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: |,3>A@
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CountBean.java .l| [e
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/* e7m>p\"
* CountData.java l EcZ/
* iP7
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* Created on 2007年1月1日, 下午4:44 ne]P -50
* gRnn}LL^
* To change this template, choose Tools | Options and locate the template under pO^PkX
* the Source Creation and Management node. Right-click the template and choose )w?DB@Tx
* Open. You can then make changes to the template in the Source Editor. /s@t-gTi
*/ ae1?8man
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package com.tot.count; @/MI
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/** (=2-*((&(A
* hA6
* @author `D44I;e^1;
*/ -6Y@_N
public class CountBean { YUzx,Y>k
private String countType; ''bh{
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int countId; -0QoVGw
/** Creates a new instance of CountData */ iyA=d{S;V
public CountBean() {} InO;DA\
public void setCountType(String countTypes){ iS p +~
this.countType=countTypes; @U8}K#
} %^bHQB%
public void setCountId(int countIds){ `fnU p-
this.countId=countIds; O$qxo
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} VjI=5)+~
public String getCountType(){ SmpYH@
return countType; J?wCqA
} x0KW\<k
public int getCountId(){ j8cIpbp8x
return countId; r}**^"mFy
} e(=() :4is
} wtl3Ex,DO
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CountCache.java a2!U9->!
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/* L@5j? N?F
* CountCache.java @%'1Jd7-Wp
* ^xyU*A}D
* Created on 2007年1月1日, 下午5:01 )>=!</@
* yTxrbE
* To change this template, choose Tools | Options and locate the template under r|_@S[hZg
* the Source Creation and Management node. Right-click the template and choose }T5
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* Open. You can then make changes to the template in the Source Editor. P=[_W;->}
*/ RoFOjCc>D.
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package com.tot.count; {;L,|(o^
import java.util.*; O"GuVC}B
/** f:K>o.
* BXb=NE
* @author l(y,lK=YP1
*/ n)Z u>
public class CountCache { 45,): U5
public static LinkedList list=new LinkedList(); 2dyS_2u
/** Creates a new instance of CountCache */ eJ%b"H!
public CountCache() {} !X[P)/?b0+
public static void add(CountBean cb){ -d. i4X3j
if(cb!=null){ *x &
list.add(cb); 64L;np>
} iG ,z3/~v
} oF~+L3&X
} WM;5/;bB
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CountControl.java p9E/#U8A_
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/* .0rTk$B
* CountThread.java n)j0h-
* sVpET
* Created on 2007年1月1日, 下午4:57 v:P=t2q
* S"t\LB*'Ls
* To change this template, choose Tools | Options and locate the template under jqj4(J@%yr
* the Source Creation and Management node. Right-click the template and choose o%,?v
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* Open. You can then make changes to the template in the Source Editor. AQ?;UDqU
*/ r1Hh @sxn
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package com.tot.count; oj[~H}>
import tot.db.DBUtils; (hBph+
import java.sql.*; EOZ 6F-':
/** Na4O( d`
* 8`wKq6
* @author 9q+W>wt
*/ +w7U7"
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public class CountControl{ ts%
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private static long lastExecuteTime=0;//上次更新时间 P+Gz'
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 -G~/ GO
/** Creates a new instance of CountThread */ `-e9#diQe
public CountControl() {} ^We}i
public synchronized void executeUpdate(){ PJ4/E
Connection conn=null; F!phTu
PreparedStatement ps=null; <d"nz:e
try{ ?lfyC/
conn = DBUtils.getConnection(); KLW>O_+
conn.setAutoCommit(false); =''WA:,=h
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); k~Q
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for(int i=0;i<CountCache.list.size();i++){ [y}h
CountBean cb=(CountBean)CountCache.list.getFirst(); Hj(K*z
CountCache.list.removeFirst(); 4x}U+1B
ps.setInt(1, cb.getCountId()); t%G.i@{pkp
ps.executeUpdate();⑴ (7N!Jvg9
//ps.addBatch();⑵ 5]up%.
} ce#Iu#qT
//int [] counts = ps.executeBatch();⑶ G'u[0>
conn.commit(); *];QPi~
}catch(Exception e){ Tr s2M+r)
e.printStackTrace(); mQ<4(qd)
} finally{ ul~6zBKO
try{ `d^Q!QxE
if(ps!=null) { \NMqlxp2
ps.clearParameters(); D/Ok
ps.close(); pdR\Ne0P*
ps=null; k\qFWFR
} 4`)r1D!U
}catch(SQLException e){} f^*Yqa
DBUtils.closeConnection(conn); >e&
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} DQ3L=
} ]{#=WTp]
public long getLast(){ cD6 ^7QF
return lastExecuteTime; ]Ml
} cfilH"EK
public void run(){ {d*OJ/4
long now = System.currentTimeMillis(); e ><0crb
if ((now - lastExecuteTime) > executeSep) { n42\ty9
//System.out.print("lastExecuteTime:"+lastExecuteTime); ^\Z+Xq1~/
//System.out.print(" now:"+now+"\n"); q4Wr$T$gs=
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); qbD
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lastExecuteTime=now; 1++g@8
executeUpdate(); U;WwEta ]
} >W8"Ar
else{ I/O/*^T
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); tuIZYp8tIN
} Pf;OYWST
} g\aO::
} $(1t~u<17
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 :5kDc"
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类写好了,下面是在JSP中如下调用。 4H8r[
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<% *bK=<{d1P
CountBean cb=new CountBean(); (kL"*y/"p
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); &8VH m?h
CountCache.add(cb); X9*n[ev
out.print(CountCache.list.size()+"<br>"); =ejcP&-V/
CountControl c=new CountControl(); >N^<Q4%2
c.run(); .][yH[F
out.print(CountCache.list.size()+"<br>"); o$@/@r
%>