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: SFh6'v'1N@
e&wWlB![
CountBean.java ,!Q2^R
}t]CDa_n
/* W**a\[~$
* CountData.java >0u4>=#
* Qs*g)Yr
* Created on 2007年1月1日, 下午4:44
4INO .
* o,u-%
* To change this template, choose Tools | Options and locate the template under ` NcWy
* the Source Creation and Management node. Right-click the template and choose r6j
3A
* Open. You can then make changes to the template in the Source Editor. _ea!psA0
*/ qL3*H\9N
EAx@a%
package com.tot.count; H{9di\xnEm
Cg-khRgLS
/** O~ w&4F;{
* ~u-mEdu3C
* @author Ga$+x++'*
*/ rHh<_5-/>
public class CountBean { 6x6PP}IX
private String countType; @R>J\>
int countId; nKufVe
/** Creates a new instance of CountData */ 7pmhH%Dn$
public CountBean() {} =3l%ZL/
public void setCountType(String countTypes){ 1_*o(HR
this.countType=countTypes; [,$] %|6wt
} BEN=/
v
public void setCountId(int countIds){ =A04E
this.countId=countIds; V%
psaT=)P
} }"%tlU!}
public String getCountType(){ ;#cb%e3
return countType; 8
<EE4y
} KK}^E_v
public int getCountId(){ 0Ocy$
return countId; WFULQQ*
} ,;hIyT
} HTvA]-AuM
%fo +Y+t
CountCache.java !A, ]
Y6&w0~?!
/* x{j|Tf3,G
* CountCache.java W{Ine>
a'
* nB WVG
* Created on 2007年1月1日, 下午5:01 O2-9Oo@#,
* c54oQ1Q&"
* To change this template, choose Tools | Options and locate the template under fOtL6/?
* the Source Creation and Management node. Right-click the template and choose ehV`@ss
* Open. You can then make changes to the template in the Source Editor. 6`+dP"@
*/ |Xlpgdiu
lqTTTk
package com.tot.count; D({%FQ"
import java.util.*; >A;Mf*E
/** C%9;~S
* 4%0eX]
* @author mADq_`j
*/ O=?WI
public class CountCache { b*\K I
public static LinkedList list=new LinkedList(); xlZ"F
/** Creates a new instance of CountCache */ yO;r]`j0
public CountCache() {} #H fvY}[o
public static void add(CountBean cb){ K*xqQ]&
if(cb!=null){ FctqE/>}I
list.add(cb); ]d=SkOq
} nlOM4fJ(
} $!)Sgb
} }RowAGWL
$1y8gm
CountControl.java [p^N].K$
yV,ki^^
/* UE3(L
^
* CountThread.java `z=U-v'H)D
* sEP-jEuwG
* Created on 2007年1月1日, 下午4:57 ^1^k<
* qpjtF'
* To change this template, choose Tools | Options and locate the template under Ab ,n^
* the Source Creation and Management node. Right-click the template and choose =NMT H[
* Open. You can then make changes to the template in the Source Editor. SR7$m<0t*
*/ [%7y !XD
B8;jRY
package com.tot.count; |\;oFuCv##
import tot.db.DBUtils; (L}
import java.sql.*; ufyqfID
/** _H@Y%"ZHJ6
* /T1zz2l~
* @author |:BKexjHL
*/ "uf*?m3
public class CountControl{ Ysbd4rN
private static long lastExecuteTime=0;//上次更新时间 pESlBQ7{I
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 t[* ;v
/** Creates a new instance of CountThread */ /I&Hq7SW`
public CountControl() {} zO8`xrN!
public synchronized void executeUpdate(){ G|MjKe4}
Connection conn=null; d*Q:[RUf,
PreparedStatement ps=null; |W4
\
try{ G8b/eWtP
conn = DBUtils.getConnection(); {C3AxK0
conn.setAutoCommit(false); Fb#.Gg9b>
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); db#QA#^S
for(int i=0;i<CountCache.list.size();i++){ AT Dm$ *
CountBean cb=(CountBean)CountCache.list.getFirst(); `2`Nu:r^
CountCache.list.removeFirst(); b Lag&c)
ps.setInt(1, cb.getCountId()); :?W {vV
ps.executeUpdate();⑴ pn3f{fQ
//ps.addBatch();⑵ yZkHBG4
} 9QE|p
//int [] counts = ps.executeBatch();⑶ $Lg%CY
conn.commit(); dayp1%d
}catch(Exception e){ jusP
aAdW
e.printStackTrace(); ;ELQIHnD"
} finally{ bU'{U0lM
try{ $jMU|{
if(ps!=null) { [)UF@Sq4+Q
ps.clearParameters(); .C=&`;Vs
ps.close(); $mFsf)1]]?
ps=null; "a;z
} nTrfbK@
}catch(SQLException e){} C {.{>M
DBUtils.closeConnection(conn); uV1H iv-
} K^z-G=|N
} yH_L<n
public long getLast(){ FkJa+ZA
return lastExecuteTime;
/;LteBoY
} `< 8Fc`;[
public void run(){ 47I5Y5
long now = System.currentTimeMillis(); u*_I7.}9
if ((now - lastExecuteTime) > executeSep) { J]uYXsC
//System.out.print("lastExecuteTime:"+lastExecuteTime); f:iK5g
//System.out.print(" now:"+now+"\n"); ;:xOW$
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); il^SGH
lastExecuteTime=now; ]P/eg$u'I
executeUpdate(); *0bbSw1kc
} Fs_,RXW"
else{ {m5tgVi&
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); :H[E
W3Q
} U!m-{7s$
} |u8hxa
} y$@d%U*rW^
//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 k f~71G+
$IUP;
类写好了,下面是在JSP中如下调用。 =y >P>&sI
)f#@`lf[<
<% @(.?e<
CountBean cb=new CountBean(); =!NYvwg6;o
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); Y+N^_2@+C
CountCache.add(cb); b7fP)nb695
out.print(CountCache.list.size()+"<br>"); } {/4sll
CountControl c=new CountControl(); |E@G sw
c.run(); b!hxx Z
out.print(CountCache.list.size()+"<br>"); G-oCA1UdN
%>