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: u~a<Psp&|
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CountBean.java 97<Y.
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/* +O\6p
* CountData.java 1gCp/m2r7
* ' 71D:%p
* Created on 2007年1月1日, 下午4:44 |bB..b
* b\6w[52m
* To change this template, choose Tools | Options and locate the template under MUVp8!*@
* the Source Creation and Management node. Right-click the template and choose s}/YcUK
* Open. You can then make changes to the template in the Source Editor. OG}0{?
*/ E-Cj^#OY|N
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package com.tot.count; ~Dgui/r9J
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/** ^Z2%b>
* cl14FrpYu
* @author =p^*y-z
*/ 2nOQ48haT
public class CountBean { a-8~f8na{(
private String countType; ]Alu~ Dw
int countId; U4^dDj
/** Creates a new instance of CountData */ rK)%n!Z
public CountBean() {} S(/@.gI:f
public void setCountType(String countTypes){ #WfJz}P,!
this.countType=countTypes; $+V{2k4X,
} sF(U?)48
public void setCountId(int countIds){ K;S&91V)=
this.countId=countIds;
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} K Rm4r
public String getCountType(){ >Li
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return countType; r ZGA9duy
} >(d+E\!A
public int getCountId(){ vhKeW(z
return countId; 1~ZDHfd5
} ^c.b@BE
} SE%i@}
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CountCache.java
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/* )lH?XpfTjm
* CountCache.java 5.5dB2w
* ilpg()
* Created on 2007年1月1日, 下午5:01 zg|yW6l)9
* 9;JUc0%
* To change this template, choose Tools | Options and locate the template under "52wa<MVJ
* the Source Creation and Management node. Right-click the template and choose pOw4H67
* Open. You can then make changes to the template in the Source Editor. }]tSWVb*
*/ {s_0[>
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package com.tot.count; Awe\KJ^`
import java.util.*; Auv/w}zrr
/** ?Cmb3pX^\
* !)_5 z<
* @author @{XN}tWDOp
*/ (7-K4j`
public class CountCache { %Sxy!gGz%%
public static LinkedList list=new LinkedList(); \h_hd%'G
/** Creates a new instance of CountCache */ P,tN;c
public CountCache() {} $?I^Dk
public static void add(CountBean cb){ vT3LhN+1
if(cb!=null){ yvNYYp2r
list.add(cb); @WFjM
} aLq=%fsV)
} ZYu^Q6b3
} 0~BQ8O=+mn
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CountControl.java -hhE`Y
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/* SLZv`
* CountThread.java p|Z"<
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* /"Rh
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* Created on 2007年1月1日, 下午4:57 KasOh"W.P
* +Y 3_)
* To change this template, choose Tools | Options and locate the template under 0-FwHDxw
* the Source Creation and Management node. Right-click the template and choose
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* Open. You can then make changes to the template in the Source Editor. ^W#[6]S
*/ 0qJ 3@d
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package com.tot.count; N9{ivq|fO
import tot.db.DBUtils; $+*ZsIo
import java.sql.*; $#"}g#u
/** zz02F+H$Y
* Zad+)~@!tq
* @author | %6B#uy
*/ w&C SE
public class CountControl{ =fG(K!AQ
private static long lastExecuteTime=0;//上次更新时间 :UFf6T?
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 w_A-:S
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/** Creates a new instance of CountThread */ AGrGZ7p]
public CountControl() {} F fl`;M
public synchronized void executeUpdate(){ =>-b?F0(c
Connection conn=null; "fz-h
PreparedStatement ps=null; y~U+MtSf#
try{ n>Zkx+jLj<
conn = DBUtils.getConnection(); =U|J{^ >I
conn.setAutoCommit(false); EKwS~G.b!
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); X(Ef=:
for(int i=0;i<CountCache.list.size();i++){ MY1
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CountBean cb=(CountBean)CountCache.list.getFirst(); u'?t'I
CountCache.list.removeFirst();
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ps.setInt(1, cb.getCountId()); V 9=y@`;
ps.executeUpdate();⑴ w&f29#i;b
//ps.addBatch();⑵ swlxV@NQ
} f
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//int [] counts = ps.executeBatch();⑶ Fi*6ud\n!
conn.commit(); NW!e@;E+i
}catch(Exception e){ Km\M/j|
e.printStackTrace(); !M3IuDN
} finally{ x1A^QIuxO
try{ AO^F6Y/
if(ps!=null) { H]@Zp"7
ps.clearParameters(); (m.]0v*&c
ps.close(); XXe7w3x{
ps=null; (
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} ?nUV3#6{
}catch(SQLException e){} 7"8HlOHA
DBUtils.closeConnection(conn); ]T
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} }yB@?
} h3O5DP6~
public long getLast(){ i_gS!1Z2
return lastExecuteTime; f_;3|i
} Eb{TKz?
public void run(){ SOP=
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long now = System.currentTimeMillis(); <<n8 P5pXt
if ((now - lastExecuteTime) > executeSep) { F!a YK2
//System.out.print("lastExecuteTime:"+lastExecuteTime); ~{+J~5!;<H
//System.out.print(" now:"+now+"\n"); t7)Y@gRy
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); S :(1=@
lastExecuteTime=now; qJISB7F[%O
executeUpdate(); |k?,4
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} [C7:Yg7
else{ Qy4AuMU2
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); @X4;fd
} \6C"bQ
} :Z1_;`>CT
} yd>kJk^~/
//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 Z\dILt:#z
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类写好了,下面是在JSP中如下调用。 Or6'5e?N
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<% 3OM\R%M
CountBean cb=new CountBean(); *?\2Ohp
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); _#N~$
CountCache.add(cb); n,xK7icYNQ
out.print(CountCache.list.size()+"<br>"); 1l1X1
CountControl c=new CountControl(); vLpE|QZ s
c.run(); LU;ma((yy[
out.print(CountCache.list.size()+"<br>"); D(Xv shQ
%>