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: x5%x""VEK
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CountBean.java ^@OdY&5^
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/* %#iu
* CountData.java %)p?&_
* se&Q\!&M
* Created on 2007年1月1日, 下午4:44 )Rr0f 8
* p~f=0K
* To change this template, choose Tools | Options and locate the template under ^F:Bj&0v[
* the Source Creation and Management node. Right-click the template and choose k`h#.B J
* Open. You can then make changes to the template in the Source Editor. XWv;l)
*/ #MAXH7[
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package com.tot.count; >m#bj^F\
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/** 0UOjk.~b
* oJe`]_XZ
* @author i:\|G^h
*/ aDZ] {;
public class CountBean { }B@44HdY
private String countType; 2i)vT)~
int countId; 8=,-r`oNy
/** Creates a new instance of CountData */ (qdvvu#E
public CountBean() {} y87oW_"h
public void setCountType(String countTypes){ xj;V
this.countType=countTypes; _BHEK
} ^vha4<'-qG
public void setCountId(int countIds){ e]-%P(}Z
this.countId=countIds; oUx%ra{
} 0Ait7`
public String getCountType(){ YuFR*W;$
return countType; rceX|i>9n
} ciGJtD&P
public int getCountId(){ TeNPuY~WP
return countId; 17F<vo>l%
} ")@#B=8+3^
} jzd)jJ0M
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CountCache.java 'T(@5%Db
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/* AH?4F"
* CountCache.java 4}F~h
* y7|
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* Created on 2007年1月1日, 下午5:01 S pk8u4
* iB#*XJ;q
* To change this template, choose Tools | Options and locate the template under lb\VQZp!y
* the Source Creation and Management node. Right-click the template and choose 4Be\5Byr
* Open. You can then make changes to the template in the Source Editor. DhD^w;f]
*/ D";@)\jN
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package com.tot.count; 'wni.E&
import java.util.*; h&2l0|8k
/** fi [4F
* %jn)=;\
* @author u7lO2C7
*/ k8 z1AP
public class CountCache { $rm/{i_7
public static LinkedList list=new LinkedList(); D|$Fw5!^k6
/** Creates a new instance of CountCache */ KZ@'NnQ
public CountCache() {} n}/4em?
public static void add(CountBean cb){ M< /
if(cb!=null){ @7K(_Wd
list.add(cb); pT/z`o$#V
} '8=/v*j>?
} :*Y2na)qQ
} N5. B"l
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CountControl.java %"^8$A?>,k
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/* {A'_5 X9
* CountThread.java iTVZo?lVo
* H{hzw&dZ<P
* Created on 2007年1月1日, 下午4:57 YO9;NA{sH
* _$i)bJ
* To change this template, choose Tools | Options and locate the template under v1z
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* the Source Creation and Management node. Right-click the template and choose %rJ'DPs
* Open. You can then make changes to the template in the Source Editor. LB`{35b-
*/ oL@K{dk
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package com.tot.count; hlmeT9v{
import tot.db.DBUtils; @MO/LvD
import java.sql.*; ><I{R|bC
/** lBGYZ--
* wKKQAM6P1
* @author P1ak>T*#2
*/ B>g(i=E
public class CountControl{ u9fJ:a
private static long lastExecuteTime=0;//上次更新时间 y/+IPR
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 qP]1}-
/** Creates a new instance of CountThread */ Z)md]Twt
public CountControl() {} < n/ 2
public synchronized void executeUpdate(){ }$i/4?dYsQ
Connection conn=null;
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PreparedStatement ps=null; ~*x 2IPiH
try{ 1!NrndJ I
conn = DBUtils.getConnection(); */2nh%>$
conn.setAutoCommit(false); ~G 3txd
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); bEln.)
for(int i=0;i<CountCache.list.size();i++){ o59b#9
CountBean cb=(CountBean)CountCache.list.getFirst(); 54=*vokX_
CountCache.list.removeFirst(); }(7TiCwd
ps.setInt(1, cb.getCountId()); I-#7Oq:Np
ps.executeUpdate();⑴ )D ~ 5
//ps.addBatch();⑵ pQ>|dH+.
} OX%#8Lx
//int [] counts = ps.executeBatch();⑶ U7Oa
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conn.commit(); Bj<s!}i{[
}catch(Exception e){ 4:5M,p
e.printStackTrace(); %SuELm
} finally{ xpc{#/Nk
try{ iBI->xU[U
if(ps!=null) { Cz
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ps.clearParameters(); ~d\^ynQ
ps.close(); t
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ps=null; hZlHY9[t?
} B<i(Y1n[
}catch(SQLException e){} zK&1ti@wln
DBUtils.closeConnection(conn); ,3N>`]Km'
} d0-4KN2
} }x+6<Rp'E_
public long getLast(){ IqiU
return lastExecuteTime; 5RAhm0Op~.
} ^`k;~4'd
public void run(){ 3?&v:H
long now = System.currentTimeMillis(); GUZ.Pw
if ((now - lastExecuteTime) > executeSep) { m'QG{f
//System.out.print("lastExecuteTime:"+lastExecuteTime); u /]P
//System.out.print(" now:"+now+"\n"); V~p01f"J
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ln+.=U6Tm
lastExecuteTime=now; *V 4%&&{
executeUpdate(); *<X1M~p$
} ',K:.$My
else{ iI`vu
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); N`?|~g3
} 3dlY_z=0
} NGJst_
} Q6D>(H#"0
//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 ,H%[R+)
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类写好了,下面是在JSP中如下调用。 %}e['d h
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<% 1wFW&|>1
CountBean cb=new CountBean(); S~)`{
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cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 6VVxpDAi:
CountCache.add(cb); (Gw*xsn 1
out.print(CountCache.list.size()+"<br>"); c@Br_-
CountControl c=new CountControl(); .$7RF!p
c.run(); ]YtN6Rq/
out.print(CountCache.list.size()+"<br>"); ]tf`[bINP
%>