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: )(?,1>k`Z
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CountBean.java l@
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/* qT<OiIMj^
* CountData.java lo1<t<w`
* D#=$? {w
* Created on 2007年1月1日, 下午4:44 }#u.Of`6"
*
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* To change this template, choose Tools | Options and locate the template under =RA8^wI
* the Source Creation and Management node. Right-click the template and choose D%=VhKq
* Open. You can then make changes to the template in the Source Editor. B_gzpS]
*/ kqebU!0-
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package com.tot.count; ?5N7,|K)
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/** V<:)bG4;d
* zS9HR1
* @author `b11,lg
*/ !mjrI "_
public class CountBean { -`I&hzl6E
private String countType; B<p-qPR K
int countId; b"DV8fdX
/** Creates a new instance of CountData */ 6T?$m7c
public CountBean() {} .T2P%Jn.
public void setCountType(String countTypes){ pR3@loFQ`o
this.countType=countTypes; >@Nn_d
} m-<"`:+
public void setCountId(int countIds){ X,]E {
this.countId=countIds; LU-,B?1
} c:J;Q){Xz
public String getCountType(){ ii3{HJ*C
return countType; T J!d7
} A~@u#]]<n
public int getCountId(){ (~6D`g`B
return countId; W~!uSrY
} lYF~CNvE
} m@Q%)sc)
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CountCache.java CeZ+!-lG
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/* q':P9o*N?
* CountCache.java =tKb7:KU
* (GeOD V?U
* Created on 2007年1月1日, 下午5:01 ^$!H|
* P^)J^{r
* To change this template, choose Tools | Options and locate the template under Z\\'0yuY(
* the Source Creation and Management node. Right-click the template and choose ^Fn~@'
* Open. You can then make changes to the template in the Source Editor. B24,;2J
*/ xJ);P.
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package com.tot.count; `|rr<Tsy\
import java.util.*; [U^@Bk h
/** R5,ISD
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* ;Y^.SR"
* @author ;VS\'#{e
*/ (lzZ=T
public class CountCache { +o4W8f=Ga
public static LinkedList list=new LinkedList(); fz[-pJ5[
/** Creates a new instance of CountCache */ _Nx#)(x
public CountCache() {} o^\L41x3
public static void add(CountBean cb){ yP~O C|Z
if(cb!=null){ ,.K}uW
list.add(cb); IyV%tOy
} Z ? F*Z0y
} (6Y.|u]bq
} !eC]=PoY
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CountControl.java ?a]1$>r
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/* k-;A9!^h
* CountThread.java f]*TIYicc
* ~Pm[Ud
* Created on 2007年1月1日, 下午4:57 KE_GC ;bQ
* -Wt(t2
* To change this template, choose Tools | Options and locate the template under ?xT ^9
* the Source Creation and Management node. Right-click the template and choose C)RJjaOr
* Open. You can then make changes to the template in the Source Editor.
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*/ 9i?Q=Vuc~<
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package com.tot.count; H wu(}
import tot.db.DBUtils; 79bt%P
import java.sql.*; /7o{%~O
/** 9R1S20O
* u&npUw^Va
* @author ,K-?M5(n9
*/ B7u4e8(E*
public class CountControl{ t*Xo@KA
private static long lastExecuteTime=0;//上次更新时间 q=J8SvSRl
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 hgmo b"o
/** Creates a new instance of CountThread */ u]uUm1Er
public CountControl() {} )/Mk\``j
public synchronized void executeUpdate(){ .!^}sp,E
Connection conn=null; }Y=X{3+~.
PreparedStatement ps=null; F5(D A
try{ AB0>|.
conn = DBUtils.getConnection(); +*')0I
conn.setAutoCommit(false); .zQ'}H1.C
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 'k1vV
for(int i=0;i<CountCache.list.size();i++){ |{j\7G*5
CountBean cb=(CountBean)CountCache.list.getFirst(); *$Tz g!/
CountCache.list.removeFirst(); .271at#-
ps.setInt(1, cb.getCountId()); p4sU:
ps.executeUpdate();⑴ 7A6: *
//ps.addBatch();⑵ ,mY3oyu
} rF:l+I]
//int [] counts = ps.executeBatch();⑶ <AN=@`+
conn.commit(); 7W7yjG3g
}catch(Exception e){ [Q:C\f]
e.printStackTrace(); jFwu&e[9;
} finally{ Frd` u.I
try{ [izP1A$r#Q
if(ps!=null) { ()`cW>[
ps.clearParameters(); 7+c}D>/`:
ps.close(); EjjW%"C,
ps=null; 1(4}rB3
} 5@/hqOiu
}catch(SQLException e){} G>?'b
DBUtils.closeConnection(conn); G{!adBna
} #BOLq`9f
} 6EY W:o
public long getLast(){ 11Y4oS
return lastExecuteTime; s<b(@L 1
} 9_&N0>OF
public void run(){ U3rpmml
long now = System.currentTimeMillis(); R GC DC*\
if ((now - lastExecuteTime) > executeSep) { L8.u7(-#
//System.out.print("lastExecuteTime:"+lastExecuteTime); zYZ^/7)
//System.out.print(" now:"+now+"\n"); ^3
6oqe{
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); hI}rW^o^
lastExecuteTime=now; Q!`
executeUpdate(); )ipTm{
} %&\DCAFk
else{ X6SqOb\(a
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); Z-;I,\Y%
} (! "+\KY
} j#D (
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} .'Rz
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//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 v_L?n7c
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类写好了,下面是在JSP中如下调用。 7a5G,C#QQ
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<% .J fV4!=o
CountBean cb=new CountBean(); (|t)MnPfY
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); <HMmsw
CountCache.add(cb);
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out.print(CountCache.list.size()+"<br>"); ,Z aPY
CountControl c=new CountControl(); -s,guW |
c.run(); &O;'?/4
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out.print(CountCache.list.size()+"<br>"); %YV3-W8S0
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