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: /eNDv(g)M
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CountBean.java 1QJB4|5R#
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/* d0 qc%.s
* CountData.java ^A' Bghy
* ;J&9l
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* Created on 2007年1月1日, 下午4:44 <A@qN95m
* Ul%D}(,
* To change this template, choose Tools | Options and locate the template under '(!U5j
* the Source Creation and Management node. Right-click the template and choose ;iTZzmB
* Open. You can then make changes to the template in the Source Editor. 19 <Lgr
*/ +N:=|u.g
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package com.tot.count; LQ3J$N
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/** ^P}c0}^
* NG?- dkD
* @author
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*/ )ME'qA3K
public class CountBean { .l}oxWWoS
private String countType; "E}38
int countId; l"app]uVZ
/** Creates a new instance of CountData */ C}8 3t~Q
public CountBean() {} k~HS_b*]d
public void setCountType(String countTypes){ hz*H,E!>
this.countType=countTypes;
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} 7o4B1YD
public void setCountId(int countIds){ pA?2UZ
this.countId=countIds; w~l%xiC
} @]xHt&j
public String getCountType(){ drK &
return countType; @'fWS^ ;&
} MZK%IC>
public int getCountId(){ _W^{,*p
return countId; 0;avWa)Q
} 8KyF0r?
} 5;_&C=[
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CountCache.java `;\~$^sj}
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/* lz88//@gZ
* CountCache.java fs;pX/:FR
* 4NxI:d$&*
* Created on 2007年1月1日, 下午5:01 %% A==_b
* *e}1KcJ
* To change this template, choose Tools | Options and locate the template under u[~= a5:4
* the Source Creation and Management node. Right-click the template and choose jpRC6b?
* Open. You can then make changes to the template in the Source Editor. AxZaV;%*
*/ 3}ATt".
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package com.tot.count; CGY,I
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import java.util.*; #8;#)q_[u
/** 85 <%L:EC
* /Ym!%11`
* @author [&h%T;!Qii
*/ g&`[r6B
public class CountCache { :elTqw>pn
public static LinkedList list=new LinkedList(); kQQhZ8Ch
/** Creates a new instance of CountCache */ /Vy,6:$H3
public CountCache() {} 0FG|s#Ig
public static void add(CountBean cb){ Fooa~C"
if(cb!=null){ 'ghwc:Og|%
list.add(cb); MR-cO Pn
} =VOl
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} UVj1nom
} + 3%i7
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CountControl.java %^
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/* JDj^7\`
* CountThread.java $3D#U^7i
* f%cbBx^;
* Created on 2007年1月1日, 下午4:57 5B,HJax
* [>wvVv
* To change this template, choose Tools | Options and locate the template under 5x1_rjP$|
* the Source Creation and Management node. Right-click the template and choose Aa`'g0wmc
* Open. You can then make changes to the template in the Source Editor. JTI 'W
*/ 19#A7
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package com.tot.count; k}$k6Sr"
import tot.db.DBUtils; l5fF.A7TT
import java.sql.*; nk^-+olm
/** n,.t~
* k%fy
* @author vB;$AFh{
*/ }}MZgm~U)
public class CountControl{ ct-;L' a
private static long lastExecuteTime=0;//上次更新时间 ("-`Y'"K
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 nps"nggk
/** Creates a new instance of CountThread */ QQIU5
public CountControl() {} :dkBr@u96O
public synchronized void executeUpdate(){ k>mqKzT0$+
Connection conn=null; ;OD+6@Sr
PreparedStatement ps=null; SF?s^
try{ 3&ES?MyB#
conn = DBUtils.getConnection(); ]`GDZw`
conn.setAutoCommit(false); *, RxOz2=
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); Oxq} dX7S
for(int i=0;i<CountCache.list.size();i++){ * Qe{CE
CountBean cb=(CountBean)CountCache.list.getFirst(); [[8.Xb
CountCache.list.removeFirst(); r(ufyC&
ps.setInt(1, cb.getCountId()); elzKtVw
ps.executeUpdate();⑴ 2-!n+#Cdf
//ps.addBatch();⑵ X"p p l7o
} |y~un9j+
//int [] counts = ps.executeBatch();⑶ `p{,C`g,R
conn.commit(); N>3X! K
}catch(Exception e){ 6A \Z221E
e.printStackTrace(); Isna
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} finally{ AiE\PMF~{P
try{ %zA$+eT
if(ps!=null) { _mSQ>BBRl
ps.clearParameters(); S+Vsy(
ps.close(); Yiy|^j
ps=null; I'%(f@u~
} D"RxI)"HP
}catch(SQLException e){} ~A =?_ 5kJ
DBUtils.closeConnection(conn); 5xF R7%_&
} 'YUx&FcM
} sM8 AORd
public long getLast(){ k9iXVYQ.;r
return lastExecuteTime; baL-~`(T
} y/}ENUGR
public void run(){ {po f=G
long now = System.currentTimeMillis(); y$^.HI02jP
if ((now - lastExecuteTime) > executeSep) { b/g"ws_
//System.out.print("lastExecuteTime:"+lastExecuteTime); l5bd);Ltq
//System.out.print(" now:"+now+"\n"); ^vH3 -A;*
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ?
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lastExecuteTime=now; b$Ch2Qz0q
executeUpdate(); 6a\YD{D] _
} dxI t.h
else{ eg
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//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); _$Hx:^p:
} &?@5G
} wBK%=7
} uRu)iBd D
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 M$Of.
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类写好了,下面是在JSP中如下调用。 ;4 rTm@6
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<% |+0XO?,sZ
CountBean cb=new CountBean(); F&I ;E i
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); .0zNt
CountCache.add(cb); "p{cz(
out.print(CountCache.list.size()+"<br>"); _hb@O2f
CountControl c=new CountControl(); zxr|:KC ?&
c.run(); t% f6P
out.print(CountCache.list.size()+"<br>"); wWNHZv&
%>