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: SY>i@s+ML
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CountBean.java )Q9m,/F
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/* `4__X;
* CountData.java Ac'[(
* ~4y&]:I
* Created on 2007年1月1日, 下午4:44 evNo(U\C
* $cEl6(66iX
* To change this template, choose Tools | Options and locate the template under m5Q,RwJ!xK
* the Source Creation and Management node. Right-click the template and choose H !Z=}>TN
* Open. You can then make changes to the template in the Source Editor. uQazUFw
*/ sufidi
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package com.tot.count; rCi7q]_
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/** ]+;1)
* LvgNdVJDP|
* @author %l%5Q;t
*/ ce th )Xm
public class CountBean { u"XqWLTV
private String countType; 0"7xCx
int countId; }NW^?37
/** Creates a new instance of CountData */ -FV$Sne
public CountBean() {} _+YCwg
public void setCountType(String countTypes){ $r)+7i
this.countType=countTypes; eBX#^
} MEMD8:['
public void setCountId(int countIds){ '#gd19#
this.countId=countIds; h\".TySz
} 7yo/sb9h
public String getCountType(){ SO%x=W
return countType; 9~98v;Z1
} eWzD'3h^
public int getCountId(){ &S}%)g%Iv9
return countId; yG|^-O}L
} R}njFQvS)
}
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CountCache.java </F@5*
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/* nlJ~Q_E(
* CountCache.java ^N}zePy0
* /3->TS
* Created on 2007年1月1日, 下午5:01 h1@|UxaE#
* .r[b!o^VR
* To change this template, choose Tools | Options and locate the template under c=]qUhnH
* the Source Creation and Management node. Right-click the template and choose sKYb&2wJ
* Open. You can then make changes to the template in the Source Editor. @r4ZN6Wn
*/ S'M=P_-7
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package com.tot.count; HPl!r0 h
import java.util.*; YY-{&+,
/** }YJ(|z""
* Z&FC:4!!
* @author ^{&Vv(~!Q
*/ +g,:!5pg
public class CountCache { 1;cV [&3
public static LinkedList list=new LinkedList(); ._@Scd
/** Creates a new instance of CountCache */ 6OR5zXpk
public CountCache() {} Li~(kw3
public static void add(CountBean cb){ fD+'{ivN4
if(cb!=null){ TY~8`+bJ
list.add(cb); {wMw$Fvf
} 92_F8y*D
} pFi.?|6"
} V\^rs41$;
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CountControl.java e^kccz2f
)1ia;6}
/* h-
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* CountThread.java 2|]$hjs
*
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* Created on 2007年1月1日, 下午4:57 f`'? 2
* =H6"\`W
* To change this template, choose Tools | Options and locate the template under ^$qr6+
* the Source Creation and Management node. Right-click the template and choose v#*9rNEj0
* Open. You can then make changes to the template in the Source Editor. ]-"~?
*/ %,f|H :+>u
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package com.tot.count; Dyv 6K_,
import tot.db.DBUtils; gTWl];xja
import java.sql.*; +c4]}9f!
/** ZN>oz@jY
* ?"f\"N
* @author B:S/
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*/ O="#yE)
public class CountControl{ &LM@_P"T
private static long lastExecuteTime=0;//上次更新时间 ;;rEv5 /
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 rX*4$d0
/** Creates a new instance of CountThread */ =Q|_v}
public CountControl() {} rFJ(t7\9h
public synchronized void executeUpdate(){ v`3q0,,
Connection conn=null; 5BKga1Q
PreparedStatement ps=null; p12'^i |
try{ ut
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conn = DBUtils.getConnection(); 2)}ic2]pn
conn.setAutoCommit(false); \.h!'nfF
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); z5G<h
for(int i=0;i<CountCache.list.size();i++){ j3{8]D
CountBean cb=(CountBean)CountCache.list.getFirst(); u1K;{>4lx
CountCache.list.removeFirst(); d|5V"U]W;
ps.setInt(1, cb.getCountId()); &K2J$(.t
ps.executeUpdate();⑴ `s
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//ps.addBatch();⑵ uk%C:4T
} [1{#a {4
//int [] counts = ps.executeBatch();⑶ 4oW6&1
conn.commit(); {2wfv2hQ
}catch(Exception e){ BR\3ij
e.printStackTrace(); 1haH2F^q3
} finally{ y4* }E
try{ _ dFZR
if(ps!=null) { zK.%tx}+=k
ps.clearParameters(); +~~FfIzf#
ps.close(); ;/gH6Z?
ps=null; I*cB
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} ]BAM _
}catch(SQLException e){} >C,=elM
DBUtils.closeConnection(conn);
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} pqmb&"l
} 'r`#u@TTZ
public long getLast(){ cRYnQ{$'
return lastExecuteTime; 72rnMHq
} J9s4lsea
public void run(){ ybWb'+x
long now = System.currentTimeMillis(); AgKG>%0
if ((now - lastExecuteTime) > executeSep) { xWkCP2$?P
//System.out.print("lastExecuteTime:"+lastExecuteTime); ho*44=j
//System.out.print(" now:"+now+"\n"); T)%34gN
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); GilaON*pK.
lastExecuteTime=now; &)F8i#M
executeUpdate(); so[i"ZM)
} 8GpPyG
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else{ .hI3Uv8[
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); s$g"6;_\
} O'tVZ!C#J
} qRXQL"Pe_l
} z"4UObVs
//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 Q-<,+[/
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类写好了,下面是在JSP中如下调用。 )$18a
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<% C.SGm
CountBean cb=new CountBean(); C@!C='b,
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); [x}]sT`#a
CountCache.add(cb); P'Q|0lB
out.print(CountCache.list.size()+"<br>"); jKFypIZ4
CountControl c=new CountControl(); lMpjE
c.run(); R@lmX%Z1
out.print(CountCache.list.size()+"<br>"); UhQsT^b_
%>