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: `r?xo7
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CountBean.java %#5yC|o9Pn
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/* SvE3E$*
* CountData.java !$}:4}56F
* <UI^~Azc#
* Created on 2007年1月1日, 下午4:44 |]s/NNU
* ]Dj,8tf`H
* To change this template, choose Tools | Options and locate the template under AunX[X9
* the Source Creation and Management node. Right-click the template and choose #m
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* Open. You can then make changes to the template in the Source Editor. S.G"*'N
*/ _Z9HOl@
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package com.tot.count; B{x`^3qR
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/** LBO3){=J
* cOz8YVR-
* @author ~=xiMB;oH
*/ W@"s~I6
public class CountBean { Fog4m=b`g
private String countType; "gaurr3
int countId; $hND!T+;
/** Creates a new instance of CountData */ 'IVNqfC)u
public CountBean() {} .K
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public void setCountType(String countTypes){ "}"hQ.kAz
this.countType=countTypes; [w>T.b
} Wd9y8z;
public void setCountId(int countIds){ OPi><8x
this.countId=countIds; 2L\}
} t(d$v_*y51
public String getCountType(){ g7Xjo )
return countType; "$@>n(w
} x?5D>M/Y
public int getCountId(){ {Y0Uln5u
return countId; F?h{IH
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} {0~ Sj%Ze
} >"Tivc5
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CountCache.java S}mZU!
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/* 3
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* CountCache.java ]'
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* S_ELZO#7
* Created on 2007年1月1日, 下午5:01 ^a ,Oi%
* 3mmp5 d
* To change this template, choose Tools | Options and locate the template under } vx+/J
* the Source Creation and Management node. Right-click the template and choose fLGZ@-qA0
* Open. You can then make changes to the template in the Source Editor. i!AFXVX
*/ WR5@S&fU`
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package com.tot.count; _BC%98:WP
import java.util.*; Ln&'5D#
/** )\xDo<@
* >0^oC[ B
* @author \:7G1_o
*/ ~OdE!!
public class CountCache { -MA/:EB
public static LinkedList list=new LinkedList(); 9V ]{q
/** Creates a new instance of CountCache */ Vn7FbaO^
public CountCache() {} O1C|{
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public static void add(CountBean cb){ *#{V^}
if(cb!=null){ 9n\b!*x
list.add(cb); u;@~P
} s2IjZF {
} M&93TQU-
} -a^%9 U
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CountControl.java LtJl\m.th
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/* \ytF@"7
* CountThread.java F\K&$5J{p
* t@ _MWF
* Created on 2007年1月1日, 下午4:57 5*~]=(BE
* cN{(XmX5n
* To change this template, choose Tools | Options and locate the template under 7{"urs7 T
* the Source Creation and Management node. Right-click the template and choose 3zr95$Mt
* Open. You can then make changes to the template in the Source Editor. t9C.|6X
*/ vJ&g3ky
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package com.tot.count; |(evDS5
import tot.db.DBUtils; F]fBFDk
import java.sql.*; .m;5s45O{
/** @N(*1,s2
* NQ9/,M
* @author [9-&Lq_ g
*/ M15jwR!:M
public class CountControl{ >GV(\In
private static long lastExecuteTime=0;//上次更新时间 )qq5WShMJ
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 !e<D2><^
/** Creates a new instance of CountThread */ .+.'TY--
public CountControl() {} 8lNkY`P7s
public synchronized void executeUpdate(){ /Wx({N'h$
Connection conn=null; Kw/7X[|'G
PreparedStatement ps=null; %}`zq8Q;
try{ P{2ue`w[
conn = DBUtils.getConnection(); 1:.I0x!
conn.setAutoCommit(false); ~uUN\qx52
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); QTC-W2t]
for(int i=0;i<CountCache.list.size();i++){ Ra!Br6
CountBean cb=(CountBean)CountCache.list.getFirst(); D_)i%k\
CountCache.list.removeFirst(); Yg~$1b@
ps.setInt(1, cb.getCountId()); A.8[FkiNmD
ps.executeUpdate();⑴ *)8!~Hs
//ps.addBatch();⑵ 4?u<i=i
} w4<n=k
//int [] counts = ps.executeBatch();⑶ w>TlM*3D/
conn.commit(); ]b+Nsr~
}catch(Exception e){ Szb#:C
e.printStackTrace(); 2jT2~D.U1
} finally{ grs~<n|o\
try{ U3 -cH
if(ps!=null) { CGp7 Tx #
ps.clearParameters(); )%(V.?eW
ps.close(); Q7{/ T0
ps=null; X<8
} mne?r3d
}catch(SQLException e){} O]1aez[
DBUtils.closeConnection(conn); -Uj3?W
} x("V+y*
} 1SwKd*aRR?
public long getLast(){ xNAa,aMM
return lastExecuteTime; K}feS(Ji
} S=^kR [O"
public void run(){ ?c6`p3p3L
long now = System.currentTimeMillis(); \@eaSa
if ((now - lastExecuteTime) > executeSep) { /=i+7^
//System.out.print("lastExecuteTime:"+lastExecuteTime); />13?o#
//System.out.print(" now:"+now+"\n"); 2 {I(A2
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); "C~Zl&3
lastExecuteTime=now; <J
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executeUpdate(); ],l}J'.8<V
} |z
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else{ >u0B ~9_E
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); qF? n&>YG
} 6");NHE
} <l`xP)] X
} _@/nc:)H
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 p_:bt7
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类写好了,下面是在JSP中如下调用。 1:j[p=Q&
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<% b9L"?{
CountBean cb=new CountBean(); 9l&4mt;+&<
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); I$Ra*r
CountCache.add(cb); SKdh!*G
out.print(CountCache.list.size()+"<br>"); c*N>7IF,
CountControl c=new CountControl(); XPfheV G
c.run(); ')82a49eA
out.print(CountCache.list.size()+"<br>"); J};=)xLX;
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