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: p'!cGJL
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CountBean.java }ob#LC,
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/* QYDSE
* CountData.java fyh9U_M);w
* m{;2!
* Created on 2007年1月1日, 下午4:44 Q. @9"&)t
* %r?Y!=0
* To change this template, choose Tools | Options and locate the template under 3u_[=a
* the Source Creation and Management node. Right-click the template and choose /0@'8f\I
* Open. You can then make changes to the template in the Source Editor. 0]fzjiaGt
*/ 3+0$=ef
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package com.tot.count; /n&w|b%
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/** A+_361KH
*
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* @author X`ee}C.D_
*/ Jzo|$W
public class CountBean { 5PqL#Eu`!
private String countType; I&
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int countId; UBLr|e>dQE
/** Creates a new instance of CountData */ ^cn%]X#.
public CountBean() {} zT
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public void setCountType(String countTypes){ >;LXy
this.countType=countTypes; %
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} scT,yNV
public void setCountId(int countIds){ uD4on}
this.countId=countIds; -XRn%4EX?
} j
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public String getCountType(){ Y{ijSOl3
return countType; 49W@?:b
} yb\T<*
public int getCountId(){ s IJl9
return countId; C8W#$a
} 2<q>]G-nN
} =^\yE"a
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CountCache.java ?0*,x)t
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/* zk#"n&u0
* CountCache.java #ue WU
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* Created on 2007年1月1日, 下午5:01 ,1&Pb %}
* Pqu]?X
* To change this template, choose Tools | Options and locate the template under > mk>VM
* the Source Creation and Management node. Right-click the template and choose mSdByT+dG
* Open. You can then make changes to the template in the Source Editor. :#7"SEud}
*/ C9OEB6
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package com.tot.count; _UI*W&*
import java.util.*; 'guXdX]Gu
/**
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* VokIc&!Uz
* @author <;kcy :s
*/ ![1+=F!
public class CountCache { 'o}v{f
public static LinkedList list=new LinkedList(); P|j|0o,8p
/** Creates a new instance of CountCache */ v]{F.N
public CountCache() {} vxE#6
public static void add(CountBean cb){ {G. W?
if(cb!=null){ *@)0TL(03
list.add(cb); 08czP-)OZ
} BA(erf>
} GBeWF-`B
} *uW l 804
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CountControl.java 2~`vV'K
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/* 1V
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* CountThread.java #K#BNpG|
* /|s~X@%K
* Created on 2007年1月1日, 下午4:57 27J!oin$
* ;z2\ Q$
* To change this template, choose Tools | Options and locate the template under vG'6?%38
* the Source Creation and Management node. Right-click the template and choose #
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* Open. You can then make changes to the template in the Source Editor. WoV"&9y
*/ }Wlm#t
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package com.tot.count;
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import tot.db.DBUtils; aC90IJ8^
import java.sql.*; cV$an
/** #)r^ZA&E
* U1ZKJ<pv
* @author [x%[N)U3
*/ f`<elWgc"
public class CountControl{ 2x5^kN7
private static long lastExecuteTime=0;//上次更新时间 (n{x"rLy/
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ZWmS6?L.
/** Creates a new instance of CountThread */ jlxY|;gZ-0
public CountControl() {} YY zUg
public synchronized void executeUpdate(){ b1TIVK3m
Connection conn=null; ]J1oY]2~
PreparedStatement ps=null; yopC
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try{ =cR"_ Z[8X
conn = DBUtils.getConnection(); e j,)<*
conn.setAutoCommit(false); `' .;U=mF
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); HVd y!J
for(int i=0;i<CountCache.list.size();i++){ CP'b,}Dd?I
CountBean cb=(CountBean)CountCache.list.getFirst(); \E(^<Af
CountCache.list.removeFirst(); ~U r
ps.setInt(1, cb.getCountId()); gU&y5s~
ps.executeUpdate();⑴ LwlO)|E
//ps.addBatch();⑵ )-\C{>
} ]-j.\+(*
//int [] counts = ps.executeBatch();⑶ ,B~5;/|
conn.commit(); 57wHo[CJ
}catch(Exception e){ 'aWqj+Wbh
e.printStackTrace(); *z'v
} finally{ WKAG)4
try{ T>hrKn.!D:
if(ps!=null) { aPdEEqc\l
ps.clearParameters(); gc\/A\F<
ps.close(); bN\;m^xfu
ps=null; hp c &s
} Wsb>3J
}catch(SQLException e){} 25PZ&^G8%
DBUtils.closeConnection(conn); 4^Ss\$*
} 1=Kt.tuf
} ^Ig QIN
public long getLast(){ "T$LJ1E
return lastExecuteTime; dl.gCiI
} Cag^$nj
public void run(){ N~uc%wOA
long now = System.currentTimeMillis(); S zNZY&8
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if ((now - lastExecuteTime) > executeSep) { h#p[6}D
//System.out.print("lastExecuteTime:"+lastExecuteTime); htT9Hrx
//System.out.print(" now:"+now+"\n"); {'Y()p3kl
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); sWmqx$
lastExecuteTime=now; \G#_z|'dN
executeUpdate(); eQz.N<f"
} c/7}5#Rs
else{ gR+P!Eow
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); Mkh/+f4
} [_eT{v2B4
} )&DsRA7v
} {,!!jeOO
//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 -{}(U
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类写好了,下面是在JSP中如下调用。 *>/w,E]
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<% H u9nJ
CountBean cb=new CountBean(); <0VC`+p<)
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); xw}rFY$
CountCache.add(cb); blLl1Ak
out.print(CountCache.list.size()+"<br>"); +DG-MM%\
CountControl c=new CountControl(); `_f&T}]
c.run(); mGDy3R90
out.print(CountCache.list.size()+"<br>"); 8.G<+.
%>