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: _8t{4C
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CountBean.java RKRk,jRL
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/* |7%M:7Q
* CountData.java jR*1%.Ng
* v;irk<5
* Created on 2007年1月1日, 下午4:44 P3);R>j
* R /iB
* To change this template, choose Tools | Options and locate the template under -SZ^;t
* the Source Creation and Management node. Right-click the template and choose q^k6.5*"
* Open. You can then make changes to the template in the Source Editor. ;
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*/ !=Cd1
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package com.tot.count; iwrS>Sm
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/** A03,X;S+
* n`;=^^ B
* @author /zM
*/ Lw1~$rZg
public class CountBean { 0vf2wBK'T
private String countType; =l?5!f9
int countId; /mF%uI>:
/** Creates a new instance of CountData */ (?;Fnq
public CountBean() {} ^DM^HSm
public void setCountType(String countTypes){ vaS/WEY
this.countType=countTypes; ig)rK<@*[
} j8_WEjG
public void setCountId(int countIds){ x)5#*Q
this.countId=countIds; pd/{yX M
} 0Evq</
public String getCountType(){ 9g|o17
return countType; CZuV{Oh}?
} s^)wh v`C
public int getCountId(){ k[&+Iy
return countId; oX8e}
} h,LwC9
} s:~3|D][
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CountCache.java wspZ Eu>C;
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/* ]KBzuz%
* CountCache.java 8fY1~\G:\
* !/[/w39D0o
* Created on 2007年1月1日, 下午5:01 =TE6R 0b
* y_;LTCj?
* To change this template, choose Tools | Options and locate the template under CuR.a
* the Source Creation and Management node. Right-click the template and choose 6av]LY K
* Open. You can then make changes to the template in the Source Editor. nB[Aw7^|A
*/ /\q1,}M
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package com.tot.count; _e
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import java.util.*; 1Y'9|+y+
/** MdV-;uf
* U ]Ek5p
* @author fo;Ftf0
*/ G|*^W;(Z
public class CountCache { 87.b7 b.
public static LinkedList list=new LinkedList(); iaPrkMhd
/** Creates a new instance of CountCache */ 2m7Z:b
public CountCache() {} 5xtIez]x?
public static void add(CountBean cb){ ?`#)JG,A7
if(cb!=null){ (U#4j 6Q
list.add(cb); n&DRh.@
} ckY,6e"6
} e@}zp
} X458%)G!(K
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CountControl.java B! $a Y
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/* wcDHx#~
* CountThread.java Vj(}'h-c\
* ~?T*D*
* Created on 2007年1月1日, 下午4:57 A2.[P==
*
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* To change this template, choose Tools | Options and locate the template under XMzL\Edo
* the Source Creation and Management node. Right-click the template and choose cK6M8:KW
* Open. You can then make changes to the template in the Source Editor. YaI8hj@}
*/ G$FNofQx
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package com.tot.count; ;[9WB<t
import tot.db.DBUtils; o0t/
import java.sql.*; .b'hVOs{
/** S,A\%:Va
* `hJSo?G>
* @author fS2 ^$"B|
*/ AT.WXP0$A
public class CountControl{ N4y$$.uv2
private static long lastExecuteTime=0;//上次更新时间 H]>b<Cs
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 u
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/** Creates a new instance of CountThread */ ,QW>M$g{
public CountControl() {} g!%C_AI
public synchronized void executeUpdate(){ G ,,c,
Connection conn=null; lB_&Lq8G
PreparedStatement ps=null; l'h[wwEXm{
try{ Q?]307g7
conn = DBUtils.getConnection(); :{2exu
conn.setAutoCommit(false); bj)dYjf
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); tS!|#h-J
for(int i=0;i<CountCache.list.size();i++){ m E<n=g=
CountBean cb=(CountBean)CountCache.list.getFirst(); m<]b]FQ
CountCache.list.removeFirst(); ^}nz^+R
ps.setInt(1, cb.getCountId()); ra#s!m1
ps.executeUpdate();⑴ P5{|U"Y_
//ps.addBatch();⑵ ~bL^&o(W
} *oR`l32O0z
//int [] counts = ps.executeBatch();⑶ 'uAH, .B
conn.commit(); i&KD)&9b#
}catch(Exception e){ z=q
e.printStackTrace(); qgTN %%"~
} finally{ >9KQWeD
try{ k8]=5C?k
if(ps!=null) { f{_K%0*
ps.clearParameters(); Sg$14B
ps.close(); !B36+W+
ps=null; ]u~6fknm
} pC9Ed9uRK
}catch(SQLException e){} WPbWG$Li
DBUtils.closeConnection(conn); nFE0y3GD8
} L_$M9G|5n
} aBL+i-
public long getLast(){ bqBgq
return lastExecuteTime; 4E&=qC]S
} jTjGbC]X
public void run(){ TM_ MJp
long now = System.currentTimeMillis(); -.#He
if ((now - lastExecuteTime) > executeSep) { ("HT0a
//System.out.print("lastExecuteTime:"+lastExecuteTime); 9H~{2Un
//System.out.print(" now:"+now+"\n"); )dFTH?Mpo
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); };m.Y>=)K
lastExecuteTime=now; |UbwPL_L
executeUpdate(); tg%U2+.q
} ~4p@m>>
else{ /*B^@G |]'
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); q!l[^t|;
} H}KJd5A7
} {.
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} gB\
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//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 CfFNk "0{
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类写好了,下面是在JSP中如下调用。 (+g!~MP
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<% r{~K8!=oU]
CountBean cb=new CountBean(); pq;)l(Hi
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); nLZT3`@~,
CountCache.add(cb); ii%n:0+zm
out.print(CountCache.list.size()+"<br>"); 8e_ITqV%
CountControl c=new CountControl(); ^FLuhLS\*
c.run(); (0%0+vY
out.print(CountCache.list.size()+"<br>"); mUi|vq)`=D
%>