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: )DW".c
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CountBean.java E_z,%aD[
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/* tnXW7ej ^
* CountData.java tuo'Uk)
* m KKa0"
* Created on 2007年1月1日, 下午4:44 H!y-o'Z
* 5 "x1Pln
* To change this template, choose Tools | Options and locate the template under lP(<4mdP
* the Source Creation and Management node. Right-click the template and choose xnZ
* Open. You can then make changes to the template in the Source Editor. b3=XWzK5
*/ *z'Rl'j9[
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package com.tot.count; Ac>GF
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/** Pj^Ccd'>=
* ~W gO{@Mw
* @author +jGUp\h%9;
*/ b Sg]FB aW
public class CountBean { O4W2X@
private String countType; H[/^&1P
int countId; h5; +5B}D
/** Creates a new instance of CountData */ Bo*Wm
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public CountBean() {} pAtxEaXh
public void setCountType(String countTypes){ - :x6X$=
this.countType=countTypes; mndNkK5o
} *^%ohCUi
public void setCountId(int countIds){ i:^
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this.countId=countIds; x1`Jlzrp,
} `b5pa `\4
public String getCountType(){ [4}U*\/>C
return countType; pmDFmES
} Or()AzwE@
public int getCountId(){ V#-8[G6Ra
return countId; 74~%4
} L3C'q
} k'd=|U;(FV
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CountCache.java 4V5h1/JPm
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/* sTYA
* CountCache.java <(o) * Zmo
* z`y^o*qc]
* Created on 2007年1月1日, 下午5:01 yLvU@V@~
* Z1+1>|-iW
* To change this template, choose Tools | Options and locate the template under S?(/~Vb%
* the Source Creation and Management node. Right-click the template and choose vQ
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* Open. You can then make changes to the template in the Source Editor. kAk+Sq^n
*/ cfW;gFf
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package com.tot.count; flU?6\_UC
import java.util.*; wb-_CQ
/** Cy\! H&0wg
* &o)eRcwH`
* @author pU@&-
*/ $C&E3 'O
public class CountCache { SfwNNX%
public static LinkedList list=new LinkedList(); ~$ "P\iJ
/** Creates a new instance of CountCache */ * @'N/W/8
public CountCache() {} wEb10t,
public static void add(CountBean cb){ >VvA&p71b
if(cb!=null){ 7brC@+ZD
list.add(cb); RZ:=';
} &B ^LaRg
} -xU4s
} ,tHV
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CountControl.java 5+iXOs<
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/* ;XGO@*V5T
* CountThread.java lyyRyFfQ
* )Es|EPCx!
* Created on 2007年1月1日, 下午4:57 sxU
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* XXPpj< c
* To change this template, choose Tools | Options and locate the template under *#CUZJN\
* the Source Creation and Management node. Right-click the template and choose T
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* Open. You can then make changes to the template in the Source Editor. yK:b$S
*/ b*"%E,?
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package com.tot.count; X?OH//co
import tot.db.DBUtils; .0'FW!;FV
import java.sql.*; &^^V*O
/** 5g;i{T/6~x
* |]x>|Z?/u
* @author </jTWc'}
*/ qgw)SuwW
public class CountControl{ 77p8|63
private static long lastExecuteTime=0;//上次更新时间 p u6@X7W"
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 pK@8= +
/** Creates a new instance of CountThread */
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public CountControl() {} <Is~DjIav
public synchronized void executeUpdate(){ tx||<8
Connection conn=null; ! $8 e6
PreparedStatement ps=null; ps3jw*QZ{5
try{ 8iUj9r_
conn = DBUtils.getConnection(); _T.k/a
conn.setAutoCommit(false); 5}"9)LT@@w
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); EHX/XM
for(int i=0;i<CountCache.list.size();i++){ @PyZ u7'
CountBean cb=(CountBean)CountCache.list.getFirst(); |#`qP^E
CountCache.list.removeFirst(); me&'BQ
ps.setInt(1, cb.getCountId());
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ps.executeUpdate();⑴ tsN,yI]-VA
//ps.addBatch();⑵ Z+G/==%3#,
} (E]q>'X
//int [] counts = ps.executeBatch();⑶ ~~X-$rtU
conn.commit(); i5jsM\1j
}catch(Exception e){ 2N[/Cc2Tg/
e.printStackTrace(); q2~@z-q)b
} finally{ Alpk5o5B
try{ ($r-&]y
if(ps!=null) { $irF
ps.clearParameters(); Ud'/
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ps.close(); `ehcj
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ps=null; i9j#Tu93 f
} :"I!$_E'
}catch(SQLException e){} yJ?S7+b
DBUtils.closeConnection(conn); TnQ"c)ta
} |kh7F0';"
} 0 pPSg9
public long getLast(){ :2(U3~3:
return lastExecuteTime; 8zzY;3^h;
} `(o:;<&3
public void run(){ -]kvM
long now = System.currentTimeMillis(); ;HoBLxb P
if ((now - lastExecuteTime) > executeSep) { .l$:0a
//System.out.print("lastExecuteTime:"+lastExecuteTime); h0)Dj(C
//System.out.print(" now:"+now+"\n"); k}FmdaPI'
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); I::|d,bR!
lastExecuteTime=now; ]YWz;Z
executeUpdate(); Dg
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} TNkvdE-S
else{ fuF!3Q
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 3
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} 6w)a.^yx7
} xSy`VuSl
} \x;`8H
//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 Bw25+l Px
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类写好了,下面是在JSP中如下调用。 YML]pNB
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<% cogIkB&Ju
CountBean cb=new CountBean(); v,^W& W.
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); f O ,5
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CountCache.add(cb); h1 pEC
out.print(CountCache.list.size()+"<br>"); 5L\&"['
CountControl c=new CountControl(); "kd)dy95H
c.run(); " `FcW
out.print(CountCache.list.size()+"<br>"); jIi:tO9G^,
%>