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: pmOUl 8y4
=XK}eQ_d
CountBean.java evpy%/D
#kh:GAp]
/* tfu`_6
* CountData.java <EQaYZY=
* A7,%'.k
* Created on 2007年1月1日, 下午4:44 ~9xkiu5~
* !XM<`H/
* To change this template, choose Tools | Options and locate the template under uE<8L(*B
* the Source Creation and Management node. Right-click the template and choose ^B%c3U$o
* Open. You can then make changes to the template in the Source Editor. g"k4Z
*/ 2r;h">
ca3SE^
package com.tot.count; q"6$#o{~U
u!&T}i:
/** 5423Ky<
* wlsx|
* @author ;^u,[d
*/ _C(fz CK
public class CountBean { :U *8S\$
private String countType; n#}~/\P6
int countId; ^#Mp@HK
/** Creates a new instance of CountData */ N/ '
public CountBean() {} .ZV='i()X
public void setCountType(String countTypes){ j S[#R_
this.countType=countTypes; fVf:voh
} 9D Nd} rXO
public void setCountId(int countIds){ wy8Q=X:vP
this.countId=countIds; NbTaI{r
} V.*y_=i8t
public String getCountType(){ w%plK6:6
return countType; Tl'wA^~H
} r>7+&s*yk
public int getCountId(){ LnKgT1
return countId; Aj=GekX{
} [ZC\8tP`V
} ^)I}#
G;iH.rCH
CountCache.java KO%$
W$2\GPJt
/* 2K{'F1"RM
* CountCache.java _x1W\#
* /CMgWGI
* Created on 2007年1月1日, 下午5:01 l
U8pX$
* @;$cX2
* To change this template, choose Tools | Options and locate the template under :CK`v6 Qs
* the Source Creation and Management node. Right-click the template and choose DB65vM
* Open. You can then make changes to the template in the Source Editor. ,|3_@tUl
*/ ?o$t{AQ
OzD\*,{7
package com.tot.count; Wh)
import java.util.*; U\B9Ab
/** _P!b0x~\
* u$C\#y7
* @author ]1XtV<
*/ J*MH`;-
public class CountCache { a/J Mg
public static LinkedList list=new LinkedList(); 0nL
#-`S
/** Creates a new instance of CountCache */ Yj*T'<e
public CountCache() {} ~CbiKez
public static void add(CountBean cb){ ^<-)rzTI
if(cb!=null){ %OB>FY:|
list.add(cb); 6W{Nw<
} +Ugy=678Tr
} >
Xh=P%
} jex\5
WW{_D
CountControl.java @TD=or .&
O39
/* s~2o<#
* CountThread.java 7<*0fy5n n
* _z8"r&
* Created on 2007年1月1日, 下午4:57 VFx[{Hy
* [Z"Z5e`
* To change this template, choose Tools | Options and locate the template under /*{'p!?
* the Source Creation and Management node. Right-click the template and choose |>.MH
* Open. You can then make changes to the template in the Source Editor. @'):rFr@F
*/ 3<"j/9;K'
@&`^#pok
package com.tot.count; OylUuYy~j
import tot.db.DBUtils; yj#FO'UY
import java.sql.*; {Ji&rk}NP
/** k}qQG}hB
* A[^#8evaK
* @author dor1(@no|
*/ k ,ldi
public class CountControl{ G+Z ,ic
private static long lastExecuteTime=0;//上次更新时间 ,Yx<"2 W
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 #b;k+<n[X
/** Creates a new instance of CountThread */ mRRZ/m?A(
public CountControl() {} E;{CoL
public synchronized void executeUpdate(){ |h6!b t!=
Connection conn=null; vA!IcDP"
PreparedStatement ps=null; :Ae#+([V
try{ `^[Tu 1
conn = DBUtils.getConnection(); {<@ud0A:\
conn.setAutoCommit(false); .\T!oSb4[
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); W_E^+Wl@
for(int i=0;i<CountCache.list.size();i++){ v]EZYEXFL)
CountBean cb=(CountBean)CountCache.list.getFirst(); $Wj{B@k
CountCache.list.removeFirst(); _AX,}9
ps.setInt(1, cb.getCountId()); T9&{s-3*
ps.executeUpdate();⑴ }T(=tfv@
//ps.addBatch();⑵ ~!~i_L\V
} u&uFXOc'
//int [] counts = ps.executeBatch();⑶ &g&,~Y/z;
conn.commit(); KJ32L
}catch(Exception e){ Q"D
e.printStackTrace(); j0~am,yZ
} finally{ jT$J~MpHh
try{ 6xtgnl#T
if(ps!=null) { 89^g$ ac
ps.clearParameters(); pTG[F
ps.close(); ^.iRU'{
ps=null; bRyxP2
} ym%` l!
}catch(SQLException e){} 1E
/G+pm
DBUtils.closeConnection(conn); qpjZ-[UC
} Um\HX6
} .=Oww
public long getLast(){ A03io8D6
return lastExecuteTime; GvG8s6IZ
} L~{(9J'(
public void run(){ MXfyj5K
long now = System.currentTimeMillis(); @(35I
if ((now - lastExecuteTime) > executeSep) { r>ed/<_>m;
//System.out.print("lastExecuteTime:"+lastExecuteTime); 9v`sSTlSd
//System.out.print(" now:"+now+"\n"); <(@S;?ZEW
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 8Cp@k=
lastExecuteTime=now; Z\`SDC
executeUpdate(); |yO%w #
} >I5Wf/$
else{ VnkhY
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ?xH{7)dO
} wU!-sf;]y
} =|aZNHqH
} (?8i^T?WP=
//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 \1joW#
8)?&eE'
类写好了,下面是在JSP中如下调用。 n0co*
]X+k
x$` lQ%
<% $Z]@N
nA9N
CountBean cb=new CountBean(); [ !#Dba#
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); D!Y@Og.
CountCache.add(cb); ?M&@# lbG
out.print(CountCache.list.size()+"<br>"); c8[kL$b;j
CountControl c=new CountControl(); sV2D:%\K:
c.run(); L5 Cfa-
out.print(CountCache.list.size()+"<br>"); i"iy 0?
%>