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: y=!7PB_\|
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CountBean.java n{$! ]^>
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/* L.2!Q3&
* CountData.java ^|%u%UR
* 3!M|Sf<s
* Created on 2007年1月1日, 下午4:44 'C7$,H'
* 70-nAv
* To change this template, choose Tools | Options and locate the template under hh!4DHv
* the Source Creation and Management node. Right-click the template and choose u+
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* Open. You can then make changes to the template in the Source Editor. Z\r?>2
*/ zb3,2D+P
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package com.tot.count; G4rd<V0[D
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/** " %
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* $+|.
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* @author +I3j2u8L
*/ i0nu5kD+d
public class CountBean { nT
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private String countType; W#&BU-|2
int countId; &yRR!1n)H
/** Creates a new instance of CountData */ ?U+nR/H:6
public CountBean() {} Fe1XczB
public void setCountType(String countTypes){ !?)aZ |r
this.countType=countTypes; )LAG$Cn
} qh|fq
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public void setCountId(int countIds){ `ztp u
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this.countId=countIds; m<sCRWa-
} X2T_}{
public String getCountType(){ i&KBMx
return countType; ;;S9kNp^v
} }Qa
public int getCountId(){ jr(|-!RVMN
return countId; KwNOB _
} ?{L5=X@$$
} s2`} ~
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CountCache.java "m>BE
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/* Qe =8x7oIP
* CountCache.java kho$At)V
* ;b}cn!U]
* Created on 2007年1月1日, 下午5:01 7jw5'`;)"
* !i_~<6Wa7
* To change this template, choose Tools | Options and locate the template under %/2OP &1<
* the Source Creation and Management node. Right-click the template and choose l?A~^4(5a/
* Open. You can then make changes to the template in the Source Editor. []doLt;J
*/ `-MCI)Fq_R
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package com.tot.count; y[ZVi5) ,
import java.util.*; ,zEPdhTX
/** r:M0#
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* &r+!rL Kp
* @author *4/KK
*/ cx[[K.
public class CountCache { i0u`J
public static LinkedList list=new LinkedList(); ):\+%v^
/** Creates a new instance of CountCache */ 5?A<('2
public CountCache() {} `(r0+Qx
public static void add(CountBean cb){ #+H3b!8=
if(cb!=null){ :w]NN\
list.add(cb); v}\Fbe
} T|p%4hH
} r 6&+pSA>
} 1 F&}e&}c
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CountControl.java $F1Am%
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/* X4L@|"ZI
* CountThread.java @"B{k%+
* ~x[(1
* Created on 2007年1月1日, 下午4:57 GL _hRu
* 0v#p4@Z
* To change this template, choose Tools | Options and locate the template under /IlO
* the Source Creation and Management node. Right-click the template and choose _FU}IfG>t
* Open. You can then make changes to the template in the Source Editor. -Un"z6*
*/ uqVarRi$
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package com.tot.count;
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import tot.db.DBUtils; g 'Wr+(A_
import java.sql.*; Z5g*'
/** MO?
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* _q4Yq'dI
* @author Fr-Vq=j&
*/ k(xB%>ns
public class CountControl{ W6RjQ1
private static long lastExecuteTime=0;//上次更新时间 {8 &=t8,c
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 dkW7k^g
/** Creates a new instance of CountThread */ pgW^hj\
public CountControl() {} (Vn3g ra
public synchronized void executeUpdate(){ P'<j<h6
Connection conn=null; nt@uVwfQ
PreparedStatement ps=null; N;DE,[:<
try{ G^Y^)pc]
conn = DBUtils.getConnection(); )LsUO#%DO
conn.setAutoCommit(false); %!DTq`F
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); e0]#vqdO
for(int i=0;i<CountCache.list.size();i++){ JLjb'Bn
CountBean cb=(CountBean)CountCache.list.getFirst(); WpOH1[8v
CountCache.list.removeFirst(); g][n1$%
ps.setInt(1, cb.getCountId()); vsPIvW!V
ps.executeUpdate();⑴ 2*V]jO
//ps.addBatch();⑵ !?sB=qo
} Vh^ :.y
//int [] counts = ps.executeBatch();⑶ qoZe<jW (
conn.commit(); ;I6C`N
}catch(Exception e){ #%pY,AK:=
e.printStackTrace(); y4VO\N!
} finally{ VtMnLFMw
try{ $
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if(ps!=null) { r?|(t?
ps.clearParameters(); g-H,*^g+
ps.close(); W)^%/lAh
ps=null; %0({MU
} :UX8^+bfZ
}catch(SQLException e){} *,)1Dcv(
DBUtils.closeConnection(conn); {{)pb>E
} &XW~l>!+
} 5=fS^]- F
public long getLast(){ WR u/7$8
return lastExecuteTime; D&=+PAX
} nm)/BK
public void run(){ JEK_W<BD
long now = System.currentTimeMillis(); <<V"4 C2
if ((now - lastExecuteTime) > executeSep) { qiq=v)
//System.out.print("lastExecuteTime:"+lastExecuteTime); O|+$9#,
//System.out.print(" now:"+now+"\n"); 0b<Qs88yd>
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); F0"("4h:
lastExecuteTime=now; a'?LC)^
executeUpdate(); UR(i_T&w
} c[;A$P=
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else{ xiL+s-
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 'Hgk$Im+
} /`t}5U>S_
} S_^;#=_c
} brK7|&R<
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 b&]z^_m)
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类写好了,下面是在JSP中如下调用。 *^XMf
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<% 1/syzHjbY
CountBean cb=new CountBean(); _n4_;0
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); i2-]Xl
CountCache.add(cb); =4L%A=]`
out.print(CountCache.list.size()+"<br>"); `-Tb=o}.
CountControl c=new CountControl(); />uE)R$
c.run(); /7ShE-.5#
out.print(CountCache.list.size()+"<br>"); F&Rr&m
%>