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: }A@op+0E
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CountBean.java )HPt(Ck
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/* ILsw'
* CountData.java tYE\tbCO'
* !/pE6)a
* Created on 2007年1月1日, 下午4:44 t?&
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* E3IB> f
* To change this template, choose Tools | Options and locate the template under S!*wK-
* the Source Creation and Management node. Right-click the template and choose yht|0mZV
* Open. You can then make changes to the template in the Source Editor. ')ZM#
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*/ D[d+lq#p
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package com.tot.count; 6I,^4U
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/** <[7
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* _ ^5w f
* @author Qrr8i:Y^
*/ tPDd~fOk
public class CountBean { _T,X z_
private String countType; t[L0kF9en
int countId; Yvky=RM
/** Creates a new instance of CountData */ fTn
public CountBean() {} eC+S'Jgf
public void setCountType(String countTypes){ U-uBz4Gha
this.countType=countTypes; %`r Z]^H
} \>}G|yL
public void setCountId(int countIds){ TL%2?'G
this.countId=countIds; Bismd21F6=
} e;QPn(
public String getCountType(){ LEnm6
return countType; 5v&mK 5zZ
} lPA:aHcj
public int getCountId(){ 8t{-
return countId; 6pyLb3[e
} '`.bmiM
} &YAw~1A
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CountCache.java Yo`#G-]
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/* ~N2<-~=si
* CountCache.java _0Mt*]L }
* p-p]dV
* Created on 2007年1月1日, 下午5:01 $9_yD&&
* 7WuhYJbf
* To change this template, choose Tools | Options and locate the template under HvhP9_MB
* the Source Creation and Management node. Right-click the template and choose $JH_
* Open. You can then make changes to the template in the Source Editor. #0yU
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*/ }E?{M~"<
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package com.tot.count; y'gIx*6B@
import java.util.*; nq9|cS%-
/** }jF67c->
* Ni"M.O);t
* @author eVDO]5?
*/ "qb1jv#to
public class CountCache { "RZVv~BD
public static LinkedList list=new LinkedList(); >5,nB<
/** Creates a new instance of CountCache */ F(?A7
public CountCache() {} n*7Ytz3#'
public static void add(CountBean cb){ x>Hg.%/c[
if(cb!=null){ ^Q)&lxlxpx
list.add(cb); <,r(^Ntz
} G}MJWf Hl
} l$j/Ye]
} 5~AK+6Za
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CountControl.java Rh%c<</`0s
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/* W{z7h[?5,
* CountThread.java A^ :/*
* 5e> <i
* Created on 2007年1月1日, 下午4:57 !G`7T
* I-=H;6w7
* To change this template, choose Tools | Options and locate the template under BQ\o?={
* the Source Creation and Management node. Right-click the template and choose L.5 /wg
* Open. You can then make changes to the template in the Source Editor. V(-=@UW
*/
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package com.tot.count; (5-4`:1ux
import tot.db.DBUtils; 5Z2tTw'i
import java.sql.*; O@$wU9D<
/** ]!v:xjzT
* @vy{Q7aM
* @author w_O3];
*/ ynWF Y<VX
public class CountControl{ d nZA+Pa
private static long lastExecuteTime=0;//上次更新时间 y.pwj~s
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 $)V_oQSqn
/** Creates a new instance of CountThread */ ,qo"i7c{:
public CountControl() {} hcQky/c\#b
public synchronized void executeUpdate(){ ,5tW|=0@
Connection conn=null; ?3X(`:KB
PreparedStatement ps=null; JjD'2"z
try{ 1Wz -Z
conn = DBUtils.getConnection(); Rn"Raq7Cn*
conn.setAutoCommit(false); s]D&):
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); [;rty<Z^b
for(int i=0;i<CountCache.list.size();i++){ nPAVrDg
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CountBean cb=(CountBean)CountCache.list.getFirst(); SHc<`M'+
CountCache.list.removeFirst(); #osP"~{
ps.setInt(1, cb.getCountId()); z2EZ0vZ
ps.executeUpdate();⑴ -d|Q|zF^x
//ps.addBatch();⑵ 3hN.`G-E
} ^xBF$ua37)
//int [] counts = ps.executeBatch();⑶ 7Nw}
}
conn.commit(); v>e%5[F
}catch(Exception e){ tC4:cX
e.printStackTrace(); `^mPq?f
} finally{ mBp3_E.t
try{ PNjZbOmzS
if(ps!=null) { sYt\3/yL'
ps.clearParameters(); n0/H2>I[
ps.close(); =th(Hdk17
ps=null; -AJ$-y
} 0`{3|g
}catch(SQLException e){} dKKh ^D`~
DBUtils.closeConnection(conn); Z9TUaMhF
} .Mn+Bd4f
} eM3-S=R?<g
public long getLast(){ I04GQql
return lastExecuteTime; 4| 6<nk_
} }D/O cp~o
public void run(){ UJ}Xa&*H\
long now = System.currentTimeMillis(); 7K*\F}2)q
if ((now - lastExecuteTime) > executeSep) { QA=G+1x
//System.out.print("lastExecuteTime:"+lastExecuteTime); N2 vA/
//System.out.print(" now:"+now+"\n"); FEd We\E
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); {iz,iv/U
lastExecuteTime=now; AK7IPftlH
executeUpdate(); T7wy{;
} Lc0U-!{G
else{ v#HaZT]u
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); hkK+BmMj\
} hI&ugdf
} 2+Y8b::
} M;14s*g
//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 *{ =5AW}o
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类写好了,下面是在JSP中如下调用。 $p(,Qz(.8
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<% G>3]A5
CountBean cb=new CountBean(); p1-bq:
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); @[:JQ'R=
CountCache.add(cb); u{H'evv0O
out.print(CountCache.list.size()+"<br>"); =p1aF/1$I
CountControl c=new CountControl(); zF%'~S0{
c.run(); Ql%0%naq1
out.print(CountCache.list.size()+"<br>"); h{$mL#J
%>