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:
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CountBean.java `mcb0
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/* K-]) RIM
* CountData.java WblH}
* QyA^9@iVs
* Created on 2007年1月1日, 下午4:44 M%:\ ry4:
* yreH/$Ou8
* To change this template, choose Tools | Options and locate the template under 0 @#Jz#?
* the Source Creation and Management node. Right-click the template and choose GOxP{d?
* Open. You can then make changes to the template in the Source Editor. ulALGzPh
*/ \'=svJ
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package com.tot.count;
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/** <q'?[aKvR
* cWnEp';.
* @author y3(~8n
*/ rWWpP<
public class CountBean { "zw{m+7f,
private String countType; ]iTP5~8U
int countId; ;LgMi5dN
/** Creates a new instance of CountData */ ]foS.D,
public CountBean() {} ,sj(g/hg
public void setCountType(String countTypes){ c
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this.countType=countTypes; `%|3c
} 1?)h-aN
public void setCountId(int countIds){ %ly&~&0
this.countId=countIds; q>%.zc[x
} rui 8x4c
public String getCountType(){ BT(eU*m-
return countType; :JBtqpo2
} MA{ZmPm)
public int getCountId(){ [|$C2Dhw=
return countId; DPY+{5q2
} r!w4Br0
} IHW s<U
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CountCache.java 4NRj>y
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/* Lwtp,.)pR
* CountCache.java 0xi2VN"X
* `!X8Cn
* Created on 2007年1月1日, 下午5:01 IRLAsb3
* "$5cKbJ
* To change this template, choose Tools | Options and locate the template under QX?moW6UW
* the Source Creation and Management node. Right-click the template and choose y z3=#
* Open. You can then make changes to the template in the Source Editor. ^VzhjKSu
*/ 7lYf+&JZ
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package com.tot.count; }x6)}sz7
import java.util.*; "w 4^i!\
/** 43=)akJi
* YpZuAJm<2_
* @author ~2[kCuu
*/ `<@ "WSn
public class CountCache { L5:1dF
public static LinkedList list=new LinkedList(); i%i s<'
/** Creates a new instance of CountCache */ v\(6uej^
public CountCache() {} +bso4 }rS
public static void add(CountBean cb){ fM&
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if(cb!=null){ ) F -8
list.add(cb); wtL=^
} Z1$S(p=)L
} &n?RKcH}d
} MYJMZ3qBi
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CountControl.java KWYjN
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/* ,y0 &E8Z
* CountThread.java q(46v`u
* D
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* Created on 2007年1月1日, 下午4:57 Kl ?C[
* WOgkv(5KN
* To change this template, choose Tools | Options and locate the template under Nj?Q{ztS
* the Source Creation and Management node. Right-click the template and choose PXl%"O%d
* Open. You can then make changes to the template in the Source Editor. Q4Wz5n1yp7
*/ sWTa;Qi
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package com.tot.count; )C\/ (
import tot.db.DBUtils; ]w*` }
import java.sql.*; a_VWgPVdDS
/** dBM{]@bZ
* ]l=CiG4!M
* @author r0OP !u
*/ 4"nYxL"<4
public class CountControl{ .|P
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private static long lastExecuteTime=0;//上次更新时间 S%?%06$
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ?hrz@k|
/** Creates a new instance of CountThread */ }YiFiGf,
public CountControl() {} _9=cxwi<w
public synchronized void executeUpdate(){ !u:;Ew
Connection conn=null; '19?
PreparedStatement ps=null; SEWdhthP
try{ sA+K?_
conn = DBUtils.getConnection(); +~1FKLu
conn.setAutoCommit(false); A58P$#)?
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); IW}Wt{'m
for(int i=0;i<CountCache.list.size();i++){ @eESKg(,
CountBean cb=(CountBean)CountCache.list.getFirst(); jW^]N$>
CountCache.list.removeFirst(); Q4L7{^[X
ps.setInt(1, cb.getCountId()); "fN
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ps.executeUpdate();⑴ oBnes*
//ps.addBatch();⑵
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} qx0F*EH|
//int [] counts = ps.executeBatch();⑶ 1'\s7P
conn.commit(); -) +B!"1
}catch(Exception e){ }t|i1{%_
e.printStackTrace(); g^#,!e
} finally{ J_<6;#
try{ X_3hh} =
if(ps!=null) { 4qd(a)NdY
ps.clearParameters(); l%u8Lq
ps.close(); UsCaO<A
ps=null; 6@:<62!;
} D)[(
}catch(SQLException e){} yr.sfPnJK
DBUtils.closeConnection(conn); y34 <B)Wy
} 5]kv1nQ
} }dU!PZ9N)
public long getLast(){ SY}"4=M?l
return lastExecuteTime; $
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} $&jVEMia
public void run(){ =<TJ[,h
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long now = System.currentTimeMillis(); k O.iJcZg
if ((now - lastExecuteTime) > executeSep) { f"4w@X2F
//System.out.print("lastExecuteTime:"+lastExecuteTime); #g2&x sU
//System.out.print(" now:"+now+"\n"); XrXW6s;Z
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); |v#rSVx
lastExecuteTime=now; 4T~wnTH0Xg
executeUpdate(); SoFl]^l
} [CAFh:o
else{ j]mnH`#BL
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); _Db&f}.`
} 0hXx31JN N
} >I;.q|T
} p%#'`*<a_
//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 w xaMdA
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类写好了,下面是在JSP中如下调用。 fgA-+y
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<% <1QXZfQ"
CountBean cb=new CountBean(); ]{t!J^Xn
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); Oe "%v;-
CountCache.add(cb); sQ[N3
out.print(CountCache.list.size()+"<br>"); mM{cH=
CountControl c=new CountControl(); Jt}#,I,B
c.run(); S
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out.print(CountCache.list.size()+"<br>"); D'% O<.m
%>