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: S6|L !pO
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CountBean.java dO[pm0
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/* 6[C>"s}Ol
* CountData.java |Z{
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* q;qY#wD@
* Created on 2007年1月1日, 下午4:44 JiHk`e`
* n@| &jh
* To change this template, choose Tools | Options and locate the template under D5fhOq+g
* the Source Creation and Management node. Right-click the template and choose i<uk}
* Open. You can then make changes to the template in the Source Editor. I/w=!Ih
*/ pS<j>y
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package com.tot.count; 0VlB7oF
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/** VTJ,;p_UH
* %y2i1^
* @author {
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*/ 8#~x6\!b
public class CountBean { pr"~W8
private String countType; <-a6'g2y
int countId; -MH~1Tw6Z
/** Creates a new instance of CountData */ =5X(RGK
public CountBean() {} w}QU;rl8q
public void setCountType(String countTypes){ VZ$FTM^b8
this.countType=countTypes; w^aI1M50
} Mhj.3nN
public void setCountId(int countIds){ km#Rh^
this.countId=countIds; ye1hcQ
} "':u#UdS
public String getCountType(){ _,9/g^<
return countType; 6`hHx=L
} R4g% $}
public int getCountId(){ zJa,kN|m
return countId; n g?kl|VG
} Lr`G. e
} M%Dv-D{
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CountCache.java xp"5L8:C
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/* mg7Q~SLL{
* CountCache.java Hb{G
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* 4XL]~3 c
* Created on 2007年1月1日, 下午5:01 ZQPv@6+oY
* X`FFI6pb
* To change this template, choose Tools | Options and locate the template under /MQI5Djg
* the Source Creation and Management node. Right-click the template and choose LZG~1tf
* Open. You can then make changes to the template in the Source Editor. #}{1>g{sXt
*/ _3?7iH
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package com.tot.count; ZI'Mr:z4
import java.util.*; A#B6]j)
/** ~kAen
* XT
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* @author MX{p)(HW
*/ ir*T,O
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public class CountCache { H+ Y+8
public static LinkedList list=new LinkedList(); n9Xs sl0
/** Creates a new instance of CountCache */ Kn<z<>vO
public CountCache() {} vg/:q>o
public static void add(CountBean cb){ rG|*74Q]
if(cb!=null){ b!Z-HL6
list.add(cb); ,|
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} =W~K_jE5lo
} w %sHA
} /_G^d1T1?L
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CountControl.java qhiO( !jK
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/* d,9YrwbD
* CountThread.java )cX6o[oia
* =5sUpPV(
* Created on 2007年1月1日, 下午4:57 tu6Q7CjW8
* Q]}aZ4L
* To change this template, choose Tools | Options and locate the template under #YMU}4=:
* the Source Creation and Management node. Right-click the template and choose N6BFs(
* Open. You can then make changes to the template in the Source Editor. J~[A8o
*/ dkRG4
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package com.tot.count; 4d*=gy%
import tot.db.DBUtils; Jj$N3UCg7
import java.sql.*; ch%-Cg~%
/** >b.wk3g@>
* 6mi:%)"
* @author c_xo6+:l
*/ elBmF#,j7
public class CountControl{ _g(4-\
private static long lastExecuteTime=0;//上次更新时间 YQI&8~z
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 T]%:+_,
/** Creates a new instance of CountThread */ ,\BGxGNAmV
public CountControl() {} XfXqq[\N
public synchronized void executeUpdate(){ Iw0Q1bK(
Connection conn=null; StP7t
PreparedStatement ps=null; {)QSxO
try{ *MEDV1l_T
conn = DBUtils.getConnection(); 7EKQE>xj
conn.setAutoCommit(false); ? }2]G'7?
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ^&W(|R-,J&
for(int i=0;i<CountCache.list.size();i++){ {u}Lhv
CountBean cb=(CountBean)CountCache.list.getFirst(); >6(91J
CountCache.list.removeFirst(); P7Ws$7x
ps.setInt(1, cb.getCountId()); |hprk-R*OH
ps.executeUpdate();⑴ k2xOu9ncEj
//ps.addBatch();⑵ '}D$"2I*
} ^=nJ,-(h_
//int [] counts = ps.executeBatch();⑶ iS{8cN3R
conn.commit(); y:N
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}catch(Exception e){ D:gskK+o6M
e.printStackTrace(); ,
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} finally{ ;@$B{/Q
try{ %y/8i%@6
if(ps!=null) { ]oN:MS4r
ps.clearParameters();
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ps.close(); p -=+i
ps=null; |X6]#&g7
} xsq+RBJi
}catch(SQLException e){} s4RqMO5eI
DBUtils.closeConnection(conn); ^uu)|
} `&"-|
} :Qg3B ';
public long getLast(){ 0"~`U.k~M
return lastExecuteTime; fBptjt_
} (P-Bmu!s
public void run(){ {:VUu?5-t;
long now = System.currentTimeMillis(); v}v! hs Q
if ((now - lastExecuteTime) > executeSep) { 4&Uq\,nx
//System.out.print("lastExecuteTime:"+lastExecuteTime); AiT&:'<UT
//System.out.print(" now:"+now+"\n"); (1r.AG`g
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); L+}q !'8S
lastExecuteTime=now; ptS1d$
executeUpdate(); )vFJx[a<n`
} wj fk >
else{ pr2b<(Pm
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); p=Nord
} ubn`w=w$
} 3%<Uq%pJ
} L,&R0gxi
//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 LV'@JFT-
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1
类写好了,下面是在JSP中如下调用。 ^ $M@yWX6
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<% K; 7o+Xr
CountBean cb=new CountBean(); K +oFu%
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); S
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CountCache.add(cb); ,7mRb-*p
out.print(CountCache.list.size()+"<br>"); (Yzy;"iAu
CountControl c=new CountControl(); &^C<J
c.run(); :GU6v4u
out.print(CountCache.list.size()+"<br>"); edh?I1/
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