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: IfK%i/J
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CountBean.java zNF.nS}:
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/* P6n9yJ$,cb
* CountData.java 5#DtaVz
* @Kx@ 2#~b
* Created on 2007年1月1日, 下午4:44 |>/T*zk<
* xnBU)#<]S
* To change this template, choose Tools | Options and locate the template under {0&'XA=j
* the Source Creation and Management node. Right-click the template and choose n<}t\<LG^c
* Open. You can then make changes to the template in the Source Editor. d".Xp4}f
*/ %Sgdhgk1
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package com.tot.count; }mZsK>
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/** R\^n2gK
* !|G 8b'
* @author kp{q5J6/
*/ sQ4~oZZ
public class CountBean { MmZs|pXk
private String countType; ^}F @*A;o
int countId; cZ<@1I5QK
/** Creates a new instance of CountData */ U_X /
public CountBean() {} ^Yz.}a##w2
public void setCountType(String countTypes){ ckglDhC
this.countType=countTypes; "_g3{[es!
} Id<3'ky<N
public void setCountId(int countIds){ dbmty|d
this.countId=countIds; ;Q1/53Y<
} L\CufAN
public String getCountType(){ y<Z-f.
return countType; yY3Mv/R
} QSaJb?I
public int getCountId(){ ggy 7p44
return countId; ,h#U<CnP#
} #dd-rooQuD
} nB8JdM2h{
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CountCache.java 5Tb3Yy< .
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/* VSxls
* CountCache.java A `H&"A
* 4!I;U>b b
* Created on 2007年1月1日, 下午5:01 Q9[$8
* Z7Y+rP[l
* To change this template, choose Tools | Options and locate the template under 7jf%-X
* the Source Creation and Management node. Right-click the template and choose o:.6{+|N
* Open. You can then make changes to the template in the Source Editor. Wg V'T#*
*/ jP{W|9@(
*<5zMSZO
package com.tot.count; &ND8^lR=Y;
import java.util.*; _LOV&83O(
/** LK?V`J5wY
* DaK2P;WP
* @author
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*/ J[?7`6\M
public class CountCache { W{{{c2 .
public static LinkedList list=new LinkedList(); !Q0aKkMfL
/** Creates a new instance of CountCache */ f:).wi
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public CountCache() {} knPo"GQW
public static void add(CountBean cb){ 2&k5X-Y
if(cb!=null){ J4xJGO
list.add(cb); [xrM){ItW
} =>_k ;x
} gk*Md+
} ckZZ)lW`*
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CountControl.java jW?siQO^
v)TFpV6b{p
/* rLy<3
* CountThread.java '%D$|)
* Qxvj`Ge
* Created on 2007年1月1日, 下午4:57 \Jcj4
* 9 aE.jpN
* To change this template, choose Tools | Options and locate the template under AIx,c1G]K
* the Source Creation and Management node. Right-click the template and choose XHN`f#(w
* Open. You can then make changes to the template in the Source Editor. a9OJC4\
*/ 1VH$l(7IQ
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package com.tot.count; vbZGs7%
import tot.db.DBUtils; x+L
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import java.sql.*; )bM #s">Y
/** }iK_7g`yKa
* (IrX\Y
* @author e^Ds|}{V
*/ #*g .hL<
public class CountControl{ =Wl*.%1 b
private static long lastExecuteTime=0;//上次更新时间 ^w+jPT-n
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 %o~w
/** Creates a new instance of CountThread */ ddR_+B*H
public CountControl() {} N'#Lb0`B
public synchronized void executeUpdate(){ \n@S.Y?P
Connection conn=null; /!r#=enG7
PreparedStatement ps=null; BBub'
try{ lO+<T[
conn = DBUtils.getConnection(); A5lP%&tu(
conn.setAutoCommit(false); }>
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); #&@qmps(T
for(int i=0;i<CountCache.list.size();i++){ yxECK&&P0#
CountBean cb=(CountBean)CountCache.list.getFirst(); .CrrjS w
CountCache.list.removeFirst(); +Oae3VFf;
ps.setInt(1, cb.getCountId()); a=55bEn
ps.executeUpdate();⑴ A/ eZ!"Y
//ps.addBatch();⑵ j15TavjGh
} &wZ ggp
//int [] counts = ps.executeBatch();⑶ ,|: a7b]
conn.commit(); 0I.9m[<Fc
}catch(Exception e){ =jik33QV<
e.printStackTrace(); m_%1IJ
} finally{ =A6/D
try{ ;w(]z
if(ps!=null) { gyW*-:C
ps.clearParameters(); I5"ew=x#
ps.close(); 1MtvnPY
ps=null; -%XvWZvZ
} 6~b~[gA
}catch(SQLException e){} zS Yh ?NB5
DBUtils.closeConnection(conn); !b O8apn
} W|U!kqU
} :!a9|Fh~
public long getLast(){ Mk=;UBb$X
return lastExecuteTime; 2a;vLc4
} GHHErXT\a
public void run(){ 2Yx6.e<
long now = System.currentTimeMillis(); <v?9:}
if ((now - lastExecuteTime) > executeSep) { U*ZP>Vv
//System.out.print("lastExecuteTime:"+lastExecuteTime); p{j
}%)6n
//System.out.print(" now:"+now+"\n"); $+IE`(Ckf
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); %Fc,$ =
lastExecuteTime=now; F|*{Ma
executeUpdate(); yQ4]LyS
} PXGS5,
else{ L~1u?-zu
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); j%iz>
} O)MKEMuA
} TB] %?L:
} /&=E=S6
//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 PsDks3cG
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类写好了,下面是在JSP中如下调用。 Fzk
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<% 09"C&X~
CountBean cb=new CountBean(); d"+zDc;
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 05:`(vl
CountCache.add(cb); ZVpMR0!
out.print(CountCache.list.size()+"<br>"); L0SeG:
CountControl c=new CountControl(); kZ+nL)YQ#
c.run(); 4-[L^1%S[
out.print(CountCache.list.size()+"<br>"); Wy%q9x]}
%>