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: NLe+
*>Z|!{bI
CountBean.java m){.{Vn]
\bt+46y@]
/* KRS_6G],{
* CountData.java `={s*^Ta
* zNE"5
* Created on 2007年1月1日, 下午4:44 ;().
* *7"R[!9
* To change this template, choose Tools | Options and locate the template under >
,L'A;c}
* the Source Creation and Management node. Right-click the template and choose Oeo:V"
* Open. You can then make changes to the template in the Source Editor. $}d| ~q\
*/ Onr#p4UT
Da)rzr|}>3
package com.tot.count; U
D9&k^
NO4V{}?a
/** xl%!7?G|$>
* lYlU8l5>
* @author stnyJ9
*/ y(pHt
public class CountBean { Ol>"'
private String countType; SrV+Ox
int countId; ;H#'9p ,2
/** Creates a new instance of CountData */ lFWN[`H
public CountBean() {} WZk\mSNV
public void setCountType(String countTypes){ q% Eze
this.countType=countTypes; |Rr^K5hmD
} ?Gq'r2V
public void setCountId(int countIds){ CIt>D'/YT
this.countId=countIds; K\ww,S
} 2Wlk]
public String getCountType(){ 0dKI+zgr
return countType; ^(ks^<}
} VjU;[
public int getCountId(){ $9znRTFEj
return countId; )!1; =
} J@ x%TA
} Sd;/yC 8
0G/VbS
CountCache.java _(J 7^rN
{mPaloA
/* nZ>bOP+,
* CountCache.java (7RxCo=X
* i2{xW`AcUh
* Created on 2007年1月1日, 下午5:01 fP`g#t)4Tu
* /^~3Ib8Fw+
* To change this template, choose Tools | Options and locate the template under } d /5_X
* the Source Creation and Management node. Right-click the template and choose rs01@
* Open. You can then make changes to the template in the Source Editor. ,63hO.4M
*/ q#W|*kL3
7<Fp3N 3
package com.tot.count; pv2_A
import java.util.*; DXlP(={*
/** E3gR%t
* .O[RE_j
* @author `BKo`@
*/ G| pZ
public class CountCache { }$W4aG*[
public static LinkedList list=new LinkedList(); a^qLyF&F
/** Creates a new instance of CountCache */ \Q"o\:IoIT
public CountCache() {} [>"bL$tlo*
public static void add(CountBean cb){ >;',U<Wd
if(cb!=null){ $AAv%v
list.add(cb); ?2VY^7N[
} i^ 9PiP|U
} OYGh!sW
} (yFR;5Fo
@R=gJ:&a
CountControl.java hd~X c
v\*43RL
/* CW k#Amt.
* CountThread.java .3Nd[+[
* -UaUFJa8K&
* Created on 2007年1月1日, 下午4:57 )SZt If
* -|mWi
* To change this template, choose Tools | Options and locate the template under !|`G<WD
* the Source Creation and Management node. Right-click the template and choose ]trVlmZXH}
* Open. You can then make changes to the template in the Source Editor. ReOp,A/y
*/ f[3DKA
;aBK4<-vl
package com.tot.count; `r+"2.z*
import tot.db.DBUtils; 27*u^N*z@
import java.sql.*; PF@+~FI
/** vS-k0g;
* yc5C`r +6
* @author "Mgx5d
*/ >{i/LC^S
public class CountControl{ xwa5dtcng
private static long lastExecuteTime=0;//上次更新时间 ;crQ7}k
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ;bVC7D~~4w
/** Creates a new instance of CountThread */ ig:/60Z
public CountControl() {} ]gYnw;W$
public synchronized void executeUpdate(){ 2Yt#%bj7^
Connection conn=null; \P]w^
PreparedStatement ps=null; Ev;HV}G
try{ }f)$+mi
conn = DBUtils.getConnection(); hoI?,[@F
conn.setAutoCommit(false); J#B%
#X
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); {S(d5o8
for(int i=0;i<CountCache.list.size();i++){ E4RvVfA0F
CountBean cb=(CountBean)CountCache.list.getFirst(); c6sGjZdR
CountCache.list.removeFirst(); zyTP|SXk
ps.setInt(1, cb.getCountId()); pN/)$6=
ps.executeUpdate();⑴ M}NmA
//ps.addBatch();⑵ 0!F"s>(H
} !%x8!;za
//int [] counts = ps.executeBatch();⑶ 9Vz1*4Ln
conn.commit(); h)BRSs?v_D
}catch(Exception e){ Q[^IX
e.printStackTrace(); Dt)\q^bH)
} finally{ {dJC3/Rf
try{ 6>v`6
if(ps!=null) { Vu '/o[nF>
ps.clearParameters(); Pl<r*d)h
ps.close(); 6\ /x
ps=null; ~H/|J^ J
} %3scz)4$
}catch(SQLException e){} naCPSsei
DBUtils.closeConnection(conn); 2bxkZS]
} 'EJ8)2
}
O[f* !
public long getLast(){ Ed ,`1+
return lastExecuteTime; f7 V3 6Q8
} ZzLmsTtzIu
public void run(){ uZ( I|N$
long now = System.currentTimeMillis(); L+Yn}"gIs
if ((now - lastExecuteTime) > executeSep) { ]kq{9b';
//System.out.print("lastExecuteTime:"+lastExecuteTime); a'f"Zdh%w
//System.out.print(" now:"+now+"\n"); mdvooJ
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); LziEF-_
lastExecuteTime=now; ;T~]|#T\6
executeUpdate(); |cStN[97%
} }$3eRu +
else{ 6 ]W!>jDc
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); #k8bZ?*:
} C4],7"Sw
} xRYL{+
} t9SzZ2E
//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 Xu`c_
Mit,X
类写好了,下面是在JSP中如下调用。 V%'`nJ!
pDb5t>
<% 'gk.J
CountBean cb=new CountBean(); B
PTQm4TN
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); PHl{pE*
CountCache.add(cb); &=H{ 36i@
out.print(CountCache.list.size()+"<br>"); w*<XPBi
CountControl c=new CountControl(); NR-d|`P;
c.run(); |t*(]U2O0
out.print(CountCache.list.size()+"<br>"); t
m?[0@<s
%>