCache.add(cb); )%6h9xyXt
out.print(CountCache.list.size()+"<br>"); i
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CountControl c=new CountControl(); :5DL&,,Q3
c.run(); m5'nqy F
out.print(CountCache.list.size()+"<br>"); 5IJm_oy
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